US3415861A - Organoaluminum compound production - Google Patents

Description

Dec. 10, 1968 w. T. DAVIS ETAL 3,415,861

ORGANOALUMINUM COMPOUND PRODUCTION 2 Sheets-Sheet 2 Filed March 31, 1964 l m m A. w, 225% mm hzwzwoiawa In 29.6mm IFBOmO 2310 nOm United States Patent Ofiice Patented Dec. 10, 1968 3,415,861 ORGANOALUMINUM COMPOUND PRODUCTION Wayne T. Davis and Charles L. Kingrea, Baton Rouge,

La., assignors to Ethyl Corporation, New York, N.Y., a corporation of Virginia Filed Mar. 31, 1964, Ser. No. 356,148 16 Claims. (Cl. 260-448) ABSTRACT OF THE DISCLOSURE Molecular weight peaking of organoaluminum compounds is obtained with a twin displacement process wherein typically a chain growth aluminum alkyl mixture is reacted with olefins to release heavy olefins from the high alkyl groups contained on the growth product, the resulting aluminum alkyl mixture subjected to further growth to increase the content of heavy alkyl groups and this product reacted with heavy olefins to further increase the content of desired heavy alkyl groups. The olefins are preferably from a bank system wherein olefins are recovered after the reactions with the aluminum alkyl mixture and split into fractions for recycle to the reactions. The particular improvement herein resides in increased reaction rates despite the accompanying tendency toward increased formation of vinylidene structures. Vinyl purity of olefins and alkyls is maintained through elimination of nonvinyl materials from the olefins. Additionally is provided unique and simplified replacement for the eliminated materials by generating olefins through coordinated growth and displacement operations which avoid certain difficult distillation separations of olefins and aluminum alkyls.

This invention relates to the manufacture of organoaluminum compounds. More particularly, the invention relates to the generation and utilization of organoaluminum compounds from a low alkyl aluminum material and ethylene as a reactant.

It is known, as a result of certain discoveries by Dr. Karl Ziegler and others, that low alkyl trialkyl aluminum compounds, typically triethyl aluminum, tripropylaluminum and similar trialkyl aluminum compounds can be transformed into trialkyl aluminum products wherein relatively long alkyl groups are attached to the aluminum. Under the Ziegler et al. teachings, a low alkyl trialkyl aluminum feed is caused to react with a plurality of moles of ethylene, which add approximately randomly at eachf'valence of the aluminum. Thus, by the reaction of moles of ethylene with one mole of triethyl aluminum, a trialkyl aluminum composition is obtained, the alkyl groups of which average 12 carbon atoms, or the product approximating the composition tri-dodecyl aluminum.

In practice, the idealized result of the addition of a uniform number of moles of ethylene per alkyl aluminum moiety, or per aluminum carbon bond, is not obtained. Instead the alkyl groups are actually a mixture, approximately according to statistical distribution laws, merely averaging at the indicated composition. Thus, in the typical illustration above given, the alkyl groups will include not only unreacted ethyl groups, but also butyl, hexyl, octyl, decyl, dodecyl, tetradecyl, hexadecyl, octadecyl and even higher. The alkyl aluminum product is not suitable, as such, for conversion to ultimate end products such as olefins or alcohols, or other derivatives of trialkyl aluminum compounds, which require a significant degree of specificity as to molecular weight or molecular chain length.

If the alkyl aluminum moieties could be efficiently separated according to the chain length of the individual alkyl substituents, then an opportunity would exist for greatly increasing the efiiciency of the process by separating out a desired fraction or component, and further processing the unwanted lower alkyl aluminum moieties. Unfortunately this objective has not been effectively realized for several reasons. Particularly, alkyl aluminum compounds having six or more carbons in each alkyl group can not be efiiciently distilled, owing to the high temperatures required which results in decomposition, and further because of the apparent existence of a statistical mixture at any one time with all possible trialkyl aluminum molecular species present as dictated by the alkyl groups in the gross mixture.

A further problem in the prior art arises because of the tendency for side reactions to occur. In a chain growth reaction, in order to obtain realistic reaction rates, elevated temperatures are required, but, unfortunately, higher temperatures are also accompanied by a greater amount of side reactions resulting in release of olefin hydrocarbons. These by-product olefins include not only vinyl olefins, but also vinylidene and internal olefins. These latter olefins are not susceptible to reconversions to straight chain alkyl aluminum groups.

One method has been found for generating trialkyl aluminum products of particular definition, which is not based on separation of alkyl aluminum moieties. This method utilizes a plurality of displacement reactions, in conjunction with at least one conventional chain growth reaction and with the use of a circulating supply of olefins, which olefins alone are fractionated according to molecular weight or chain length. It is found that such a process is characterized by a significant amount of ethylene loss as purged streams and as by-product olefins materials, especially of the internal and vinylidene isomer type.

In view of these considerations, a profound need has existed for a process whereby a low cost readily available trialkyl aluminum material and ethylene can be efliciently converted into a product having controllable identity and proportions of alkyl groups, by generally, a chain growth type process. A particular :need has existed for such a process providing a good degree of materials utilization, i.e., of the feed alkyl aluminum and of the ethylene.

The general object of the present invention is then to provide a new and improved process for manufacturing trialkyl aluminum materials from a low alkyl trialkyl aluminum feed and ethylene, characterized by a high degree of controllable specificity and identity of the alkyl groups of the products. A more particular object is to provide such a process wherein separation of statistical mixtures of trialkyl aluminum streams, according to the alkyl aluminum moieties is rendered unnecessary, but nevertheless the product achieves the aforementioned objectives. An additional object is to provide a process of the character indicated providing a high degree of ethylene utilization. A further object is to provide a process wherein the normal disadvantageous effects, of by-product production of vinylidene and internal olefins, are substantially negated. Other objects appear hereinafter.

The following terminology used herein is believed well understood in the art and is defined for ready reference.

Alkyl aluminum moieties refers to a single alkyl group with one-third atomic equivalent of aluminum, sometimes indicated hereing by the expression Ral, wherein R represents and alkyl group consisting of carbon and hidrogen, and al represents one-third atomic equivalent of aluminum.

Trialkyl aluminum components or compounds refers to aluminum compounds having three alkyl groups, or alkyl group precursors, which are the same or different.

Thus the term includes not only compounds such as triethyl aluminum, or trihexyl aluminum, but other compounds such as diethylaluminum hydride, dihexylethyl aluminum, aluminum trihydride, etc. The hydride groups if in high concentration are rapidly and largely converted, to alkyl groups in the presence of olefins at the operative condition of the various reactions of the process. Usually, a trialkyl aluminum stream has some small proportions of hydride groups.

Chain growth refers to the reaction of ethylene with a trialkyl aluminum type feed, wherein the alkyl groups are increased in average length, by the addition of at least about one, or usually more, moles of ethylene per alkyl aluminum group, or per the carbon-aluminum bond ing of an alkyl aluminum moiety.

Displacement refers to the process of transfer or exchange of an alkyl group of an alkyl aluminum moiety by an alkyl corresponding to an olefin. The process is sometimes referred to as transalkylation. A typical illustrative reaction is the exchange of a hexyl group attached to aluminum and replacement by an ethyl group by reaction of an hexyl aluminum group with ethylene.

Low olefins is used herein with reference to olefin streams predominating in olefin components of lower molecular weight than those corresponding to the alkyl groups of a desired trialkyl aluminum product stream. It will be understood that this term refers to the dominant portions of a stream, so that such a low olefin mixture can include minor amounts of higher components having molecular weights corresponding to desired alkyl groups.

Heavy or high olefins refers to olefins or mixtures thereof having substantial quantities of olefin components of molucular weight corresponding to the olefins corresponding to the alkyl groups of a desired trialkyl aluminum component. Again, as in the case of low olefins, a heavy olefin stream can contain variable quantities of olefins of lower molecular weight than equivalent to the desired alkyl groups.

Vinyl olefins refers to straight chain alpha-olefins, viz., having a terminal ethylenic bond.

Vinylidene olefins refers to alpha olefins having a beta branching, a typical example, being Z-methyl-l-pentene, 2-propyl-l-heptene.

Internal olefins refers to nonalpha olefin compounds.

In all forms of the invention, at least one chain growth operation is carried out in conjunction with two displacement type operations, plus supplemental or ancillary processes and operations as enumerated below. These supplemental operations include separation of olefin streams from the efl luents from the two displacement operations mentioned, the fractionation of a mixture of essentially only olefins from said source to provide streams relatively concentrated in low and high olefins respectively and the selective chemical treatment of at least a portion of a heavy olefin fraction whereby, in effect, vinyl olefin components are separated from the nonvinyl olefins. The nonvinyl olefins are discharged as a purge stream from the process system in quantities at least approximating in quantity the corresponding nonvinyl olefins generated in the chain growth and displacement operation, whereas the vinyl olefins are selectively converted to alkyl radicals.

In one general class of embodiments, a single chain growth operation is employed, and at least a portion of the effluent trialkyl aluminum from such a chain growth is used as the feed to each of two different displacement processes, one characterized by a displacement utilizing a low olefins stream and the other characterized by a displacement utilizing a high olefins stream.

In another general and preferred class of embodiments, two chain growth operations are employed for generation of aluminum alkyl groups by chain growth. In both of said chain growth, conditions are sufiiciently drastic that a relatively substantial quantity of olefins, both of the straight chain, and of the vinylidene type, along with minor quantities of internal olefins, are generated as concurrent by-products. In these embodiments the first chain growth operation processes a low alkyl trialkyl aluminum feed, and the second chain growth operation processes an intermediate alkyl trialkyl aluminum mixture, derived as will be shown, hereinafter, from a first displacement operation.

In further refinements or classes of embodiments in addition to chemically processing a heavy olefins stream for the chemical separation of vinyl olefins from nondesired vinylidene and internal olefins, a comparable operation is carried out with at least a portion of a light olefins stream. This class of variations can be applied to the above classes of embodiments utilizing, respectively, single main chain growth and double main chain growth processes.

Still an additional and highly refined class of embodiments utilizes a special feed back of a segment of a low olefins fraction, to be admixed with and concurrently chemically processed with a heavy olefins fraction which is chemically treated for separation of nondesired olefins from the desired vinyl type olefins which are recovered as alkyl groups.

In the most highly refined and particularly preferred class of embodiments a supplemental displacement, preferably utilizing ethylene as a displacement olefin, and a supplemental chain growth operation is employed in parallel to the principal chain growth operation, the specific purpose of said supplemental operation being to generate desired vinyl olefins, to compensate at least in part for the nondesired olefins and in aid .of the objective of providing a process wherein the ultimate alkyl groups meet a desired specification.

In all the foregoing classes of embodiments of the invention it will be seen that a characteristic is the combination of at least one chain growth and two displacement .operations, a fractionation operation, limited substantially exclusively to fractionating a mixture of olefins, and a chemical separation reaction to segregate the nondesired olefins, viz., vinylidene, and internal olefins, and to recover vinyl olefins as the corresponding alkyl groups.

In all forms of the process perceptible amounts of byproduct olefins of the vinylidene and internal type are generated in the chain-growth step or steps, and in the displacement steps. Heretofore, it was thought necessary to purge these 'by-products, along with nonseparable vinylolefins of the same molecular weights, at a relatively heavy loss. The present process, however, includes a chemical separation step whereby the undesired by-products are selectively purged. In the most efficient and highly preferred embodiments, the chain growth step or steps are deliberately carried out under conditions at which production of by-products is relatively high, in order to achieve a substantial increase in overall reaction rate accompanying such drastic conditions.

The principles of the invention and an understanding of the several embodiments thereof will be readily understood from the detailed description and examples thereof given hereinafter, and from the accompanying figures, wherein:

FIG. 1 is a simplified schematic representation of the process, and

FIG. 2 is a more detailed schematic process flow diagram illustrating a particular and preferred class of embodiments.

Referring to FIG. 1 the basic operations of all of the embodiments of the invention are shown, including a chain-growth reactor 151, displacement reactor 159, 166, an olefin fractionation section 172, and a purification section 178. Numerous ancillary equipment items, such as valves, pumps, heaters, and exchangers are omitted.

The feed to the process includes ethylene provided through line 152, and a low alkyl trialkyl aluminum, or a trialkyl-alkyl aluminum hydride mixture, through line 153. The low alkyl aluminum feed can be a pure component such as triethylaluminum, tripropyl aluminum,

tri-butylaluminum, or can be mixtures having generally low alkyl groups, such as a mixture varying in alkyl groups from 2 to 6 carbon atoms each, and centering, illustratively, at the fourcarbon atom level. The low alkyl trialkyl aluminum is provided through line 153, and is joined in this illustration by a recirculated mixture of intermediate trialkyl aluminum compounds provided in line 154. This recirculated stream will vary in quantity and composition according to the ultimate desired product. Generally the average alkyl group will have approximately one-half the carbon atoms desired in the average alkyls of the trialkyl aluminum product. Thus, if the desired product is to peak or be concentrated at 10, 12 or 14 carbon atoms, the average alkyl length in this immediate stream provided through line 154 will be 5, 6, or 7 carbon atoms.

In the chain growth operation, a plurality of moles of ethylene is reacted for each mole of trialkyl aluminum in the combined feed. The product includes not only trialkyl aluminum components having alkyl groups distributed in a manner approaching a statistical distribution as predicted by Poissons Law, but in addition excess or unreacted ethylene plus a variable quantity of by-product olefins of more than two carbon atoms. The byproduct olefins are made by side reactions, such as the splitting off of olefins from an alkyl aluminum moiety which has been the result of a chain-growth reaction. The conditions of the chain growth can vary widely, and can be from, illustratively, pressures of 1,000 to 3,500 pounds per square inch, with temperatures of from 200 to 350 F. A preferred range of pressures is from 1,500 to 3,000 pounds per square inch, and a preferred range of temperatures is from about 250 to 300 F.

It will be understood, as already mentioned and as illustrated, hereinafter, instead of a single chain-growth reaction, more than one can be provided.

The majority of the product components from the chaingrowth are fed to the displacement operations, a portion of at least about one-tenth up to nine-tenths, and usually of one-third to two-thirds, going to a first displacement reactor 159 through a branch 157 of the effluent line 155. customarily a substantial amount of excess ethylene is present in the overall chain-growth eflluent, but this is largely separated by a gas-liquid separator and recycled for recompression and reuse.

in the displacement reaction in the reactor 159, reaction is conducted with a low olefin stream provided through line 173. The low olefins are concentrated or peaked in olefins having a carbon number between the alkyl of the desired alkyl aluminum products, and the alkyls of the low alkyl feed component. A substantial excess of these olefins relative to the alkyl groups present to the feed are added through line 173.

The displacement operation is conducted at significantly high temperatures, at which temperatures normally a substantial amount of branching isomerization or olefin bond shifting, will occur. This tendency is not only exhibited when concentrated trialkyl aluminum is fed, but also when the alkyl aluminum feed contains substantial quantities of intermediate range olefins in solution.

The reaction in the displacement reactor 159, thus results in the release of the heavy alkyl groups as olefins and the replacement of them by alkyl groups derived from the olefins reactant feed provided in line 173. In a typical operation, then, the alkyl groups of twelve and higher carbon atoms in the trialkyl aluminum feed to the displacement reactor are diminished and the concentration of alkyl groups of ten or lower carbon atoms are substantially increased by this operation.

The conditions and other process variables of the displacement reaction are subject to wide latitude according to the economics of the situation and the desired product.

The displacement reactions of the process can be carried out under a wide range of conditions and good results will be obtained. Among the variables of operation are the proportions of olefins to the alkyl groups fed, the temperature and pressure and the contact time. For these principal displacement reactions, generally, .a broad range of temperatures is from about 450 to 650 F., a preferred range being from about 550 to 625 F. The proportions of olefins fed can vary from as low as about 1 mole per alkyl group up to about 15 moles. Generally, a preferred range for the first displacement reaction 159 is about 2 to 15 moles, a more preferred range being from about 5 to 10: 1. In the second displacement reaction 166 a preferred ratio is from about 2 to 8: 1, a particularly preferred ratio being from 2. to 5: 1.

Generally, the conditions of operation are such that the reactants are in a single phase, usually above the critical conditions for the system. This is not essential, however, and in certain cases the reacting mixture is in the two phase region.

The technique of the displacement operations can also be varied. One highly preferred technique involves preheating the olefin streams only and then intensively mixing the hot olefin reactant stream with the alkyl aluminum feed. The mixture is then allowed to react at substantially adiabatic conditions, the total mixing and reaction time being very brief, of the order of several seconds, preferably one second or less.

The effluent from the first displacement reactor 159, is passed through line to a separation zone 1617 The eflluent includes the trialkyl aluminum component from the reaction, plus the olefins, and separation is eflected by at least one, and more usually, a series of flash operations, customarily conducted at descending pressures, so that the last flashing operation is at a very low pressure in order to allow transmittal of as much as practical of the olefin components to the flash overhead line 163. The bottoms from the separation, predominating in the intermediate trialkyl aluminum components, is returned through line 154, to the chain-growth operation,

A parallel displacement and separation sequence is effected on a second portion of the chain-growth materials, this portion being fed through line 158 to a second displacement reactor 166. Reaction is conducted with a heavy olefins stream provided through line 168. Illustratively, the olefins of this reactant stream can be centered or peaked at the ten, twelve, fourteen, or even higher carbon-atom chain length range, according to the desired product. As in the preceding first displacement, the olefins are preferably used in excess.

The effluent passing through line 167 enters a separation section 169 which is normally a plurality of partial pressure flashing Zones, wherein a major portion of the olefin components are taken overhead through a line 170 and the bottoms are concentrated in trialkyl aluminum materials of the desired product range and are passed to delivery or to successive processing operations through a a product line 170a.

In all forms of the process the generation of the product materials of the desired alkyl group identifies and proportions is accomplished by the combination of the two displacement reactions already mentioned in conjunction with a fractionation operation accomplished on solely olefin streams. Thus, the olefins from the separation 161, 169, are fed through line 163, 170 and a joint line 171 to a fractionation section 172. In practice, this section includes a plurality of fractionating columns, the number depending upon the particular complexity of the separations to be made. At least one low olefins overhead stream is withdrawn through line 173, and at least a portion of this is employed as the olefins feed to the selective displacement reactor 159. In addition at least one heavy olefin stream is discharged through line 174, and a portion of this comprises the higer olefins reactant feed through line 168 to the second displacement reactor as heretofore previously described.

It will be understood that various other olefin streams can be withdrawn from the olefins section as desired.

A portion of the heavy olefin stream discharged through line 174 is diverted through line 175 to a chemical selective purification section 178 which is also fed, through line 177, with a trialkyl aluminum stream susceptible to selective reaction with the vinyl component of the olefins feed. This trialkyl aluminum reactant is most desirably, a component, or mixture of components consisting of or predominantly consisting of alkyl aluminum moieties wherein the alkyl group is a beta branched radical. A typical and readily available material for this purpose is triisobutylaluminum. However, other alkyl aluminum feeds can be employed for this purpose, including for example, tri-normal alkyls whose alkyl groups difier significantly in chain length from the chain length of the olefins to be recovered.

In the purification reaction section 178, the vinyl olefins are reacted with the trialkyl aluminum releasing olefins corresponding to the former alkyl groups, and converting the vinyl olefins to corresponding alkyl aluminum moieties. The vinylidene and internal olefin components of the olefin feed through the displacement section 178 are substantially nonreactive at the reaction conditions, and pass through essentially unchanged.

The typical stream compositions of an olefins feed will be roughly about 20 mole percent internal olefins and 10 mole percent vinylidene olefins, leaving about 70 mole percent of vinyl olefins available for recovery as alkyl aluminum moieties.

The conversion of the vinyl olefin compounds to alkyl aluminum compounds makes possible an efficient separation in separation zone 180, the separated streams including olefins derived from the trialkyl aluminum reactant discharged through line 182, nonreacted olefins discharged through line 181 and consisting of the internal and vinylidene olefins, and alkyl aluminum compounds discharged through line 183, which generally are in the same molecular weight range desired for the product stream and are fed through line 183 to the product discharge line 184.

In a more advanced and further refined embodiment, two principal chain growth operations are carried out instead of the single chain growth illustrated by FIG. 1. In addition, a supplemental reaction train is provided for deliberately developing olefins, this supplemental reaction train including a chain growth and an ethylene displacement reaction. Lastly, a chemical purification or recovery is applied to at least a portion of low olefins stream as well as a heavy olefins stream from the olefin fractionation section.

This class of embodiments is schematically illustrated by FIG. 2. Referring to FIG. 2, a first chain growth reactor 11 has a trialkyl aluminum feed line 13. Ethylene required for the chain growth is provided through a line 12, and an effluent line 15 transfers the chain growth product to an ethylene separator 20. The vaporized ethylene is recovered by overhead line 21. The bottoms, including the trialkyl aluminum chain growth material is passed through line 14, from which a branch line 19 is diverted, for passage of a portion of this material when desired.

The branch line 19 feeds a displacement reactor 117 which is also fed by an ethylene line 118. Connecting line 119 transfers the effluent from the displacement reactor 117 to a cooler 120, which in turn discharges through line 121 to a flash chamber 122. Leading from the flash chamber 122 is an overhead excess ethylene line 123 and a bottoms line 124, which feeds a regrowth reactor 111. A compressed ethylene line 125 also feeds the regrowth reactor 111.

The efiiuent line 112 connects to a flash chamber 113, having overhead line 114 for vaporized excess ethylene. The bottoms line 115 returns to line 14, forming line 14a which connects to flash chamber 16, having an overhead line 18 and a bottoms line 17. The bottoms line is joined by a cross-over line 51 and passes to a displacement reactor 23. Also feeding the displacement reactor 23 is a hot low olefins 1ine 35. Immediately after the displacement reactor 23 is a pressure reducing valve 27. Downstream from this valve a cold olefins line 33 is joined, the line then passing to a cooler 27a, which is connected by transfer line 22a to a flash chamber 24. An overhead line 25 i provided for transmittal of the flashed components, essentially only olefins, the bottoms liquid being discharged through line 26. The bottoms discharge line 26 is joined by a supplemental alkyl aluminum line 43 from the chemical separation section, hereafter described, and becomes line 44 for feeding the combined mixture to a second chain growth reactor 45. Also connected to the second chain growth reactor 45 is an ethylene line 46. An effluent line 47 passes to an ethylene flash drum 48. Overhead line 49 combines with recovered ethylene line 21 to form a total recovered ethylene line 50, which masses to a recompresser unit 50a for repressurizing.

A bottoms line 52 passes from the ethylene recovery flash drum 48 to a second displacement reactor 54. Also feeding the displacement reactor 54 is a hot olefins line 53. A control valve 55 downstream from the reactor 54 is provided to maintain pressure in the reactor. A cooler 55a is provided in the eflluent line 56 from the reactor 54. The discharge or effluent line 56 feeds a flash drum 57. An overhead olefin line 58 is provided for discharge of the overhead vapors which are essentially only olefin components, and is joined by a further olefin line 59, to provide an olefin transfer line 60, which is in addition joined by olefin line 25 already described, forming a combined olefin feed line 28 to an olefin fractionation unit 29.

A bottoms line 62 from the olefin flash chamber 57 is provided for the liquid phase bottoms. These are concentrated in trialkyl aluminum components but normally have a significant quantity of nonvaporized olefins. The line 62 passes in this embodiment to a first oxidation reactor 63. A feed line 64 is provided for introducing an oxidizing gas. An overhead line 65 is provided to discharge oxygen lean gas from the oxidation reactor 63. A transfer line 66 leads from the first oxidation reactor 63 to an olefin flash chamber, 67. An olefin overhead line 59 discharges from this flash chamber to join with the olefin line 58 already mentioned. A bottoms line 68, is provided to transfer the partly oxidized trialkyl aluminum component containing stream, this line being joined by an alkyl aluminum line from a secondary chemical separation section, hereinafter described, the combied line 71 being a feed line to a second oxidation reactor 72. An oxidizing gas feed line 73 feeds a gaseous oxidant thereto, an oxygen lean discharge gas line 74 being provided to discharge the stripped oxidizing gas. The discharge line 75 transmits the oxidized product material to further operations.

The olefins fractionation unit 29 represents a series of several, up to four or five, fractionators for fractionally separating the feed olefins mixture provided through line 28. It will be understood that, if desired, separate fractionation trains can be provided for the olefins from the first and second displacement. However, as both olefins mixtures will include the same components, but in different proportions, it is usually more desirable and more economical to process the olefins from both displacement operations in a single fractionating train 29.

A plurality of product streams can be withdrawn from the fractionation section 29, according to the needs of a particular operation. In the present instance, a light ends overhead line 30 is connected to a stripping reactor 38. A second overhead line 32 has a branch 31 therefrom, and this branch is joined by a trialkyl aluminum line 37. A heater 36 is provided to heat the mixture to reacting temperatures. A flash chamber 38 is fed by the line from the heater 36 and also by the lightest olefins line 30. Discharge lines from the flash chamber 38 include the overhead line 41 and a bottoms line 40, which feeds a vaporizer separator 39, from which discharges an overhead line 42 and bottoms line 43.

It is seen that in typical operation of the above described overhead treating section, a portion of the light olefins fraction in line 32 can be diverted for treatment with a trialkyl aluminum for purification purposes as hereinafter described. The major part of the low olefins stream is passed through line 32 for use in the first displacement reactor section, being preheated in furnace 34.

An additional low olefins fraction line 30a is provided, for transfer, when desired, of particular olefin components for purification in the heavy olefins purification section described below. Purge lines 30b and 31b are also provided for discard or purge of portions of light olefin fractions when desired.

A heavy olefins line 79 provides for release of at least one heavy olefins fraction. A branch line 80 is connected thereto for diverting a portion of the heavy olefins to a purification section, for selective reaction of the vinyl olefin components and the recovery of the vinyl olefins as corresponding alkyl aluminum moieties.

The diverted heavy olefins line 80 is joined by a trialkyl aluminum feed line 82. The line then passes to a heat exchanger 84. The heated, partly reacted mixture can then be passed to flash chamber-reactor 81, which is also fed by a hot stripping solvent line 83. An overhead line 85 is provided to discharge vapor by-products of the purification reaction. The liquid bottoms line 70 passes to connect with line 68, the merged line 71 passing to the final oxidation reactor 72.

' EXAMPLE 1 In the working example following, the process is used to generate, from triethyl aluminum and ethylene, a trialkyl product having high and controlled proportions of decyl-through-hexadecyl aluminum alkyls. The plant installation of FIG. 2 is used. Also, the above operation is integrated in a particularly effective manner with the conversion of the trialkyl aluminum to corresponding aluminum trialkoxides.

Fresh triethyl aluminum is fed through line 13 to the first chain growth reactor 11. Ethylene is fed through line 12, in the proportions of well over 4.5 moles per alkyl aluminum group.

The chain growth reactor is operated at a temperature of about 290300 F. and a pressure of about 2,500 pounds per square inch. A typical composition of the alkyl aluminum components of the eflluent from the reactor 11 is as follows:

Alkyl aluminum components Mole percent Butyl and lower 6 Hexyl 11 Octyl 17 Decyl l9 Dodecyl 17 Tetradecyl 13 Hexadecyl 8 Octadecyl and higher 8+ The eflluent mixture passes to the flash drum 20 and the excess or unreacted ethylene is taken off overhead and passes in lines 21 and 50 to recovery and recompression. The bottoms from the flash drum 20 pass through line 14, and about one-fifth is diverted through line 19 and fed to the displacement reactor 117. Ethylene is concurrently fed in excess through line 118, and is reacted with the trialkyl aluminum to give olefins corresponding to the alkyl groups. Typical operating conditions of the reactor 117 are 550-575 F., and 150-250 pounds per square inch. The eflluent is discharged through line 119 and cooler 120 to flash drum 122 for separation of the excess ethylene through line 123. The bottoms, including the olefins and the triethyl aluminum generated in the displacement reaction, then are fed to the supplemental chain growth reactor 111 and chain growth is again accomplished with ethylene provided through line 125. This chain growth is at about the same conditions as in reactor 11 and is carried out to provide trialkyl aluminum components essentially matching the chain growth product from the principal reactor 11. The excess ethylene is similarly separated in the flash chamber 113. The bottoms, .including the trialkyl aluminum and olefins, are returned in line to join with the rest of the chain growth trialkyl aluminum in line 14. The combined streams pass through line 14a to flash chamber 16, wherein certain of the lower olefins present, particularly butenes, can be removed through line 18 if desired. The trialkyl aluminum bottoms pass through line 17 to the first principal displacement reactor 23. In this specific operation, no crossover trialkyl aluminum is provided through line 51.

In the displacement reactor 23, reaction is with a low olefin stream provided through line 35, said olefins having been preheated in furnace 34. A typical composition of the olefin supply is as follows:

Olefin- Mole percent Butenes 9 Hexenes r 21 Octenes 3 2 Decenes 3 8 Dodecenes 1 percent). The displacement reaction thus provides a trialkyl aluminum efiluent enriched in alkyl groups of 6 to 10, inc., carbon atoms corresponding to the principal olefins of the reactant stream. The olefins portion of the effluent is enriched in higher olefins, i.e., of twelve and higher carbon atoms.

A typical composition of the olefin components of the eflluent from the displacement reactor 23 is:

Olefin-- Mole percent Butene 9 Hexene 19 Octene 3O Decene 35 Dodecene 3 Tetradecene 2 Hexadecene 1 Octadecene and higher 0.7

In this operation, immediately on being discharged the mixture passes through pressure reducing valve 27 and is then immediately mixed with cold olefins provided through line 33. After passing through the cooler 27a, the mixture, no longer at reaction conditions, passes through line 22a to the flash vaporizer 24.

The bottoms, discharged through line 26, contain a high proportion of trialkyl aluminum components, a typical alkyl aluminum distribution being as follows:

Aluminum component Mole percent Butyl and lower 17 Hexyl 21 Octyl 24 Decyl 28 Dodecyl and higher 10 This stream is accompanied by a minor quantity of olefins not separated by the flashing operations, and is joined by a recovered stream of trialkyl aluminum components received through line 43. This recovered stream amounts to about six percent of the alkyl aluminum mixture from the displacement reaction.

The combined streams are passed through line 44 to the second chain growth reactor 45. The average amount of chain growth provided in this reaction is appreciably below the level in the first chain growth, amounting to 0.9 to 1.3 moles of ethylene per alkyl aluminum moiety. As this chain growth system involves alkyls of appreciably higher molecular weight, lower temperatures are customarily used. In this example, the conditions are about 250-260 F. and 2,500 pounds per square inch.

The excess ethylene from the chain growth is flashed in drum 48. A typical composition of the trialkyl aluminum components in the bottoms from the flash chamber 48, in line 52, is:

Alkyl aluminum components- Mole percent The alkyl aluminum components cited above amount to about three-fourths of the total eflluent, the balance being olefins. In this operation none of the chain growth materials are transferred through line 51, but the stream is fed in its entirety to the second displacement reactor 54 for reaction with a heavy olefins stream provided through line 53, having a high concentration of olefins of 12 through 16 carbon atoms. These are fed in substantial excess, providing about 8 to 9 moles of the indicated chain length components per mole of the trialkyl aluminum feed. The displacement reactor is operated at a temperature of about 570 F. and a pressure of about 250 pounds per square inch.

The displacement reaction results in the conversion in high yield of lower-than-desired alkyl groups of the trialkyl aluminum mixture fed to the second displacement reaction, to alkyl groups in the desired product range. A typical efiluent from the second displacement reactor 54, in line 56, on an olefin free basis, will exhibit the following composition:

Alkyl aluminum component-- Mole percent Ethyl 2.0 Butyl 1.2 Hexyl 2.8 Octyl 4.9 Decyl 9.6 Dodecyl 35.5 Tetradecyl 23.6 Hexadecyl 13.2 Octadecyl 6.3 Eicosyl et al. 1.2

The effluent from the displacement reactor 54 passes through the pressure reducing control valve 55, and the pressure is immediately dropped about 250 pounds per square inch to a subatmospheric pressure. The mixture at the lower pressure passes through the cooler 55a to flash drum 57, in which a substantial portion of the olefin components are vaporized overhead to line 58. The bottoms, containing the alkyl aluminum compounds, pass through line 62 to the first oxidation zone 63, wherein partial oxidation of the alkyl aluminum moieties is effected to the corresponding alkoxide group, by air or other oxidizing gas provided through line 64, the oxygen stripped gas being discharged through line 65. The thus oxidized material, oxidized to the extent of converting 50 to 70 percent of the alkyl groups to the corresponding alkoxides, is transferred through line 66 to an additional vaporizing chamber 67 wherein heat is supplied and additional olefin components are discharged overhead through line 59,

which joins line 58 to provide a heavy olefins feed line 60 to the olefin fractionation section 29.

The olefins provided from the first displacement section through line 25, and the olefins provided through line 60, are combined in the feed line 28 to the olefins fractionation section 29. The olefin fractionation includes a plurality of columns for separating into streams of desired analyses. In this operation the overhead stream taken off in line 30 is concentrated in hexenes, whereas the side stream discharged through line 32 contains substantial concentrations of octene and decene.

The olefins fractionation does not separate the isomeric olefins of equal molecular weight. A typical proportion of non-reactive isomers in the light olefins stream 32 is about 20 mole percent internal and 5 mole percent vinylidene isomers. Several percent of this stream is diverted through line 31 and is blended with trialkyl aluminum provided through 37, then passed through a heater 36. The triisobutylaluminum, or similarly selectively reactable trialkyl aluminum material is fed in proportions approaching equal molal ratios between the vinyl olefin content and the alkyl aluminum groups. A substantial portion of the displacing reaction occurs in the heat exchanger 36, which then feeds this reaction mixture to the column 38. This feed contains nonreacted olefins, viz., internal and vinylidene olefins, as well as the olefin released as a result of the displacement reaction, which is isobutylene in the case of triisobutyl aluminum. Typical reaction conditions for this operation are about 500 F., 5 to 50 pounds per square inch gauge, and a total reaction time of about one to three minutes.

This mixture is then contacted in a counter current manner with vapor phase lighter olefins provided through line 30, in stripping column 38, which purges the liquid phase of the isobutylene components, for release through line 41. The isobutylene can, desirably, be subsequently used to regenerate triisobutyl aluminum.

The bottoms from the stripping column 38 pass to a fiash chamber 39, wherein the nonreacted undesired isomeric olefins are vaporized overhead for purging through line 42. Bottoms from this flash chamber are trialkyl aluminum materials approaching in composition the trialkyl aluminum components from the effluent from the first displacement reactor 23, and are mixed therewith by connection of the transfer line 43.

The treatment of a heavy olefin fraction for purging of the nondesired olefin isomers is accomplished in very much the same manner as with respect to the light olefins purge treatment described above. A portion of the heavy olefins efliuent from the fractionation section 29 is passed through line 80 and is supplied through line 82 with a selectively reactable trialkyl aluminum material, again, desirably, a trialkyl having vinylidene or beta branched alkyl groups, such as triisobutylaluminum. The thus formed mixture passes through the heater 84, wherein a substantial portion of the reaction occurs. The mixture, partially or almost completely reacted, then passes into a reactor stripper unit 81, which is also fed by a circulated solvent through line 83, the solvent in this case being of sufficiently 10w volatility, so that it dilutes the trialkyl aluminum compound formed by the displacement reaction and facilitates a high degree of the purification reaction. Reaction conditions employed are about 500 F a moderate pressure of about 5 pounds per square inch, and a reaction time of one to three minutes. The isobutylene resulting from the displacing reaction is discharged overhead through line 85, and the bottoms from the reactor 81 includes recoverable trialkyl aluminum compounds derived from the vinyl olefins, nondesired isomeric olefins, viz., vinylidene and internal isomers, and the circulated solvent provided through line 83. This mixture is transferred by line and joins line 68, which contains the partially oxidized trialkyl aluminum material from the stripping chamber 67. The thus formed mixture passes to a second oxidation unit 72, wherein additional oxidation is provided by an oxidizing gas fed through line 73, the stripped gas being discharged through line 74. The product from this oxidizer, discharged through line 75, contains essentially trialkoxide aluminum components and inert hydrocarbon diluents. The mixture discharged through line 75 is thereafter processed by distilling out the hydrocarbon components. These include any unreacted vinyl olefins, undesired internal and vinylidene olefins, and the circulated solvent component which is suitably a parafiinic stream of about eight carbon atoms. The bottoms from such a fractionationagare substantially high purity aluminum trialkoxide, and are thereafter reacted with a dilute aqueous solution of an inorganic acid or a caustic to generate an alcohol product.

A typical alcohol composition derived from this operation is as follows:

The hydrocarbons stripped out are fractionated into the purged portion including the nondesired isomers, and the solvent portion which is recirculated through line 83 to the selective chemical processing in the reactor 81.

A high yield of the final product, on the basis of both the ethylene and triethyl aluminum feed, is obtained.

In the following example the composition of the growth alcohol product made differs from that provided by the operation of Example 1, in that a particular light olefins component from the fractionation section is sent to the heavy olefins purification section and is treated concurrently with the portion of the heavy olefins stream provided through line 80.

EXAMPLE 2 The operations of Example 1 are repeated, except that a side stream is taken from the olefin fractionation section 29, through line 30a, this stream being highly concentrated in octene olefins. These are blended with the heavy olefins provided through line '80, and the l-octene content is reacted with triisobutyl aluminum in addition to the vinyl components of the heavy olefins stream. As a consequence, the trialkyl aluminum recovered materials discharged from a separatory drum 81 through line 70 include consequential amounts of octyl aluminum groups, and, in the ultimate alcohol product obtained in this class of embodiments, the octyl alcohol concentration is significantly raised. Thus, a typical increase in the amount of octyl alcohol is an increase of from about one-half to a full doubling, illustratively from about 4 to 7 weight percent in the final gross product.

EXAMPLE 3 In this operation, the same procedures as used in Example 1 are carried out, but there is no purification treatment applied to the overhead light olefins provided by the fractionation section 29. Instead, proportions of the overhead streams are purged to flares or other waste treatments by lines 30b and 31b. The stream compositions, however, are not significantly altered, but the consumption of ethylene for the production is increased by from three to ten percent.

EXAMPLE 4 In this operation, the procedures are essentially the same as in Example 1, but special provision is made for altering the product composition by a split of the chain growth product from the second chain growth operation in reactor 45-, whereby a portion of such trialkyl aluminum components is subjected to reaction in the first displacement reactor 23. In addition, a particular light olefins component is transferred from an overhead from the fractionation section 29 to the heavy olefins purification section for the purpose of providing a skewed product composition enriched in said particular alkyl (or alcohol) components.

In this operation, essentially the same conditions are preserved as in Example 1, but approximately one-half of the chain growth product in line 52 is diverted in line 51 and combined with the feed to the first displacement reactor 23. In addition, a light olefins recovered stream which is highly concentrated in octenes is transferred through line 30a and is combined with the heavy olefins provided through line 80, for the selective reaction of the vinyl components thereof, with a reactable trialkyl aluminum, such as triisobutyl aluminum provided through line 82.

In this operation, the trialkyl aluminum components in the recovered trialkyls from the heavy olefins purification operation, in line 70, will have a composition relatively high in octyl aluminum components. The following table gives typical analyses of these recovered trialkyl aluminum materials and the trialkyl aluminum components provided by the second displacement reactor in line 62, prior to the oxidation thereof.

Second displace Trialkyl aluminum Alkyl alumlnum component ment product (62),

from purification mole percent (70), mole percent Ethyl 3 Butyl 2 Hexyl 4 Octyl. 6 DecyL. 9 Dodecyl 39 Tetradeoyl 22 Hexadecyl 10 Octadecyl 4 Eicosyl and higher 1 The trialkoxide components delivered through line 75, upon conversion to alcohols, yield a product having the following composition:

EXAMPLE 5 In this operation, the supplemental olefin generation provided by the ethylene displacement reactor 117, and the regrowth-chain growth reactor 111 are entirely omitted. This is done by close-off of appropriate valves in lines 19, 114, and 115. In order to achieve essentially the same net production of trialkyl aluminum product materials, or the aluminum trialkoxides derived as therefrom when desired, it is necessary to operate the chain growth reactors, especially the first chain growth reactor '11 at more drastic temperature conditions and lower pressures whereby an increased quantity of olefins are concurrently generated, along with the chain growth trialkyl aluminum products components from said reactor. Typical operating conditions for this chain growth reaction would then be about 300-310 F. and a pressure of about 1,500 pounds per square inch. In addition a larger portion of the chain growth product from the I 15 second chain growth reactor 45 is transferred through line 51, for processing in the first displacement reactor 23.

Although this mode of operation provides substantially the same raw materials utilization as Example 1, the invest'ment or size of the plant installation is appreciably enlarged, because the alteration of conditions in the chain growth reaction, in order to produce more olefins, also results in a further departure of the alkyl aluminum distribution from a Poisson equation type product distribution. In other words, the distribution is less peaked than at lower temperature, higher pressure operation. An increased amount of crossover in line 51 would be necessary to achieve the same final product internal distribution. This necessitates greater investment in the first displacement reactor section, olefin separation equipment, and the second chain growth reactor.

The foregoing examples illustrate certain of the numerous variations of the process. Instead of integrating the formation of the trialkyl aluminum with the oxidation to the corresponding trialkoxides as in the foregoing examples, the trialkyl aluminum product can be collected and stored. In order to do this, the oxidation steps are omitted, and the trialkyl aluminum is freed of olefin impurities by distilling off the olefins at low pressures.

The alcohol products derived from the foregoing operations contain, as noted, varying amounts of individual alcohols, with high concentrations of the components dodecanol, tetradecanol, and hexadecanol. In Example 4, the operations were modified slightly to give an alcohol product more concentrated in dodecanol, and also having a skewed distribution in that the concentration of octanol is significantly raised.

Fractions or selected mixtures separated from the gross alcohol products made according to the foregoing examples are highly effective as raw materials in detergent manufacture, or for various other purposes. It will be clear that a desired pure alcohol component, such as essentially pure myristyl alcohol (tetradecanol) can be separated by conventional fractionation techniques. The alcohol product derived from the trialkyl aluminum made according to the present process is usually a high quality material in that it is low in carbonyl oxygen impurity content (aldehydes and ketones) and also is very high in normal vinyl alcohol content.

It will be apparent that, instead of generating a mixture having three, four or five alkyl groups in preselected defined proportions, the present process is fully adapted to making a product having essentially only two alkyl groups therein, or in extreme cases, to producing a material having only one alkyl group. The principles applied in such embodiments are the same as already illustrated herein, viz., the parallel operation of two displacement reactions, in one of which the alkyl groups are decreased in average length and a second in which the alkyl groups are generally increased in length, plus the continuous fractionation of a supply of olefins circulated in considerable excess relative to the alkyl aluminum groups.

When the end alkyl aluminum products are to contain essentially only two, or even one, alkyl group, it will be" apparent that more rigorous olefin fractionation operations are necessary and that investment costs will increase.

The particular benefits of the numerous embodiments of the present process also arise from minimizing the effects of certain side reactions occurring in the chain growth operations and displace-ment reactions. In fact, the present invention makes it possible to deliberately cultivate certain side reactions for beneficial purposes, as explained further below.

In a chain growth operation reaction is possible at quite a low temperature and at low temperatures practically no side reactions or by-products resulting in olefin formation occur. However, the rate of reaction at moderate temperatures is extremely slow, so that a great incentive exists for operating at high temperatures. The overall rate of reaction increases by a factor of two for approximately every Temperatures Pressure, p.s.l.g.

The foregoing data represents the percentage of feed ethylene occurring as olefins in the chain growth product, when the starting alkyl aluminum material is triethyl aluminum. It will be seen that the increase in temperature of about 30 C. results in a substantial increase in the quantity of the by-product materials. The corresponding data, when the feed alkyl is a mixture of trialkyl aluminum compounds averaging six carbon atoms in the alkyl groups is as follows:

Temperatures Pressure, p.s.1.g.

A small portion of the olefins formed as by-products in the chain growth operation, in the order of one or two percent, are nonreusable vinylidene and internal olefins. The intrinsic quantity of these by-products is not inherently so large as to be an extreme expense, but unfortunately, they are always in mixture with desired or usable vinyl olefins. By usable it is meant that the vinyl olefins can be employed for rereaction with alkyl aluminum compounds to provide the desired alkyl aluminum moieties of a desired product or an alkyl aluminum group convertible to a desired group. In any case, the vinylidene and internal olefins must be removed from the system, and this normally results in the loss of vinyl olefins, as the isomeric olefins cannot be separated from the vinyl olefins by conventional fractionation.

The two displacement reactions also result, under the very best of conditions, in the formation of nonusable isomeric olefins of the vinylidene and internal type. The amount of these materials formed in any single pass through a displacement reaction zone is so low as to be almost nondetectable, but, because the preferred and necessary form of operation utilizes a substantial molal excess of reacting olefins to alkyl aluminum compounds in a displacement operation, the olefins inventory corresponds to a substantial number of passes through the displacement reaction zones. Thus the olefin inventory is reused approximately 20 to 40 times in the displacement reactions.

If the vinylidene and internal olefins are allowed to build up to a relatively high concentration, so that purging by discarding the mixture of the nondesired isomeric olefins and vinyl olefins at an appropriate point, results in loss of only a moderate quantity of usable vinyl olefins, then the investment for a plant installation increases very much, because of a much greater investment in larger fractionation, compressing, reactor, and other equipment. Illustratively, if the nonusable isomeric olefins are allowed to build up from, say a 20 mole percent concentration, on the average, of the circulating olefin stream, up to a concentration of, say 60 mole percent the quantity of circulating olefins streams is doubled, hence the investment in fractionating columns, compressors, heat ex- 17 changers, lines and related equipment is also approximately doubled.

According to the present process, however, the chain growth and displacement reaction can be carried out under the relatively drastic conditions which results in a rapid reaction rate. The consequent high production of nonusable olefins and high loss of vinyl olefins, is avoided by discovery that the vinyl olefins of a purged stream can be selectively recovered so that the actual purge is a stream concentrated in the nonusable isomeric olefins, and material efiiciency is preserved.

Typical contributions of the chain growth and displacement reactions, in operations carried out in the installation shown by FIG. 2 (as in Examples 1 and 4) are given below:

Nondesired olefin, 1b./lb. mole AlR Reaction Internal Vinylidene olefins olefins First chain-growth (11) 0.1 0. 6 First displacement (23) 7 1 Second chain-growth (45) 6.

1 1. 1 Second displacement (54) 7 3.0

The impurities above indicated build up in the circulating olefins streams, as indicated by the following typical compositions of the combined feed to the olefin fractionation in line 28, the low olefins overhead stream 30, and the heavy olefins bottoms stream in line 79.

Having described the principles of the invention and the best mode of its operation, what is claimed is:

1. Process for generating a trialkyl aluminum having alkyl groups controlled as to identity and proportions from a low molecular weight trialkyl aluminum and ethylene comprising:

(a) reacting by a chain growth reaction ethylene and a feed low alkyl trialkyl aluminum to make an intermediate chain growth product, said chaingrowth producing trialkyl aluminum compounds and byproduct olefins,

(b) selectively dipslacing high alkyl groups from at least part of the trialkyl aluminum from (a) by reaction with a mixture of low olefins predominating in vinyl olefins lower than the desired alkyl groups of the final trialkyl aluminum product, and separating at least part of the olefins from the mixture from said displacement,

(c) reacting by chain growth with ethylene at least part of the trialkyl aluminum from (b) to form a chain growth product, said chain growth being under relatively severe conditions from about 250 F. to about 350 F. and from about 1,500 pounds per square inch to about 3,000 pounds per square inch resulting in concurrent production of straight and branched chain olefins,

(d) selectively displacing low alkyl groups from at least part of the trialkyl aluminum from (c) by reaction with a high olefin stream in proportions to produce desired alkyl groups in a final trialkyl aluminum product, and separating at least part of the olefins from the mixture from said displacement,

. (e) fractionating the olefins separated in (b) and (d) into fractions including the low and high olefins for the displacement reactions of (b) and (d),

(f) selectively reacting the vinyl olefins in a portion of the high olefins fraction from (e) by reacting with a trialkyl aluminum compound susceptible to displacement by vinyl olefins, forming trialkyl alu- 18 minum components corresponding to said selectivelyreacted vinyl olefins and nonreacted olefins, and olefins released by said displacement, separating at least part of said olefins mixture and purging said olefins.

2. The process for generating a trialkyl aluminum having controlled alkyl groups from a low molecular weight trialkyl aluminum and ethylene comprising:

(a) reacting by a chain growth reaction ethylene and a mixture of fresh low alkyl trialkyl aluminum with a recirculated intermediate alkyl trialkyl aluminum as hereafter defined, at least a part of said chain growth being under relatively severe conditions from about 250 F. to about 350 F. and from about 1,500 pounds per square inch to about 3,000 pounds per square inch producing trialkyl aluminum compounds and by-product olefins,

(b) reacting by displacement at least a first part of the trialkyl aluminum mixture from (a) with a mixture of low olefins predominating in vinyl olefins lower than the desired alkyl groups of the final trialkyl aluminum product and forming thereby an intermediate alkyl trialkyl aluminum enriched in alkyl groups corresponding to said vinyl olefins and olefins enriched in higher olefins, and separating at least part of the olefins from the mixture from said reaction,

(c) recycling at least part of the intermediate alkyl trialkyl aluminum from (b) to (a),

(d) reacting at least a second part of the trialkyl aluminum mixture from (a) with a mixture of high olefins concentrated in vinyl olefins corresponding to the alkyl groups of the desired trialkyl aluminum product and forming thereby a mixture of trialkl aluminum of the desired product composition and olefins enriched in lower olefins, and separating at least part of the olefins from said mixture,

(e) fractionating the olefins from (b) and (d) into low olefins and high olefin fractions including the olefins fractions for the displacement reactions of and (if) selectively reacting the vinyl olefins in a part of the high olefins fraction from (e) by reacting with a beta-branched alkyl trialkyl aluminum reactant, forming thereby trialkyl aluminum components having alkyls corresponding to said vinyl olefins, vinylidene olefins released by said reaction, and nonreacted heavy olefins including internal and vinylidene olefins, separating at least part of said olefins and purging said part, in proportions at least about equal in molal quantity to the total quantity of byproduct nonvinyl olefins of equivalent molecular Weight generated in the chain growth (a) and the displacement reactions (b) and (d).

3. The process for generating trialkyl aluminum products having alkyl groups controlled as to identity and proportions, from a low alkyl trialkyl aluminum and ethylene comprising:

(a) reacting in a first chain growth reaction a low alkyl trialkyl aluminum feed and ethylene,

(b) reacting by displacement at least part of the trialkyl aluminum product from (a) with a mixture of low olefins in proportions of about two to fifteen moles per alkyl group, said low olefins predominating in vinyl olefins lower than the desired alkyl groups of the final trialkyl aluminum product, and separating at least part of the olefins present in the mixture from said displacement,

(c) reacting in a second chain growth reaction ethylene and at least part of the trialkyl aluminum from (b),

(d) reacting by displacement at least part of the trialkyl aluminum products from (c) with a mixture of heavy olefins in proportions of from about two to eight moles per alkyl group, said heavy olefins predominating in vinyl olefins equal in chain length to the desired alkyl groups of the final trialkyl aluminum product, and separating at least part of the olefins in the mixture from said displacement, the reactions of (a), (b), (c) and (d) being carried out under conditions resulting in concurrent production of vinylidene and internal olefin by-products, the chain growth being from about 250 F. to about 350 F. and from about 1,500 pounds per square inch to about 3,000 pounds per square inch,

(e) fractionating the olefins separated in (b) and (d) into fractions including the low and heavy olefin mixtures for the displacement reactions of (b) and (f) selectively reacting the vinyl olefins in a portion of heavy olefins fraction from (e) by reacting with a beta-branched alkyl trialkyl aluminum reactant forming thereby trialkyl aluminum components having alkyl groups corresponding to said selectively reacted vinyl olefins, vinylidene olefins resulting from said reaction, and nonreacted olefins including vinylidene and internal olefins, separating at least part of said olefins mixture and purging said olefins, the quantity of the olefins thus purged being at least about equal in molal quantity to the total quantity of by-product nonvinyl olefins of equivalent molecular weight generated in the chain growth reactions (a), (c) and the displacement reactions (b) and (d).

4. The process for generating trialkyl aluminum products having alkyl groups controlled as to identity and proportions, from a low alkyl trialkyl aluminum comprising:

(a) reacting in a first chain growth reaction a low alkyl trialkyl aluminum feed and ethylene,

(=b) reacting by displacement at least part of the trialkyl aluminum product from (a) with a mixture of low olefins in proportions of about two to fifteen moles per alkyl group, said low olefins predominating in vinyl olefins lower than the desired alkyl groups of the final trialkyl aluminum product, and separating at least part of the olefins present in the mixture from said displacement,

(c) reacting in a second chain growth reaction ethylene and at least part of the trialkyl aluminum from (b),

(d) reacting by displacement at least part of the trialkyl aluminum products from (c) with a mixture of heavy olefins in proportions of from about two to eight moles per alkyl group, said heavy olefins predominating in vinyl olefins equal in chain length to the desired alkyl groups of the final trialkyl aluminum product, and separating at least part of the olefins in the mixture from said displacement,

the reactions of (a), (b), (c) and (d) being carried out under conditions resulting in concurrent production of vinylidene and internal olefin by-products, the chain growth being from about 250 F. to about 350 F. and from about 1,500 pounds per square inch to about 3,000 pounds per square inch,

(e) fractionating the olefins separated in (b) and ((1) into fractions including the low and heavy olefin mixtures for the displacement reactions of (b) and (d),

(i) selectively reacting the vinyl olefins in a portion of heavy olefins fraction from (e) by reacting with a beta-branched alkyl trialkyl aluminum reactant forming thereby trialkyl aluminum components having alkyl groups corresponding to said selectively reacted vinyl olefins, vinylidene olefins resulting from said reaction, and nonreacted olefins including vinylidene and internal olefins, separating at least part of said olefins mixture and purging said olefins, the quantity of the olefins thus purged being at least about equal in molal quantity to the total quantity of by-product nonvinyl olefins of equivalent molecular weight generated in the chain growth reactions (a), (c) and the displacement reactions (b) and (d),

(g) selectively reacting the vinyl olefins in part of a low olefins fraction from (e) by reacting the mixture with a beta-branched alkyl trialkyl aluminum reactant forming thereby trialkyl aluminum components having alkyls corresponding to said selectively reacted vinyl olefins, vinylidene olefins resultant from said reaction, and nonreacted olefins including internal and vinylidene olefins, separating at least part of said olefins and purging said part, and feeding the trialkyl aluminum components to the second chain growth reaction (c).

5. The process for generating trialkyl aluminum products having alkyl groups controlled as to identity and proportions, from a low alkyl trialkyl aluminum and ethylene comprising:

(a) reacting in a first chain growth reaction a low alkyl trialkyl aluminum feed and ethylene,

(b) reacting a portion of the trialkyl aluminum chain growth product from (a) with ethylene and generating a mixture including olefins and triethyl aluminum, then (c) reacting the thus formed mixture with additional ethylene and forming by chain growth trialkyl aluminum components approximating in composition the trialkyl aluminum chain growth product from (d) combining the material from (c) and the product from the chain growth (a),

(e) reacting by displacement at least part of the trialkyl aluminum from (d) with a mixture of low olefins in proportions of about two to fifteen moles per alkyl group, said low olefins predominating in vinyl olefins lower than the desired alkyl groups of the final trialkyl aluminum product, and separating at least part of the olefins present in the mixture from said displacement,

(f) reacting in a second chain growth reaction ethylene and at least part of the trialkyl aluminum from (e),

(g) reacting by displacement at least part of the trialkyl aluminum products from (f) with a mixture of heavy olefins in proportions of from about two to eight moles per alkyl group, said heavy olefins predominating in vinyl olefins equal in chain length to the desired alkyl groups of the final trialkyl aluminum product, and separating at least part of the olefins in the mixture from said displacement,

the reactions of (a), (b), (c), (e), (f) and (g) being carried out under conditions resulting in concurrent production of vinylidene and internal olefin by-products, the chain growth being from about 250 F. to about 350 F. and from about 1,500 pounds per square inch to about 3,000 pounds per square inch,

(h) fractionating the olefins separated in (e) and (g) into fractions including the low and heavy olefin mixtures for the displacement reactions of (e) and (i) selectively reacting the vinyl olefins in a portion of heavy olefins fraction from (h) by reacting with a beta-branched alkyl trialkyl aluminum reactant forming thereby trialkyl aluminum components having alkyl groups corresponding to said selectively reacted vinyl olefins, vinylidene olefins resulting from said reaction, and nonreacted olefins including vinylidene and internal olefins, separating at least part of said olefins mixture and purging said olefins, the quantity of the olefins thus purged being at least about equal in molal quantity to the total quantity of by-product nonvinyl olefins of equivalent molecular Weight generated in the chain growth reactions 21 (a), (c) and (f) and the displacement reactions (e), and

(j) selectively reacting the vinyl olefins in part of a low olefins fraction from (h) by reacting the mixture with a beta-branched alkyl trialkyl aluminum reactant forming thereby trialkyl aluminum components having alkyls corresponding to said selectively reacted vinyl olefins, vinylidene olefins resultant from i said reaction, and nonreacted olefins including internal and vinylidene olefins, separating at least part of said olefins and purging said part, and feeding the trialkyl aluminum components to the second chain growth reaction (f).

6. Process for generating a trialkyl aluminum having alkyl groups controlled as to identity and proportions from a low molecular weight trialkyl aluminum and ethylene comprising:

(a) reacting by displacement with ethylene trialkyl aluminum material whose alkyl groups are predominantly higher than ethyl and generating olefins higher than ethylene and ethyl aluminum material,

(b) reacting at least a portion of the material produced by (a) with ethylene forming by chain growth a trialkyl aluminum mixture whose alkyl radicals are predominantly higher than ethyl containing olefins produced by step (a),

(c) selectively displacing high alkyl groups from at least part of the trialkyl aluminum from (b) by reaction with a mixture of low olefins predominating in vinyl olefins lower than the desired alkyl groups of the final trialkyl aluminum product, and separating at least part of the olefins from the mixture from said displacement,

(d) reacting by chain growth with ethylene at least part of the trialkyl aluminum from (c) to form a chain growth product, said chain growth being under relatively severe conditions from about 250 F. to about 350 F. and from about 1,500 pounds per square inch to about 3,000 pounds per square inch resulting in concurrent production of straight and branched chain olefins,

(e) selectively displacing low alkyl groups from at least part of the trialkyl aluminum from (d) by reaction with a high olefin stream in proportions to produce desired alkyl groups in a final trialkyl aluminum product, and separating at least part of the olefins from the mixture from said displacement, and

(f) fractionating the olefins separated in (c) and (e) into fractions including the low and high olefins for the displacement reactions of (c) and (e).

7. The process of claim 6 wherein the steps (a) and (b) occur in the same environment from about 250 F. to about 350 F. and from about 1,500 pounds per square inch to about 3,000 pounds per square inch.

8. Process for generating a trialkyl aluminum having alkyl groups controlled as to identity and proportions from a low molecular weight trialkyl aluminum and ethylene comprising:

(a) reacting by chain growth with ethylene low alkyl trialkyl aluminum material producing an intermediate chain growth material,

(b) reacting by displacement with ethylene at least a portion of the intermediate chain growth material of (a) generating olefins higher than ethylene and ethyl aluminum material,

(c) reacting at least a portion of the materials produced by (b) with ethylene forming by chain growth a trialkyl aluminum mixture whose alkyl radicals are predominantly higher than ethyl containing olefins produced by step (b),

(d) selectively displacing high alkyl groups from at least part of the trialkyl aluminum from the system of (a) and (c) by reaction with a mixture of low olefins predominating in vinyl olefins lower than the desired alkyl groups of the final trialkyl aluminum product, and separating at least part of the olefins from the mixture from said displacement, (e) reacting by chain growth with ethylene at least part of the trialkyl aluminum from (d) to form a chain growth product, said chain growth being under relatively severe conditions from about 250 F. to about 350 F. and from about 1,500 pounds per square inch to about 3,000 pounds per square inch resulting in concurrent production of straight and 1 branched chain olefins,

(f) selectively displacing low alkyl groups from at least part of the trialkyl aluminum from (e) by reaction with a high olefin stream in proportions to produce desired alkyl groups in a final trialkyl aluminum product, and separating at least part of the olefins from the mixture from said displacement, and

(g) fractionating the olefins separated in (d) and (f) into fractions including the low and high olefins for the displacement reactions of (d) and (f).

9. The process of claim 8 wherein steps (a), (b), and (c) occur in the same environment from about 250 F. to about 350 F. and from about 1,500 pounds per square inch to about 3,000 pounds per square inch.

10. The process for generating a trialkyl aluminum having controlled alkyl groups from a low molecular weight trialkyl aluminum and ethylene comprising:

(a) reacting by chain growth with ethylene a mixture of fresh low alkyl trialkyl aluminum material and recycled intermediate alkyl trialkyl aluminum material as hereinafter defined to produce a chain growth material,

(b) reacting by displacement with ethylene at least a portion of the chain growth material of (a) generating olefins higher than ethylene and ethyl aluminum material,

(c) reacting at least a portion of the materials produced by (b) with ethylene forming by chain growth a trialkyl aluminum material whose alkyl radicals are predominantly higher than ethyl containing olefins produced by step (b),

(d) feeding to steps (e) and (g) trialkyl aluminum material from (0), including at least part of the olefins produced in (b),

at least a substantial part of the foregoing chain growth being under relatively severe conditions from about 250 F. to about 350 F. and from about 1,500 pounds per square inch to about 3,000 pounds per square inch,

(e) reacting by displacement trialkyl aluminum material from (d) with a mixture of low olefins predominating in vinyl olefins lower than the desired alkyl groups of the final trialkyl aluminum product and forming thereby an intermediate alkyl trialkyl aluminum enriched in alkyl groups corresponding to said vinyl olefins and olefins enriched in higher olefins, and separating at least part of the olefins from the mixture from said reaction,

(f) recycling at least part of the intermediate alkyl trialkyl aluminum from (e) to the system of (a), (b) 1 and (c).

(g) reacting by displacement trialkyl aluminum material from (d) with a mixture of high olefins concentrated in vinyl olefins corresponding to the alkyl groups of the desired trialkyl aluminum product and forming thereby a mixture of trialkyl aluminum of the desired product composition and olefins enriched in lower olefins, and separating at least part of the olefins from said mixture, and

(h) fractionating the olefins from (e) and (g) into low olefins and high olefin fractions including the olefin fractions for the displacement reactions of and 11. The process of claim 10 wherein steps (a), (b) and (c) occur in the same environment from about 250 F. to about 350 F. and from about 1,500 pounds per 75 square inch to about 3,000 pounds per square inch.

12. In a process for making a high alkyl trialkyl aluminum product having alkyl groups controlled as to identity and proportions including:

(a) reacting by chain growth with ethylene trialkyl aluminum material relatively high in low alkyl groups, producing trialkyl aluminum first mixture,

(b) reacting by chain growth with ethylene trialkyl aluminum second mixture at least part of which is trialkyl aluminum fourth mixture from step (d) below, producing trialkyl aluminum third mixture;

(c) reacting by a first displacement at least a part of at least one of said first and third mixtures with low first olefins producing:

(1) second olefins enriched in olefins corresponding to displaced alkyl groups, and

(2) trialkyl aluminum fourth mixture enriched in alkyl groups corresponding to said low olefins,

(d) delivering at least a part of said fourth mixture to step (b) to provide at least part of said second mixture,

(e) reacting by a second displacement at least part of at least one of said first and third mixtures with high third olefins producing:

(l) fourth olefins enriched in olefins corresponding to displaced alkyl groups, and

(2) trialkyl aluminum fifth mixture enriched in alkyl groups corresponding to said high olefins, and

(f) recovering at least part of the second and fourth olefins and fractionating to provide first and third olefins,

the improvement wherein at least a part of the first and third mixture material fed to displacement (c) is pretreated by:

(c-i) displacement with ethylene to displace alkyl groups producing olefins higher than ethylene and ethyl aluminum material, and

(c-ii) chain growth with additional ethylene on ethyl aluminum material and olefins produced in (c-i) providing at least part of the trialkyl aluminum and olefins for the first displacement,

and wherein at least a substantial part of the chain growth of the foregoing is under relatively severe conditions from about 250 F. to about 350 F. and from about 1,500 pounds per square inch to about 3,000 pounds per square inch.

13. In a process for making a trialkyl aluminum product predominating in alkyl groups of 12 to 18 carbon atoms from triethyl aluminum and ethylene including:

(a) chain growing from about one-half to three-fourths of the ethylene required to produce the desired high alkyl trialkyl aluminum product on triethyl aluminum producing trialkyl aluminum first mixture hav ing at least some alkyl groups of 12 to 18 carbon atoms,

(b) chain growing the rest of the ethylene required to produce the desired high alkyl trialkyl aluminum product on trialkyl aluminum second mixture which is composed at least in part of trialkyl aluminum fourth mixture later defined producing trialkyl aluminum third mixture enriched in alkyl groups of 12 to 18 carbon atoms,

(c) separating a portion of said third mixture and feeding it to a first displacement reaction (d) hereafter defined,

(d) reacting by a first displacement at least a part of said first mixture and the aforementioned portion of said third mixture with first olefins predominating in olefins of less than 12 carbon atoms producing:

(1) second olefins enriched in higher olefins of 12 to 18 carbon atoms, and

(2) trialkyl aluminum fourth mixture enriched in alkyl groups of less than 12 carbon atoms,

(e) separating at least a major portion of the second 24 olefins and leaving concentrated trialkyl aluminum fourth mixture,

(f) reacting by a second displacement at least part of the nonseparated portion of said third mixture from (c) with third olefins concentrated in olefins of 12 to 18 carbon atoms producing:

(1) fourth olefins enriched in olefins of less than 12 carbon atoms, and

(2) product trialkyl aluminum fifth mixture concentrated in alkyl groups of 12 to 18 carbon atoms;

(g) recovering at least part of the fourth olefins; and

(h) fractionating olefins from at least one of the second and fourth olefins to provide at least part of the first and third olefins,

the improvement wherein at least a part of the material fed to displacement (d) is pretreated by:

(d-i) displacement with ethylene to displace alkyl groups producing olefins higher than ethylene and ethyl aluminum material, and

(d-ii) chain growth with additional ethylene on ethyl aluminum material and olefins produced in (d-i) providing at least part of the trialkyl aluminum and olefins for the first displacement,

the ethylene thus added to the system providing part of the total ethylene used, and wherein at least a substantial part of the chain growth of the foregoing is under relatively severe conditions from about 250 F. to about 350 F. and from about 1,500 pounds per square inch to about 3,000 pounds per square inch.

14. A process for generating aluminum trialkoxides having alkoxide groups controlled as to identity and proportions and predominating in materials Whose groups have from about eight to about sixteen, inclusive, carbon atoms per group, comprising:

(a) reacting by a chain growth reaction ethylene and a feed low alkyl trialkyl aluminum to make an intermediate chain growth product,

(b) selectively displacing high alkyl groups from at least part of the trialkyl aluminum from (a) by reaction with a mixture of low olefins predominating in vinyl olefins lower than the desired alkyl groups of the final trialkyl aluminum product, and separating at least part of the olefins from the mixture from said displacement,

(c) reacting by chain growth with ethylene at least part of the trialkyl aluminum from (b) to form a chain growth product,

(d) selectively displacing low alkyl groups from at least part of the trialkyl aluminum from (c) by reaction with a high olefin stream in proportions to produce desired alkyl groups in a final trialkyl aluminum product, and separating only part of the olefins from the mixture from said displacement,

(e) reacting the trialkyl aluminum mixture from (d) with an oxidizing gas in the presence of the nonseparated olefins and converting from about 50 to 70 percent of the alkyl aluminum groups to the corresponding aluminum alkoxides, and then vaporizing olefins from the oxidized mixture for use in step (f),

(f) fractionating the olefins separated in (b), (d) and (e) into fractions including the low and high olefins for the displacement reactions of (b) and (d),

(g) selectively reacting the vinyl olefins in a portion of the high olefin fraction from (f) by reacting with a trialkyl aluminum compound susceptible to selective reaction with the vinyl components of the olefins, forming trialkyl aluminum components corresponding to said selectively-reacted vinyl olefins in admixture with nonreacted olefins and olefins released by said displacement,

(h) combining the aluminum alkoxides from (e) and the trialkyl aluminum components from (g) the lat ter containing nonreacted olefin and reacting with an oxidizing gas to convert essentially all the alkyl aluminum groups to the corresponding aluminum alkoxides, and

(i) then distilling the alkoxides to remove hydrocarbon components.

15. The process of claim 14 further characterized in that the chain growths steps (a) and (c) are conducted under severe conditions from about 250 F. to about 350 F. and from about 1,500 pounds per square inch to about 3,000 pounds per square inch.

16. The process for generating aluminum trialkoxides convertible to an alcohol mixture predominating in primary alcohols having an even number of carbon atoms of from eight to sixteen, inclusive comprising:

(a) reacting in a first chain growth reaction triethyl aluminum feed and ethylene and producing thereby a trialkyl aluminum chain growth product and 01efins, the trialkyl aluminum predominating in alkyl groups of eight to twelve carbon atoms, inclusive, the olefins including vinylidene and internal olefin by-products and vinyl olefins,

(b) reacting a portion of the trialkyl aluminum chain growth product from (a) with ethylene and generating a mixture including olefins and triethyl aluminum, then (c) reacting the thus formed mixture with additional ethylene and forming by chain growth trialkyl aluminum components approximating in composition the trialkyl aluminum chain growth product from (a), and

(d) combining the mixture from (c) and the re mainder of the chain growth product from (a),

(e) reacting by displacement the combined mixture from (d) and at least part of a chain growth product from a second chain growth reaction as hereafter defined with a mixture of low olefins predominating in olefins of six through eight carbon atoms and forming thereby an intermediate alkyl trialkyl aluminum enriched in alkyl groups corresponding to said low olefins and olefins enriched in higher olefins, and separating at least part of the olefins from the mixture from said reaction,

(f) reacting in a second chain growth reaction ethylene and at least part of the trialkyl aluminum from (e) and a trialkyl aluminum mixture from a low olefins purification step (i) as hereafter defined and producing thereby a trialkyl aluminum chain growth product and olefins, the trialkyl aluminum predominating in alkyl groups of ten to fourteen carbon atoms, inclusive, the olefins including vinylidene and internal olefin by-product and vinyl olefins,

(g) reacting by displacement only a portion of the trialkyl aluminum product from (f) with a mixture of high olefins predominating in olefins of twelve to sixteen carbon atoms, inclusive, and forming thereby a trialkyl aluminum mixture enriched in alkyl group corresponding to said high olefins, and olefins enriched in low olefins, and separating only part of the olefins from the mixture from said reaction,

(h) reacting the trialkyl aluminum mixture from (g) with an oxidizing gas in the presence of the nonseparated olefins and converting from about to 70 percent of the alkyl aluminum groups to the corresponding aluminum alkoxides, and then vaporizing the olefin therefrom,

(i) fractionating the olefins separated in (e), (g), and (h) into fractions including the low and heavy olefins mixture for the displacement reactions of (e), and (g), and a fraction concentrated in octenes,

(j) selectively reacting the vinyl olefins in part of the low olefins fraction from (i) by reacting the mixture with a beta branched trialkyl aluminum reactant, forming thereby trialkyl aluminum components having alkyls corresponding to said selectively reacted vinyl olefins, vinylidene olefins resultant from said reaction, and non-reacted olefins including internal and vinylidene olefins, separating at least part of said olefins and purging said part and feeding the trialkyl aluminum components to the second chain growth reaction, (f),

(k) selectively reacting the vinyl olefins in a portion of the heavy olefins fraction and the octenes fraction from (i), by reacting with a beta-branched alkyl trialkyl aluminum reactant forming thereby trialkyl aluminum components having alkyl groups corresponding to said selectively reacted vinyl olefins, vinylidene olefins resultant from said reaction, and nonreacted olefins including vinylidene and internal olefins, separating at least part of said olefins mixture and purging said olefins, the quantity of the olefins thus purged being at least about equal in molal quantity to the total quantity of byproduct nonvinyl olefins of equivalent molecular weight generated in the chain growth (a), (f) and the displacement reactions (e) and (g).

(l) combining the aluminum alkoxides from (h) and the trialkyl aluminum components from (k) and reacting with an oxidizing gas and converting essentially all the alkyl aluminum groups to the corresponding aluminum alkoxides.

References Cited UNITED STATES PATENTS 2,863,896 12/1958 Johnson.

2,976,306 3/1961 Walde 260-448 3,014,941 12/1961 Walsh 260-448 3,017,438 5/1959 Atwood.

3,042,696 7/1962 Aldridge 260-448 3,066,162 11/1962 Ziegler et al. 260-448 3,104,251 9/1963 Foster et al. 260-448 3,180,881 4/1965 Zosel et al. 260-448 3,210,435 10/1965 Kennedy et al.

3,218,343 11/1965 Acciarri et al. 260-448 TOBIAS E. LEVOW, Primary Examiner. H. M. S. SNEED, Assistant Examiner.

US. Cl. X.R.

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