US3352776A - Process for the preparation of binder oils - Google Patents

Description

United States Patent 3,352,776 PROCESS FOR THE PREPARATION OF BINDER OlLS Ralph Burgess Mason, Denham Springs, and Glen Porter Hamner, Baton Rouge, La., assignors to Esso Research and Engineering Company, a corporation of Delaware N0 Drawing, Filed May 24, 1965, Ser. No. 458,457 2 Claims. (Cl. 208-125) ABSTRACT OF THE DISCLGSURE Binder oils are produced by heat soaking residua in the absence of a catalyst and oxygen and recycling the binder oil fraction until it has a Conradson carbon above 40.

The present invention is directed to upgrading virgin residua, viz., the 850 F.+ fraction obtained from crude oil, by converting it noncatalytically to a major product composed of desulfurized, demetallized, fuel oil boiling above about 500 F. and a minor product composed of 900 F.+ binder oils having a combination of a softening point range of 200 to 280 F. coupled with a Conradson carbon value above 40.

More specifically, the present invention is directed to a noncatalytic, liquid phase thermal depolymerization process for upgrading (A) 850 F.+ virgin residual feedstock having (1) a Conradson carbon of greater than 15, (2) a sulfur content between 0.5 and 8 wt. percent, (3) a metals content (chiefly nickel and vanadium) from greater than about 50 to as high as 4000 ppm, and (4) a 650 to 900 F. gas oil fraction content of about wt. percent by converting it to (B) a major product, viz., usually greater than 60 wt. percent, composed of 500 F.+ fuel oils having 1) a reduced Conradson carbon content, (2) a reduced sulfur content of less than 50% of the sulfur content present in the feed, (3) a reduced metals content of less than 60% of that present in the feed, and (C) a minor product, viz., usually less than 30 wt. percent, of a 1000 F.+ binder oil having a combination of a high Conradson carbon value, viz., greater than 40 Conradson carbon and preferably greater than 50 Conradson carbon, with a softening point ranging from 200 to 280 F. and more preferably from 220 to 270 F.

The above and other objectives are obtained by the process of the present invention which, in brief compass, comprises what can be conveniently considered as a multistep process with an internal recycle. First, the crude residua feedstock having the above characteristics is intimately blended into a suitable aromatic or hydrogenated aromatic (cyclic) solvent which can be, and preferably is, heated at 200 to 450 F. before or after blending of the feed with the solvent to aid in dissolving the feed; then the residua feed-aromatic solvent solution is thermally depolymerized in a liquid phase operation by heating it at temperatures of 650 to 900 F. for from 0.1 to 6 hours, substantially in the absence of oxygen. Following the thermal depolymerization step, the depolymerized feed solution is filtered to remove insolubles, including metals, sulfur compounds, and carbonaceous ash. Then, the filtered liquid product-containing stream from thermal depolymerization is fractionallydistilled to obtain: 1) a top stream (less than 400 F.) composed of naphthas, gasoline, and lighter fractions, (2) a light side stream (400. to 650 F.) composed of the aromatic solven t(s) initially employed, (3) a heavier side stream composed of the major product, which is the low sulfur, low metals, low Conradson carbon, 650 to 900 F. fuel oil component, and (4) a 900 F.+ bottoms stream, which is composed of unreacted feed and materials having a higher Conradson carbon than the feedstocks initially employed,

but lower than the Conradson carbon rating sought in the binder Stream (4) can be combined with stream (3) to yield maximum 650 F. fuel oil product. Or when a .400 to 500 F. boiling range solvent is employed, solvent side stream (2) is a 400 to 500 F. stream, stream (3) will be a 500 to 900 F. fuel oil component. In such a case a portion of the 900 F.+ bottoms stream (4) can be blended with the 500 F. to 900 F. stream (3) to yield maximum 500 F.+ fuel oil product.

This bottoms stream .(4) is recycled with a portion of .the side stream (2) for. further thermal depolymerization to increase the Conradson carbon rating up to greater than 40. Or all or a portionof the solvent side stream (2) can be mixed with fresh residua feed, and combined with all or a portion of the 900 F.+ bottoms stream (4) and Subjected to thermal depolymerization. The recycle of the 900 F.+ bottoms stream (4) with a portion of side stream (2) and/or fresh residua feed is continued ,until it has the combination of a .Conradson carbon greater than 40 coupled with a softening point range of 200 to 280 F., and preferably a .Conradson carbon greater than 50 coupled with a softening point range of 22.0 to 270. As mentioned above the recycling of the 900 F.+ bottoms stream (4) can be via direct recycle to the thermal depolymerization step; or it can be first mixed with incoming feedstock, and then passed to thermal depolymerization. The former procedure is preferred for the preparation of binder oil because a higher Conradson carbon is produced without dilution effects from the fresh feed, At lined-out conditions the recycle stream of bottoms (4) is removed, intermittently or continuously, to yield a high grade binder oil (as a minor product) suitable for making prebaked and Soderberg electrodes for production of aluminum in known manner.

The present process is characterized by two critical features. The first critical process feature of this invention is that the residua feed and portions thereof should be heated at the above thermal depolymerization temperatures, viz., 65.0 to 900 F., in the absence of the solvent for no longer than 30 minutes, and preferably no longer than 10 minutes at these temperatures during the fractional distillation step (when the solvent is being vaporized from the remaining products),

In other words it is very important in this thermal depolymerization of high Conradson carbon feedstocks to have solvent present in all stages of the process at temperatures greater than about 500 F. Failure to observe this process feature will result in increased coke formation taking place, and reversal of the thermal depolymerization process.

The other essential and critical feature of the process of. this invention is the substantial exclusion of oxygen from the process at least until such time as the fractional distillation has been completed. Thus, the oxygen content of the feedstock and solvent should be less than 0.1 wt. percent; and preferably the feedstock and solvent should contain less than ppm. oxygen from the onset of processing until the completion of the fractional distillation step. The blending of the feedstocks in the solvent and the heating thereof prior to thermal depolymerization is likewise accomplished substantially in the absence of both oxygen (molecular), and oxygen-containing compounds which thermally release molecular oxygen in situ during the subsequent heat treatment. Failure to observe the substantial absence of OXYg n during the present process will not only lower yields of the improved quality fuel oil but also cause decreased quality in both the fuel oil and binder oil and will result in higher coke yields.

In accordance with this invention, various high molcular weight sulfur containing, metal containing residua feeds, usually vhaving Conradson carbon ratings greater than 15, which can be the bottoms from crude oil conversion processes, can be employed as feedstocks for the instant process. Exemplary feedstock materials of the present process can be: atmospheric residua and vacuum residua; asphaltenes; aromatic tars; coal tars; shale oils; heavy synethetic oils; natural tars and asphalts; aromatic abstracts; cycle stocks; pitches; and like 1000 F.+ hydrocarbon materials. These materials usually possess API gravities of -8 to +30, molecular weights of 200 to 20,000 and intial boiling points above 650 F. Particularly preferred feedstocks are heavy virgin residua characterized by API gravities of to 20, molecular weights of 400 to 6000 and intiial boiling points above about 900 F.

In accomplishing the process of this invention, the sulfur-containing, metals-containing, high molecular weight feedstock is blended with an aromatic solvent in a volume ratio of about 0.5 to :1 volumes of aromatic solvent(s) per volume of virgin residua feedstock. Dur' ing the blending step, the solvent is preferably preheated to a temperature of 200 to 450 F., and more preferably from about 200 to 300 F.; and the system is usually blanketed with an inert gas, for example, nitrogen, hydrogen, etc. The available (molecular) oxygen content includnig peroxides of the feedstocks and solvent should be less than 0.1 wt. percent, and preferably less than 100 p.p.m.

The blended solution of feed andaromatic solvent(s) is then heated in the substantial absence of oxygen at temperatures ranging from 650 to900 F. usually at temperatures ranging from about 650 to about 850 F., and more perferably at temperatures ranging from about 675 F. to 775 F. The heating is continued to allow an average residence time for which the residua feed-solvent solution is subjected to these temperatures in the presence of the solvent for time periods of 0.1 to 6 hours, usually 0.5 to 6 hours, and more preferably from about 1 to 4 hours. During the thermal depolymerization step, pres-- sures ranging from atmospheric pressure to about 2000 p.s.i.g. can be used. Usually, however, the pressures employed range from about 20 p.s.i.g. to 2000 p.s.i.g., and preferably from about 200 p.s.i.'g. to 1600 p.s.i.g. with hydrogen being employed as the inert gas to establish all or part of the pressure. As noted hereinabove the thermal depolymerization is conducted in the liquid phase so the pressure is adjusted upwards to insure the solvent remains in the liquid phase throughout depolymerization. Subsequent to the thermal depolymerization step, the solution containing the lower molecular weights gas oil product, naphthas, gasolines, and lighter fraction, and a 900 F.+ fraction is filtered using any conventional filtration system, e.g., filters, centrifuge, settling tanks, etc., useful to separate solid residues, containing metals, sulfur compounds, carbonaceous residues (coke) etc., from the product-solvent stream.

These metals, sulfur containing compounds, and carbonaceous solid materials removed by the above filtration step usually represent less than about 10% by weight solids based on the originalresidua feed. The solids, removed by filtration or centrifugation from the productcontaining stream prior to fractional distillation, can be processed for recovery of nickel, vanadium, sulfur compounds, and other metals present therein which are concentrated in the insoluble as a result of the thermal depolymerization step.

Subsequent to the filtration step, the product containing stream is fractionally distilled preferably by flash distillation at temperatures between 500 and 750 F., and more preferably at temperatures between 650 and 725 F. on the up-stream side of the fractioning column. Steam can be added to the system during the fractional distillation step. If steam and/or vacuum are employed, the flash distillation can be conducted at lower temperatures, e.g., 300 to 600 F.

The top stream of the fractionator (less than 400 F.) is composed of naphthas, and lighter fractions. The

upper side stream (400 to 650 F. boiling point) is composed of the starting aromatic solvent(s) and is recycled as mentioned hereinabove. The heavier side stream product is blended with a portion of the 900 F.+ flash product stream to produce either the 500 F+ or 650 F.+ fuel oil. The bottoms stream obtained by flash distillation is composed of 900 F.+ unreacted feed hydrocarbons and partially reacted materials having a higher Conradson carbon rating than the feedstock. As mentioned above, this bottoms side stream is recycled with a portion of the solvent in order to increase the Conradson carbon rating thereof to at least 40 prior to being removed as a portion of the minor product binder oil stream. The major product, viz., the 500 F.+ or 650 F.+ desulfurized, demetallized, fuel oil has a significantly higher economic value than the residual feedstock from which it was produced. The present invention is capable of obtaining conversions from the lower value residual feedstock to the higher value fuel oils of as high as about 70 to This constitutes a significant improvement over the more complicated and expensive hydrogen donor diluent cracking Visbreaking and coking processes. Thus, the present invention requires neither use of a catalyst, nor the regeneration of a hydrogen donating solvent; and consequently, the benefits and advantages of the improved process of this invention require neither a catalyst nor replacement of hydrogen to the aromatic solvent. Furthermore, as a highly sought minor product stream, lesser amounts of a high quality binder oil are secured, which binder oil can be employed to produce prebaked and Soderberg electrodes which in turn can be employed to produce aluminum by the conventional electrolytic processes.

Moreover the demetallization secured by the present process is applicable. Thus, for example, when the feedstock contains 50 or more p.p.m. metals, the metals content in the fuel oil product stream usually is below about 25 p.p.m. Another outstanding feature of the presentv invention, as compared to a coking procedure, is a significant reduction in the sulfur content of the gas oil fraction used in the fuel oil blend and a greater production of the fuel fraction, itself. Thus, sulfur reductions of from 2 to 5 wt. percent in the feed to the process to from 1 to 2.5 wt. percent in the product stream can be readily achieved in accordance with the practice of this invention.

A special advantage of the present invention resides in the fact that it enables the metal components to be segregated (concentrated) in the filtered solids thus rendering more amenable the economic recovery of the metals and of the other materials sought to be recovered from the insolubles. This is particularly true with respect to nickel and vanadium. For example, the conversion of asphaltene feedstock from Bachaquero crude to naphthas, fuel oils, and high grade binder oil with low coke production, can be readily accomplished in accordance with this invention. Analysis of the insoluble residues removed by filtration and/ or settling showed a high concentration of vanadium. The solid residues (insolubles) obtained by filtration and setting contained from 2.5 to about 5 wt. percent vanadium. The Bachaquero crude from which these insolubles were obtained, by the present process, originally contained about 2000 p.p.m. vanadium and from 200 to 250 p.p.m. nickel.

Improved fuel oil may be obtained from other residua feeds, e.g., West Texas Residuum. For example, the feed containing 31 p.p.m. nickel and 27 p.p.m. vanadium is reduced to a fuel oil containing 12 p.p.m. nickel and 10 p.p.m. vanadium with the simultaneous removal of appreciable amounts of sulfur. This shows a further indication of the economically attractive nature of the improved process of this invention.

A wide variety of solvents can be employed in accordance with the present invention. Preferably, however, the solvents employed are selected from the group consisting of aromatic or partially or completely hydrogenated aromatic solvents. Usually, the boiling point range of the solvents employed in accordance with this invention lies in the range of about 150 to 800 F. Thus, such solvents as benzene; toluene; ortho-, meta-, and para-xylenes; ethyl benzene, etc. can be used. Preferably, however, the solvents employed in this invention have a boiling point range of from about 400 to 600 F.; and preferably are the substituted monocyclic, the bicyclic, and tricyclic aromatic solvents. Exemplary preferred materials suitable for use in accordance with this invention include, but are not limited to, the following: naphthalene; alkyl substituted naphthalenes, such as methyl naphthalene; anthracenes; phenanthreses; tetralin; decalin; phenol; xylidine; toluidine; phenylene diamine; amino phenol; a-methyl naphthyl amine; a-naphthol; fi-naphthol and compounds of a similar nature which can have a variety of substituents, said substituents being inert to the thermal depolymerization reactions involved to the extent that they do not interfere therewith. Mixtures of any two or more of the above solvents can be employed.

Multiple staging of the thermal depolymerization step can be conducted in order to minimize any problems encountered during thermal deploymerization due to different rates of deploymerization of various feed and/ or various components in the same feedstock. Different rates of depolymerization can cause some depolymerized products to be subjected to temperature conditions which are too high and for too long a period of time than will be ideally desirable. To counteract this, the thermal deploymerization can be conducted by the use of two or more depolymerization stages in the same processing scheme, each operating at a different temperature and residence time to accomplish depolymerization. Thus, the readily depolymerizable materials are removed at relatively mild conditions, and the more refractory materials are removed at more severe conditions, usually in the absence of the products in the milder depolymerization operation. Furthermore, in addition to varying the severity of temperature and time during the thermal depolymerization over a plurality of thermal deploymerization zones in the same depolymerization step; it is also possible to operate the various depolymerization zones using different aromatic solvents or diflerent mixtures of aromatic solvents. However, in order to minimize the amount of recovery equipment necessary, use of the same solvent throughout the thermal depolymerization step is a preferred procedure even when the depolymerization operation is conducted in a plurality of zones.

According to an embodiment of the present invention, the processing temperatures, to which the 900 F.+ portion of the thermally depolymerized product components are subjected, can be minimized by solvent precipitation of the major portion of this component prior to flash distillation and prior to filtration thereof. The solvent precipitation step is conducted conveniently by contacting the thermally depolymerized, filtered product stream with a suitable naphtha or C to C liquid alkane solvent at temperatures of 50 to 250 F. for 5 to 180 minutes depending upon the specific precipitating solvent chosen. Preferably the solvent is n-pentane, and the contact is conducted at 60 to 150 F. for 10 to 120 minutes. The solvent precipitated 900 F.+ fraction can be concentrated readily by filtration; and then is solutized by a portion of the recycle aromatic solvent for further thermal depolymerization. This embodiment further reduces coke formation, and insures minimum exposure of the major portion of the 1000 F.+ component to elevated temperatures in the absence of the solvent (because it allows the major portion of the 1000 F.+ component to bypass the flash distillation step and thus avoid high temperatures in the absence of solvent).

According to another preferred embodiment of this invention, the eflluent from the thermal cracking step is quenched so as to reduce the temperature thereof to a value in the range of about 200 to 500 F.; and the product stream is then vacuum flashed at this reduced temperature to remove the volatile materials therefrom, which volatile materials include some 900 F.+ product. This vacuum flashing operation is controlled so that the bottoms product remains as a mobile liquid at the temperatures of flashing. The vapor product from the vacuum flashing step is passed to a normal fractionation step Where product is separated into naphtha solvents, gas oils, and the 900 F.+ portion. The latter (900 F.+) is recycled to the thermal depolymerization step. A special adaptation of this separation, which is compatible with the facet of minimum exposure to high temperature in the absence of solvent, comprises fractionating to remove only the solvents, and to separate the 650 F. to 900 F. gas oils from the 900 F.+ bottoms product by solvent precipitation using a C to C naphtha or C to C n-hydrocarbon solvent, e.g. n-pentane. Since the amount of the 900 F.+ material from the vacuum flashing step is not usually too great, there is very little increase in facilities required for filtation. Regardless of the method of separation, however, recycle of the 900 F.+ product from this phase of the processing to the thermal depolymerization step is preferred. The bottoms product from the vacuum flashing step, which is still a mobile liquid, is mixed with the recycle aromatic solvent; and the temperature thereof is maintained at a temperature within the range of 200 to 500 F. This mixture is then passed to a settling zone so that ash materials and other insoluble materials contained therein are concentrated at the bottom. This bottoms concentrate can then be filtered and the filtrate obtained therefrom combined with the settled layer. This combination of concentrate and the settled layer can then be recycled to the thermal depolymerization step.

According to yet another preferred embodiment of this invention, the residual heavy feed can be topped in a flashing operation prior to thermal depolymerization so that the liquid bottoms temperature does not exceed the temperature employed in the subsequent thermal cracking step. When such a pretopping procedure is employed, the liquid bottoms temperature in this flashing step preferably does not exceed about 750 F. This bottoms product can then either be subjected to the thermal depolymerization step disclosed hereinabove; it can be first combined with either an aromatic or naphthenic solution of the residua previously precipitated from the unconverted residual feed; and the total feed can then be thermally depolymerized as disclosed hereinabove. However, temperatures of the thermal depolymerization treatment preferably are about 700 to 825 F. when this particular embodiment is employed (viz., the preflashing operation). The efliuent therefrom can then be cooled and treated with a precipitation naphtha, e.g., a naphtha within the C to C, range; and separation is achieved by either settling, filtration, or a combination of these procedures. In either event, the residua (unconverted residua feed) and/ or the included precipitant solvent as well as the aromatic solvent are taken in solution with added portions of the thermal depolymerization solvent at temperatures in the range of about 300 to 600 F.; and the insolubles formed in the combined operation, together with the precipitated ash components, are removed by filtration. With adequate settling,

the filtration requirement is kept to a minimum. Thus,

with good settling, the only filtration requirement is for removal of the small amount of coke and other carbona ceous ash materials (plus the insoluble metals and sulfur containing compounds) which are rendered insoluble by the thermal depolymerization step. During the solution of the unreacted residua feed in the solvent, the embodied quantities of the precipitation naphtha, although low boil ing n-alkane hydrocarbons, are flashed off; and these mate rials are passed through the fractionating column which is employed to separate the product. As mentioned above,

the solvent. solution. of the unconverted residua feed is. thenreturnedzto the thermaldepolymerization step.

Example 1 Experiments. illustrating thermal depolymerization in presence. ofa solvent and flashing the volatiles at temperatures less than 500 F. were conducted in acne-liter stirred: autoclave. The feed. of this procedure consisted of a. 1'/ 1 blend by weight ofv West Texas vacuum residuum and methyl naphthalene as component A and methyl naphthalene as: component B. The methylnaphthalene of component A.was frcedof peroxides. by refluxingat the boilingpointin presence of hydrogen. at one atmosphere The production of a major portion of gas oil-of reduced.

sulfur and of negligible metal content is demonstrated in.

this operation. Also the conversion. of some ofthe Conradson carbon material to useful products is noted.

Example 2 which are high in metals and sulfur content. The-liquid.

product is fractionated to yield products ex solvent as.

pressure prior. to, the; blend. preparation. The blend was follows:

Feed Light Heavy Gas Oil Fuel Oil Binder Naphtha Naphtha Blend Oil Boiling Range, "F 1, 000+ IBP-BOO 300-430 500-650 650+ 1, 000+ Yi b.l 375 1, 200 3, 400 4, 050 1, 200 Gravity, API. 8.4 61 47 18.7 Sulfur, wt. percent- 2. 4 1. 2 1. 7 2. 8 Nickel, p.p.m.-.- 31 0 21 56 Vanadium, p.p.m. 27 0 17 45 The 4,050 b./d. consists of 2,750 b./d. of 650-1,000 F. gas oil (metals free) and 1,300 b./d. 0f 1,000

maintained under a hydrogen. blanket. The initial operation was forv 3 hours at 750 F. using 506. grams of componentA andahydrogen. partial pressure of about 700 p.s.i.g. The volatile products, after. cooling to, about 500 F. were flashed from theautoclave until the pressure was reduced to the atmospheric level and then at about 0.5 mm. mercury. pressure and temperature of 500 F. Feed components A and B were recharged in an amount approximately equal to. the flashedproduct and in proportions such thatthe methyl naphthalene of the total autoclave charge was approximately 250 grams and the total residuum. (fresh charge plus recycle) was approximately 250 grams. This procedure provides an internal recycle of the nonfiashed materials. After such cycles the nonvolatiles were removed at ambient temperature as a solution and suspension in methylnaphthalene. This product was filtered and the solids were extracted first with methyl naphthalene andthen with benzene in Soxhlet equipment. The methyl naphthalene. extraction was in an atmosphere of hydrogen. The filtrate and the methyl naphthalene Soxhlet extract were combined and then vacuum distilled to obtain a 1000 F.+ product.

The combined flashed products from the autoclave operation and from thevacuum distillation ofthe filtrate and extractate. were fractionated in. a. laboratory column (/5 operation) to obtain 65-430 F. naphtha, 430- 485 F. portion containing primarily the methyl naphthalene solvent, and a 485-1000. F. fuel oil portion.

The overall operationresulted in. 1.6% based. on. the combined solvent plus residuum charged. Recovery and inspections ofthe higher boiling products. from the residuum are compared withthe original feed as follows:

1 253 grams in original charge, 597 in nine successive recycle charges; 1 N.D'.=Not determined.

C -gas yield.

F.+ material of same composition as binder oil.

The process is operable over a range of.conditions and. options can beemployed concerning the amount of.sol-- vent, the fuel oil-binder oil split and other process.vari-- ables. The process as set forth herein is superior tocoking for production of gas oil, fuel oil and binder oil.

fractions as shown by the comparison with cokingyield. data.

650 F. boiling range from the fuel oil. This example illustrates another embodiment of this invention wherein 500- 650 F. fuel oil components are blended with portions of the 1000 F.+ product and the heavy gas oil'(650 F. to 1000 F.) to effect yet further reductions in sulfur ash content of the product fuel oil, all other'conditions' being the same as in Example 2'. With this embodiment, the product distribution is as follows:

A series of five runswere madev similiar to that in Example 1 except that other than the presence of hydrogen at one atmosphere. after purging the reactor system, no extraneous hydrogen was emp1oyed..Fo1l0wing the initial operation inwhich a 1/1 methyl naphthalene-West Texas vacuum residuum was employed as feed, the subsequent. charges. were made from a. 2/1 blend together b./d. solvent is thermally treated and. the

With methyl naphthalene to bring the solvent to the original value after the flashing operation. Thus the charges were:

The nonvolatized product, remaining in the autoclave after the fifth cycle, was removed in methyl naphthalene solution. This material was filtered and the filter residue was extracted with methyl naphthalene in Soxhlet equipment, and the high boiling solvent was removed by benzene extraction. The filtrate was vacuum distilled to remove the solvent and leave the 1000 F.+ material which had not been converted to lower boiling compounds. The products flashed from the autoclave were combined and fractionated in a laboratory column into C -430 F. naphtha, 430-485 F. solvent portion, and 4851000 F. gas oil. These results (ex solvent) are summarized as follows:

10 equivalent to the original charge and the operation was repeated. A second and a third repetition was made in a similar manner so that a total of four such cycles was made. The naphtha fraction was not recovered in this operation; other yieldand inspection data are:

Asphal- 485-1,000 1,000 Solids tene Feed, F. Fuel Oil F.+ Residue grams Component Product Grams 295. 5 74.5 163 24 4 Conradson Carbon,

wt. percent 37.7 0 57. 6 1 N.D Nickel, p.p.m 31 1 N.D. N.D Vanadium, p.p. 117 1 1 N.D. 1 N.D Sulfur, wt. percent.-. 5.1 1 N.D. N.D. N.D

1 N.D.=Not determined.

Thus in operation with recycle, the asphaltenes precipitated from West Texas atmospheric residuum are (1) converted to low metals fuel oil component without appreciable metal increase in the unreacted portion, and (2) the Conra-dson carbon of the recycle stream is brought to a level where it is useful as a binder oil.

Example 4 The precipitation and use of asphaltenes as in Example Residuum C5-43O F. 4S51,000 F. 1,000 F.+ Solids Feed N aphtha Gas Oil Product Residue Grams 484. 5 89. 8 237. 5 176 16. 5 Conradson Carbon. 16. 5 0 O 47 1 N.D. Sulfur, wt. percent 2. 4 1 N .D 1. 3 1 N .D. N.D Nitrogen, wt. percent- 0. 4 1 N.D O. 24 ND 1 N.D Nickel, p.p.m 31 1 N.D 4 78 N.D Vanadium, p.p.m 27 N.D 4 N.D

1 N.D.=Not determined.

residuum were precipitated with normal pentane to yield 388 grams of asphaltenes and a oil product of reduced ash 5 provides for improved fuel oil product from the depolymerization and from removal of the high meals high sulfur components from the feed. The yield of 7.7 weight percent asphaltenes and 92.3 weight percent (94.5 vol. percent of oil product is apparent from the previous data. The remaining oil product is more useful as a fuel oil or portions as heating oils, catalytic cracking and hydrocracking feeds and the like. The following data show yields and oil quality that result from (1) the asphaltene precipitation and (2) the asphaltene precipitation plus thermal depolymerization as in Example 5.

DEMETALLIZATION OF WEST TEXAS ATMOSPHERIC RESIDUUM BY PENTANE PRECIPITATION PLUS DEPOLYMERIZATION YIELDS ON 1 N.D. =Not determined.

components. These asphaltenes were mixed in a 1/1 weight ratio with methyl naphthalene and a 591 gram portion of the mixture was charged to the autoclave as in Example 1 and 24 grams of aqueous ammonium hydroxide was employed as a polymerization inhibitor. The charge was heated to 750 F. for a period of three hours and the system was allowed to cool. The product was discharged, filtered and the filtrate was vacuum flashed in laboratory glass equipment so that localized hot spots which might be encountered in flashing from a heavy metal autoclave could be avoided. The 1000" F.+ portion was dissolved in methyl naphthalene so that the total charge was about What is claimed is:

1. A non-catalytic, liquid phase process for upgrading residua having an initial boiling point of 900 F.|, a molecular Weight ranging from 400 to 6,000 and A.P.I. gravities of 0 to 20 which comprises:

(A) heating an intimate blend of said residua and an organic solvent selected from the group consisting of aromatic solvents, partially hydrogenated aromatic solvents or completely hydrogenated aromatic solvents, each having a boiling range of about to about 800 F. at temperatures of 650 to 850 F for an average residence time of 0.5 to 6 hours d ingiwhich said heating in the absence of saidsolvent is for no longer than 10 minutes to produce light products boiling up to. 650 F., a product stream containing a side stream low sulfur, low metals, low Conradsoncarbon fuelroil componenthaving a boiling range of 650 to 900 F. and a 900 F.+ bottoms stream. binder: oil precursor component;

(B) filteringv said product stream to remove insolubles therefrom;

(C) recycling said 900 F; bottoms binder oil precursor component of said product stream to said heating; step (A) to increase theConradson carbon content thereoffto a value. greater than 40; and

(D) withdrawing. from said recycle step (C) a binder oil. product havingv a combination of a Conradson 15 carbon greater than 40 and a softening point ranging from. 200-280 F. said steps (A), (BY), andv (C) being carried out in an essentially oxygen-free atmosphere. 2. A process as in claim 1 wherein said feed and said solvent contain less than 100 parts per million oxygen.

References Cited UNITED STATES PATENTS 8/1959 Newchurch et al 208-86 SAMUEL P. JONES, Primary Examiner. DELBERT E. GA-NTZ, Examiner.

Claims (1)

1. A NON-CATALYTIC, LIQUID PHASE PROCESS FOR UPGRADING RESIDUA HAVING AN INTIAL BOILING POINT OF 900*F.+, A MOLECULAR WEIGHT RANGING FROM 400 TO 6,000 AND A.P.I. GRAVITIES OF 0 TO 20* WHICH COMPRISES: (A) HEATING AN INTIMATE BLEND OF SAID RESIDUA AND AN ORGANIC SOLVENT SELECTED FROM THE GROUP CONSISTING OF AROMATIC SOLVENT, PARTIALLY HYDROGENATED AROMATIC SOLVENTS OR COMPLETELY HYDROGENATED AROMATIC SOLVENTS, EACH HAVING A BOILING RANGE OF ABOUT 150 TO ABOUT 800*F. AT TEMPERATURE OF 650 TO 850*F., FOR AN AVERAGE RESIDENCE TIME OF 0.5 TO 6 HOURS DURING WHICH SAID HEATING IN THE ABSENCE OF SAID SOLVENT IS FOR NO LONGER THAN 10 MINUTES TO PRODUCE LIGHT PRODUCTS BOILING UP TO 650*F., A PRODUCT STREAM CONTAINING A SIDE STREAM LOW SULFUR, LOW METALS, LOW CONRADSON CARBON FUEL OIL COMPONENT HAVING A BOILING RANGE OF 650 TO 900*F. AND A 900*F.+ BOTTOMS STREAM BINDER OIL PRECURSOR COMPONENT; (B) FILTERING SAID PRODUCT STREAM TO REMOVE INSOLUBLES THEREFROM; (C) RECYCLING SAID 900*F.+ BOTTOMS BINDER OIL PRECUSOR COMPONENT OF SAID PRODUCT STREAM TO SAID HEATING STEP (A) TO INCREASE THE CONRADSON CARBON CONTENT THEREOF TO A VALUE GREATER THAN 40; AND (D) WITHDRAWING FROM SAID RECYCLE STEP (C) A BINDER OIL PRODUCT HAVING COMBINATION OF A COHRADSON CARBON GREATER THAN 40 AND A SOFTENING POINT RANGING FROM 200-280*F. SAID STEPS (A), (B), AND (C) BEING CARRIED OUT IN AN ESSENTIALLY OXYGEN-FREE ATMOSPHERE.