WO2016040661A1

WO2016040661A1 - Catalyst handling method and hydrogenation process

Info

Publication number: WO2016040661A1
Application number: PCT/US2015/049465
Authority: WO
Inventors: Tseng H. Chao; Michael C. QUINN III; John J. Ostermaier; Douglas J. RIESTERER
Original assignee: Invista North America LLC
Current assignee: Invista North America LLC
Priority date: 2014-09-12
Filing date: 2015-09-10
Publication date: 2016-03-17
Anticipated expiration: 2017-03-12

Abstract

Disclosed is method and apparatus for at least partially hydrogenating an organonitrile by reducing an iron oxide catalyst precursor contained in a movable cartridge comprising a casing, an inlet standpipe and at least one exit aperture, in a first, activation vessel through contact with a hydrogen-containing gas stream to produce an activated heterogeneous iron catalyst, moving and loading the movable cartridge containing the activated heterogeneous iron catalyst into a second, reaction vessel for carrying out an organonitrile hydrogenation reaction, flowing a feed stream comprising a charge of an organonitrile, hydrogen, and ammonia into the inlet standpipe of the movable cartridge such that it contacts the activated heterogeneous iron catalyst to produce a reaction mixture, and withdrawing the reaction product mixture, comprising an organic amine, hydrogen, and ammonia, from the second vessel via the exit aperture.

Description

CATALYST HANDLING METHOD AND HYDROGENATION PROCESS

FIELD OF THE INVENTION

[001] The disclosures herein relate to a cartridge for containing a labile catalyst for a chemical reactor, which cartridge can be replaced as a unit with fresh or regenerated catalyst, a converter vessel for containing the cartridge, a method for handling a catalyst, and to the hydrogenation process for which the same catalyst is effective. More particularly the invention relates to the catalytic hydrogenation of an organonitrile in the presence of a heterogeneous iron catalyst.

BACKGROUND OF THE INVENTION

[002] Some chemical reactions require the use of very labile catalysts, such as pyrophoric catalysts, which cannot be loaded into a reactor in a conventional manner. For example, some catalysts are so reactive that they must be maintained sealed in an inert atmosphere prior to placement into the reactor stream.

[003] Processes for the hydrogenation of compounds comprising nitrile groups to amines and aminonitriles are known. Hydrogenation of dinitriles to the corresponding diamines is a process which has been used for a long time, in particular the hydrogenation of adiponitrile to hexamethylenediamine, a basic material in the preparation of nylon 6,6.

[004] There has been an increasing interest in recent years in the hydrogenation (also sometimes known as partial hydrogenation) of aliphatic dinitriles to aminonitriles, in particular the hydrogenation of adiponitrile to 6-aminocapronitrile, resulting either directly, or via caproiactam, to form nylon-6.

[005] U.S. Patent No. 3,696,153 to Kershaw et al. discloses a process for the catalytic hydrogenation of adiponitrile at elevated temperatures and pressures in the presence of a catalyst derived from an iron compound in granular form which has been activated with hydrogen at a temperature not exceeding 600° C.

[006] U.S. Patent No. 3,986,985 to Dewdney discloses a fused and solidified iron oxide catalyst containing at least 96.5% of iron oxide having an atomic ratio of oxygen to iron of 1.2:1 to 1.4:1 , activated by heating in hydrogen and used for the hydrogenation of organic compounds especially of adiponitrile to hexamethylene diamine.

[007] U.S. Patent No. 7,638,039 to Schirmer et al. discloses in-situ replacement of catalyst within a reactor. In an embodiment, the device comprises a method for the in- situ replacement of catalyst bodies in a catalytic reactor comprising removing catalyst bodies in-situ from at least one modularized section of a catalytic layer within a catalytic reactor and replacing the removed catalyst bodies in-situ with replacement bodies comprising catalytic function wherein at least 10% of the total catalyst bodies within the layer are replaced. However, Shirmer et al. fail to disclose how to initially load the reactor with a labile catalyst, such as a catalyst which must be maintained under inert gas.

[008] However, improved processes for hydrogenation of organonitriles and improved catalyst handling techniques are desired.

[009] For example, it would be desirable to solve the technical problem of transferring solid catalyst from a chemical reactor to a regenerator and back again without contacting the catalyst with ambient air.

[0010] It would further be desirable to solve the technical problem of improving handling efficiency and reducing handling costs for transferring solid catalysts among chemical reactors and regenerators.

[0011] It would also be advantageous to have a system in which loading and unloading catalyst in a reactor could be accomplished in a shorter time period as compared to conventional reactor systems.

[0012] It would also be desirable to operate such a process at commercial scale on a continuous or semi-continuous basis.

[0013] The present application discloses a cartridge for containing a labile catalyst in a sealed condition against contact with ambient air, which is easily and quickly transferrable from an activation vessel into a chemical reactor vessel, such as can be used for hydrogenation of dinitriles to the corresponding diamines. SUMMARY OF THE INVENTION

[0014] The present application discloses a cartridge for containing a catalyst in a sealed condition against contact with ambient air, which is easily transferrab!e into a chemical reactor.

[0015] In one aspect, the device of the invention resides in a catalyst cartridge for a chemical reactor comprising a cylindrical casing having a top end and a base; one or more exit apertures in the base, a standpipe having an inlet aperture located in said base and having an upper end slightly less than the height of said cylindrical casing; and catalyst disposed within the casing.

[0016] In a preferable embodiment, the standpipe and its inlet aperture are centrally located in said cartridge.

[0017] In one embodiment, the cartridge can have an inverted conical screen surrounding the upper end of said standpipe, or in the alternative, a portion of the upper end of the standpipe has an array of holes drilled through the pipe, which are surrounded by screening.

[0018] in another embodiment, the cartridge has a plurality of lifting rings connected on an upper surface thereof.

[0019] in another aspect, the device resides in a catalyst cartridge for a chemical reactor comprising a cylindrical casing having a top end and a base; one or more exit apertures in the base, a standpipe having an inlet aperture located in said base and having an upper end slightly less than the height of said cylindrical casing; an inverted conical screen surrounding the upper end of said standpipe; and catalyst disposed within the casing.

[0020] In a preferable embodiment, the standpipe and its inlet aperture are centrally located in said cartridge.

[0021] In one embodiment, the standpipe is open at the upper end.

[0022] In another embodiment, the cartridge has a plurality of lifting rings connected on an upper surface thereof.

[0023] In another aspect, the device resides in a converter for a chemical reactor comprising a bottom portion comprising a generally cylindrical shell having an internal void, an inlet pipe extending vertically through a bottom end of the bottom portion and at !east one exit orifice radially displaced from said inlet pipe and extending through said bottom end; a middle portion comprising a hollow cylindrical vessel in sealed fluid communication with the bottom portion; a top portion comprising a generally cylindrical shell of greater diameter than said middle portion, having a breech lock mechanism comprising a first series of breech lock ridges on an inner circumference of said top portion for sealing said converter; and a removable upper head assembly comprising a cylindrical retainer ring having a second series of breech lock ridges forming a breech lock engagement on an outer circumference thereof, and a cylindrical top head held in place by said retainer ring, wherein said second series of breech lock ridges are structured and arranged to coact with said first series of breech lock ridges to lock a catalyst cartridge into and seal said converter. The internal void can be generally hemispherical or generally ellipsoidal in shape.

[0024] The catalyst cartridge can comprise a cylindrical casing having a top end and a base; a standpipe having an upper end extending to nearly the height of said cylindrical casing, and a lower end fitting over and in fluid communication with said inlet pipe; one or more exit apertures in the base; and catalyst disposed within the casing.

[0025] The present application discloses a cartridge for containing a catalyst in a sealed condition against contact with ambient air, which is easily transferrable into a chemical reactor, and in which catalyst particles are prevented from exiting the cartridge by one or more Johnson screens® positioned at the bottom of the cartridge.

[0026] In one aspect, the device resides in a catalyst cartridge for a chemical reactor comprising a cylindrical casing having a top end and a base; one or more exit apertures in the base, each exit aperture being covered inside of the cartridge by a Johnson screen®, a standpipe having an inlet aperture located in said base and having an upper end nearly the height of said cylindrical casing; and catalyst disposed within the casing forming a catalyst bed.

[0027] In another embodiment, the Johnson screens® are positioned on an upper surface of the base, above said exit aperture.

[0028] Advantageously, the Johnson screens® extend into the catalyst bed.

[0029] In one aspect, the device resides in a catalyst cartridge for a chemical reactor comprising a cylindrical casing having a top end and a base; one or more exit apertures in the base, a standpipe having an inlet aperture located in said base and having an upper end nearly the height of said cylindrical casing; and a collection trough disposed on the bottom of said base, below and in fluid communication with said exit apertures.

[0030] Conveniently, the exit apertures are connected in fluid communication to an equal number of exit distributors positioned on an upper surface of the base.

[0031] In various embodiments, the coilection trough is toroidal, i.e. having a generally U-shaped cross-section, or has a generally rectangular cross-section, or can even have a V-shaped cross-section, and surrounds said inlet aperture.

[0032] In one form, the collection trough has at least one exit pipe, preferably a single exit pipe, extending below the collection trough and in fluid communication with the inside of the collection trough.

[0033] in one aspect, the device resides in a catalyst cartridge for a chemical reactor comprising a cylindrical casing having a top end and a base, one or more exit apertures in the base, an internal standpipe having an inlet aperture located in said base, and having an upper portion and a top end terminating above a top of a catalyst bed within said casing, said upper portion perforated by a plurality of openings extending below the top of the catalyst bed.

[0034] In another embodiment, the plurality of openings is a Johnson screen®.

[0035] Advantageously, the plurality of openings can extend from just below a top of the catalyst bed for about 10% of the length of the standpipe, into the catalyst bed, or even for about 25% of the length of the standpipe, into the catalyst bed.

[0036] In another embodiment, disclosed is a method for at least partially hydrogenating an organonitrile by first reducing an iron oxide catalyst precursor contained in a movable cartridge including a casing, an inlet standpipe and at least one exit aperture, in a first, activation vessel through contact with a hydrogen-containing gas stream to produce an activated heterogeneous iron catalyst. The activated heterogeneous iron catalyst is then moved and loaded into a second, reaction vessel for carrying out an organonitrile hydrogenation reaction including flowing a feed stream of at least a charge of an organonitrile, hydrogen, and ammonia into the inlet standpipe of the movable cartridge, such that it contacts the activated heterogeneous iron catalyst to produce a reaction mixture. The method additionally includes withdrawing the reaction product mixture, including an organic amine, hydrogen, and ammonia, from the second vessel via the exit aperture. Preferably, the casing of the movable cartridge is cylindrical. Preferably, the inlet standpipe of the movable cartridge is a central inlet standpipe. Preferably, the movable cartridge has at least one exit aperture in a base of the moveable cartridge. Particularly preferably, the movable cartridge includes a cylindrical casing, a central inlet standpipe and has at least one exit aperture in its base.

[0037] The method can further include after the activated heterogeneous iron catalyst has been deactivated to form a deactivated catalyst, subsequently moving the movable cartridge containing the deactivated catalyst from the second reaction vessel to a third, passivation vessel and contacting the deactivated catalyst with a controlled amount of oxygen to at least partially passivate the catalyst. The passivation gas can be one containing increasing concentrations of oxygen over a period of time and passivation can be monitored by measuring the temperature of the passivation gas after the contacting.

[0038] Advantageously, the movable cartridge can be purged with a gas such as helium, nitrogen, or argon prior to each moving step.

[0039] Conveniently, the organonitrile can be one or more of the group consisting of adiponitrile, methylglutaronitriie and 6-aminocapronitrile, and the resulting organic amine to be separated and recovered from the reaction product mixture can be one or more of hexamethylenediamine, 6-aminocapronitriie and 2-methylpentamethylene- diamine. When the organonitrile is a dinitriie, it can be partially hydrogenated, so as to form an aminonitrile, or fully hydrogenated to form a diamine.

[0040] Preferably, the method benefits if a charge of adiponitrile or 6- aminocapronitri!e is not followed by a charge of methylglutaronitriie in the absence of an intervening catalyst washing step, such as passing ammonia, and optionally hydrogen, through the catalyst in the cartridge within the reaction vessel.

[0041] The method can be conducted through multiple reaction vessels in series communication, and can include flowing a charge of the organonitrile into each of the multiple reaction vessels. Since the hydrogenation reaction is exothermic, it is advantageous to cool an effluent stream exiting a reaction vessel in the series prior to introducing the cooled effluent stream into the next reaction vessel in the series. Particularly preferably, the method is conducted through four reaction vessels in series communication, each containing a movable catalyst cartridge.

[0042] The hydrogenation catalyst can be formed from an iron oxide catalyst precursor which includes a total iron content greater than 65% by weight, Fe(li) to Fe(lll) ratio from 0.60 to 0.75, total magnesium content less than 6000 ppm by weight, total aluminum content greater than 700 ppm to less than 2500 ppm by weight, total sodium content iess than 400 ppm by weight, total potassium content less than 400 ppm by weight, and having a particle size distribution greater than 90% in the range of 1.0 to 2.5 millimeters. In order to activate the catalyst, the iron oxide catalyst precursor is reduced with a hydrogen-containing gas stream further including from about 3-5 vo!% ammonia, at a pressure from about 60-140 psig, and a temperature from about 360-420°C.

[0043] The present invention is also directed to a method of hydrogenating multiple organonitriles by flowing a first feed stream including a charge of a first organonitriie, hydrogen, and ammonia into a movable cartridge containing an activated heterogeneous iron catalyst, such that the first feed stream contacts the activated heterogeneous iron catalyst. The hydrogenation reaction produces a first reaction product mixture, including a first organic amine, hydrogen, and ammonia, which is withdrawn and collected from the movable cartridge. Subsequently, the heterogeneous iron catalyst is regenerated by purging the movable cartridge with ammonia, and optionally hydrogen, after which a second feed stream including a charge of a second organonitriie, hydrogen, and ammonia is passed into the movable cartridge, such that the second feed stream contacts the reduced heterogeneous iron catalyst to produce a second reaction product mixture, which includes a second organic amine, hydrogen, and ammonia. The second reaction product mixture is then withdrawn and collected from the movable cartridge.

[0044] Similarly to the above-recited method, the first organonitriie is either adiponitrile or 6-aminocapronitrile and the second organonitriie is methylgiutaronitrile, and the resulting first organic amine is either hexamethylenediamine or 6- aminocapronitri!e, and the second organic amine is 2-methylpentamethylenediamine. [0045] The hydrogen ation method is conducted such that the first and second feed streams contact the heterogeneous iron catalyst at a pressure from about 4500-5500 psig, and a temperature from about 80-130°C.

BRIEF DESCRIPTIONS OF THE DRAWINGS

[0046] Further details and the advantages of the applicant's disclosures herein will become clearer in view of the detailed description of a method for implementing the hydrogenation of an organonitrile in the presence of a heterogeneous iron catalyst, given here solely by way of illustration and with references to the appended figures. Reference is now made to FIGS. 1-17, wherein like numerals are used to designate like elements throughout.

[0047] FIG. 1 is a plan view of a movable catalyst cartridge useful with the present invention.

[0048] FIG. 2 is a side view of a movable catalyst cartridge useful with the present invention.

[0049] FIG. 3 is a cross-sectional view of a movable catalyst cartridge of Fig. 2, along line 3-3.

[0050] FIG. 4 shows a cross-sectional view of an alternative movable catalyst cartridge useful with the present invention.

[0051] FIG. 5 is a cross-sectional view of another alternative movable catalyst cartridge useful with the present invention, having a catalyst bed and Johnson screens over the exit apertures.

[0052] FIGS. 6A and 6B are detailed views of Johnson screens®.

[0053] FIGS. 6C and 6D are plan views of portions of Johnson screens®.

[0054] FIG. 7 a cross-sectional view of another alternative movable catalyst cartridge useful with the present invention, having a catalyst bed and Johnson screens over both the exit apertures and the standpipe.

[0055] FIG. 8A is an exploded plan view of a catalyst cartridge having a collection trough according to the present invention.

[0056] FIG. 8B is a plan view of the catalyst cartridge of Fig. 8A with the collection trough in place. [0057] FiG. 8C is a sectional view of a toroidal collection trough with a generally rectangular cross-section in position under the catalyst cartridge.

[0058] FIG. 8D is a sectional view of a toroidal collection trough with a generally U- shaped or semi-circular cross section in position under the catalyst cartridge.

[0059] FIG. 8E is a sectional view of a toroidal collection trough with a generally V- shaped cross-section in position under the catalyst cartridge.

[0060] FIG. 9 is a cutaway view of another alternative movable catalyst cartridge useful with the present invention with a generally U-shaped or semi-circular cross section collection trough in position under the catalyst cartridge.

[0061] FIG. 10A is a plan view of the converter of the present device.

[0062] FIG. 10B is an exploded view of the converter of Fig. 10A.

[0063] FiG. 11A is a side view of the converter of the present device.

[0064] FiG. 11 B is a cutaway view of the converter of Fig. 11 A along line 11 B-11 B.

[0065] FiG. 12A is a detailed cross-sectiona! view of the bottom portion of the converter.

[0066] FIG. 12B is a detailed cross-sectional view of the bottom portion of a converter vessel containing a catalyst cartridge.

[0067] FIG. 12C is a detailed cross-sectional view of the bottom portion of a converter vessel containing a catalyst cartridge with a collection trough.

[0068] FIG. 13 is a detailed cross-sectiona! view of the top portion of the converter.

[0069] FIG. 14 shows a simplified schematic representation of the arrangement of the various vessels and flowpaths useful in the present invention.

[0070] FIG. 15 shows a cross-sectional representation of a multiple reaction vessel version according to the present invention.

[0071] FIG. 16 shows a simplified schematic representation of the catalyst activation processing steps according to the present invention.

[0072] FIG. 17 is a diagram showing a four stage conversion process for hydrogenating dinitriles to produce diamines. DETAILED DESCRIPTION OF THE INVENTION

[0073] Various aspects wili now be described with reference to specific forms selected for purposes of illustration. It will be appreciated that the spirit and scope of the apparatus, system and methods disclosed herein are not limited to the selected forms. Moreover, it is to be noted that the figures provided herein are not drawn to any particular proportion or scale, and that many variations can be made to the illustrated forms.

[0074] Each of the following terms written in singular grammatical form: "a," "an," and "the," as used herein, may also refer to, and encompass, a plurality of the stated entity or object, unless otherwise specifically defined or stated herein, or, unless the context clearly dictates otherwise. For example, the phrases "a device," "an assembly," "a mechanism," "a component," and "an element," as used herein, may also refer to, and encompass, a plurality of devices, a plurality of assemblies, a plurality of mechanisms, a plurality of components, and a plurality of elements, respectively.

[0075] Each of the following terms: "includes," "including," "has," "'having," "comprises," and "comprising," and, their linguistic or grammatical variants, derivatives, and/or conjugates, as used herein, means "including, but not limited to."

[0076] Throughout the illustrative description, the examples, and the appended claims, a numerical value of a parameter, feature, object, or dimension, may be stated or described in terms of a numerical range format. It is to be fully understood that the stated numerical range format is provided for illustrating implementation of the forms disclosed herein, and is not to be understood or construed as inflexibly limiting the scope of the forms disclosed herein.

[0077] Moreover, for stating or describing a numerical range, the phrase "in a range of between about a first numerical value and about a second numerical value," is considered equivalent to, and means the same as, the phrase "in a range of from about a first numerical value to about a second numerical value," and, thus, the two equivalently meaning phrases may be used interchangeably.

[0078] It is to be understood that the various forms disclosed herein are not limited in their application to the details of the order or sequence, and number, of steps or procedures, and sub-steps or sub-procedures, of operation or implementation of forms of the method or to the details of type, composition, construction, arrangement, order and number of the system, system sub-units, devices, assemblies, sub-assemblies, mechanisms, structures, components, elements, and configurations, and, peripheral equipment, utilities, accessories, and materials of forms of the system, set forth in the following illustrative description, accompanying drawings, and examples, unless otherwise specifically stated herein. The apparatus, systems and methods disclosed herein can be practiced or implemented according to various other alternative forms and in various other alternative ways.

[0079] It is also to be understood that all technical and scientific words, terms, and/or phrases, used herein throughout the present disclosure have either the identical or similar meaning as commonly understood by one of ordinary skill in the art, unless otherwise specifically defined or stated herein. Phraseology, terminology, and, notation, employed herein throughout the present disclosure are for the purpose of description and should not be regarded as limiting.

[0080] The invention includes an apparatus and process for the heterogeneous catalytic hydrogenation of an organonitrile wherein the catalyst is formed and activated in a separate vessel from that in which the hydrogenation process is conducted, and subsequently deactivated or passivated in another separate vessel. Forms of the process can be semi-continuous and can allow the hydrogenation to take place with a high selectivity and relatively high yield on an industrial scale.

[0081] The invention relates to a method for the reaction of an organonitrile with hydrogen in the presence of a heterogeneous iron catalyst, it is advantageous in such a process to provide an iron oxide catalyst precursor which is initially placed in a movable cartridge to hold the catalyst charge. The cartridge is then placed in a first vessel and the precursor chemically reduced to an active heterogeneous iron catalyst with hydrogen at elevated temperature. The term "movable cartridge" refers to a catalyst container with inlet and outlet conduits, as depicted in Fig. 1 , which can be generally cylindrical in shape, having an outside diameter of from 0.1 to 10 meters (m), such as from 0.2 to 5 m, or even from 0.5 to 2 m, and a length from 1 to 20 m, such as from 1.5 to 10 m, or even from 0.5 to 5 m, and preferably from 0.2 to 3 m. The movable cartridge can be selectively loaded into one or more reactor vessels of the invention. Preferably, each reactor vessel includes a breech-lock head so that the movable cartridge can be easily inserted, sealed and removed, in one form, the catalyst resides in an essentially fixed bed within the movable cartridge.

[0082] Described herein is a cartridge for containing a catalyst, in particular a labile catalyst for insertion into a chemical reactor. In some chemical reactions the catalyst, which is often in the form of pellets or granules or the like, when activated is very labile, and can even be pyrophoric, necessitating blanketing the entire catalyst bed in a non- reactive gas, such as nitrogen, or other such gas, such as the noble gases.

[0083] When such catalysts are necessary, loading and unloading of a reactor can be quite dangerous, since contact with ambient air must be avoided. Accordingly, such catalysts cannot be merely poured into the catalyst bed in a conventional manner, but must be blanketed with a non-reactive gas during the loading and unloading operations. Additionally, loading and unloading such catalysts in a conventional manner is very time consuming, especially for catalysts which require activation prior to use. Under such circumstances use of such catalysts in conventional reactors requires activation-in- place, which can result in weeks of delay when changing catalyst.

[0084] Catalyst cartridges as disclosed herein provide certain benefits for fixed bed catalyst systems, in that the catalyst particles within a given cartridge remain relatively still with respect to the catalyst cartridge and the surrounding catalyst particles, such that catalyst attrition is reduced and the disclosed process moves catalyst cartridges from one or more reaction vessel(s) to one or more regeneration vessel(s) and back again as needed without imparting relative motion between the catalyst particles.

[0085] Turning now to the drawings, Fig. 1 is a plan view of the catalyst cartridge 100 of the present device having a cylindrical casing 110, which has a top end 105, a base 106 perforated by an inlet aperture 120a of a lower end of a central standpipe (not shown) for incoming chemical reactants and one or more exit orifices 1 16 for the chemical products. The chemical reaction occurs entirely within cartridge 100, from which ambient air can be readily excluded.

[0086] Fig. 2 is a side view of the structure of Fig. 1. Standpipe inlet aperture 120a is advantageously centrally positioned in base 106 to accept a mating inlet pipe 206 (Fig. 10B) through which the chemical reactants are fed to the reactor cartridge 100. The top end 105 of catalyst cartridge 100 is provided with a plurality of lifting rings 55 attached to its upper surface, to facilitate lifting of the cartridge 100 with an overhead crane for placing it into and removing it from a reactor containment vessel or converter 200 (Fig. 0A). The cartridge can be generally cylindrical in shape, having an outside diameter of from 0.1 to 10 meters (m), such as from 0.2 to 5 m, or even from 0.5 to 2 m, and a length from 1 to 20 m, such as from 1.5 to 10 m, or even from 0.5 to 5 m, and preferably from 0.2 to 3 m.

[0087] Fig. 3 is a cutaway view of Fig. 2 along line 3-3, revealing interna! structures of the catalyst cartridge. The upper end of stand pipe 120 extends nearly to the top of the cartridge, such as within about 10% of the top of the cartridge, or even within about 5% of the top of the cartridge, and above the top of the catalyst bed (not shown for clarity), such that the chemical reactants entering the cartridge are transported to the top and out of standpipe 120, then to the top of the catalyst bed, through which they percolate by gravity, or are forced by the pressure of the reactant feed. In order to equally distribute the incoming reactant feed across the top of the catalyst bed and to prevent catalyst pellets and fines from back flowing into the standpipe 120, the upper end of standpipe 120 can be equipped with an inverted conical screen 124, such that the chemical reactants exit the top of the standpipe 120 and are distributed through the inverted conical screen 124 across the top of the catalyst bed. Alternatively, the upper end of standpipe 120 can be closed and an plurality of holes or openings 126 drilled around the circumference of the upper end of the standpipe provide a fluid exit, such that the chemical reactants are equally distributed across the top of the catalyst bed. In the latter embodiment, the plurality of openings 126 are advantageously surrounded with screening (not shown for clarity), or can be a Johnson screen®, described below, such that the reactants can exit the standpipe but no catalyst pellets or granules can enter and clog it.

[0088] After passing through the catalyst bed, the chemical reactants are reacted and transform into chemical products, which then collect on the upper surface of base 106 of the cartridge, and exit the cartridge by passing downward through exit apertures 116 at the bottom of the cartridge. The chemical products are subsequently collected and processed further, if necessary. [0089] Fig. 4 is a cutaway, cross-section of an alternative movable catalyst cartridge 100 according to the present invention, having a top head 150 covering the top end 05 of a cylindrical casing 110, Top head 150 pressure seals the catalyst cartridge 100 which has a plurality of lifting rings (not shown) attached to its upper surface, to facilitate lifting of the cartridge 100 with an overhead crane for placing it into and removing it from the reactor vessel. The cartridge has a centrally positioned standpipe 120 for inlet of the reaction feed stream, extending to within about 5 % to about 10 % of the top of the cartridge, which can terminate in either an open end and/or a closed end with a Johnson screen 140a (available from Johnson Screens of New Brighton, MN, USA) for distribution of the reaction components over the top of the heterogeneous iron catalyst bed (not shown). The bottom or base of the movable cartridge includes at least one exit aperture 116 for removal of the reaction product mixture.

[0090] Fig. 5 is a cutaway view of alternative catalyst cartridge. The upper end of stand pipe 120, which is preferably centrally located within the cartridge, extends nearly to the top of the cartridge, such as within about 10% of the cartridge height, or even within about 5% of the cartridge height, and above the top of a catalyst bed 115, only partially shown for clarity, such that the chemical reactants entering the cartridge are transported to the top of the catalyst bed, through which they percolate by gravity, or are forced by the pressure of the reactant feed, in order to equally distribute the incoming reactant feed across the top of the catalyst bed, the upper end of standpipe 120 can be equipped with an inverted conical screen 124, such that the chemical reactants exit the top of the standpipe 120 and are distributed through the inverted conical screen 124. Alternatively, the upper end of standpipe 120 is closed and a plurality of openings 126 drilled around the circumference of the upper end of the standpipe provide a fluid exit, such that the chemical reactants are equally distributed across the top of the catalyst bed. In the latter embodiment, the plurality of openings 126 are advantageously surrounded with screening (not shown for clarity), such that the reactants can exit the standpipe but no catalyst pellets or granules can enter and clog it.

[0091] After passing through the catalyst bed 115, the chemical reactants are reacted and transformed into chemical products, which then collect on a the upper surface of base 106 of the cartridge, and exit the cartridge by passing through slots in exit distributor pipes, such as Johnson screens®, 140b covering exit apertures 1 16 at the bottom of the cartridge. The chemicai products are subsequently collected and processed further, if necessary.

[0092] Advantageously, the distributor pipes are Johnson screens® 140 (Fig. 6D), positioned above each exit aperture 116, which extend into the catalyst bed 115 to prevent catalyst particulate from exiting the cartridge in combination with the collected reaction product. Johnson screens®, as the term is used herein, are made by winding triangular wire around a series of support rods, separated by very accurately-sized slots, and welding each point of contact between the apex of the triangular wire to the support rods. These are also known as vee-wire outlet collectors, and are available from Johnson Screens of New Brighton, MN, USA. This design provides a virtually non- plugging slot design, and because of the converging inner portions formed by the triangular wire apices, a high open area for flow of the reaction product fluid.

[0093] Figs. 6A and 6B illustrate detailed views of portions of Johnson screens®, wherein Fig. 6A illustrates a side-view of a portion of the screen construction. Two triangular wires 144 are shown welded in-position to supporting rod 142 at their apices, and a slot 145 is positioned between their bases. Flow of reaction product progresses through slot 145, past supporting rod 142, and ultimately downward through exit aperture(s) 116 (see Fig 5). Fig. 6B is an illustration showing collection of catalyst particles 115 on the bases 144 and the slots 145 between the triangular wires 144.

[0094] Figs. 6C and 6D are plan views of Johnson screens® 140 illustrating the arrangement of the individual components thereof. As discussed above, each screen is a series of triangular wires 144 which are wound around and welded-to a series of, in this case vertical support rods 142, with slots 145 between each individual wire. In place in the reactor cartridge, the Johnson screens® are covered by a top cover 146 which can be of similar design.

[0095] Fig. 7 is a cutaway view of another alternative catalyst cartridge, revealing internal structures of the catalyst cartridge. The upper end of standpipe 120 extends nearly to the top of the cartridge and above the top 1 15a of the catalyst bed 1 15, only partialiy shown for clarity, such that the chemical reactants entering the cartridge are transported to the top of the catalyst bed 115a, through which they percolate by gravity, or are forced by the pressure of the reactant feed. The upper end of standpipe 20 can be open for delivering the incoming reactants to and across the top of catalyst bed 1 15a, and perforated by a plurality of openings 126 for about 10% to 25% of the overall length of the standpipe 120, down into the catalyst bed 115. The openings 126 are surrounded by a section of screening 140a. In a preferred embodiment, the top of standpipe 120 terminates in a Johnson Screen®, which provides the plurality of openings 126 as slots 145 between individual screen wires 144 (Figs. 6A and 6B).

[0096] The incoming mixture of gas and liquid preferentially flows through the top end of the standpipe 120, down through the catalyst bed 1 5, exits through the exit distributor screens 140b and out through exit orifices 116. However, during the course of the reaction process, the pressure of the incoming reactants can cause mechanical displacement of the catalyst particles at the top of the catalyst bed 115a, forming catalyst fines. As more and more fines are generated, a thin layer of fines at the top 1 15a of the catalyst bed 1 5 gradually increases the pressure drop through the cartridge and catalyst bed.

[0097] According to the present invention, as the pressure drop across the top layer of fines increases over time, more inflow is automatically directed through the plurality of openings 126, through the screening 140a surrounding the upper portion of the inlet pipe 120 and into the catalyst bed 1 15 below the layer of fines. This invention prevents the catalyst 115 from having to be changed out prematurely due to excessive pressure drop. The screening 140a surrounding the upper portion of the standpipe is basically the same as the exit distributor screens 140b above the exit orifices 1 16, except that the end of the screen 140a surrounding the standpipe can be open to accommodate the upper portion of the standpipe, instead of being sealed as for the exit distributor screens 140b.

[0098] in either situation, the chemical reactants are equally distributed across the top of or into the catalyst bed 1 15. Since the plurality of openings 126 are advantageously surrounded with screening 140a, or are entirely formed by a Johnson screen®, the reactants can exit the standpipe 120 without catalyst pellets or granules entering the standpipe. [0099] While passing through the catalyst bed, the chemical reactants are reacted and transformed into chemical products, which then collect on the upper surface of base 106 of the cartridge and exit the cartridge by passing first through perforations in the exit distributor screens 140b, then downward through exit apertures 1 16 at the bottom of the cartridge. The exit distributor screens 140b are positioned above each exit aperture 1 16 and extend upward into the catalyst bed 1 15 to prevent catalyst particulate from exiting the cartridge in combination with the collected reaction product. The chemical products are subsequently collected and processed further, if necessary. In this embodiment, both upper screen 140a and exit distributor screens 140b are Johnson Screens® 140, Fig. 6D.

[00100] Fig. 8A is an exploded plan view of the catalyst cartridge 100 of the present device having a cylindrical casing 1 10 and a collection trough 1 17 on a lower end, a top end 105, a base 06 perforated by an inlet aperture 20a at the lower end of a central standpipe (not shown) for incoming chemical reactants and one or preferably more exit orifices 1 16 for the chemical products. The chemical reaction occurs entirely within cartridge 100, from which ambient air can be readily excluded. The collection trough

1 17, shown in place below the catalyst cartridge in Fig. 8B, is positioned below and in fluid communication with the exit orifices 1 16, but does not come into contact or interfere with the area below inlet aperture 120a, such that an inlet pipe (not shown) in the reaction converter vessel can mate with the central stand pipe through inlet aperture 120a. The collection trough 1 17 has at least one exit pipe 1 18 extending below it and in fluid communication with the inside of the collection trough, for draining the reaction products in a controlled manner out of the trough.

[00101] in a preferred embodiment the collection trough 1 17 has only a single exit pipe

1 18. When so structured, all fluids exhausted from the catalyst cartridge, including activation gases, reaction products and passivation gases can be collected at a single location, reducing the requirements for additional collection piping.

[00102] Figs. 8C-8E are sectional views of a lower portion of the catalyst cartridge with the collection trough 1 17 in place below the exit orifices 1 16; Fig. 8C illustrates a toroidal collection trough, i.e. having a generally retangular cross-section. Fig. 8D illustrates a collection trough having a generally U-shaped or semi-circular cross- section; and Fig, 8E i!iustrates a collection trough having a generally V-shaped cross- section. In each case standpipe 120 is visible.

[00103] Fig. 9 is a cutaway view of a catalyst cartridge with a collection trough 17 in place below the cartridge, as described above, illustrating the relationship between the internal exit distributor pipes 140b positioned over exit apertures 116, and the external collection trough 7 positioned below the cartridge. Chemical products which collect on the upper surface of base 106 of the cartridge exit the cartridge by passing first through slots in the exit distributor pipes 140b, downward through the exit apertures, into collection trough 117 positioned below the cartridge, and ultimately out of exit pipe 118. The exit distributors 140b can be slotted pipes surrounded by screens, such as Johnson screens®, 140 (Fig. 6D) available from Johnson Screens of New Brighton, N, USA. The chemical products are subsequently collected and processed further, if necessary.

[00104] Fig. 10A is a plan view of the converter vessel 200 (sometimes referred to as the "converter") of the presently claimed device showing it from the bottom. The converter 200 as a whole is substantially cylindrical, having a bottom portion 205, a middle portion 210 and a top portion 215 of somewhat larger diameter than the rest of the device. Bottom portion 205 is penetrated by an inlet pipe 206, preferably centrally located, and at least one exit orifice 208, displaced from said inlet pipe.

[00105] Fig. 10B is an exploded view of the converter of Fig. 10A, which additionally illustrates that the inlet pipe 206 is comprised of at least three distinct portions: an inlet pipe connection flange 206a for connection to incoming piping for chemical reactant fluids; a reduced diameter inlet pipe insertion portion 206b, sized and structured to fit inside a standpipe 120 of the catalyst cartridge (Fig. 3); and a connection flange 206c by which the inlet pipe is bolted to the bottom of the converter 200. The top portion 215 of the converter has a retainer ring 230 with a longitudinal series of interrupted breech lock ridges 235 on an outer circumference thereof.

[00106] Fig. 11 A is a side view of the converter 200, and Fig. 11 B is a cutaway view of Fig. 11A along line 11 B-1 B, which illustrates the entire system in more detail. For exampie, the fluid connection between exit orifice 208 with an internal void 205a of lower portion 205 is visible, as is the overall arrangement of inlet pipe 206. Likewise the interior arrangement of top portion 215 can be seen in the cross-sectional view. The arrangement of catalyst cartridge 100 having a top 105, a bottom 106 and a standpipe 120, preferably centrally disposed within said cartridge, is shown within the converter, such that the lower end of standpipe 120 fits over the upper insertion portion 206b of inlet pipe 206, the combination providing an inlet for chemical reactants to the catalyst (not shown for clarity). Exit apertures 116 at the bottom of the catalyst cartridge provide an exit for chemical products. The cartridge can also be equipped with lifting hooks (not shown) at the top thereof, to facilitate lifting the cartridge into and out of the converter vessel, with such as an overhead crane.

[00107] Breech lock mechanisms are well-known in the art and are used for example for pressure sealing the breeches and barrels of military cannons. The construction of such mechanisms comprises inner and outer cylindrical members each having a longitudinal series of coacting (when engaged) interrupted ridges on the respective inner and outer circumferential surfaces of the cylindrical members. When the members are rotated relative to one another to disengage the breech lock, the ridges on one member rotate out of alignment with the coacting ridges on the other member, and into alignment with a series of empty longitudinal voids, which permits the inner cylindrical member to be withdrawn from the outer cylindrical member.

[00108] According to the present invention as illustrated in Figs. 11A and 11 B, converter top portion 2 5 contains a removable upper head 225 which is a combination of retainer ring 230 and a top head 150, having a breech iock mechanism 240 comprising a longitudinal series of interrupted breech lock ridges 218 formed on the interior circumference of top portion 215 and a coacting longitudinal series of interrupted breech lock ridges 235 formed on the outer circumference of retainer ring 230. When engaged and rotated in a first direction, breech iock mechanism 240 locks the top head 150 into the converter 200, securing the catalyst cartridge 100 and pressure sealing the converter. When rotated in the opposite direction, the breech lock mechanism is disengaged and top head 150 can be lifted out of converter 200, providing access to a spent catalyst cartridge 100.

[00109] Fig. 12A is a detailed cross-section of converter bottom portion 205. The upper portion 206b of inlet pipe 206 is shown to be of smaller diameter to facilitate fitting into the lower end of standpipe 120 of the catalyst cartridge. Bottom portion 205 has an internal void 205a, which can be hemispherical or ellipsoidal, and an exit orifice 208 for removal of reaction products.

[00110] Fig. 12B is a detailed cross-section of a converter vessel bottom portion 205 into which catalyst cartridge 100 is seated. The upper portion of inlet pipe 206 is shown to be of a diameter suitable to fit into standpipe inlet aperture 120a of the catalyst cartridge when it is resting on shoulder 206b of the inlet pipe 206. Bottom portion 205 has an internal void 205a, which can be hemispherical or ellipsoidal, and an exit orifice 208 for removal of reaction products. Inlet pipe 206 is provided with connection flange 206c which can be bolted onto the lower surface of the bottom portion 205, and an inlet flange 206a for connection to externa! inlet piping (not shown).

[00111] Fig. 12C is a detailed cross-section of a converter vessel bottom portion 205 into which a catalyst cartridge 100, provided with a collection trough 117, is seated. The upper portion of inlet pipe 206 is shown to be of a diameter suitable to facilitate fitting into standpipe inlet aperture 120a of the catalyst cartridge. Bottom portion 205 has an internal void 205a, which can be hemispherical or ellipsoidal, and an exit orifice 208 for removal of reaction products. Inlet pipe 206 is provided with connection flange 206c which can be bolted onto the lower surface of lower portion 205 and an inlet flange 206a for connection to external inlet piping (not shown). The collection trough 117 and exit pipe 1 18 are shown in place below the catalyst cartridge 100.

[00112] Fig. 13 is a detailed cross-section of converter top portion 215, with removable upper head 225 disposed therein and illustrating the arrangement of the breech lock mechanism 240, such as the coacting breech lock ridges 218 on the interior circumference of top portion 215 engaged with the breech lock ridges 235 on the exterior circumference of retaining ring 230.

[00113] In another form the present invention is also directed to a method for at least partially hydrogenating an organonitrile by first reducing an iron oxide catalyst precursor contained in a movable cartridge including a cylindrical casing, a central inlet standpipe and having at least one exit aperture in a base thereof, in a first activation vessel through contact with a hydrogen-containing gas stream to produce an activated heterogeneous iron catalyst. [00114] !n practice, an iron oxide catalyst precursor of magnetite is advantageous. One suitable magnetite comprises one or more selected from the group consisting of precursors having a total iron content greater than 65% by weight, Fe(ll) to Fe(l!l) ratio from about 0.60 to about 0.75, total magnesium content less than 6000 ppm by weight, total aluminum content greater than about 700 ppm to less than 2500 ppm by weight, total sodium content less than about 400 ppm by weight, total potassium content less than about 400 ppm by weight, and a particle size distribution greater than about 90% in the range of 1.0 to 2.5 millimeters. Substantially similar iron oxide catalyst precursors are known from U.S. Patent Nos. 4,064, 172 and 3,986,985 to Dewdney et al., the disclosures of which are hereby incorporated by reference in their entirety.

[00115] Activation of the iron oxide catalyst precursor includes a reduction step wherein the iron oxide catalyst precursor is contacted with a hydrogen-containing gas, advantageously containing ammonia at concentrations typically from about 1 to about 5 volume percent of the reduction gas, for example about 2 to about 4 volume percent, preferably about 3% by volume at elevated temperature, for example, from about 350°C to about 425°C, or from about 375°C to 425°C, for example from 385 to 415°C, or from about 395°C to 405°C, for example 400°C, before entering the cartridge, and a pressure from about 60 psig to about 140 psig, for about 100 to about 190 hours.

[00116] During the reduction, gas is withdrawn from the first (activation) vessel, the reduction gas is typically cooled to about 1 °C to 10°C to condense and remove water before it is reheated to about 350°C to about 420°C and recirculated back to the cartridge. During the reduction process, hydrogen is consumed and water is produced as a byproduct. This process is continued until the desired degree of magnetite reduction is achieved, about 85 to 90% based upon the water produced. Once the catalyst is activated it is cooled under a hydrogen atmosphere, purged with nitrogen and if necessary, stored in the vessel.

[00117] The activated heterogeneous iron catalyst is then moved and loaded into a second (reaction) vessel for carrying out an organonitrile hydrogenation reaction including flowing a feed stream of at least a charge of an organonitrile, hydrogen, and ammonia into and up through the inlet standpipe 120 of the movable cartridge, such that it exits the top thereof and contacts the activated heterogeneous iron catalyst to produce a reaction product mixture. The method additionally includes withdrawing the reaction product mixture, including an organic amine, hydrogen, and ammonia, from the second vessel via the exit apertures 116.

[00118] The hydrogenation method is conducted such that the reactant feed stream(s) contact the heterogeneous iron cataiyst at a pressure from about 3000 psig to about 5500 psig, preferably from about 4500 psig to about 5500 psig, and a temperature from about 80°C to about 130°C, preferably from about 80°C to about 120°C, at which temperatures and pressures ammonia and the organonitriles in the feed stream are primarily in the liquid state.

[00119] Once the catalyst becomes deactivated it must be replaced with fresh catalyst in a movable cartridge as described above. Accordingly, the method can further include subsequently moving the movable cartridge containing deactivated catalyst to a third (passivation) vessel and contacting the deactivated catalyst with a controlled amount of an oxygen-containing gas to at least partially passivate the catalyst. The passivation gas can be one in which the concentration of oxygen is increased over a period of time, and passivation can be monitored by measuring the temperature of the passivation gas after the contacting.

[00120] Before the deactivated catalyst is removed from the second vessel, it is flushed with hydrogen and ammonia to remove organic species, depressurized, and purged with one or more first gases, which can be pre-heated, selected from the group consisting of hydrogen, natural gas, methane, ethane, and propane, through the one or more vessels, then with one or more second gases including helium, nitrogen or argon, or combinations thereof, to remove the ammonia and hydrogen. Advantageously, gas purging is continued until the gas composition exiting the one or more vessels is not explosive in air under ambient conditions and comprises less than 5 ppm by volume ammonia. The temperature of gas flow exiting the one or more vessels can be from about 150°C to about 180°C.

[00121] The cartridge is then removed from the second vessel, and placed in a third vessel where it is passivated to render it non-pyrophoric. In the third vessel air diluted with nitrogen to an oxygen concentration of less than 2 vol % is passed through the catalyst for a period of up to 2 weeks, (typically about 5 days), or until the exit gas temperature falls below 75°C.

[00122] The process may optionally include step-wise passivation starting with about 1 vol% oxygen/nitrogen. In this optional step-wise passivation, the 1 vol% oxygen/nitrogen stream is charged to the cartridge and the exit temperature typically increases to about 150°C and then cools to about 105°C. After the outlet temperatures rises and fails at the first oxygen concentration, then the step is repeated with oxygen concentration increased slightly, for example, by 0.25%, 0.5%, 0.75%, 1 % or 2%, while the outlet temperature is monitored. The outlet temperature rises and falls during each sequential step, generally remaining below 200°C, until a stream containing up to about 9 vol% oxygen/nitrogen is charged to the cartridge in a final treatment step. Cartridge inlet temperature is typically controlled below about 80°C and exit temperature is controlled below about 200°C, for example, below about 160^aC in each sequential step. Following the last step of the passivation, a relatively low concentration oxygen- containing passivation gas is circulated across the cartridge until the gas temperature is below about 60°C.

[00123] The passivated catalyst is then discharged from the cartridge for disposal. The empty cartridge is then filled with fresh catalyst precursor and the cycle repeated. The use of the movable cartridges greatly reduces the down time associated with a catalyst change, since if the activation, hydrogenation, and passivation were done in a single vessel there would be more than two weeks down-time associated with every catalyst change. Using movable cartridges reduces this time to two days or less.

[00124] In the method of the invention for the hydrogenation of an organonitriie in the presence of a heterogenous iron catalyst, illustrated in Fig. 14, the catalyst is first loaded into movabie cartridge 100, which is placed in a first vessel 360. Preparation and activation of the heterogenous iron catalyst is performed through reduction of an iron oxide catalyst precursor in first vessel 360 by contacting a suitable iron oxide precursor, described above, with a hydrogen-containing gas stream introduced through pipe 363 at a suitable temperature and pressure as discussed above. Then, the hydrogen-containing gas stream leaves the first vessel 360 via a pipe 364. This reduction step is conducted for a period of time suitable to change the iron oxide cataiyst precursor into an activated, heterogeneous iron catalyst.

[00125] The movable cartridge 100 containing the activated heterogeneous iron cataiyst is transferred to reaction vessel 200, the transfer represented by dashed line 365. The movable cartridge 100 substantially isolates the catalyst from contact with air during the transfer step between vessels 360, 370 and 200. The subsequent transfer of cartridge 100 between reaction vessel 200 and passivation vessel 370 is represented by dashed line 366. Cartridge 100 is blanketed with inert gas such as nitrogen during each transfer step. The deactivated catalyst in the passivation vessel 370 is contacted with a controlled amount of oxygen supplied via a pipe 373 to at least partially passivate the catalyst. Finally, the used deactivation gas is discharged from the passivation vessel 370 via a pipe 374.

[00126] As further illustrated in Fig. 14, a fluid composition comprising an organonitrile, hydrogen and ammonia is provided to one or more compression devices 310 via pipe 300, which is in turn conducted via pipe 315 to reaction vessel 200, in which the compressed composition is contacted with the activated heterogeneous iron catalyst to form a reaction product mixture. This reaction product mixture, comprising an organic amine, unreacted hydrogen, and unreacted ammonia, is conducted from reaction vessel 200 to high pressure separation vessel 330 via pipe 325. Separation of the hydrogen from the crude organic amine and ammonia takes place in vessel 330. High pressure hydrogen exits vessel 330 through pipe 336 and is recycled to feed line 315. The crude organic amine product and ammonia are fed via pipe 335 to one or more lower pressure separator(s) 340, where ammonia gas and any remaining hydrogen are vented or recycled via pipe 346, as desired, and the crude organic amine product is discharged via pipe 344. The gaseous ammonia stream 346 is then absorbed in water to give a liquid ammonia solution, from which anhydrous ammonia is recovered for recycle. These features representing recycle of ammonia and reintroduction to the reaction vessel 200 are not shown in Fig. 14. They however form a portion of the applicant's overall disclosure herein.

[00127] The method herein contemplates the use of an organonitrile comprising or selected from the group consisting of: adiponitrile (ADN), methylg!utaronitriie (MGN), and 6-aminocapronitrile. Depending on the extent of hydrogenation, the organic amines produced by the present method include: hexamethylenediamine (H DA), 6- aminocapronitrile and 2-methy!pentamethyiene-diamine (MPMD).

[00128] Advantageously, the movable cartridge can be purged with a gas such as helium, nitrogen, or argon prior to each moving or transfer step.

[00129] Preferably the method benefits if a charge of adiponitrile or 6-aminocapronitrile is not followed by a charge of methyiglutaronitrile in the absence of an intervening ammonia wash step, such as by passing ammonia through the catalyst in the cartridge within the reaction vessel. The ammonia wash affects a partial catalyst regeneration that reduces operating temperature, increases catalyst lifetime and reduced by-product formation.

[00130] The method can be conducted through multiple reaction vessels in series communication, and can include flowing a charge of the organonitriie into each of the multiple reaction vessels. However, in the case of using multiple vessels, the organonitriie can be introduced into the second, third, etc. vessels in the absence of additional hydrogen and ammonia.

[00131] Fig. 15 illustrates a configuration of multiple reaction vessels, in this case having two cylindrical reaction vessels 200, each containing a cylindrical catalyst cartridge 100, one of which is shown loaded with catalyst 1 15 and locked therein by breech lock mechanisms 240. As stated above, the movable cartridges 100 each has a centra! standpipe 120 for inlet and distribution of reactants, and at least one exit aperture 1 16 at the bottom of the cartridge. The breech lock mechanisms have a series of breech lock threads 218 formed on an inner cylindrical surface of the upper end of said reaction vessels 200, and retainer rings 230 having coacting breech lock threads 235 on outer circumferences thereof. Retainer rings 230 are each attached to respective top heads 150 above cartridges 100. Those skilled in the art are well-aware of the configuration and functioning of breech lock threads, for example as used in military cannons and the like. Upon partial rotation of the inner portion, in this case the retainer ring 230, relative to the outer portion, in this case the inner cylindrical surface of the upper portion of the reaction vessel 200, the respective breech lock threads 218, 235 coact to lock the retainer ring 230 axially, relative to the containment vessel 200 and either lock or unlock the mechanism 240, depending on the direction of rotation. Advantageously, each retainer ring 230 has attached to its upper surface lifting rings 316 suitable for lifting the unlocked retainer ring out of the breech mechanism 240 to provide access to the catalyst cartridge 100.

[00132] The cylindrical reaction vessels 200 are both equipped with inlet 315 and outlet 325 pipes, the outlet pipe 325 of the first being connected to the inlet pipe 315 of the second, such that the reaction vessels are connected in series flow communication. In each case, inlet pipes 315 are disposed in fluid communication with standpipes 120. Fluid flow through the vessels is generally indicated by arrows A and B; arrow A representing the inlet flow of chemical reactants and arrow B representing the outlet flow of chemical products. Additional reaction vessels may be connected in series to enhance the disclosed method. Particularly preferably, the method is conducted through three, or even four reaction vessels in series communication, each containing a movable catalyst cartridge.

[00133] Since the hydrogenation reaction is exothermic, it is advantageous to cool an effluent stream exiting a reaction vessel in the series, such as to about 120°C, or even to about 80 °C, prior to introducing the cooled effluent stream into the next reaction vessel in the series, such as by passing the hot reaction product stream through heat exchangers (not shown) between reaction vessels.

[00134] The present invention is also directed to a method of hydrogenating multiple organonitriies by flowing a first feed stream including a charge of a first organonitrile, hydrogen, and ammonia into a movable cartridge containing an activated heterogeneous iron catalyst, such that the first feed stream contacts the activated heterogeneous iron catalyst. The hydrogenation reaction produces a first reaction product mixture, including a first organic amine, hydrogen, and ammonia, which is withdrawn and collected from the movable cartridge. Subsequently, the heterogeneous iron catalyst is washed by purging the movable cartridge (and thereby the catalyst) with ammonia, after which a second feed stream including a charge of a second organonitrile, hydrogen, and ammonia is passed into the movable cartridge, such that the second feed stream contacts the activated heterogeneous iron catalyst to produce a second reaction product mixture, which includes a second organic amine, hydrogen, and ammonia. The second reaction product mixture is then withdrawn and collected from the movable cartridge.

[00135] Similarly to the above-recited method, the first organonitrile is methy!giutaronitriie, and the second organonitrile is either adiponitrile or 6- aminocapronitrile, and the resulting first organic amine is 2- methylpentamethylenediamine, and the second organic amine is either hexamethylenediamine or 6-aminocapronitrile.

[00136] The hydrogenation method is conducted such that the first and second feed streams contact the heterogeneous iron catalyst at a pressure from about 4500 psig to about 5500 psig, and a temperature from about 80°C to about 130°C.

[00137] Specific forms will now be described further by way of example. While the following examples demonstrate certain forms of the subject matter disclosed herein, they are not to be interpreted as limiting the scope thereof, but rather as contributing to a complete description.

APPARATUS EXAMPLES

EXAMPLE A

[00138] A precursor of a pyrophoric catalyst is loaded into a catalyst cartridge according to the present invention and subjected to activation with an activation gas at elevated temperature for about 4 to 8 days. Once the catalyst is activated it is cooled under a gaseous atmosphere, purged with nitrogen and if necessary, stored in the vessel until needed. The activated catalyst cartridge is then moved and loaded into a reaction vessel for carrying out a chemical reaction and the chemical reaction is commenced until the catalyst is deactivated. Once the catalyst becomes deactivated it can be replaced with fresh activated catalyst provided in a different movable cartridge, and the deactivated catalyst cartridge is subsequently moved to a passivation vessel, wherein the deactivated catalyst is passivated with a controlled amount of another gas over time to render the catalyst at least less pyrophoric, or non-pyrophoric. The turnaround time for changing the activated catalyst and cartridge in the reactor is a total of about 2 days or less, resulting in rapid resumption of the catalytic reaction process. COMPARATIVE EXAMPLE A

[00139] A precursor of a pyrophoric catalyst is loaded into a conventional reaction vessel and subjected to activation with an activation gas at elevated temperature for about 4 to 8 days. Once the catalyst is activated it is cooled under a gaseous atmosphere. The chemical reaction is commenced until the catalyst is deactivated. When the catalyst becomes deactivated it is passivated with a controlled amount of another gas to render the catalyst at least less pyrophoric, or non-pyrophoric, after which time it is removed from the reaction vessel and replaced with fresh catalyst precursor. The time required to passivate the deactivated catalyst, discharge the passivated catalyst from the reactor, refill the reactor with fresh catalyst precursor, and activate the catalyst can range from 14 to 21 days, before the chemical reaction can be re-commenced, resulting in significant down-time associated with every catalyst change.

EXAMPLE B

[00140] A precursor of a pyrophoric catalyst is loaded into a catalyst cartridge according to the present invention and subjected to activation with an activation gas at elevated temperature for about 4 to 8 days. Once the catalyst is activated it is cooled under a gaseous atmosphere, purged with nitrogen and if necessary, stored in the vessel until needed. The activated catalyst cartridge is then moved and loaded into a reaction vessel for carrying out a chemical reaction and the chemical reaction is commenced until the catalyst is deactivated. Once the catalyst becomes deactivated it can be replaced with fresh activated catalyst provided in a different movable cartridge, and the deactivated catalyst cartridge is subsequently moved to a passivation vessel, wherein the deactivated catalyst is passivated with a controlled amount of another gas over time to render the catalyst at least less pyrophoric, or non-pyrophoric. The turnaround time for changing the activated catalyst and cartridge in the reactor is a total of about 2 days or less, resulting in rapid resumption of the catalytic reaction process. COMPARATIVE EXAMPLE B

[00141] A precursor of a pyrophoric catalyst is loaded into a conventional reaction vessel and subjected to activation with an activation gas at elevated temperature for about 4 to 8 days. Once the catalyst is activated it is cooled under a gaseous atmosphere. The chemical reaction is commenced until the catalyst is deactivated. When the catalyst becomes deactivated it is passivated with a controlled amount of another gas to render the catalyst at least less pyrophoric, or non-pyrophoric, after which time it is removed from the reaction vessel and replaced with fresh catalyst precursor. The time required to passivate the deactivated catalyst, discharge the passivated catalyst from the reactor, refill the reactor with fresh catalyst precursor, and activate the catalyst can range from 14 to 21 days, before the chemical reaction can be re-commenced, resulting in significant down-time associated with every catalyst change.

EXAMPLE C

[00142] A precursor of a pyrophoric catalyst is loaded into a catalyst cartridge disposed in an activation vessel according to the present invention and subjected to activation with an activation gas at elevated temperature for about 4 to 8 days. Once the catalyst is activated it is cooled under a gaseous atmosphere, purged with nitrogen and if necessary, stored in the activation vessel until needed. The activated catalyst cartridge is then moved and loaded into a converter vessel with a breech lock top for carrying out a chemical reaction. The breech lock is opened and the top removed. The catalyst cartridge is inserted into the converter vessel with an overhead crane, and the breech lock top replaced and locked into position on top of the catalyst cartridge. The chemical reaction is commenced until the catalyst is deactivated. Once the catalyst becomes deactivated ail reaction gases are purged from the cartridge with an inert gas, the breech lock mechanism is unlocked and removed, and the spent cartridge is lifted out of the converter vessel with an overhead crane. The spent cartridge is moved to a passivation vessel, wherein the deactivated catalyst is passivated with a controlled amount of another gas over time to render the catalyst at least less pyrophoric, or non- pyrophoric. Then a fresh activated catalyst in a different movable cartridge is inserted into the converter vessel, and the breech lock mechanism returned and locked. The turnaround time for changing the activated catalyst and cartridge in the converter is a total of about 2 days or less, resulting in rapid resumption of the catalytic reaction process. The removal and replacement of the catalyst cartridge and sealing of the converter vessel with the breech lock mechanism is accomplished in two hours.

COMPARATIVE EXAMPLE C1

[00143] A precursor of a pyrophoric catalyst is loaded into a conventional reaction vessel and subjected to activation with an activation gas at elevated temperature for about 4 to 8 days. Once the catalyst is activated it is cooled under a gaseous atmosphere. The chemical reaction is commenced until the catalyst is deactivated. When the catalyst becomes deactivated it is passivated with a controlled amount of another gas to render the catalyst at least less pyrophoric, or non-pyrophoric, after which time it is removed from the reaction vessel and replaced with fresh catalyst precursor. The time required to passivate the deactivated catalyst, discharge the passivated catalyst from the reactor, refill the reactor with fresh catalyst precursor, and activate the fresh catalyst can range from 14 to 21 days, before the chemical reaction can be re-commenced, resulting in significant down-time associated with every catalyst change.

COMPARATIVE EXAMPLE C2

[00144] A converter reactor vessel with a conventional top portion, secured by a series of boits to the lower portion of the vessel is prepared for catalyst cartridge loading, !n order to retain the pressure of the chemical reaction, each bolt is about 200 mm diameter, about 200 cm long and weighs about 500 kg, with ten to thirty boits distributed around the top portion in a generally circular pattern. Each bolt is unscrewed separately, necessitating a minimum of two people or a small crane to lift each bolt. Once all bolts are removed, the top head of the converter vessel is removed with an overhead crane, and the catalyst cartridge inserted into the converter vessel. The top head is replaced, and each bolt inserted into the bolt holes around the circumference of the top head. Each bolt must be accurately torqued to a proper specification using hydraulic tensioning or torquing equipment, requiring a total of about 24 hours to accomplish the replacement of the catalyst cartridge.

EXAMPLE D

[00145] An activated catalyst cartridge having Johnson screens® disposed over the exit apertures in the bottom of the cartridge, according to the present invention, is loaded into a reaction vessel for carrying out a chemical reaction and the chemical reaction is commenced, continuing uninterrupted for about 60 to about 120 days depending on the nature of the reactants and reaction conditions, until the catalyst is deactivated. Once the catalyst becomes deactivated it can be replaced with fresh activated catalyst provided in a different movable cartridge, and the deactivated catalyst cartridge is subsequently moved to a passivation vessel, wherein the deactivated catalyst is passivated with a controlled amount of another gas over time to render the catalyst at least less pyrophoric, or non-pyrophoric. The turnaround time for changing the activated catalyst and cartridge in the reactor is a total of about 2 days or less, resulting in rapid resumption of the catalytic reaction process.

COMPARATIVE EXAMPLE D

[00146] As in the Example D, an activated catalyst cartridge, but without having Johnson screens® disposed over the exit apertures in the bottom of the cartridge, is loaded into a reaction vessel for carrying out a chemical reaction and the chemical reaction is commenced. Shortly after commencing the chemical reaction, one or more exit apertures becomes clogged with catalyst particulate and the reaction must be stopped, the cartridge removed, the catalyst passivated and the cartridge cleaned of the particulate clog. The entire catalyst bed in the plugged cartridge must be discarded and replaced, at great expense.

EXAMPLE E

[00147] A catalyst cartridge according to the present invention is supplied with a toroidal collection trough on the base. The collection trough covers a series of exit apertures disposed in a generally circular pattern around the base of the cartridge. The collection trough has a single exit pipe extending below it, providing for a single exit point for all fluids which might be sent through the catalyst cartridge. The cartridge is filled with a catalyst precursor and an incoming stream of activation gas is passed into the standpipe of the cartridge and forced down through the catalyst precursor bed. The activation gas then exits the cartridge through the series of exit apertures in the base of the cartridge, is collected by the collection trough, then passes into the exit pipe below the trough. The single exit pipe in the trough is connected to a single downstream exhaust pipe, through which the activation gas can be exhausted and/or recycled. The cartridge is subsequently blanketed with inert gas(es) for storage and or transfer into a chemical converter vessel for conducting the chemical reaction. Similar to the activation vessel, the converter vessel has only a single exhaust pipe for removal of the product of the chemical reaction from the cartridge/collection trough.

COMPARATIVE EXAMPLE E

[00148] A catalyst cartridge is provided having a series of exit apertures disposed in a generally circular pattern around the base of the cartridge. Each exit aperture is connected to a separate exhaust pipe for removing fluids from the cartridge. The cartridge is filled with a catalyst precursor and an incoming stream of activation gas is passed into the standpipe of the cartridge and forced down through the catalyst precursor bed. The activation gas then exits the cartridge through the series of exit apertures in the base of the cartridge, is collected by the separate exhaust pipes which mate with each exit aperture, into a collection manifold, and then passes into a single downstream exhaust pipe, through which the activation gas can be exhausted and/or recycled. The cartridge is subsequently blanketed with inert gas(es) for storage and or transfer into a chemical converter vessel for conducting the chemical reaction. Similar to the activation vessel, the converter vessel has multiple exhaust pipes and a collection manifold for removal of the product of the chemical reaction from the cartridge. The cost of repeatedly and accurately fabricating and sealing the multiple exhaust pipes and the collection manifolds therefor far exceeds the cost of the fabricating the collection trough/exit pipe according to the present invention. [00149] An activated catalyst cartridge having a stand pipe terminating in a Johnson screen®, according to the present invention, is loaded into a reaction vessel for carrying out a chemical reaction and the chemical reaction is commenced, continuing uninterrupted for about 60 to about 120 days depending on the nature of the reactants and reaction conditions, until the catalyst is deactivated. Once the catalyst becomes deactivated it can be replaced with fresh activated catalyst provided in a different movable cartridge, and the deactivated catalyst cartridge is subsequently moved to a passivation vessel, wherein the deactivated catalyst is passivated with a controlled amount of another gas over time to render the catalyst at least less pyrophoric, or non- pyrophoric. The turnaround time for changing the activated catalyst and cartridge in the reactor is a total of about 2 days or less, resulting in rapid resumption of the catalytic reaction process.

COMPARATIVE EXAMPLE F

[00150] As in the Example F, an activated catalyst cartridge, but with a standpipe having an open top end, is loaded into a reaction vessel for carrying out a chemical reaction and the chemical reaction is commenced. After commencing the chemical reaction, catalyst fines form on the top of the catalyst bed, clogging interstices between catalyst particles and raising the one or more exit apertures becomes clogged with catalyst particulate impeding process flow through the remainder of the catalyst bed. The reaction must be stopped, the cartridge removed and the catalyst passivated. The entire catalyst bed in the plugged cartridge must be discarded and replaced at great expense.

PROCESS EXAMPLES EXAMPLE 1

[00151] This Example describes an embodiment where a catalyst is formed by reducing iron oxide using separate sources of hydrogen and ammonia. [00152] Referring to Fig. 16, hydrogen is supplied from source 400. in this Example, hydrogen source 404 is not used. The hydrogen supplied from source 400 comes from a hydrogen pipeline, which has been purified, conveniently by a pressure swing adsorption treatment.

[00153] The hydrogen in source 400 is pressurized to a pressure of from 200 to 400 psig, for example, from 250 to 350 psig, for example 300 psig. Hydrogen from source 400 is passed, sequentially, through line 402 and line 408 to preheater 410. Heated hydrogen is passed through line 412 to hydrogen/ammonia mixer 418. The ammonia feed to the hydrogen/ammonia mixer 418 originates from ammonia source 414, which is anhydrous, liquid ammonia, pressurized to a pressure from 300 to 500 psig, for example, from 350 to 450 psig, for example, 400 psig. The ammonia feed passes into the hydrogen/ammonia mixer 418 though line 416.

[00154] The liquid ammonia fed to the hydrogen/ammonia mixer 4 8 vaporizes in the presence of hydrogen to form a gaseous hydrogen/ammonia mixture. This mixture may comprise from 96 to 98 voi%, for example, 97 vo!%, hydrogen and from 2 to 4 vol%, for example, 3 vol% ammonia. The liquid ammonia may be introduced into the hydrogen/ammonia mixer 418 at about ambient temperature, for example, a temperature of less than about 30°C. The hydrogen in preheater 410 is heated to a temperature sufficient to sustain the gaseous state of ammonia in the hydrogen/ammonia mixer 418 and downstream thereof. For example, the temperature of hydrogen in line 412 may be at least 120°C, for example, from 120 to 140°C, for example, 130°C. The temperature of the hydrogen/ammonia mixture exiting the hydrogen/ammonia mixer 418 to line 420 may be at least 30°C, for example, from 30 to 50°C, for example, 40°C.

[00155] The temperature of the hydrogen/ammonia mixture is ramped up to a suitable reaction temperature in two heating steps. In a first heating step, the mixture passes from line 420 to line 422 into heat exchanger 424. The temperature of the hydrogen/ammonia mixture exiting the heat exchanger 424 through line 426 may be, for example, at least 50°C, for example, from 300 to 350°C. The hydrogen/ammonia mixture is directed into preheater 428 and exits preheater 428 through line 363 and into catalyst activation unit 360 (Fig. 14), at which point the mixture temperature may be from 375 to 425°C, for example from 385 to 415°C, for example, from 395 to 405°C, for example 400°C. The pressure of the hydrogen/ammonia mixture entering the catalyst activation unit 360 may be at least 50 psig, for example, from 60 to 140 psig, for example, 130 psig.

[00156] The reaction of iron oxide with hydrogen in the catalyst activation unit 360 produces water (H₂0) as a byproduct. Also, some decomposition of ammonia takes place to produce hydrogen (H₂) and nitrogen (N₂). Therefore the gaseous effluent, which exits the catalyst activation unit 360 and enters line 364 is a mixture of hydrogen, ammonia, water and nitrogen.

[00157] The reduction reaction, which takes place in the catalyst activation unit 360 is endothermic. The temperature of the effluent exiting catalyst activation unit 360 may be from 325 to 400°C, for example, from 350 to 385°C, for example, from 360 to 375°C, for example 370°C. The pressure of the effluent exiting the catalyst activation unit 360 may be at least 40 psig, for example, from 50 to 130 psig, for example, 120 psig. The catalyst precursor reduction process is conducted for a period of about 100 hours, or even up to about 190 hours.

[00158] The temperature of the effluent from the catalyst activation unit is reduced in two steps. In a first step, the effluent temperature is partially reduced by passing the effluent from line 364 through heat exchanger 424, thus supplying heat to the hydrogen/ammonia mixture entering the heat exchanger 424 through line 422 and exiting the heat exchanger 424 as cooled stream 436. In a second cooling step the partially cooled effluent from the heat exchanger 424 is cooled in cooler 438. In this way, the temperature of the effluent is reduced to a temperature sufficient to permit phase separation, which takes place in separator 442.

[00159] The cooled effluent from the catalyst activation unit 360 is passed from cooler 438 through line 440 into separator 442. In separator 442, the effluent from the catalyst activation unit 360 separates at atmospheric pressure into a liquid phase comprising ammonia and water and a gas phase comprising hydrogen and ammonia. In order to maximize the amount of water in the liquid phase and to minimize the amount of water which remains in the gaseous phase, the effluent entering separator 442 may be cooled to a temperature of 10°C or iess, for exampie, 5°C or less, by means of the heat exchanger 424 and cooler 438.

[00160] Water, in admixture with ammonia, is removed as the liquid phase from separator 442 through line 448. At least a portion of the gas phase in separator 442 is removed from the separator through line 444 for recycle to the catalytic activation unit 360. The temperature of the gas in line 444 may be 10°C or less, for example, 5°C or less, for example, 2°C. A portion of the gas phase in separator 442 may also be removed via line 450 as a purge stream. By taking a purge from the gas phase of separator 442, the build-up of nitrogen in the recycle loop may be minimized.

[00161] The gas phase used for recycle passes through line 444 and through compressor 446. In this way the pressure of the gas is increased to the pressure of the gas in lines 420 and 422.

EXAMPLE 2

[00162] This Example describes an embodiment where a catalyst is formed by reducing iron oxide using a recycle source of hydrogen and ammonia.

[00163] Referring again to Fig. 16, hydrogen and ammonia are supplied as a recycle mixture from source 404, and hydrogen source 400 and ammonia source 414 are not used, or used only as make-up gases. The hydrogen and ammonia supplied from source 404 can come from the low pressure separator 340 (Fig 14). Line 406 transfers recycle mixture to line 408, where hydrogen may optionally be added from hydrogen source 400 through line 402, carried forward through line 408 and charged to preheater 410.

[00164] With these exceptions, the remainder of the process is carried out in essentially the same manner as the process described in Example 1 .

EXAMPLE 3

[00165] This Example describes an embodiment of hydrogenating adiponitrile to form an organic amine.

[00166] Referring again to Figs. 14 and 15, one or more movable cartridges 100 containing activated heterogeneous iron catalyst 1 15, made according to Examples 1 or 2 is internaiiy blanketed with nitrogen, removed from the activation vessel 360 and transferred to one or more reaction vessels 200 using an overhead crane. Upon insertion into the reaction vessel, the crane connections (hooks/chains) are removed from the movable cartridge 100, and the retainer ring 230 and top head 150 portions of the breech lock mechanism 240 are axially aligned in an upper cylindrical portion of the reactor vessel The coacting breech lock teeth 218, 235 of the retainer ring and the inner circumferential portion of the reactor vessel are engaged and the retainer ring is rotated so as to lock and seal the movable cartridge 100 within the reactor vessel 200.

[00167] Subsequently, hydrogen gas, optionally containing ammonia, is passed through the reaction vessel iniet pipe 315 under a temperature, pressure and flow rate sufficient to purge nitrogen from the movable cartridge/catalyst bed and out of the outlet pipe 325. After sufficient purging of nitrogen, a reactant feed stream comprising hydrogen, ammonia and ADN is supplied to a first reaction vessel 200 through the inlet pipe 315 thereof and is transmitted upward into the central standpipe 120 of the movable cartridge 100. The pressure of the reactant feed stream to the first reactor vessel may be at least 3500 psig, for example, at least 4000 psig, or for example, at least 4500 psig. The temperature of the reactant feed stream to the first reactor vessel may be at least 80°C, for example at least 95°C, for example, at least 110°C, which can be achieved by passing the reactant feed stream through a heat exchanger or the like. The pressure of the system is maintained such that the ammonia and ADN are essentially in the liquid state.

[00168] The reactant feed stream mixture exits the top of standpipe 120, is distributed across the top of the activated heterogeneous catalyst bed 115 and is forced downward by both pressure and gravity and into contact with the catalyst. Depending upon the severity of conditions, including temperature, pressure and flow rate, the ADN is either partially hydrogenated to form the desired organic amine reaction product of 6- aminocapronitrile, or fully hydrogenated to form hexamethylenediamine (HMDA). Optionally, and in order to increase the efficiency of the reaction process, a reaction product mixture containing the desired organic amine reaction product, unreacted hydrogen and unreacted ammonia is withdrawn from the exit pipe 325 of the first reaction vessel and forwarded to the inlet pipe 315 of a second, and optionally subsequent reactors, such as for example third and fourth reaction vessels for additional hydrogenation of unreacted organonitrile. Optionally, fresh organonitrile feed is fed to each of the subsequent reaction zones.

[00169] Since the reaction of hydrogen with dinitrile in the reactor vessel is exothermic, the temperature of the effluent stream may be from 50°C to 80°C greater than the temperature of the stream entering the reaction vessel. The temperature of the effluent stream exiting the reactor vessel(s) should preferably not exceed 200°C, for example, 190°C, for example, 185°C. Accordingly, the effluent reaction product stream from each hydrogenation step is cooled, such as by heat exchange, prior to introduction into a subsequent reaction vessel and catalyst cartridge.

[00170] Upon completion of the reaction, the reaction product mixture containing the desired organic amine reaction product, unreacted hydrogen, unreacted ammonia and other byproducts is withdrawn from the reactor series and sent to a series of high pressure and lower pressure separator vessels.

[00171] Referring again to Fig. 14, the reaction product mixture passes through a line to a heat exchanger (not shown), wherein it may be reduced to a temperature range of from 30 to 60°C at a pressure of from 4100 to 4500 psig. The cooled reaction product mixture then passes from the heat exchanger to a high pressure separator 330, wherein flash evaporation occurs and the pressure of the reaction product mixture may be reduced to a range of from 450 to 500 psig, causing separation of a liquid phase comprising ammonia and the desired organic amine reaction product, exiting pipe 335 and a vapor phase comprising hydrogen and ammonia, exiting pipe 336.

[001 2] The liquid phase 335 from the high pressure separator comprising the desired organic amine (i.e. 6-aminocapronitriie or hexamethyienediamine) passes to lower pressure separator 340, wherein a vapor phase comprising primarily ammonia exits through pipe 346, and a liquid phase comprising primarily the desired organic amine exits through pipe 344. Subsequently, stream 344 passes through another heat exchanger (not shown), wherein it is heated to a temperature of from about 65 to 85°C and passed into an ammonia recovery system (not shown) at a pressure of from 465 to 480 psig. The stream entering the ammonia recovery system may comprise from 55 to 65 wt % ammonia, from 35 to 45 wt % of the desired organic amine and less than 1 wt %, for example, from 0.1 to 0.5 wt %, hydrogen.

[00173] The ammonia recovery system comprises an ammonia recovery column and condenser, as are known in the art, operated under super atmospheric pressure at a base temperature of about 150°C and a head temperature of about 67°C. A crude product comprising at least about 90 wt % of the desired organic amine is taken from the bottom of the ammonia column and exits the ammonia recovery system. The crude product may be further refined to remove impurities by known methods.

[00174] The gas phase overhead from the ammonia recovery column passes into a condenser where a disti!iate phase comprising ammonia and a vapor phase comprising hydrogen is formed. A portion of the distillate phase may be returned to the ammonia recovery column as reflux and/or transported to at least one storage tank for storage. A portion of the distillate phase may also be recycled as ammonia feed to the hydrogenation reaction.

EXAMPLE 4

[00175] This Example describes an embodiment of hydrogenating methylglutaronitrite (MGN) to 2-methyipentamethyienediamine (MPMD).

[00176] The method of Example 3 is followed, except that MGN is substituted for ADN in the reactant feed stream. The reaction results in full hydrogenation and the organic amine product is MPMD.

EXAMPLE 5

[00177] This Example describes an embodiment of hydrogenating adiponitri!e (ADN) to form HMDA, followed by hydrogenating methylgiutaronitrile (MGN) to 2-methylpenta- methyienediamine (MPMD).

[00178] The activation process of Examples 1 or 2 is followed, and the activated heterogeneous iron catalyst/cartridge(s) is transferred into one or more reaction vessel and locked and sealed therein with the above-described breech lock mechanism.

[00179] As described in Example 3 above, hydrogen gas, optionally containing ammonia, is passed through the reaction vessel inlet pipe under a temperature, pressure and flow rate sufficient to purge nitrogen from the movable cartridge/catalyst bed and out of the outlet pipe. After sufficient purging of nitrogen, a reactant feed stream comprising hydrogen, ammonia and ADN is supplied to a first reaction vessel through the inlet pipe thereof and is transmitted upward into the central standpipe of the movable cartridge. The pressure of the reactant feed stream to the first reactor vessel may be at least 3500 psig, for example, at least 4000 psig, or for example, at least 4500 psig. The temperature of the reactant feed stream to the first reactor vessel may be at least 80°C, for example at least 95°C, for example, at least 110°C, which can be achieved by passing the reactant feed stream through a heat exchanger or the like. The pressure of the system is maintained such that the ammonia and ADN are essentially in the liquid state.

[00180] The reactant feed stream mixture exits the top of the standpipe in the movable cartridge, is distributed across the top of the activated heterogeneous catalyst bed and is forced downward by both pressure and gravity and into contact with the catalyst. The ADN is fully hydrogenated to form H DA. Optionally, and in order to increase the efficiency of the reaction process, a reaction product mixture containing HMDA, unreacted hydrogen and unreacted ammonia is withdrawn from the exit pipe of the first reaction vessel and after heat exchange forwarded to the inlet pipe of a second, and optionally subsequent reactors, such as for example third and fourth reaction vessels for additional hydrogenation of unreacted organonitrile. Optionally, fresh organonitrile feed is fed to each of the subsequent reaction zones.

[00181] Since the reaction of hydrogen with dinitri!e in the reactor vessel is exothermic, the temperature of the effluent stream may be at least 5°C, for example, at least 10°C, greater than the temperature of the stream entering the reactor vessel. The temperature of the effluent stream exiting the reactor vessei(s) should preferably not exceed 200°C, for example, 190°C, for example, 185°C. Accordingly, the effluent reaction product stream from each hydrogenation step is cooled, such as by heat exchange, prior to introduction into a subsequent reaction vessel and catalyst cartridge.

[00182] Upon completion of the reaction, the reaction product mixture, containing HMDA reaction product, unreacted hydrogen, ammonia and other byproducts, is withdrawn from the reactor series and sent to a series of high pressure and lower pressure separator vessels.

[00183] The reaction product mixture passes through a line to a heat exchanger, wherein it may be reduced to a temperature range of from 30 to 60°C at a pressure of from 4500 to 4900 psig. The cooled reaction product mixture then passes from the heat exchanger to a high pressure separator, wherein flash evaporation occurs at a pressure of from 4500 to 4900 psig, causing the separation of a liquid phase comprising ammonia and the H DA reaction product and a vapor phase comprising hydrogen and ammonia.

[00184] The liquid phase from the product separator comprising HMDA and ammonia passes to a lower pressure separator operating at a pressure of about 1500 psig to effect separation of a vapor phase stream comprising ammonia and hydrogen, and a liquid phase stream comprising HMDA and ammonia. Subsequently, the liquid phase stream is passed to another heat exchanger, wherein it is heated to a temperature of about 65 to 85°C and passed into an ammonia recovery system (not shown) at a pressure of from 465 to 480 psig. The stream entering the ammonia recovery system may comprise from 55 to 65 wt % ammonia, from 35 to 45 wt % HMDA and less than 1 wt %, for example, from 0.1 to 0.5 wt %, hydrogen.

[00185] The ammonia recovery system comprises an ammonia recovery column and condenser, as are known in the art, operated under super atmospheric pressure of 450 psig at a base temperature of about 150°C and a head temperature of about 67°C. A crude product comprising at least about 90 wt % HMDA is taken from the bottom of the ammonia column and exits the ammonia recovery system. The crude product may be further refined to remove impurities by known methods.

[00186] The gas phase overhead from the ammonia recovery column passes into a condenser where a distillate phase comprising ammonia and a vapor phase comprising hydrogen is formed. A portion of the distillate phase may be returned to the ammonia recovery column as reflux and/or transported to at least one storage tank for storage. A portion of the distillate phase may also be recycled as ammonia feed to the hydrogenation reaction. [00187] The reactor train comprising the inlet piping, reactor vessels in series and downstream piping and other vessels are washed with liquefied ammonia for a period of time sufficient to remove any remaining ADN or H DA. The ammonia wash prevents cross contamination of the HMDA and MPMD products.

[00188] A reactant mixture feed stream comprising hydrogen, ammonia and MGN is supplied to the first reaction vessel through the inlet pipe thereof and is transmitted upward into the central standpipe of the movable cartridge, as in Example 4, above. The pressure of the reactant feed stream to the first reactor vessel may be at least 3500 psig, for example, at least 4000 psig, or for example, at least 4500 psig. The temperature of the reactant feed stream to the first reactor vessel may be at least 100°C, for example at least 105°C, for example, at least 110°C, which can be achieved by passing the reactant feed stream through a heat exchanger or the like. The pressure of the system is maintained such that the ammonia and MGN are essentially in the liquid state.

[00189] The reactant feed stream mixture exits the top of the standpipe, is distributed across the top of the activated heterogeneous catalyst bed and is forced downward by both pressure and gravity and into contact with the catalyst. The MGN is fully hydrogenated to form MPMD. Optionally, and in order to increase the efficiency of the reaction process, a reaction product mixture containing MPMD, unreacted hydrogen and unreacted ammonia is withdrawn from the exit pipe of the first reaction vessel and forwarded to the inlet pipe of a second, and optionally subsequent, such as for example third and fourth reaction vessels for additional hydrogenation of unreacted organonitrile. Optionally, fresh organonitrile feed is fed to each of the subsequent reaction zones.

[00190] Since the reaction of hydrogen with dinitrile in the reactor vessel is exothermic, the temperature of the effluent stream may be from 50°C to 80°C greater than the temperature of the stream entering the reactor vessel. The temperature of the effluent stream exiting the reactor vessel(s) should preferably not exceed 200°C, for example, 190°C, for example, 185°C. Accordingly, the effluent reaction product stream from each hydrogenation step is cooled, such as by heat exchange, prior to introduction into a subsequent reaction vessel and catalyst cartridge. [00191] Upon completion of the reaction, the reaction product mixture, containing MPMD reaction product, unreacted hydrogen, ammonia and other byproducts, is withdrawn from the reactor series and sent to a series of high pressure and low pressure separator vessels.

[00192] The reaction product mixture passes through a line to a heat exchanger (not shown), wherein it may be reduced to a temperature range of from 30 to 60°C at a pressure of from 4500 to 4900 psig. The cooled reaction product mixture then passes from the heat exchanger to a high pressure separator 230, wherein flash evaporation occurs at a pressure of from 4500 to 4900 psig, causing separation of a liquid phase comprising ammonia and the MPMD reaction product, exiting pipe 235 and a vapor phase comprising hydrogen and ammonia, exiting pipe 236.

[00193] The liquid phase from the high pressure separator comprising MPMD and ammonia passes to a lower pressure separator operating at a pressure of about 1500 psig to effect separation of a vapor phase stream comprising ammonia and hydrogen, and a liquid phase stream comprising MPMD and ammonia. Subsequently, the liquid phase stream is passed to another heat exchanger (not shown), wherein it is heated to a temperature from 65 to 85°C and passed into an ammonia recovery system (not shown) at a pressure of from 465 to 480 psig. The stream entering the ammonia recovery system may comprise from 55 to 65 wt % ammonia, from 35 to 45 wt % MPMD and less than 1 wt %, for example, from 0.1 to 0.5 wt %, hydrogen.

[00194] The ammonia recovery system comprises an ammonia recovery column and condenser, as is known in the art, and is operated at pressures from about 450 and 500 psig and at a base temperature of about 50°C and a head temperature of about 67°C. A crude product comprising at least about 90 wt % MPMD is taken from the bottom of the ammonia column and exits the ammonia recovery system. The crude product may be further refined to remove impurities by known methods.

[00195] The gas phase overhead from the ammonia recovery column passes into a condenser where a distillate phase comprising ammonia and a vapor phase comprising hydrogen is formed. A portion of the distillate phase may be returned to the ammonia recovery column as reflux, and/or transported to at least one storage tank for storage. A portion of the distillate phase may also be recycled as ammonia feed to the hydrogenation reaction.

EXAMPLE 6

[00196] This Example describes an embodiment of hydrogenating methylglutaronitrile (MGN) to form 2-methylpentamethyienediamine (MPMD), followed by hydrogenating adiponitrile to HMDA.

[00197] The process described in Example 5 is followed, except that MGN is substituted for ADN in the first reaction, and ADN is substituted for MGN in the second reaction.

RECYCLE

[00198] In any or all of Examples 3-6, the ammonia and hydrogen collected at the end of the process can be recycled into various points of the process.

[00199] For example, the gas phase from the high pressure separator which may comprise from 92 to 96 vol% hydrogen and 4 to 8 vol% ammonia, can be passed to a gas circulation pump to promote flow of hydrogen and ammonia through a recycle line and back to an inlet line of the process. Of course, either or both of the hydrogen or ammonia can be supplemented by fresh feed, if necessary.

EXAMPLE 7

[00200] This Example describes a method for converting methylg!uteronitrile (MGN) to 2-methyIpentamethylenediamine (MPMD) and for converting adiponitrile (ADN) to hexamethylenediamine (HMD) over a catalyst in the same conversion system.

[00201] The method comprises steps (a) - (d). Step (a) comprises running at least a first reaction cycle by passing either MGN or ADN into the reaction system to convert either MGN to MPMD or ADN to HMD. Step (b) comprises discontinuing the first reaction cycle of step (a). Step (c) comprises providing an ammonia wash step to the reaction system. Step (d) comprises running at least a second reaction cycle by passing either MGN or ADN into the reaction system to convert either MGN to MPMD or ADN to HMD, provided that, if MGN is fed in the first reaction cycle, then ADN is fed in the second reaction cycle, and, if ADN is fed in the first reaction cycle, then MGN is fed in the second reaction cyc!e,

[00202] The first and second reaction cycles of steps (a) and (d) each comprise passing hydrogen and either MGN or ADN and in the presence of ammonia over an iron-containing hydrogenation catalyst in at least three separate reaction zones under conditions sufficient to cause a hydrogenation reaction of MGN or ADN with hydrogen.

For example, ADN can be charged to the unit until the catalyst is deactivated, after which the catalyst is replaced and MGN is charged to the unit as feed.

[00203] Ail of the hydrogen and all of the ammonia are fed to the first reaction zone, and wherein fresh MGN feed is fed to all three of the reaction zones.

[00204] The ammonia treatment of step (c) comprises interrupting the flow of either

MGN or ADN and hydrogen to each of the reaction zones and flowing ammonia to each of the reactions zones.

[00205] The ammonia is introduced to each of the reaction zones at a temperature of at least 100°C and a pressure of at least 4000 psig.

EXAMPLE 8

[00206] Example 7 is repeated except that make-up hydrogen and ammonia are charged to each of the three reaction zones along with the effluent from the preceding reactor in the cases of the second and third reactors.

EXAMPLE 9 - Adiponitrile Feed

[00207] This Example describes the conversion of adiponitrile (ADN) to hexamthyienediamine (HMDA). Referring to Fig. 17, a source of ammonia is passed through line 502 and ammonia pump 510 via line 512 into a hydrogen/ammonia recycle stream in line 518. The source of ammonia may also include recycled ammonia introduced into line 502 through line 574. A source of hydrogen is also passed through line 504 into hydrogen compressor 514. Ammonia from ammonia pump 510 passes through line 512 into line 518, and hydrogen from hydrogen compressor passes through line 516 into line 518. The ammonia and hydrogen in line 518 is partially heated in heat exchanger 520 before it passes through line 522 to converter preheater 524. The heated ammonia and hydrogen from preheater 524 then passes through a series of four converters, depicted in Fig. 17 as converters 542, 544, 546, and 548.

[00208] A source of ADN feed is fed from line 528 into dinitri!e pump 530. ADN feed from dinitriie pump 530 passes through iine 532 to !ine 534. A portion of the ADN feed may pass through line 534 to the ammonia feed line 502. A portion of the ADN feed may also pass from line 534 to line 526 via side stream 536 for introduction into the first stage converter 542. Similarly, side streams 538 and 540 provide fresh ADN feed to the second stage converter 544 and the third stage converter 546. Also fresh ADN feed in line 534 is introduced into the fourth stage converter 548, as depicted in Fig. 17.

[00209] Feed streams comprising ADN and both fresh feed and recycled hydrogen and ammonia is passed into a series of four converters 542, 544, 546 and 548. The pressure of the feed to the first converter 542 may be at least 3500 psig, for example, at least 4000 psig, for example, at least 4500 psig. The temperature of the feed to the first converter may be at least 80°C, for example at least 95°C, for example, at least 1 10°C. The reaction of hydrogen with dinitriie in the first converter 542 is exothermic. Therefore, the temperature of the effluent stream exiting may be at least 5°C, for example, at least 0°C, greater than the temperature of the stream entering the first converter 542. The temperature of the stream exiting the first converter 542 should preferably not exceed 200°C, for example, 190°C, for example, 185°C.

[00210] Before the effluent stream from the first converter 542 is introduced into the second converter 544, it is preferably cooled by at least 5°C, for example, at least 10°C. This cooling may take place at least in part by passing the effluent from converter 542 into a cooler (not shown in Fig. 17) and by introducing a fresh feed of ADN of a temperature less than that of the effluent from converter 542 into line 550 via line 538.

[00211] The pressure of the feed to the second converter 544 may be at least 3500 psig, for example, at least 4000 psig, for example, at least 4500 psig. The temperature of the feed to the first converter may be at least 80°C, for example at least 95°C, for example, at least 110°C. The reaction of hydrogen with ADN in the second converter 544 is exothermic. Therefore, the temperature of the effluent stream exiting may be at least 5°C, for example, at least 10°C, greater than the temperature of the stream entering the second converter 544. The temperature of the stream exiting the second converter 544 should preferably not exceed 200°C, for example, 190°C, for example, 185°C.

[00212] Before the effluent stream from the second converter 544 is introduced into the third converter 546, it is preferably cooled by at least 5°C, for example, at least 10°C. This cooling may take place at least in part by passing the effluent from the second converter 544 into a cooler (not shown in Fig. 17) and by introducing a fresh feed of ADN of a temperature less than that of the effluent from second converter 544 into line 552 via line 540.

[00213] The pressure of the feed to the third converter 546 may be at least 3500 psig, for example, at least 4000 psig, for example, at least 4500 psig. The temperature of the feed to the third converter may be at least 80°C, for example at least 95°C, for example, at least 110°C. The reaction of hydrogen with ADN in the third converter 546 is exothermic. Therefore, the temperature of the effluent stream exiting may be at least 5°C, for example, at least 10°C, greater than the temperature of the stream entering the third converter 546. The temperature of the stream exiting the third converter 546 should preferably not exceed 200°C, for example, 190°C, for example, 185°C.

[00214] Before the effluent stream from the third converter 546 is introduced into the fourth converter 548, it is preferably cooled by at least 5°C, for example, at least 10°C. This cooling may take place at least in part by passing the effluent from third converter 546 through line 554 and heat exchanger 520 into line 556. The temperature of the stream in line 556 may be further reduced by introducing a fresh feed of ADN of a temperature less than that of the effluent from third converter 546 into line 556 via line 534.

[00215] The pressure of the feed to the fourth converter 548 may be at least 3500 psig, for example, at least 4000 psig, for example, at least 4500 psig. The temperature of the feed to the fourth converter may be at least 95°C, for example at least 110°C. The reaction of hydrogen with ADN in the fourth converter 548 is exothermic. Therefore, the temperature of the effluent stream exiting the fourth converter 548 may be at least 5°C, for example, at least 10°C, greater than the temperature of the stream entering the fourth converter 548. The temperature of the stream exiting the fourth converter 548 should preferably not exceed 200°C, for example, 190°C, for example, 185°C. For example, the stream exiting the fourth converter 548 may have a temperature within the range of 140 to 180°C and a pressure within the range of 3500 to 5000 psig.

[00216] The effluent from the fourth stage converter 548 passes through line 558 to heat exchanger 560. The cooled effluent then passes from heat exchanger 560 through line 562 to product separator 564. Flash evaporation occurs in product separator 564. The liquid phase, comprising diamine, from the product separator 564 passes through line 566 to heat exchanger 560. The gas phase, comprising hydrogen and ammonia, from the product separator 564 passes through line 586 to gas circulation compressor 588 to promote flow of hydrogen and ammonia through line 518.

[00217] The liquid phase from the product separator 564, which is heated in heat exchanger 560, passes through line 568 to ammonia recovery system 570. The ammonia recovery system comprises an ammonia recovery column (not shown in Figure 17) and condenser (not shown in Figure 17). A crude product comprising diamine is taken from the bottom of the ammonia column and exits the ammonia recovery system through line 572. The gas phase overhead from the ammonia recovery column passes into a condenser where a distillate phase comprising ammonia and a vapor phase comprising hydrogen is formed. A portion of the distillate phase may be returned to the ammonia recovery column as reflux. A portion of the distillate phase may be transported to at least one storage tank for storage. A portion of the distillate phase may also be recycled as ammonia feed to the hydrogenation reaction, in Fig. 17, this recycle of ammonia is represented by ammonia passing from the ammonia recovery system through line 574 to line 502.

[00218] The gas phase, comprising hydrogen and ammonia, from the product separator 564 passes through line 586 to gas circulation pump 588 to promote flow of hydrogen and ammonia through line 5 8. The gas in line 586 may comprise from 92 to 96 wt % hydrogen (H₂) and 4 to 8 wt % ammonia (NH₃).

[00219] Optionally, at least a portion of the vapor phase comprising hydrogen and ammonia in line 576 is passed through a line not shown in Fig. 17 as a feed to a catalyst activation unit for preparing a catalyst by reducing iron oxide with hydrogen. This stream may comprise 55 to 65 wt % hydrogen (H₂) and 35 to 45 wt % ammonia (NH₃).

[00220] The vapor phase from the condenser in the ammonia recovery system 570 passes through line 576 to ammonia absorber 578. This vapor phase comprises hydrogen and residual ammonia. The vapor phase is treated by scrubbing with water from line 580 in the ammonia absorber 578. Aqueous ammonia is removed from the ammonia absorber through line 582. A vapor phase comprising hydrogen exits the ammonia absorber 578 through line 584. Hydrogen in the stream in line 584 may be burned in a combustion device, such as a boiler or a flare. At least a portion of the vapor phase from the ammonia absorber 578 may be recycled as hydrogen feed, provided that water is removed from the stream. If water is not sufficiently removed from this stream, water may poison catalyst in the converters.

EXAMPLE 10

[00221] This Example 10 describes a method for converting methyiglutaronitrile (MGN) to 2-methylpentamethy!enediamine (MPMD) and for converting adiponitrile (ADN) to hexamethylenediamine (HMDA) over a catalyst in the same conversion system.

[00222] The method comprises steps (a) - (d). Step (a) comprises running at least a first reaction cycle by passing either MGN or ADN into the reaction system to convert either MGN to MPMD or ADN to HMDA. Step (b) comprises discontinuing the first reaction cycle of step (a). Step (c) comprises providing an ammonia wash step to the reaction system. Step (d) comprises running at least a second reaction cycle by passing either MGN or ADN into the reaction system to convert either MGN to MPMD or ADN to HMDA, provided that, if MGN is fed in the first reaction cycle, then ADN is fed in the second reaction cycle, and, if ADN is fed in the first reaction cycle, then MGN is fed in the second reaction cycle.

[00223] The first and second reaction cycles of steps (a) and (d) each comprise passing hydrogen and either MGN or ADN and in the presence of ammonia over an iron-containing hydrogenation catalyst in at least three separate reaction zones under conditions sufficient to cause a hydrogenation reaction of MGN or ADN with hydrogen. [00224] Ali of the hydrogen and ail of the ammonia are fed to the first reaction zone, and wherein fresh MGN feed is fed to ali three of the reaction zones.

[00225] The ammonia treatment of step (c) comprises interrupting the flow of either MGN or ADN and hydrogen to each of the reaction zones and flowing ammonia to each of the reactions zones.

[00226] The ammonia is introduced to each of the reaction zones at a temperature of at least 100°C and a pressure of at least 4000 psig.

EXAMPLE 11 - Fixed Bed Reactor

[00227] Activated iron catalyst of Examples 1 or 2 is blanketed in nitrogen in a catalyst cartridge and loaded into a high pressure hydrogenation reactor vessel rated for at least 6000 psig at 500°C. The hydrogenation reactor vessel of this Example 1 1 uses conventional flanged through-bolted hemispherical or ellipsoidal heads.

[00228] Hydrogen circulation is initiated and a controlled amount of ammonia is charged to the circulating hydrogen to provide hydrogen partial pressure of about 5500 psig and 3 to 5 weight percent ammonia in the circulating gas.

[00229] The adiponitrile feed enters the reactor near the top with the circulating hydrogen and ammonia and flows through a distributor nozzle and at least three layers of progressively smaller inert spheres to evenly distribute the downward flow through the reactor. The flowrate is initially controlled at about 25% of the continuous operating capacity of the unit, and ramping up to full capacity as the temperature rise across the reactor stabilizes. Feed temperature is controlled from 80 and 130°C, and increasing over time to convert from about 10% (ten percent) of the nitrile feed to diamine in a single pass, up to about 50% (fifty percent). Per-pass conversion is regulated by outlet temperature, since the reaction is exothermic. The outlet temperature is continuously monitored, and the inlet temperature is controlled such that the outlet temperature does not exceed 200°C to avoid thermally degrading the product. When the outlet temperature reaches about 195°C, the nitrile feed to the reactor is shut off, while the hydrogen and ammonia continue to circulate and the inlet temperature is maintained at about 105°C. The ammonia and hydrogen flows are then terminated, and the reactor is purged with an inert gas such as nitrogen to remove all of the ammonia and hydrogen. At this point air is gradually added to the circuiating nitrogen to passivate the catalyst and render it non-pyrophoric. The passivated catalyst can then be discharged safely from the reactor. This passivation process requires about five (5) days to complete.

[00230] While the catalyst in the fixed-head reactor of Example 11 is being regenerated, the reactor is unavailable for making diamine. This reflects a streamtime loss of about twelve days. The option of placing catalyst cartridges in fixed-head vessels is therefore rejected due to loss of streamtime in comparison with the disclosed process.

EXAMPLE 12 - Slurry Bubble Column Reactor

[00231] Example 12 is an evaluation of a slurry bubble column reactor with a riser and a downcomer as described in U.S. Published Application 2011/0165029 to Zhang et al., U.S. Pat. No. 6,068,760 to Benham et ai. and U.S. Patent 8,236,007 to Hou et al. The slurry bubble column reactor is selected for its ability to readily remove heat of reaction and to provide substantially isothermal operation.

[00232] Evaluation of a slurry bubble column reactor system for the operating pressures disclosed herein reveals exorbitant capital costs for the reactor body due to the wall thickness required for operation at pressures of 5000 psig. While the increased liquid volume of the system {in comparison to movable fixed bed catalyst cartridges) is beneficial for removing the exothermic heat of reaction and maintaining substantially isothermal operation, the slurry bubble column reactor option is rejected due to equipment costs as described above.

EXAMPLE 13 - Moving Bed Reactor

[00233] A method for hydrogenating nitriles over iron catalyst at pressures above 4500 psig was evaluated for a moving-bed reactor. The mechanical complexity for handling a pyrophoric catalyst at these pressures makes such a design capital cost prohibitive. Such reactors are usually employed for catalyst with much shorter regeneration cycles than the iron catalyst used for nitrile hydrogenation. EXAMPLE 14 - Streamtime Comparison

[00234] A typical catalyst lifetime for iron catalyst hydrogenating nitriies is 2 to 3 months. Using movable cartridges it is possible to perform a catalyst change in four reactors in less than 36 hours, which corresponds to a 2% loss of operating time. If catalyst was added directly to the reactors, rather than using movable cartridges, it would take 48 hours to add the catalyst, one week to activate the catalyst in place, and 72 hours to discharge the deactivated catalyst. This represents a down time of 12 days, which corresponds to a 14% loss of operating time. This much down time is untenable, and would necessitate the installation of a second parallel reactor line, which doubles the cost for these very expensive reactors.

EXAMPLE 15A - MGN Feed Using Parallel Reactor System

[00235] Example 4 is repeated except that fourth, fifth and sixth reactor vessels are added to the unit piped in parallel with the first, second and third reactors to form two parallel banks of three reactors each. Reactors 1-3 are referred to as "Reactor Bank A" and reactors 4-6 are referred to as "Reactor Bank B". Additionally, the reactors have fixed hemispherical heads and retain the catalyst directly using a support grid rather than a catalyst cartridge.

[00236] The reactors are filled with magnetite iron oxide catalyst precursor of Example 1. The catalyst of Reactor Bank A is reduced to iron catalyst using the procedure of Example 1. The hydrogen gas is then heated and circuiated and ammonia and fresh MGN feed is charged to the Reactor Bank A in accordance with Example 4.

[00237] After MGN feed is started to Reactor Bank A, then Reactor Bank B is filled with magnetite iron ore catalyst and reduced to iron catalyst using the procedure of Example 1.

[00238] When the outlet temperature of the third reactor [the last reactor in the series of Reactor Bank A] reaches 180°C then Reactor Bank B is brought up to operating temperature using the circulating hydrogen ammonia mixture and fresh MGN feed is diverted from the feed to Reactor Bank A to feed Reactor Bank B. [00239] The process of this Example 15A is then operated in swing mode such that one bank of reactors processes nitrile feed while the other bank of reactors is being regenerated.

EXAMPLE 15B - ADN Feed Using Parallel Reactor System

[00240] Example 15A is repeated with ADN as the nitrile feed using the hydrogenation conditions of Example 3.

[00241] Compared with the selective regeneration process of Example 3, capital cost for the unit approximately doubles due to the use of two banks of parallel reactors.

[00242] The foregoing disclosure constitutes a description of specific embodiments illustrating how the invention may be used and applied. Such embodiments are only exemplary. The invention in its broadest aspects is further defined in the claims which follow.

Claims

CLAIMS:

1. A catalyst cartridge 100 for a chemical reactor comprising:

a cylindrical casing 110 having a top end 105 and a base 106;

one or more exit apertures 116 in the base;

a standpipe 120 having an inlet aperture 120a located in said base, and having an upper end slightly less than the height of said cylindrical casing; and

catalyst disposed within the casing.

2. The cartridge of claim 1 , wherein the standpipe 120 and its iniet aperture 120a are centrally located in said cartridge.

3. The cartridge of claim 1 or 2, further comprising an inverted conical screen 124 surrounding the upper end of said standpipe 120.

4. The cartridge of any preceding claim, further comprising a plurality of openings 126 in a portion of the upper end of said standpipe 120 and surrounded by screening.

5. The cartridge of any preceding claim, further comprising a plurality of lifting rings 155 connected on an upper surface of said catalyst cartridge.

6. The cartridge of any preceding claim, wherein each exit aperture 116 is covered by a Johnson screen 140.

7. The cartridge of claim 6, wherein the Johnson screens 140 are positioned on an upper surface of the base 106, above said exit aperture 116.

8. The cartridge of claim 6 or 7, wherein the Johnson screens 140 extend into the catalyst bed.

9. The cartridge of any preceding claim, wherein the upper end of the standpipe has an upper portion and a top end terminating above a top 115a of a catalyst bed 1 5 within said casing, said upper portion perforated by a plurality of openings 126 extending below the top of the catalyst bed.

10. The cartridge of claim 9, wherein the plurality of openings is a Johnson screen 140.

11. The cartridge of claim 9, wherein the plurality of openings 126 extend from just below the top of the catalyst bed 115a for about 10% of the length of the standpipe 120, into the catalyst bed 115.

12. The cartridge of claim 9, wherein the plurality of openings 126 extend from just below the top of the catalyst bed 115a for about 25% of the length of the standpipe 120, into the catalyst bed 115.

13. The cartridge of any preceding claim, further comprising a toroidal collection trough 117 disposed on the bottom of said base 106, below and in fluid communication with said exit apertures 116.

14. The cartridge of claim 13, wherein the exit apertures 116 are connected in fluid communication to an equal number of exit distributors 140b, such as Johnson screens® 140, positioned on an upper surface of the base 106.

15. The cartridge of claim 13, wherein the collection trough 117 is U-shaped or semi-circular and surrounds said inlet aperture 120a.

16. The cartridge of claim 13, wherein the collection trough 1 7 has a rectangular cross-section and surrounds said inlet aperture 120a.

17. The cartridge of claim 13, wherein the collection trough 117 has a vee-shaped cross-section and surrounds said inlet aperture 120a.

18. The cartridge of claim 13, wherein the collection trough 117 has at least one exit pipe 118 extending below the collection trough and in fluid communication with the inside of the collection trough 117.

19. A converter 200 for a chemical reactor comprising:

a bottom portion 205 comprising a generally cylindrical shell having an internal void 205a, an inlet pipe 206 extending vertically through a bottom end of the bottom portion 205 and at least one exit orifice 208 displaced from said inlet pipe 206 and extending through said bottom end;

a middle portion 210 comprising a hollow cylindrical vessel in sealed fluid communication with the bottom portion 205;

a top portion 215 comprising a generally cylindrical shell of greater diameter than said middle portion 210, having a breech lock mechanism 240 comprising a first series of breech iock ridges 218 on an inner circumference of said top portion 215 for sealing said converter; and

a removable upper head 225 comprising a cylindrical retainer ring 230 having a second series of breech iock ridges 235 forming a breech lock engagement on an outer circumference thereof, and a cylindrical top head 150 held in place by said retainer ring 230,

wherein said second series of breech lock ridges 235 are structured and arranged to coact with said first series of breech iock ridges 218 to lock a catalyst cartridge 100 into and seal said converter 200.

20. The converter of claim 19, wherein the converter is structured and arranged to receive and support said cylindrical catalyst cartridge 100 within said converter.

21. The converter of claim 19, wherein the catalyst cartridge 100 comprises:

a cylindrical casing having a top end 105 and a base 106; a standpipe 120 having an upper end extending nearly the height of said cylindrical casing, and a lower end fitting over and in fluid communication with said inlet pipe 206;

one or more exit apertures 116 in the base; and

catalyst disposed within the casing.

22. A method for at least partially hydrogenating an organonitriie comprising the steps of:

reducing an iron oxide catalyst precursor contained in a movable cartridge comprising a casing, an inlet standpipe and at least one exit aperture, in a first, activation vessel through contact with a hydrogen-containing gas stream to produce an activated heterogeneous iron catalyst,

moving and loading the movable cartridge containing the activated heterogeneous iron catalyst into a second, reaction vessel for carrying out an organonitriie hydrogenation reaction,

flowing a feed stream comprising at least a charge of an organonitriie, hydrogen, and ammonia into said inlet standpipe of said movable cartridge such that it contacts said activated heterogeneous iron cataiyst to produce a reaction mixture, and withdrawing the reaction product mixture, comprising an organic amine, hydrogen, and ammonia, from the second vessel via said exit aperture.

23. The method of claim 22, further comprising after the activated heterogeneous iron catalyst has been deactivated to form a deactivated catalyst, moving the movable cartridge containing the deactivated catalyst from the second, reaction vessel to a third, passivation vessel and contacting the deactivated catalyst with a controlled amount of oxygen to at least partially passivate the catalyst.

24. The method of claim 23, wherein said deactivated catalyst is contacted with a passivation gas containing increasing concentrations of oxygen over a period of time and passivation is monitored by measuring the temperature of the passivation gas after said contacting.

25. The method of claim 23, further comprising purging said movable cartridge with a gas selected from the group consisting of helium, nitrogen, and argon prior to each moving step.

26. The method of any one of claims 22 to 25, wherein the organonitrile is one or more selected from the group consisting of adiponitriie, methy!glutaronitrile and 6- aminocapronitri!e.

27. The method of any one of claims 22 to 26, wherein a charge of adiponitriie or 6-aminocapronitrile is not followed by a charge of methylglutaronitrile in the absence of an intervening catalyst wash step.

28. The method of claim 27, wherein said intervening catalyst wash step comprises passing ammonia through said catalyst in said cartridge within said reaction vessel.

29. The method of claim 28, further comprising passing hydrogen through said catalyst with said ammonia within said reaction vessel.

30. The method of any one of claims 22 to 29, comprising passing hydrogen through multiple reaction vessels in series communication.

31. The method of claim 30, further comprising flowing a charge of said organonitrile into each of said multiple reaction vessels.

32. The method of claim 31 , further comprising cooling an effluent stream exiting a reaction vessel in said series prior to introducing the cooled effluent stream into the next reaction vessel in said series.

33. The method of any one of claims 22 to 32, comprising passing hydrogen through four reaction vessels in series communication.

34. The method of any one of claims 22 to 33, wherein the iron oxide catalyst precursor comprises a total iron content greater than 65% by weight, Fe(ll) to Fe(MI) ratio from 0.60 to 0.75, total magnesium content less than 6000 ppm by weight, total aluminum content greater than 700 ppm to less than 2500 ppm by weight, total sodium content less than 400 ppm by weight, total potassium content less than 400 ppm by weight, and having a particle size distribution greater than 90% in the range of 1.0 to 2.5 millimeters.

35. The method of any one of claims 22 to 34, wherein said iron oxide catalyst precursor is reduced with a hydrogen-containing gas stream further comprising from 3 to 5 vol% ammonia, at a pressure from 60 to 140 psig, and a temperature from 360 to 420°C.

36. The method of any one of claims 22 to 35, further comprising separating and recovering said organic amine from said reaction product mixture.

37. The method of any one of claims 22 to 36, wherein said organic amine is selected from the group consisting of hexamethylenediamine, 6-aminocapronitri!e and 2-methylpentamethylene-diamine.

38. A method of hydrogenating multiple organonitriles, comprising:

flowing a first feed stream comprising a charge of a first organonitri!e, hydrogen, and ammonia into a movable cartridge containing an activated heterogeneous iron catalyst, such that said first feed stream contacts said activated heterogeneous iron catalyst to produce a first reaction product mixture, comprising a first organic amine, hydrogen, and ammonia,

withdrawing and collecting said first reaction product mixture from said movable cartridge, washing said heterogeneous iron catalyst by purging said movable cartridge with ammonia and optionally hydrogen,

flowing a second feed stream comprising a charge of a second organonitrile, hydrogen, and ammonia into said movable cartridge, such that said second feed stream contacts said activated heterogeneous iron catalyst to produce a second reaction product mixture, comprising a second organic amine, hydrogen, and ammonia, and

withdrawing and collecting said second reaction product mixture from said movable cartridge.

39. The method of claim 38, wherein said first organonitrile is methylglutaronitrile and said second organonitrile is either adiponitrile or 6-aminocapronitrile.

40. The method of claim 39, wherein said first organic amine is 2- methylpentamethylenediamine, and said second organic amine is selected from the group consisting of hexamethylenediamine and 6-aminocapronitri!e.

41. The method of any one of claims 37 to 40, wherein said first and second feed streams contact said heterogeneous iron catalyst at a pressure from 4500 to 5500 psig, and a temperature from 80 to 130°C.