CA1229569A - Partial oxidation of heavy refinery fractions - Google Patents

Abstract

PARTIAL OXIDATION OF HEAVY REFINERY FRACTIONS
(D#77,783-F) ABSTRACT OF THE DISCLOSURE

This is a partial oxidation process in which heavy hydrocarbonaceous fractions from a petroleum refinery and light liquid paraffinic hydrocarbon extractants are used in the production of synthesis gas, reducing gas, or fuel gas i.e. gaseous mixtures comprising H2 and CO. In the process, substantially all of the particulate carbon and soot that are simultaneously produced are recovered and recycled to the reaction zone. A dispersion of carbon-soot-light paraffinic hydrocarbon extractant from the decanting zone is combined with a heavy refinery fraction in admixture with a liquid aromatic-rich hydrocarbon to produce a pumpable single liquid phase mixture which is introduced into a fractionation zone where the following streams are separated from each other: (a) a stream of light paraffinic hydrocarbon extractant which is recycled to the decanting zone, (b) a stream comprising at least a portion of the aromatic-rich hydrocarbon which is recycled for mixing with the heavy refinery fraction, and (c) a stream of pumpable dispersion of carbon-soot heavy refinery fraction and any remaining aromatic-rich hydrocarbon which may be used as fuel in the system or exported. Troublesome asphaltene precipitation that causes operational problems and increased viscosity is avoided by the subject process. Comparatively low cost heavy refinery fractions which ordinarily are difficult to handle may be now used along with light liquid paraffinic hydrocarbon extractants.

Description

PARTIAL OXIDATION OF HEAVY REFINERY FRACTIONS
(D~77,783-F) BACKGROUND OF THE INVENTION
This invention relates to the partial oxidation process. More specifically, it pertains to the use of heavy refinery fractions and light liquid paraffinic hydrocarbon extract ants in the partial oxidation process for producing - synthesis gas, reducing gas, or fuel gas.
Gaseous mixtures comprising Ho and CO i.e.

synthesis gas, reducing gas, or fuel gas may be prepared from hydrocarbonaceous materials by partial oxidation.
Particulate carbon and soot are entrained in the hot raw gas stream leaving the reaction zone of the gas generator. A
dispersion of carbon and water is produced when the hot raw effluent gas stream is quenched and/or scrubbed with water.
A liquid organic extract ant is used to resolve the carbon-water dispersion, and the extract ant is recovered by distillation in the manner described in coassigned U. S.
Patent Numbers 2,992,906 and 4,038,186.
It is economically desirable to use in the partial ` 20 oxidation gas generating process comparatively low cost heavy refinery fractions, such as very heavy residue, or the residues from disaffiliating or hydrogenation of residue or heavy oils. However, these materials are difficult to handle since at ordinary temperatures they may range from viscous liquids to solids. Further, when these materials are contacted by light liquid paraffinic hydrocarbons such as light straight run naphtha, asphaltene precipitation results that can cause plugging, carry over of carbon, clogging of pumps, and other operational problems in the Sue system. In addition, the viscosity of the blend is sub Stan-tidally increased thereby impairing pump ability. These dill-iculties are avoided by the subject improved partial oxidation.
process.
Sommelier OF THE INVENTION
This is an improved partial oxidation process for the production of synthesis gas, reducing gas, or fuel gas in which a heavy refinery fraction i.e., very heavy residue, or the residues from disaffiliating or hydrogenation of residue or heavy oil is used in the recovery of carbon-soot, and prefer-ably as at least a portion of the feed stock to the gas goner-atop. At least about 85 to 100 wt. and preferably all of the carbon-soot entrained in the gas stream leaving the gas goner-atop is recovered in a carbon-recovery zone and recycled to the gas generator as a portion of the reactant fuel feed stock.
According to one aspect of the present invention there is provided in the process for the partial oxidation of a hydrocarbonaceous fuel with a free oxygen-containing gas in the reaction zone of a free-flow non catalytic gas generator at a temperature in the range of about 1700 to 3500F. and a pressure in the range of about 1 to 300 atmospheres in the presence of a temperature moderator to produce a raw gas stream comprising Ho, CO, HO and at least one gas from the group COY, HIS, COST SHEA, No, A, and containing entrained soot; contacting the raw gas stream with water in a gas quenching and/or scrub-bring zone to produce a soot-water dispersion; separating said soot in a decanting zone; and recycling at least a portion of said soot to said gas generator as a portion of the feed, the improvement comprising:
(1) mixing a stream of said soot-water dispersion

-2-with a first stream of light paraffinic hydrocarbon extract ant, and introducing said mixture into a decanter along with a second stream of light paraffinichydrocarbon extract ant; wherein said light paraffinic hydrocarbon extract ant is selected from the group consisting of butane, pontoon, hexane, light straight run naphtha, and mixtures thereof;
(2) removing from said decanter a stream of part-curate carbon and soot dispersed in light paraffinic hydrocarbon extract ant, and a separate stream of ash dispersed in grew water;

(3) mixing together an asphaltene containing heavy refinery fraction having an initial boiling point yin the range of about 650F.-1300F. and being selected from the group consisting of very heavy residue from the refining of petrol Lomb, asphalt residuum from solvent disaffiliating and the both toys product from the hydrogenation and hydrocracking of nest-due or heavy crude oil with an aromatic-rich hydrocarbon liquid or vapor containing from about 20-100 wt. % aromatics to produce a first single liquid phase pump able mixture;

(4) mixing together the mixture from (3) with the dispersion of particulate carbon-soot-light paraffinic hydra-carbon extract ant from to) to produce a second single liquid phase pump able mixture with no precipitation of asphaltenes;
and

(5) separating the mixture from (4) in a fraction-anion zone and removing (a) a stream of light paraffinic hydrocarbon extract ant, and recycling said stream to (1) as said first and second streams of extract ant; (b) a stream comprising at least a portion of the aromatic-rich hydrocarbon, Jo 30 and recycling at least a portion of said stream to (3); and -pa-I: ' I

(c) a pump able dispersion comprising particulate carbon-soot-heavy refinery fraction and the remainder of the aromatic-rich hydrocarbon, if any, and recycling from about 0 to 100 wt. %
of said stream to the partial oxidation gas generator, and removing the remainder, if any, of said dispersion stream.
According to another aspect of the present invention there is provided in a process for the partial oxidation of a hydrocarbonaceous fuel with a free oxygen-containing gas in the reaction zone of a free-flow non catalytic gas generator at a temperature in the range of about 1700 to 3500 F. and a pressure in the range of about 1 to 300 atmospheres in the presence of a temperature moderator to produce a raw gas stream comprising Ho, CO, Ho and at least one gas from the : group COY, HIS, COST SHEA, No, A, and containing entrained soot;
contacting the raw gas stream with water in a gas quenching and/or scrubbing zone to produce a soot-water dispersion;
separating said soot in a decanting zone; and recycling at least a portion of said soot co said gas generator as a portion of the feed, the improvement comprising:
(1) mixing a stream of said soot-water dispersion with a first stream of light paraffinic hydrocarbon extract ant, and introducing said mixture into a decanter along with a second stream of light paraffinic hydrocarbon extract ant;
wherein said light paraffinic hydrocarbon extract ant is sol-acted from the group consisting of butane, pontoon, hexane, light straight run naphtha, and mixtures thereof;
(2) removing from said decanter a stream of part-curate carbon and soot dispersed in light paraffinic hydrocar-bun extract ant, and a separate stream of ash dispersed in grew water;

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(3) mixing together an asphaltene containing heavy refinery fraction having an initial boiling point in the range of about 650F. - 1300F. and being selected from the group consisting of very heavy residue from the refining of petroleum, asphalt residuum from solvent disaffiliating and the bottoms product from the hydrogenation and hydrocracking of residue or heavy crude oil with an aromatic-rich hydrocarbon selected from the group consisting of heavy cycle gas oil, light cycle gas oil, vacuum gas oil, gas oil from a fluid catalytic crack-I in unit, crude still gas oil, and mixtures thereof to produce first single liquid phase pump able mixture;
(4) mixing together the mixture from (3) with the dispersion of particulate carbon-soo-t-light paraEfinic hydra-carbon extract ant from (2) to produce a second single phase pump able mixture with no precipitation of asphaltenes; and 5) separating the mixture from (4) in a fraction-anion zone and removing (a) a stream of light paraffinic hydra-carbon extract ant, and recycling said stream to (1) as said first and second streams of extract ant; and (b) a pump able dispersion of particulate carbon-soot-heavy refinery fraction and all of the aromatic-rich hydrocarbon, and recycling from about 0 to 100 wt. % of said stream to the partial oxidation gas generator, and removing the remainder, if any, of said dispersion stream.
In the subject process, the hot raw gas stream leave in the reaction zone is quenchcooledand/or scrubbed with water.
The resulting soot-water dispersion is mixed with a light paraffinic hydrocarbon extract ant; and the mixture is intro-` duped into a decanter along with a second stream of light paraffinic hydrocarbon extract ant. A stream of particulate I:
2c-so carbon-soot dispersed in light paraffinic hydrocarbon extract ant is removed from the decanter along with a separate stream of grew water. A heavy refinery fraction is first mixed with a normally liquid aromatic-rich hydrocarbon fraction such as Bunsen, Tulane, zillion, or a gas oil in the amount of about 40 to 95 wt. % of heavy refinery fraction and the remainder comprising aromatic-rich hydrocarbon to produce a pump able mixture. This mixture is -Ed-I

then mixed with the dispersion of carbon-soot-light paraffinic hydrocarbon extract ant from the decanter to unexpectedly produce a pump able mixture comprising a single liquid phase. In one embodiment, the resulting mixture is then separated in a fractionation zone into the following streams which are distributed as follows: (a) a stream of light paraffinic hydrocarbon extract ant which is recycled to the decanter; (b) a stream comprising at least a portion of the aromatic-rich hydrocarbon which is recycled for mixing with that portion of the heavy refinery fraction going into the fractionation zone; and (c) a pump able dispersion of carbon-soot-heavy refinery fraction and the remainder of the aromatic-rich hydrocarbon if any, and wherein from about 0 to 100 wt. %, such as at least a portion of said pump able dispersion is recycled to the gas generator as at least a portion of the fuel feed, and the remainder, if any of said dispersion stream is removed for use as fuel in the system or for export.
By the subject process, problems such as plugging, carryover of carbon from the fractionator, and other operational difficulties that would come with disaffiliating of partial oxidation feed materials are avoided. Further, low-cost heavy refinery fractions which ordinarily are difficult to handle may be now efficiently used along with - 25 desirable light paraffinic hydrocarbon extract ants in the partial oxidation process for making synthesis gas, reducing `, gas, or fuel gas.
BRIEF DESCRIPTION OF THE DRAWING
The invention will be further understood by reference to the accompanying drawing. The drawing is a , .
,.

I

schematic representation of a preferred embodiment of the process.
DESCRIPTION OF THE INVENTION
The present invention pertains to an improved non catalytic partial oxidation process in which a hydrocarbon-assess fuel comprising a heavy liquid refinery fraction in admixture with carbon-soot is the preferred feed stock. A
conventional partial oxidation synthesis gas generator may be used in this process, such as shown in co-assigned US. Patent No. 2,818,326 and US. Patent 3,544,291. The gas generator comprises a vertical free-flow unpacked cylindrically shaped steel pressure vessel lined on the inside with refractory.
There is no obstruction to the free-flow of the reaction products passing down through the gas generator.
A conventional burner is located in the top of the gas generator, along the central vertical axis, or introducing the reactant feed streams. A suitable annulus-type burner is shown in co-assigned US. Patent No. 2,928,~60.
The reactant feed streams to the partial oxidation reaction include a stream of hydrocarbonaceous fuel which may include a mixture of heavy liquid refinery fraction and carbon-soot, a stream of free-oxygen containing gas, and a stream of temperature moderator.
The term hydrocarbonaceous fuel as used herein, is intended to include various liquid hydrocarbon materials, such as liquefied petroleum gas, petroleum distillates and residues, gasoline, naphtha, kerosene, crude petroleum, 35~
.

asphalt, gas oil, residual oil, tar-sand oil, shale oil, oil derived from coal, aromatic hydrocarbons (such as Bunsen, Tulane, and zillion fractions), coal tar, cycle gas oil from fluid catalytic-cracking operations, furfural extract of coyer gas oil, and mixtures thereof. Included within the definition of liquid hydrocarbonaceous fuel are oxygenated hydrocarhonaceous organic materials including carbohydrates, cellulosic materials, aldehydes, organic acids, alcohols, kittens, oxygenated fuel oil, waste liquids and by-products from chemical processes containing oxygenated hydrocarbon-assess organic materials, and mixtures thereof.
The terms heavy refinery fraction and heavy hydrocarbonaceous fraction from a petroleum refinery as used herein are synonymous and are intended to include by definition very heavy residue from the refining of petroleum, such as (1) vacuum residuum and the asphalt residuum from solvent disaffiliating, and lo) the bottoms product from the hydrogenation and hydrocracking of residue or heavy crude oil. At ordinary temperatures, these materials may be viscous liquids or solids. The heavy refinery fractions contain asphaltenes. Further, they are pump able at temperatures in the range of about 200 to 700F., such as about 300 to 500F., and have the following properties, as determined by conventional test methods e.g.
A.S.T.M.
, -Initial Boiling Point, OF. about 650- 1300 Viscosity, IFS @ 300F.40 - 300 Pontoon Insoluble, wt. about 5 - 50 The term free-oxygen containing gas, as used herein is intended to include air, oxygen-enriched air, I

i.e., greater than 21 mole % oxygen, and substantially pure oxygen, i.e., greater than 95 mole oxygen, (the remainder comprising No and rare gases). Free-oxygen containing gas may be introduced into the burner at a temperature in the range of about ambient to 1200F. The atomic ratio of free-oxygen in the oxidant to carbon in the feed stock (O/C, atom/atom) is preferably in the range of about 0.7 to 1.5, such as about 0.80 to 1.2.
The term temperature moderator, as used herein is intended to include steam, water, Carwash gas, liquid COY, cooled effluent gas from the gas generator, by-product nitrogen from the air separation unit used to produce substantially pure oxygen for use in the gasifies, and mixtures of the aforesaid temperature moderators.
The temperature moderator may be introduced into the gas generator in admixture with either the hydrocarbon-assess fuel such as heavy refinery fraction fuel feed, the free-oxygen containing stream, or both. Alternatively, the temperature moderator may be introduced into the reaction zone of the gas generator by way of a separate conduit in the fuel burner. With HO as the temperature moderator, the weight ratio of HO to the hydrocarbonaceous fuel, such as heavy refinery fraction fuel plus recycle carbon-soot and any liquid aromatic-rich hydrocarbon is in the range of 25 about 0.3 to 3.0, and preferably in the range of about 0.5 to 1Ø
The relative proportions of hydrocarbonaceous fuel, such as heavy hydrocarbonaceous fraction and recycle carbon, temperature moderator, and free oxygen in the feed streams to the gas generator are carefully regulated to

-6-35~

convert a substantial portion of the carbon in the fuel feed to the partial oxidation gas generator e.g. 75 to I wt. %, such as 80 to I wt. % of the carbon to carbon oxides e.g., CO and COY and to maintain an autogeneous reaction zone temperature in the range of about 1700 to 3500F., such as about 2000 to 2900F. The pressure in the reaction zone is in the range of about 1 to 300 atmospheres, such as about 10 to 200 atmospheres. The time in the reaction zone of the partial oxidation gas generator in seconds is in the range of about 0.5 to 20, such as normally about 1.0 to 5.
The effluent gas stream leaving the partial oxidation gas generator has the following composition in mole % (dry basis) depending on the amount and composition of the feed streams: Ho 8.0 to 60.0, CO 8.0 to 70.0, COY 1.0 to 50.0, SHEA 0.0 to 2.0, HIS 0.0 to 2.0, COY 0.0 to 1.0, No to 80.0, and A 0.0 to 2Ø
The effluent gas stream leaving the reaction zone of the non catalytic partial oxidation gas generator at a temperature in the range of about 1700F to 3500F. may be either (1) clench cooled and scrubbed with water, 1~2) cooled in a gas cooler and then scrubbed with water, or both (1) and (2). Thus, as shown in coassigned US. Patent No.
2,818,326, the hot effluent stream of gas from the reaction zone may be cooled to a temperature in the range of about 180 to 600F. by direct contact with water in a quench tank.
At least a portion of the entrained solids is thereby removed from the process gas stream by the turbulent quench water.
Any remaining entrained solids may be removed from the process gas stream by additional scrubbing with water in a gas Jo .~.Z2.~

scrubbing zone at a temperature in the range of about 100 to 600F., and a pressure in -the range of about 1-300 atmospheres. Suitably the pressure in the scrubbing zone is about the same as that in the gas generator, less ordinary pressure drop in the line. A pump able dispersion of soot and water in which the soot is present in the range of about 0.1 to 3.0 wt. %, such as about 0.5 to 2.0 wt. %, say below about 1.5 wt. % are produced in the quench tank and scrubbing zone.
lo Alternatively, the effluent gas stream from the partial oxidation gas generator may be cooled to a temperature in the range of about 350 to 750F. but above the dew point of water by indirect heat exchange with water in a gas cooler, such as shown and described in coassigned US. Patent No. 3,709,669~ By this means by-product steam for use elsewhere in the process may be produced, The cooled process gas stream is then cleaned by scrubbing with water in a conventional gas scrubbing zone. For example, a venturi or jet scrubber or gas scrubber may be used. By this means clean product gas and a dispersion of soot in water may be produced.
It is economically expedient in the subject process to resolve the soot-water dispersion from the quench and scrubbing operations and to recycle the components.
Thus, clarified water may be recycled to the gas quench cooling and/or scrubbing operation(s). In the subject process, the carbon-soot is recovered as a pump able dispersion of carbon-soot-heavy refinery fraction. Further from about 0-100 wt. %, and preferably at least a portion of Sue this dispersion comprising about 0-50 wt. %, such as about 5-30 wit % of aromatic-rich hydrocarbon may be recycled to the gas generator as at least a portion of the hydrocarbonaceous feed. By this means, there may be no net production of carbon.
First,suf~icient light liquid paraffinic hydrocarbon extract ant at a temperature in ire range of about 100 to 350F. and preferably 180 to 290F. is mixed with the soot-water dispersion at a temperature in the range of about 200 to 700F. and preferably 250 to 400F. in a two stage decanting operation, such as described in coassigned US. Patent No. 4,038,186. Two feed streams are simultaneously introduced into the decanter, such as shown in Fig. 1 of co-assigned US. Patent 4,033,168. About 3-40 wt. of the total light liquid paraffinic hydrocarbon extract ant is mixed with all of the soot-water dispersion to comprise the first feed stream in which the weight ratio of liquid paraffinic hydrocarbon extract ant to soot is in the range of about 1.5 to 15, such as about 3 to 8. The remainder of the I light liquid paraffinic hydrocarbon extract ant comprises the second feed stream.
The decanter is operated at a temperature in the range of about 150 to 650F., and preferably above 250F.
The pressure in the decanter is basically set by the temperature. The pressure must be high enough to keep the light liquid paraffinic hydrocarbon extract ant and the water from vaporizing in the decanter, e.g. 5 to 250 atmospheres depending upon the temperature. Thus, when the decanter bottoms outlet temperature is 300F. and the liquid go ., paraffinic hydrocarbon extract ant is light straight run naphtha, the pressure in the decanter may be at least 300 Asia. The volume of the decanter is such as to provide a sufficient residence time for phase separation to occur at a specified flow rate. Thus the residence time for the grouter phase and the carbon-soot-liquid paraffinic hydrocarbon extract ant phase in the decanter may be in the range of about 2 to 20 minutes and preferably about 6 to 15 minutes. The dispersion of carbon-soot-liquid paraffinic hydrocarbon extract ant floats on the grouter in the decanter.
The term light liquid paraffinic hydrocarbon extract ant includes by definition butane, pontoon, hexane, and light straight run naphtha, and mixtures thereof.
Typical properties of the light liquid paraffinic hydrocarbon extract ant follows:

Boiling point, I.B.P.,atm. OF. 100 to 200 APT Gravity about 40 to 80 Aromatics, wt. % less than 7 A pump able dispersion stream of carbon-soot in light liquid paraffinic hydrocarbon extract ant with or without small amounts of water is continuously removed from the top of the decanter at a temperature in the range of about 100 to 350F., such as about 200 to 275F. This dispersion comprises about 0.5 to 9.0 wt. % carbon-soot, such as about 0.5 to 5.0 wt. % soot, 0 to about 10 weight %
; water, and the remainder light liquid paraffinic hydrocarbon extract ant. The light liquid paraffinic hydrocarbon extract ant is separated from the carbon-soot in a conventional fractionation zone located downstream. The I

fractionation zone may comprise one or more fractionation columns.
A first single liquid phase pump able mixture comprising about 40-95 wt. I such as about 65-85 wt. % of fresh heavy refinery fraction and the remainder comprising an aromatic-rich hydrocarbon is prepared in a first mixing zone. Heavy refinery fractions that are solid at room temperature are first broken into small pieces. Suitable conventional mixing equipment may be used, depending on the temperature and viscosities of the materials being mixed.
For example, a mixing or blending tank may be used with or without a recirculating pump and/or an internal heating coil or an externally fired heater. The viscosity of the first single liquid phase pump able mixture is preferably less than 300 centistokes, such as less than 150 centistokes at a temperature of about 450F., or above. The temperatures and weight ratios of the streams being mixed are adjusted to achieve proper mixing and pump ability.
Suitable aromatic-rich hydrocarbons include pump able liquid hydrocarbons containing from about 20-100 wt. %, such as 30-95 wt. % aromatics. The boiling point of ; the aromatic-rich hydrocarbon is less than that of the heavy refinery fraction. Two types of aromatic-rich hydrocarbons are included by definition. Type I materials are single ring aromatic liquid hydrocarbons r i.e. Bunsen, Tulane, Zillion, and mixtures thereof in which the aromatic content is in the range of about 95-100 wt. %. Type II materials are liquid hydrocarbons that contain single and multi-ring aromatics such as listed in Table 4 of ASTM D3239 and which includes heavy I' . -56~

and light cycle gas oils, vacuum gas oils, and gas oils from a fluid catalytic cracking unit (FCCU) or a crude still, and mixtures thereof. The aromatic content of Type II materials is in the range of about 20-60 wt. %. Typical properties of the aromatic-rich liquid hydrocarbons follows:

Boiling Point, IMP elm. OF.
Type I about 95 to 115, such as about 100 to 110 Type II about 320 to Lowe, such as about 500 to 900 APT Gravity at 60F.
lo Type I about 75 to 85, such as about 79 to 82 Type II about 10 to 40, such as about 25 to 35 The first single liquid phase pump able mixture at a temperature in the range of about 250F. to 550F., such as about 400F.-500F., is then mixed with the overhead dispersion from the decanter comprising carbon-soot, light ` liquid paraffinic hydrocarbon, and any carry-over water to produce a second mixture which is introduced into a fractionation column. The weight ratio of heavy refinery fraction to aromatic-rich hydrocarbon in the first mixture is such that the second mixture is also a single liquid phase pump able liquid. There is no precipitation of asphaltenes. For example, the second mixture may comprise about 2 to 85 wt. %, such as about 10 to 50 wt. % of first mixture and the remainder comprises said overhead dispersion from the decanter. Actual wt. ratios of the components may be determined experimentally based on such variables as the asphaltene content of the heavy refinery fraction, the ' aromatic content of the aromatic-rich hydrocarbon, ` temperature, viscosity, and the amount of carbon-soot in the second mixture.
., - .

.

, :

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The second mixture may be optionally preheated to a temperature in the range of about 175F. to 800F., such as about 230F. to 725F. before being introduced into the fractionation zone. The amount of heavy petroleum refinery fraction in the feed mixture to the fractionator is such that the dispersion stream leaving at or near the bottom of the fractionator is pump able at the discharge temperature and comprises a heavy refinery fraction containing carbon-soot in the amount of about 0.5-25 weight %, such as about 1.0 to 12.0 wt. I, say about 2-5 wt. %, and may or may not contain aromatic-rich hydrocarbon. This slurry stream may be removed from the bottom of the fractionation column at a temperature in the range of about 375F. to 1300F., such as about 400F. to 900F. Separation of the liquid components in the second mixture by means of conventional fractionation may be facilitated by selecting the components so that their respective boiling points differ by about 25F. or more.
The pressure in the fractionating zone may vary yin the range of about 25 atmospheres to a vacuum, such as about 1-5 atmospheres.
About 0 to 100 wt. I, such as at least a portion i.e. about lo to 100 wt. %, and preferably about 100 wt.
of the aromatic-rich hydrocarbon is separated and removed from the fractionation zone at a temperature in the range of about 175F.-800F., such as about 175F.-350F. for Bunsen, Tulane and zillion; and about 350F.-1100F. for cycle gas oils. The separated aromatic-rich hydrocarbon is then recycled for mixing with the fresh heavy refinery fraction. The remainder, if any, of the aromatic-rich hydrocarbon is removed from the bottom or bottom portion of I

the fractionator in admixture with the heavy refinery fraction. The split is determined by the amount of aromatic-rich hydrocarbon required to produce the aforesaid first and second pump able mixtures and the pump able bottoms dispersion.
Substantially all of the comparatively small amount of water that may enter the fractionator dispersed in the second mixture, and any HO introduced by the optional steam distillation procedure, may be preferably removed with the stream of light paraffinic hydrocarbon whose boiling point is usually less than that of the aromatic-rich hydrocarbon, In one embodiment, the boiling point of the aromatic-rich hydrocarbon is close to that of water and at least a portion of the water may be removed with the stream of light low boiling aromatic-rich hydrocarbon leaving the fractionator. This stream is then cooled, condensed, and the aromatic-rich hydrocarbon is separated from the water and recycled to the mixing zone for admixture with the heavy refinery fraction.
From about Lowe wt. %, such as at least a portion i.e. about Lyle wt. I, say about 50-90 wt. % of the bottoms slurry stream may be recycled to the gas generator.
At least a portion i.e. about 10-100 wt. %, such as about 30-90 wt. % of the fuel feed to the gas generator may be thereby provided. In one embodiment all of the bottoms slurry stream with substantially no reduction in temperature is recycled to the gas generator to provide at least a portion of and preferably all of the fuel feed.
Advantageously, such a feed stream is already preheated. The remainder of the bottoms slurry stream, if any, may be used ;

;' I

elsewhere in the process, for example as a fuel for the fired heaters, and/or for export as fuel.
In another embodiment, the fractionator is continuously fed with a mixture comprising Type II
aromatic-rich hydrocarbons, as previously described, in admixture with a separate portion of heavy refinery fraction and the dispersion of carbon-soot and light liquid paraffinic hydrocarbon. A separate portion of the heavy refinery fraction may be continuously introduced into the gas generator. A stream of light liquid paraffinic hydrocarbon and any water is continuously distilled off of the fractionator and cooled, condensed, and separated. The light liquid parafinic hydrocarbon is then recycled to the decanter inlet. A pump able mixture comprising carbon-soot, substantially all of the Type II aromatic-rich hydrocarbon, and the heavy refinery fraction is continuously removed from the bottom or bottom section of the fractionator. This bottoms stream may be exported for use as fuel oil. From about from 0 to 100 wt. %, such as at least a portion i.e.
about Lyle wt. % of this bottoms stream may be recycled to the gas generator. The remainder of the bottoms slurry stream, if any, may be used elsewhere in the process as a fuel and/or for export as fuel.
Advantageously, in the subject process when the - 25 aforesaid mixture of heavy refinery fraction and aromatic-rich hydrocarbon is mixed with the dispersion of carbon-soot and light liquid paraffinic hydrocarbon, a second liquid phase does not form. Unexpectedly, there is no precipitation of asphaltenes nor increase in viscosity of -the mixture. Plugging problems in the fractionation column and carry-over of carbon are thereby avoided.
DESCRIPTION OF THE DRAWING
A more complete understanding of the invention may be had by reference to the accompanying drawing which illustrates a preferred embodiment of the invention.
Although the drawing illustrates a preferred embodiment of the invention, it is not intended to limit the subject invention to the particular apparatus or materials described.
A stream of soot-water dispersion in line 1 from a conventional quench tank and/or gas scrubber used to quench cool and/or scrub the raw effluent gas stream from the reaction zone of a conventional free-flow non catalytic partial oxidation gas generator is mixed in line 2 with a portion of light liquid paraffinic hydrocarbon extract ant, for example light straight run naphtha from line 3, valve 4, lines 5 7, and separation tank 8. Make-up liquid paraffinic hydrocarbon extract ant is introduced into the system through 20 line 9, valve 10~ and line 11.
The soot-water-extractant mixture in line 2 is passed through inlet 15 of decanter 16, the annular passage between outer pipe 17 and inner pipe 18 and is then discharged through lower horizontal radial nozzle 19.
Simultaneously, a second stream of light liquid paraffinic hydrocarbon extract ant from separator 8 is passed into decanter 16 by way of lines 7, 6, and 20, valve 21, line 22, and inlet 23. The extract ant is passed up through pipe 18 and is then discharged through upper horizontal radial nozzle 30.

';

;~2~i6~ -Separation takes place in the decanter. A pool of grew water 31 forms at the bottom of the decanter, and a dispersion of particulate carbon, soot and light liquid paraffinic hydrocarbon 32 floats on top of grew water 31 at the interface level 33. A stream of grew water is removed from the bottom of decanter 16 by way of outlet 34 and line 35. Most of the grew water is recycled to the hot raw gas quench cooling and/or scrubbing zone (not shown) by way of line 24, valve 25, and line 26. The remainder of the stream of grew water is Senate a waste water treatment facility (not shown) by way of line 27, valve 28, and lines 29 and 14. A stream of dispersion comprising carbon-soot, light liquid paraffinic hydrocarbon, and water; if any, is removed from decanter 16 by way of upper outlet 37, line 38, and passed into venturi mixer 39.
A first pump able single liquid phase mixture is produced by passing a stream of heavy fuel fraction from a petroleum refinery in line 40, into mixing zone 41 where it is mixed with a stream of aromatic-rich hydrocarbon liquid or vapor. For example, aromatic-rich hydrocarbon vapor may 'I be supplied to line 42 from line 43, open valve 44, lines 45-46, open valve 47, line 48 and fractionation column 49.
In such case valves 50 and 51 are closed. Alternatively, ; the aromatic-rich hydrocarbon in line 42 may be in liquid 25 phase. In such case, with valves 44 and 51 closed and 47 and 50 open, the aromatic-rich hydrocarbon vapor in line 48 is passed through lines 46, 55, 56 and condensed in cooler 57. The liquid aromatic-rich hydrocarbon in line 58 is passed into tank 59 and then through lines 60, valve 61, 30 line 62, and lines 63 and 42 into mixing zone 41.

Depending on the amount of aromatic-rich hydrocarbon that is necessary to be mixed with the heavy refinery fraction to provide the first pump able mixture of desired viscosity in line 70 and the second pump able mixture of single liquid phase material of desired viscosity in line 71 and the amount of fresh aromatic-rich hydrocarbon entering the system through line 64, from about 0-100 wt. %
of the aromatic-rich hydrocarbon entering fractionator 49 is removed through line 48. The remainder, if any, of the aromatic-rich hydrocarbon is removed through line 100 in admixture with the bottoms stream to be further described.
In another embodiment, valves 44, 47, and 61 are closed and valve 51 is open. The fresh aromatic-rich hydrocarbon continuously enters the system through lines 64, 65, 63 and 42. In such case, all of the aromatic-rich hydrocarbon may leave fractionator 49 through line 100 at ; the bottom of fractionator 49 in admixture with the dispersion of heavy refinery fraction and corniest. The pump able mixture in line 100 may be used as a fuel.
Alternatively, at least a portion may be recycled to the gas generator as at least a portion of the feed.
The previously described first mixture comprising heavy refinery fraction and aromatic-rich hydrocarbon from mixing zone 41 is pumped through line 70 and into mixer 39 where it is mixed with the overhead dispersion from decanter 37 comprising carbon-soot, light liquid paraffinic hydrocarbon and water, if any, from line 38 to produce a second pump able mixture comprising a single liquid phase dispersion of carbon-soot. The second mixture is passed into fractionator 49 by way of lines 71-72, open valve 73, and lines 74-75, pressure reducing valve 76, and line 77.
In such case valve 78 would be closed. Optionally, by closing valve 73 and opening valve 78 the second mixture in line 71 may be preheated by being passed through lines 79, 80, heater 81, and line 82. Fractionator 49 is equipped with recoiler 85. Optionally, steam may be introduced through line 86, valve 87, and line 88.
A stream of light paraffinic hydrocarbon extract ant vapors is removed by way of line 89 at the top of fractionator 49, cooled below the dew point in cooler 90, and passed into separator 8 by way of line 91. Any water settles to the bottom of separator 8, and is removed through line 92. The water in line 92 is sent to the waste water treatment facility (not shown) by way of line 14. First and second streams of light liquid paraffinic hydrocarbon extract ant are simultaneously removed from separator 8. The first stream is removed through line 7 and is recycled to the decanter as previously described. The second stream of light liquid paraffinic hydrocarbon extract ant is recycled 20 to fractionation column 49 by way of line 93, valve 94, and line 95. Uncondensed gases selected from the group consisting of HIS, NH3, COY, and hydrocarbon vapors are removed through line 96 and may be sent to a Claus operation (not shown) for recovery of sulfur, or sent to flare.
A pump able slurry stream of heavy refinery ; fraction and carbon soot with or without all or a portion of the aromatic-rich hydrocarbon that is introduced into the fractionator may be removed at the bottom of or the lower portion of the fractionation column through line 100. From 30 about 0-100 wt. % of the slurry stream in line 100 is pumped through line 101 to the partial oxidation gas generator.
The remainder, if any, of the slurry stream in line 100 is removed through line 102, valve 103, and line 104. This material may be used as fuel in heaters 81 and/or 85 or exported.
EXAMPLE
The following example illustrates a preferred embodiment of the process of this invention as related to Fig. 1 of the drawing. The example should not be construed as limiting the scope of the invention. The process is continuous and the flow rates are specified on an hourly basis for all streams of materials.
371.4 lobs. of the bottoms from a solvent disaffiliating process (SPA) having the properties shown in Table 1 below are mixed in a first mixing zone with 92.9 lobs. of heavy cycle gas oil (HUGO) from a fluid catalytic cracking unit (FCCU) having the properties shown in Table 1 to produce a pump able single liquid phase first mixture at a temperature of 400F.

SPA FCCU
Bottoms HUGO

Gravity, APT @ 60F. -6.7 10.8 Ultimate Analysis, %
C 85.70 88.82 H 9.37 9.42 N 1.52 0.28 S 2.52 1.07 Ash 0.28 0.006 O 0.61 Ball & Ring Softening Point, OF. 194 ~iscosity-Centistokes, 415F. 182 Viscosity SSF @ 122F. 12.2 ASTM Distillation - OF.

5% 550 10% 580 56~

The aforesaid pump able single liquid phase first mixture is mixed with 318.9 lobs. of a dispersion from a decanter comprising 7.4 lobs. of carbon-soot, 295.6 lobs. of light straight run naphtha, and 15.9 lobs. of water to produce a second single liquid phase pump able mixture.
There is no precipitation of asphaltenes. The light straight run naphtha has an APT gravity of 40 min. The second mixture at a temperature of 498F. is flashed into a fractionation column operating at 19 prig. The reflex ratio of the naphtha stream is .55 lb/lb.
The following streams are removed from the fractionation column:
(a) 295.6 lobs. of light straight run naphtha in admixture with 15.0 lobs. of water at a temperature of 265F. After separation from the water, about 51.7 lobs. of the light straight run naphtha is recycled and mixed with about 369 lobs. of carbon-soot water. Simultaneously, about 243.9 lobs.
of the light straight run naphtha are separately introduced into the decanter;
(b) about 92.9 lobs. of the FCCU heavy cycle gas oil as described in Table 1 at a temperature of about 650F. This stream is recycled to said first mixing zone for mixing with said bottoms from a solvent disaffiliating process to produce said first mixture; and (c) about 378.8 lobs. of a pump able dispersion comprising 1.95 wt. carbon soot and the remainder comprising said bottoms from a solvent disaffiliating process (SPA in Table 1) at a temperature of about 700F,.

i~.2~5~Sg~

All of the pump able dispersion in (c) is introduced into a free-flow non catalytic partial oxidation gas generator operating at a temperature of 1961F. and a pressure of 700 prig, along with 182.0 lobs. of steam and 403.6 lobs. of substantially pure oxygen i.e. 99.9 mole % 2 18,178 standard cubic feet per hour of synthesis gas (dry basis) are produced by partial oxidation having the following analysis in mole (dry basis):

H 44.022 10 I 47.g84 C2 7.023 No 0.279 A 0.078 OH 0.296 15 H 0.281 US 0.031 In addition 102.9 lobs. of HO and 7.4 lobs. of unconverted soot are included in the stream of raw synthesis gas. With respect to performance, advantageously the cold gas efficiency of the process i.e. BTU (Ho -I CABOT fuel x 100 ; of 83.85% is high; and, the specific oxygen consumption i.e.
standard cubic ft. of oxygen consumed per thousand standard cubic feet of Ho + CO produced, of 285.8 is comparatively low. Further, an efficient light paraffinic hydrocarbon extract ant and a comparatively low cost heavy refinery fraction having a comparatively high asphaltene content are used together in this partial oxidation process without precipitation of the asphaltenes. Clogging of pumps and other operational problems are thereby avoided.
Although this invention has been illustrated by reference to specific embodiments, it will be apparent to those skilled in the art that various changes and it modifications may be made which clearly fall within the scope of this invention.

,:

: 25 '

Claims (16)

THE EMBODIMENTS OF THE INVENTION IN WHICH AN EXCLUSIVE
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:

1. In the process for the partial oxidation of a hydrocarbonaceous fuel with a free oxygen-containing gas in the reaction zone of a free-flow noncatalytic gas generator at a temperature in the range of about 1700° to 3500°F. and a pressure in the range of about 1 to 300 atmospheres in the presence of a temperature moderator to produce a raw gas stream comprising H2, CO, H2O and at least one gas from the group CO2, H2S, COS, CH4, N2 A, and containing entrained soot; con-tacting the raw gas stream with water in a gas quenching and/or scrubbing zone to produce a soot-water dispersion; separating said soot in a decanting zone; and recycling at least a portion of said soot to said gas generator as a portion of the feed, the improvement comprising:
(1) mixing a stream of said soot-water dispersion with a first stream of light paraffinic hydrocarbon extract-ant, and introducing said mixture into a decanter along with a second stream of light paraffinic hydrocarbon extractant;
wherein said light paraffinic hydrocarbon extractant is sel-ected from the group consisting of butane, pentane, hexane, light straight run naphtha, and mixtures thereof;
(2) removing from said decanter a stream of parti-culate carbon and soot dispersed in light paraffinic hydro-carbon extractant, and a separate stream of ash dispersed in grey water;
(3) mixing together an asphaltene containing heavy refinery fraction having an intial boiling point in the range of about 650°F.-1300°F. and being selected from the group consisting of very heavy residua from the refining of petro-leum, asphalt residuum from solvent deasphalting and the bot-toms product from the hydrogenation and hydrocracking of res-idua or heavy crude oil with an aromatic-rich hydrocarbon liquid or vapor containing from about 20-100 wt. % aromatics to produce a first single liquid phase pumpable mixture;
(4) mixing together the mixture from (3) with the dispersion of particulate carbon-soot-light paraffinic hydro-carbon extractant from (2) to produce a second single liquid phase pumpable mixture with no precipitation of asphaltene;
and (5) separating the mixture from (4) in a fraction-ation zone and removing (a) a stream of light paraffinic hydrocarbon extractant, and recycling said stream to (1) as said first and second streams of extractant; (b) a stream com-prising at least a portion of the aromatic-rich hydrocarbon, and recycling at least a portion of said stream to (3); and (c) a pumpable dispersion comprising particulate carbon-soot-heavy refinery fraction and the remainder of the aromatic-rich hydrocarbon, if any, and recycling from about 0 to 100 wt. %
of said stream to the partial oxidation gas generator, and removing the remainder, if any, of said dispersion stream.

2. The process of claim 1 wherein the pentane insolu-bles of the heavy refinery fraction are in the range of about 5-50 weight percent.

3. The process of claim 1 wherein the aromatic-rich hydrocarbons are single ring compounds.

4. The process of claim 3 wherein said aromatic-rich hydrocarbons are selected from the group consisting of benzene, toluene, xylene, and mixtures thereof.

5. The process of claim 1 wherein said aromatic-rich hydrocarbons are selected from the group consisting of heavy cycle gas oil, light cycle gas oil, vacuum gas oil, gas oil from a fluid catalytic cracking unit, crude still gas oil, and mixtures thereof.

6. The process of claim 1 where from about 10 to 100 wt. % of the aromatic-rich hydrocarbon separated in (5) (b) is recycled to (3).

7. The process of claim 1 where the mixture produced in (3) comprises about 40-95 wt. % of heavy refinery fraction and the remainder comprises aromatic-rich hydrocarbon.

8. The process of claim 1 wherein the remainder of the pumpable dispersion removed in (5) (c) is used as fuel in the system and/or for export.

9. The process of claim 1 where in (3) said pumpable mixture is a single liquid phase mixture comprising about 65-85 wt. % of fresh heavy refinery fraction and the remainder comprising an aromatic-rich hydrocarbon.

10. The process of claim 1 where the stream of particu-late carbon and soot dispersed in light paraffinic hydrocarbon extractant from (2) includes 0 to about 10 wt. % of H2O, and provided with the steps of removing any H2O if present along with said stream of light paraffinic hydrocabon extractant in (5) (a), and separating the H2O from the light paraffinic hydrocarbon prior to recycling said light paraffinic hydro-carbon to (1) as said first and/or second streams of light paraffinic hydrocarbon extractant.

11. The process of claim l wherein from about 10 to 100 wt. % of the pumpable dispersion produced in (5) (c) is recycled to the gas generator as at least a portion of the fuel feed.

12. In a process for the partial oxidation of a hydro-carbonaceous fuel with a free oxygen-containing gas in the reaction zone of a free-flow noncatalytic gas generator at a temperature in the range of about 1700° to 3500° F. and a pre-sure in the range of about l to 300 atmospheres in the presence of a temperature moderator to produce a raw gas stream com-prising H2, CO, H2O, and at least one gas from the group CO2, H2S, COS, CH4, N2, A, and containing entrained soot; con-tacting the raw gas stream with water in a gas quenching and/or scrubbing zone to produce a soot-water dispersion;
separating said soot in a decanting zone, and recycling at least a portion of said soot to said gas generator as a portion of the feed, the improvement comprising:
(1) mixing a stream of said soot-water dispersion with a first stream of light paraffinic hydrocarbon extract-ant, and introducing said mixture into a decanter along with a second stream of light paraffinic hydrocarbon extractant;
wherein said light paraffinic hydrocarbon extractant is sel-ected from the group consisting of butane, pentane, hexane, light straight run naphtha, and mixtures thereof;
(2) removing from said decanter a stream of part-iculate carbon and soot dispersed in light paraffinic hydro-carbon extractant, and a separate stream of ash dispersed in grey water;
(3) mixing together an asphaltene containing heavy refinery fraction having an initial boiling point in the range of about 650° F.-1300° F. and being selected from the group consisting of very heavy residua from the refining of petro-leum, asphalt residuum from solvent deasphalting and the bottoms product from the hydrogenation and hydrocracking of residua or heavy crude oil with an aromatic-rich hydrocarbon selected from the group consisting of heavy cycle gas oil, light cycle gas oil, vacuum gas oil, gas oil from a fluid catalytic cracking unit, crude still gas oil, and mixtures thereof to produce a first single liquid phase pumpable mixture;
(4) mixing together the mixture from (3) with the dispersion of particulate carbon-soot-light paraffinic hydro-carbon extractant from (2) to produce a second single phase pumpable mixture with no precipitation of asphaltenes; and (5) separating the mixture from (4) in a fraction-ation zone and removing (a) a stream of light paraffinic hydrocarbon extractant, and recycling said stream to (1) as said first and second streams of extractant; and (b) a pump-able dispersion of particulate carbon-soot-heavy refinery fraction and all of the aromatic-rich hydrocarbon, and re-cycling from about 0 to 100 wt. % of said stream to the partial oxidation gas generator, and removing the remainder, if any, of said dispersion stream.

13. The process of claim 12 where the stream of part-iculate carbon and soot dispersed in light paraffinic hydro-carbon extractant from (2) includes 0 to about 10 wt. % of H2O, and provided with the steps of removing any H2O if present along with said stream of light paraffinic hydro-carbon extractant in (5) (a), and separating the H2O from the light paraffinic hydrocarbon prior to recycling said light paraffinic hydrocarbon to (1).

14. The process of claim 12 wherein the remainder of the pumpable dispersion removed in (5) (b) is used as fuel in the system and/or for export.

15. The process of claim 12 wherein at least a portion of the pumpable dispersion produced in (5) (b) is recycled to the gas generator as at least a portion of the fuel feed.

16. The process of claim 1 where in (4) the first single liquid phase pumpable mixture at a temperature in the range of about 250°F. to 550°F. is mixed with said dispersion of particulate carbon-soot-light paraffinic hydrocarbon extract-ant from the decanter which is operated at a temperature in the range of about 150°F. to 650°F.