CA1080474A

CA1080474A - Production of clean synthesis or fuel gas

Info

Publication number: CA1080474A
Application number: CA266,740A
Authority: CA
Inventors: George N. Richter; William B. Crouch; William L. Slater; Lawrence E. Estabrook
Original assignee: Texaco Development Corp
Current assignee: Texaco Development Corp
Priority date: 1975-12-22
Filing date: 1976-11-29
Publication date: 1980-07-01
Also published as: GB1519090A; FR2336470B1; AU1984676A; FR2336470A1; AU497294B2; ES453761A1; GR62017B; SE7613834L; JPS5277106A; YU302776A; DK574176A; JPS5333601B2; IT1203052B

Abstract

PRODUCTION OF CLEAN SYNTHESIS OR FUEL GAS
(D#74,665-FB) ABSTRACT OF THE DISCLOSURE
An improved continuous partial oxidation process for producing clean synthesis or fuel gas from a hydrocar-bonaceous fuel feed is disclosed wherein the hot effluent gas stream from the reaction zone of the gas generator is cooled and cleaned by discharging the gas stream directly into a relatively large body of hot liquid hydrocarbon im-mersion fluid. A portion of the immersion fluid is contin-uously removed from the immersion vessel and is cooled in an external cooler to a temperature in the range of about 300 to 850°F. but above the due point of the water in the process gas stream. For example, the external cooler may be a waste heat boiler for the production of high pressure steam. Portions of the cooled immersion fluid optionally in admixture with scrubbing fluid obtained subsequently in the process are recycled to the immersion vessel, and op-tionally to the gas generator as at least a portion of the hydrocarbonaceous fuel feed. The effluent gas stream leav-ing said immersion zone may be subjected to additional cleaning by being scrubbed with said scrubbing fluid com-prising make-up hydrocarbonaceous fuel and particulate carbon in a separate scrubbing zone. Additional cleaning of the effluent gas stream may be effected by scrubbing with noxious by-product water.

Description

47~L

This invention relates to a continuous l~rocess for the prc)duction of uel gclS or synthesis gas by the partial oxida~ion of a l~yclrocarbonaceous fuel More specifically, the present invclltion relates to an iml)ro~ed procedure for producing cooJc~l and cleaned gas mixturcs comprising hydrogen and carbon loonoxide.
Liquill hy(lrocarl)orl fuels have previously l~een partially o~idized with oxygen in the presence of stearn to produce a mixture of gaseous products comprising carbon monoxide and hydrogen. See, fo~ exampleJ U.S. Patent No. 2,809,104, where the effluent gas stream from the reaction zone is cooled by quenching in water. Scrubbing a precooled gas stream with an oil-water emulsion containing ;-lbout 10 to 90 volume % water is described in U. S. Patent No. 3, 010, 8]3.
By quenching the effluent gas stream in water or in emulsions containing large amounts of water, large amounts of I2O will be introduced into the gas stream, and may be costly to remove. Moreover, dispersions of particulate carbon and watcr a-re produced, and complex systems are required to :~0 separate the carbon from the water.
; By the present invention, traditional costly carbon removal system~ may be eliminated and the waste water treatment facilities now required to meet water disposal standard~ may be simplified.
The present invention provides a process for the production of clean synthesis gas or fuel gas which comprises:
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(a) partial oxidation o~ a ~eed comprising dispersion of par~iculate carbon in a liquid hydrocarbonaceous fuel with a free oxygen-con-taining gas in a free flow, unpacked gas generator, at a tempera-ture of from about 1300 to 3000F., and a pressure of from about 1 to 250 atmospheres, to produce an effluent gas stream comprising H2, C0, CO2, H2O and entrained particulate carbon;
(b) cooling the effluent gas stream in a quench zone to a temperature of from about 300 to 900F., but above the dew point of water in ~he effluent gas stream, and simultaneously removing the entrained particulate carbonJ by discharging the effluent gas stream directly into a body of hot immersion fluid comprising a dispersion of par-~ ticulate carbon in hot liquid hydrocarbonaceous ~uel, and recover-ing a clean gaseous stream comprising H2, CO, CO2, and H20;
~c) cooling at least a portion of the hot immersion fluid to a tempera-ture of from about 300 to 850F., by indirect heat exchange, and recycling at least a portion of the resulting cooled immersion fluid to the quench zone; and (d) introducing a portion of the hot immersion fluid produced in step ~b) or a portion of the cooled immersion fluid into the gas gener-ator as at least a portion of the feed.
In accordance with one preferred embodiment, the partial oxidation is carried out in the presence of a -temperature moderator, for example H20, C02, flue gas, cooled and recycled effluent gas from the gas generator, or a mixture thereof.
Preferably, the temperature moderator and liquid hydrocarbonaceous fuel are employed in a weight ratio of up to 3Ø
In accordance with another embodiment of the invention~
the clean gaseous stream is further purified by scrubbing in a scrubber with a scrubbing fluid comprising liquid hydro-carbonaceous fuel; an effluent stream from the scrubber isintroduced into a gas liquid separator; clean product gas and a separate stream of scrubblng fluid are removed from -the separator; a first portion of the scrubbing fluid is recycled to the scrubbi~g zone; a second portion of the scrubbing fluid is mixed with a portion of immersion fluid being recycled; and additional liquid hydrocarbonaceous fuel is introduced into the s-eparator, or into a ~tream of scrubbing fluid from the separator.
In accordance with an alternative embodiment of the invention, the clean gaseous stream is ~urther pur~fied by scrubbing in a scrubber with a scrubbing ~luid comprising wa-ter;
an effluent stream from the scrubber is introduced into a gas-liquid separator; by-product water, and clean product gas are recovered from the separator and separate por-tions of by-product water are recycled to the gas generator as temperature moderator, and to the scrubber as scrubbing fluid. In this embodiment, make up water is advantageously ineorporated in recycled wa-ter from the separa-tor.
When a scrubber is employed, effluent from the scrubber can, if desir~ed, be cooled before i-t is passed to the separator.
Cl ~ C10 hydrocarbon vapors may be obtained as a result of thermal cracking or volatilization of a portion of -the immersion fluid during quenching of the hot process gas stream in the quench zone. C5 - C10 hydrocarbon vapors that may be entrained in the product gas stream may be condensed by cooling and thereby separated from the prdduct gas stream.
By -the process of -the present invention, cooled and cleaned synthesis gas or fuel gas may be produced.
The gas generator for carrying out -the partial oxidation reaction preferably consists of a compact, unpacked, free-flow, noncatalytic, refractory-lined steel pressure vessel of the ~ype described in U.S. Patent No. 2809,104.
The ratio of free-oxygen in the free-oxygen-containing gas, to carbon in the feedstock (OtC atom/atom) is generally in the range of abou-t 0.6 to 1.5. Substantially pure oxygen is preferred to minimize introducing nitrogen and other gaseous impurities into the product gas.
The term "liquid hydrocarbonaceous fuel" as used herein is intended to mean by definition a liquid material containing carbon and hydrogen, and optionally other elements.
Examples include petroleum distillates and residual, gas oil, : . :

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residual fuel, reduced crude, whole crude, asphalt, coal tar, coal oil, shale oil, tar sand oil, and mixtures thereof.
Thermally cracked and vaporized constituents thereof which are normally liquid C5 - C10 hydrocarbons are lso by definition "liquid hydrocarbonaceous fuels". An economic advantage is obtained whenilow cost sulfur-containlng petroleum oils with a sulfur content in the range of abou-t 1 to 7 weight % are used.
Pumpable slurries of solid carbonaceous fu~ls, e.g.
particulate carbon, petroleum coke, and mixtures thereo* in a liquid hydrocarbonaceous fuel~ such as one previously listed, may also be fed to the gas generator and are included within the definition of liquid hydrocarbonaceousf~uel. ~`
The liquid hydrocarbon ceous fuel may preferably be introduced into the gas generator in liquid phase at a temperature in the range of ambient to below the vaporæzation temperature. Alternatively, the hydrocarbonaceous fuel feed may be atomized and dispersed in steam or some other temperature moderator.
Typical effluent gas streams f~m the gas generator may have the following composition in mole %: H2 10 to 60;
C0 10 to 70; C02 1 to 50; H20 2 to 50; CI14 nil to 30;
N nil to 75; H2S nil to 2.0; COS nil to 0.7; r nil to 2;
and may contain from 0.2 to 20 weight ~ of particulate carbon (basis weight of C in the hydrocarbonaceous fuel).
The effluent gas stream leaving the gas generator is passed directly into a relatively large body of pumpable .. . :. : : . '....... -immersion fluid contained in a cooling and cleaning zone in an oil immersion tank or quench tank. The immersion fluid comprises a liquid hydrocarbonaceous fuel and may con-tain dispersed particulate carbon.
In a preferred embodiment the effluent gas stream from the gas generator is introduced below the surface of a pool of liquid hyd~ocarbonaceous fuel-particulate carbon dispersion contained in an immersion or quench tank, preferably a vertical tank with an axially disposed dip leg.
The gas stream is passed through the dip leg and is discharged beneath the surface of a pool of the liquid hydrocarbonaceous fuel contained in the steel pressure vessel. A concentric draft tube, open at both ends, may surround the dip leg, leaving an annular passage -therebe-tween. In operation, the direction of the down-flowing gas stream may thereby be reversed and a mixture of gas and cooling fluid may then pass up through the liquid hydrocarbon. The gas then separates in the space above -the surface level of the immersion fluid, near the top of the oil immersion tank. Generally, about 30 to 60 gallons of immersion fluid are contained in the immersion tank for each 1000 Standard Cubic Feet of effluent gas from the gas generator that is quenched therein.
The turbulent conditions in the oil immersion tank, caused by the large volumes of gases bubbling up through the ; annular space, help the immersion fluid to scrub substantially all the solids from the effluent gas, forming a dispersion of unconverted par-ticulate carbon and immersion fluid. Thus as used herein, the term "immersion fluid" is intended -to mean either the mixtures of liquid hydrocarbonaceous fuels or a pumpable dispersion of liquid hydrocarbonaceous fuels and particulate carbon. The solids content of this oil - carbon pumpable dispersion is generally in the range of about nil to 50.0 % by weight, preferably from about 2.0 -to 8.0% by weight.
The cooled clean process gas stream ~eaving the imm~rsion fluid has an exit temperature in the range of about 300 to 900F., and preferably a temperature in the range of about 600 to 700F. The lower temperature should be above the dew point of wa-ter to prevent water from condensing out of the process gas stream. The time in the immersion zone is generally about 5 to 60 seconds. The effluent gas stream leaving the immersion zone comprises H2, CO, CO2, and H2O, and optionally contains at least one ma-terial from the group H2S, COS, N2 r, par-ticulate carbon, and Cl - C
hydrocarbons. There may be up to 40 mole % of Cl - C10 hydrocarbons, which may result from thermal cracking or volatilization of the immersion fluid.
The immersion f~uid may be maintained at a temperature in the range of about 300 to 850~)F., and preferably about 600 to 750F. The pressure in the i.mmersion tank is generally in the range of about 1 - 250 atmospheres and is "~.
preferably ~he same as in the gas generator. A pressure in `~
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tl-le range of al)o~1t ~3 to 250 atn1os~ eI~cs is suital)le. ~ c it is desirat)l,e to minimize volatilization of the imn ersion fluicl, higher pressures may be used, e. g. 1500 psia or more~ To minimize Cl - C4 hydrocarbons in tl1e product gas, the upper temperature of the immersion fluid should be kept below its thermal cracking temperature. Optionally, a r)ortion of the hot immersion fluid m.~y be removed from the immersion tanlc at a temperature in the range of about 300 to 850 F., and m~y ~e introduced into the gas generator at substantially the same temperature, as feed thereto. In this mcmner the immersion tank serves as a fuel preheater The liquid hydrocarbon immersion fluid is pumpable at the operating conditions existing in the quench tank. The liquid hydrocarbonaceous fuels which were previously described as feedstock for the gas generator, and the immersion fluid are substantia~y the same type of materials.
The temperature of the immersion fluid may be controlled by continuously removing at least a portion of the hot immersion fluid from the immersion tankJ cooling it, and recycling to the immersion tank at least a portion of sa1d cooled irnmersion fluid, optionally in admixture with a liquid dispersion coml~rising particulate carbon, make~up liquid hydrocarbonaceous fuel, and any condensed C5 - Cl0 hydrocarbons. This liquid .~ . , dispersion may be obtained from subsequent gas scrubbing and gas liquid, separation steps. Optionally, a portion of the cooled immersion fluid may be recycled to the gas generator as , .
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feed. Optionally, a portion of the immersion fluid may be removed rom the system and burned elsewhere as fuel.
Cooling of the hot immersion fluid that is removed from the immersion tank may be effected in a heat exchange zone by indirect heat exchange with a coolant in a cooler, or alternatively in a steam generator, producing by-product ste~m and cooled immersion fluid.
At start-up, the immersion fluid may have to be heated by conventional means -to a temperature that is above the dew point for H2O in the effluent gas stream from the gas generator.
The cleaned and cooled process gas stream ~eaving from the -top of the oil immersion tank has a temperature in the ;~
range of about 300 to 900F., and preferably about 600 to 750F.
Residual solids contained in the gas stream may be removed by passing the gas stream through a nozzle scrubber. A
conventional orifice or venturi scrubber may alternatively be employed. For example, the process gas stream may be passed through the throat of a nozzle-type scrubber at a velocity in the range of about 100 - 400 feet per second. About 5 to 10 gallons of scrubbing fluid per 1,000 standard cubic feet are injected into the process gas s-tream a-t the throat of -the scrubbing nozzle.
In a first embodiment of the subject process, the pumpable scrubbing fluid comprises liquid hydrocarbonaceous ~` fuel, optionally containing particulate carbon, and any condensed :

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ligllt liquid hydrocarbons in the range C5 - C10 that n-~ay be preserlt.
In t~le Eirst cmbodiment, the product gas leaving the gas-liquid separcltor may contain from about nil to 40 mole percent of Cl ~ C10 saturated and unsaturated hydrocarbons due to cracking or vaporization of the immersion fluid. Other ;~
gaseous constituents incl-lde II2, CO, C02, and optionally gaseous impurities selected from the group ~I2O, N2, ~r, H2$, COS, and mixtures thereof. For example, synthesis 0 g.lS product may preferably contain up to 5 mole % Cl - C10 hydrocarbons, while fuel gas may preierably contain from 10 to 40 mole % of Cl - C10 hydrocarbons. The greater the amount of Cl - C10 hydrocarbons present, the higher the heating value of the product gas. Thus, for the same oxygen consumption in the gas generator, fuel gas may be produced by i the process according to the present invention, having a greater heating value, e. g. from 400 to 800. I3. T, IJ. per standard cubic feet (SCF).
The amount of Cl - C10 hydrocarbons in the product gas is a function of the characteristics of the immersion fluid, and the temperature of the immersion fluid. Thermal cracking of the -~ immersion fluid should be controlled or minimized when synthesis ga,s is produced. In such case refractory oils such as residual aromatic oils, high flow rates, low quench temperatures, preferably below the thermal cracking temperature, i, e. 300 to 500F., and pressures of at least 1500 psia are . ~ : . . .

preferred operating condi-tions for producing a product gas containing up to 5 mole % Cl - C hydrocarbons However, when the product gas is fuel gas, some thermal cracking of the immersion fluid in the immersion zone is preferred, to increase the heating value of the gas.
If desired~ additional conven-tional gas purification steps such as solvent absorp-tîon or cryogenic cooling may be employed to eliminate any or all of the gaseous impuri-ties from the product gas stream. For example, the product gas leaving the gas-liquid separator may be cooled to condense out water or a mixture of water and at least part of the C5 - C10 hydrocarbons.
In a second embodiment oE the process according to the present invention, cleaned and cooled process gas stream leaving from the top of the oil immersion tank is scrubbed fur-ther in a scrubber, pre~erably a nozzle scrubber, with a pumpable scrubbing fluid comprising by-product water collected -subsequently in the process in admixture with fresh make-up water. The process gas stream is then cooled below the ~` 20 dew points of the H20 and any normally liquid light hydrocarbons, i.e. C5 - C10 that may be contained thereîn.
In a gas-liquid separator, the product gas from this second embodiment may be separa-ted from the normally liquid constituents, i.e. water and C5 - C10 hydrocarbons present in the scrubbed gas stream. Any C5 - C10 liquid hydrocarbons present will form a dispersion with the particulate carbon ~ 8~7~ ~

scr~lbbecl fl~onl t~le ~clS stl~ea~ lC (~ sl)cr,si~ ;el)al~ales out an(l floats on the by-product water layer that sinlcs to the bottom of the gas~liquid separator. If there is only a small quantity of C5 - C10 liq~ hydrocarbons present, or if there are no such hydrocarbons, the particulate carbon will form a dispersion with the by-product water.
Before leaving the gas~ uid separator, the process gas stream is was}led with clean n~ake-up water. The clean product gas leaving the gas-liquid separator may then contain from about nil to a~0 mole % of Cl - C4 saturated and unsaturated normally gaseous hydrocarbons, produced by thermal cracking of the immersion fluid. Other gaseous constituents include ~I2, CO, CO2, and optionally gaseous inlpurities selected frorn the group N2, Ar, ~12S, COS, and mixtures thereof. For example, syn-thesis gas product m.ly preferably contain rom about nil to 5 nJole ~0 of Cl ~ C4 hydrocarbons, while fuel gas may preferably contain from 10 to 40 mole % of Cl - C4 hydrocarbons.
-~ The greater the amount of Cl - C4 hydrocarbons present, the higher the heating value of the product gas Thus, for the same o~cygen consumption in the gas generator, fuel ~as may be produced by the subject process having a greater heating value e, g. about d,00 to 800 B. T, U, per standard cubic foot (SCF).
The amount of Cl - C4 hydrocarbons in the product gas is a f~nction of the characteristics of the immersion fluid, and the temperature of immersion fluid. If desired, dditional conventional gas purification steps such as by solvent absorption or cryogenic cooling may be employed to elimmnate any or all oE the gaseous impurities from the produc-t gas stream.
In this second embodiment, the by-product water in liquid phase separates by gravity from the product gas and ;~
any C5 - C10 liquid hydrocarbons in the gas-liquid separator.
A first portion of the by-product water in admixture wlth make-up water is recycled to the nozzle scrubber as scrubbing fluid, and a second portion is consumed in the gas generator as a temper~ture moderator, as previously described.
Optionally, a third portion may be removed and used elsewhere in the system. Any C5 - C1O liquid hydrocarbons separated in the gas-liquid separator may be consumed in the gas ;
generator as a portion of the feed.
Advantages of the process according to the present invention, include: (1) elimination of the conventional carbon-extraction step employing naphtha for extracting carbon from carbon-water slurries followed by decan-ting and naphtha stripping; (2) production of synthesis gas or enrlched fuel , .
gas having a high B.T.U. per SCF; and ~3) increased thermal efficiency, by employing heat from the effluent gas from the gas generator to preheat the oil feed to the gas generator.
A more complete understanding of the invention may be had by reference to F~gs 1 and 2 of the accompanying Drawings which show in detail, two embodiments of the process according to the present invention. Quantities have been assigned to ` ~:

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various streams so that -the following descrip-tion in Examples 1 and II may also serve as an example of the subject inven-tion.
E AMPLE I
This employs the apparatus shown schematically in Fig. 1 of the accompanying Drawings.
On an hourly basis, about 2000 lbs. of an oil-carbon feed dispersion in line 1 at a tempera-ture oP about 300F. is passed through inlet 2 and inner annulus passage 3 of burner 4.
Simultaneously, about 1200 lbs. of steam at a temperature of about 650F, in line 5 is passed through inlet 6 and outer annulus passage 7. Burner 4 extends axially into upper port 8 of conventional, vertical, free-flow, unpacked, non- ~;
;~ catalytic ~refractor~-lined gas generator 9. The oil-carbon dispersion has a solids content of about 3.6 weight % of particulate carbon. The oil in said d~spersion is 15.0 PI
California Reduced Crude having the following ultimate analysis in wt. %: C 85.99; H 11.28; 0 0.13; N 0.88; S 1.69 and Ash 0.03. The Heat of Com~ustion of the oil is 18,514 BTU
per lb.
Simultaneously, 2135 lbs. of substantially pure oxygen in line 10 at a temperature of about 3000F. is passed through central passage 15 of ~urner 4. The reactant streams converge at the -tip of the burner where atomization of the fuel and dispersal in the oxidant takes place.
Partial oxidation of the fuel takes place in reaction -lS-: - :. . . .: -zone 16 of gas generator 9, at an au-togenous temperature of about 2260Fo and a pressure of about 28 atmospheres.
121,700 standard cubic feet per hour (SCFH) of effluent gas leave the gas generator by way of axially located bottom , flanged exit port 17 and directly passes down through dip tube 18 and is discharged below the surface 19 of the immersion f~uid constituted by the pool of oil-carbon dispersion 20 contained in vertical oil immersion vessel 21. Dip tube 18 , is axially mounted in the top flanged inlet port 22. The direction of the process gas stream moving down dip tube 18 s reversed upon being discharged into the immersion fluid ~: :
confined in vessel 21. The gas stream then passes vigorously ~; up through the immersion fluid contained in the annular :
space 23 located between the outside surface of dip tube 18 and inside surface of open-ended concentric draft tube 24.
Spacers 25 support draft tube 24 and position it with respect to dip tube 18. The turbulent action cools and cleans the process gas stream, which then separates from the immersion fluid in space 26 at the top of the immersion vessel at a temperature of about 500F. The pressuresiin the immersion vessel and in the gas generator are substantially the same.
Solid residues, such as ash and heavy metal constituents, which separate from -the gas stream, sink to the :: :
bottom of the oil-carbon dispersion in vessel 21 and are periodical~y removed through bottom axial flanged port 30, and a conventional lock hopper system co~prising line 31, valve 32, - :.

line 33, tank 34, line 35, valve 36 and line 37.
The temperature of the immersion fluid 20 is reduced by removing 39,000 lbs. of the immersion fluid at a temperature of about 500F. and containing about 4.0 wt. % of ~ar-ticulate carbon through line 38. It is then passed through cooler 39 and lines 40-41. About 2000 lbs. of scrubbing fluid from line 42, coming from a downstream gas scrubbing step to be further described below, are mixed in l~ne 41 with the cooled immersion fluid from line 40. By means of pump 43, about ;;
39,000 lbs. of this mixture of fluids at a temperature of about 300F. are pumped through lines 44 and 45 into, the top of immersion vessel 21 as immersion fluid, About 2000 lbs. of the mixture of fluids in line 44 are passed through line 46, valve 47, lmne 1, and nozzle 2 into ~urner 4 as the liquid hydrocarbonaceous fuel feed to gas generator 9. Alternatively~
coQler 39 may be placed in line 45. In such a case, a portion -of the hot mixture of fluids in line 44 may be introduced, without being substantially cooled, into gas generator 9 as at least a portion of the feed, Optionally, a portion of the mixture of fluids in line 44 may be passed through line 48, valve 49, and line 50 and used for heating fuel.
Alternatively, the cooler 39 may be employed as a steam generator, in order to make more efficient use of the sensible heat of the immersion fluid.
The process gas stream is removed from space 26 at the top of immersion vessel 21 and is passed through line 55 into conventional nozzle scrubber 56 where it is scrubbed with 6200 lbs. of scrubbing fluid from lines 57 - 59. The process gas stream, in admixture wi~h -the scrubbing fluid is then passed through line 60 into gas-liquid separator 70 where the ,~
product gas separates, passes through a spray stream of clean make-up California Reduced Crude Oil from line 71 at ambient -temperature. Clean product gas is removed through line 72 at the top of separator 70. In this example, there are substantially no C2 - C10 hy~rocarbons in the product gas stream. This is because the temperature of the immersion ;~ fluid in immersion vesse~ 21 is main-~ained below -the thermal cracking temperature and below the vaporization temperature for the existing pressure. The composition of the product ~as in line 72 in mole % (dry basis) is: H2 48.12; CO ~i4.99;
C2 5.89; CH4 0~33; H2S 0.36; COS 0.02; N2 0.22;
and Ar 0.07.
A pumpable liquid dispersion comprising scrubbing .
fluid, make-up oil, and 0.25 wt. % of particulate carbon is removed through line 73 at the bottom of separator 70. By ~;
means o~ pump 74, a first portion is passed through lines 75 and 57 into nozzle scrubber 56. second portion is passed through line 76 into line 42 and mixed in line 41 with the immersion fluid from line 40, as previously described. Optionally, further make up oil can be introduced .into line 42 through line 77, valve 78 and line 79.

~8~4 EXAMPLE II
This is carried out in the apparatus shown schematically in Fig. 2 of ~he accompanying Drawings. The same reference numerals as in Fig. 1 have been used where appropriate. ~-On an hourly basis about 2000 lbs. of an oil-carbon feed dispersion in line la at a *emperature of about 300F. is passed into line 1 where ;t is mixed with 500 lbs. of by-product noxious water at a -temperature of about 200F. ~rom line 65.
The by~produot water acts as a temperature moderator in the ~;~ ensuing reaction. The feed mixture in line 1 is passed through ;
burner 4 by way of flanged inlet 2 and outer annulus 7. .
Burner 4 extends downwardly into upper port 8 of refraetory~
lined gas generator 9. The oil-carbon dispersion has a `
solids content of about 3.6 weight % of particulate carbon.
Theooil in said dispersion is the same as in Example I.
Simultaneously, 2254 lbs. of substantially pure oxygen in line 10 at a temperature of about 300F. is passed through central passage 15 o~ burner 4. The reactant streams converge at the tip of -the burner where atomization of the fuel and dispersal in the oxidant takes place.
Partial oxidation of the ~uel takes place. In reaction zone 16 of gas generator 9, at an autogenousstemperature of about 2520F, and a pressure of about 28 atmoæpheres.
107,600 standard cubic feet per hour (SCFH) of effluent gas leave the gas generator by way of exit port 17 and directly passes ., ' '~, 47~

down through dip tube 18 and ~as in Example I) is discharged below the surface 19 of the pool of oil-carbon dispersion 20 contained in vertical oil immersion vessel 21. The arrangement of the dip tube, and -the means for cooling the immersion fluid, and for removing solid residues and cooled product gas are substantially the same as in Fig. 1 and will not be described in detail.
The temperature of the immersion fluid 20 is reduced by removing about 38,500 lbs. of the immersion fluid at a temperature of about 500F. and containing about 4.0 wt. % of particulate carbon through line 38. It is then passed through cooler 39 and lines 40-41. About 1,950 lbs.
of fresh California Reduced Crude make-up fluid from line 42 are mixed in line 41 with cooled immersion fluid ;
from line 40. By means of pump 43, about 38,500 lbs. of this mixture of fluids at a temperature of about 300F. are pumped through lines 44 and 45 into the top of immersion vessel 21 as said immersion fluid. About 2,000 lbs. of the mixture of fluids in line 44 are passed through line 46, valve 47, and lines la and 1 as previously described. As in Example I, cooler 39 may be located in line 45, so that a portion of the hot mixture of fluid in line 44 may be intro-duced into gas generator 9 by way of lines 46, la and 1, as at least a portion of the feed without being substantially cooled. By this means make-up oil may be preheated by contact with hot immersion fluid. Optionally, a portion of the mixture of fluids in line 44 may be passed through line ~8, valve 49, and line 50 and used as a heating fuel.
The process gas stream is removed from space 26 at the top of immersion vessel 21 and is passed through line 55 into conventional nozzle scrubber 56 where it is scrubbed with -100 lbs. of by-product water scrubbing fluid ~, from lines 57, 58~and 59 in order to remove any entrained - particulate carbon remaining in the process gas stream.
Preferably, a portion of the by-product water may be passed through line 63 and valve 64, and introduced into the burner through lines 65 and 1, as previously described. The process ~;
gas stream, in admixture with the scrubbing fluid is then passed through line 60 into cooler 61, where the temperature of the process stream is reduced to below the condensation temperature of wa-ter and any C5 - C10 jhydrocarbons that may be present.
From cooler 61 the process stream is passed through line 62 into gas-liquid separator 70, where the product gas separates from the liquids present. Before leaving separator 70, the ;~
product gas receives a final scrubbing with fresh make-up water at ambient temperature from line 71. Clean product gas is removed through line 72 at the top o~ separator 70. In this example there are substantially no C2 - C10 hydrocarbons in the product gas s-tream~ This is because the temper~ture of the immersion fluid in immersion vessel 21 is maintained below the thermal cracking temperature and below the vaporization temperature for the existing pressure. The composition of the product gas in line 72 in mole % (dry basis) is: H2 45.14; CO 51.30; CO2 2,62; CH4 0.22;
H2S 0.38; COS 0.02; N2 0.24; and Ar 0.08.
- Optionally, the product gas in line 72 may be fuel gas with a gross heating value in the range of about 400 to 7 00 BTU per SCF. This may be accomplished by operating quench tank 21 at a temperature above the thermal cr~cking temperature so that from about 10 to 40 mole % of Cl - C~ ;
gaseous hydrocarbons become mixed in the product gas.
A pumpable liquid dispersion scrubbing fluid comprising noxious by-product wate~, in admixture with make-up water and 0.2 wt. % of particulate carbon is removed through line 73 at the bottom of soparator 70. By means of pump 74, a first portion is passed through line 57 into nozzle scrubber 56.
second portion of the nozzle scrubbing fluid may be passed into line 63, valve 64, line 65 and mixed in line 1 with the oil-carbon dispersion from line la, as previously described. Any C5 - C10 liquid hydrocarbons may be drawn off through line 66 and burned in the gas generator as a portion of the feed.

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Claims

The embodiments of the invention in which an ex-clusive property or privilege is claimed are defined as follows:

1. A process for the production of clean synthesis gas or fuel gas which comprises:
(a) partial oxidation of a feed comprising a dis-persion of particulate carbon in a liquid hydro-carbonaceous fuel with a free-oxygen-containing gas in a free flow, unpacked gas generator, at a temperature of from 1300 to 3000°F., and a pres-sure of from 1 to 250 atmospheres, to produce an effluent gas stream comprising H2, CO, CO2, H2O
and entrained particulate carbon;
(b) cooling the effluent gas stream in a quench zone to a temperature of from 300 to 900°F., but above the dew point of water in the effluent gas stream, and simultaneously removing the entrained par-ticulate carbon, by discharging the effluent gas stream directly into a body of immersion fluid comprising a dispersion of particulate carbon in liquid hydrocarbonaceous fuel, and recovering a clean gaseous stream comprising H2, CO, CO2, and H2O;
(c) cooling at least a portion of the thus heated immersion fluid to a temperature of from 300 to 850°F. by indirect heat exchange, and recycling at least a portion of the resulting cooled immersion fluid to the quench zone; and (d) introducing a portion of the hot immersion fluid produced in step (b) or a portion of the cooled immersion fluid into the gas generator as at least a portion of the feed.

2. A process as claimed in Claim 1, wherein the partial oxidation is carried out in the presence of a temperature moderator.

3. A process as claimed in Claim 2, wherein the temperature moderator is H2O, CO2, flue gas, cooled and recycled effluent gas from the gas generator, or a mixture thereof.

4. A process as claimed in Claim 2 or 3, wherein the temperature moderator and liquid hydrocarbonaceous fuel are employed in a weight ratio temperature moderator/liquid hydrocarbonaceous fuel of up to 3.0:1.

5. A process as claimed in Claim 1 wherein the clean gaseous stream is further purified by scrubbing in a scrubber with a scrubbing fluid comprising liquid hydrocarbonaceous fuel; an effluent stream from the scrubber is introduced into a gas-liquid separator; clean product gas and a separate stream of scrubbing fluid are removed from the separator;
a first portion of the scrubbing fluid is recycled to the scrubbing zone; a second portion of the scrubbing fluid is mixed with a portion of immersion fluid being recycled; and additional liquid hydrocarbonaceous fuel is introduced into the separator or into a stream of scrubbing fluid from the separator.

6. A process as claimed in Claim 1, wherein the clean gaseous stream is further purified by scrubbing in a scrubber with a scrubbing fluid comprising water; an effluent stream from the scrubber is introduced into a gas-liquid separator;
by product water, and clean product gas are recovered from the separator and separate portions of by-product water are recycled to the gas generator as temperature moderator, and to the scrubber as scrubbing fluid.

7. A process as claimed in Claim 6, wherein make-up water is incorporated in recycled water from the separator.

8. A process as claimed in Claim 6, wherein effluent from the scrubber is cooled before it is passed to the separator.

9. A process as claimed in Claim 1, wherein the clean gaseous stream from the quench zone contains normally liquid C5 - C10 hydrocarbons, and these hydro-carbons are recovered from the separator.

10. A process as claimed in Claim 1, wherein the liquid hydrocarbonaceous fuel employed in step (a) and/or step (b) is a petroleum distillate or residuum, gas oil, residual fuel, reduced crude, whole crude, asphalt, coal tar, coal oil, shale oil, tar sand oil, or a mixture thereof.

11. A process as claimed in Claim 1, wherein the hydro-carbonaceous fuel is a pumpable slurry of solid carbonaceous fuel.

12. A process as claimed in Claim 1, wherein the free-oxygen-containing gas is air, oxygen-enriched air containing at least 22 mole % of oxygen, or substantially pure oxygen containing at least 95 mole % of oxygen.

13. A process as claimed in Claim 1, wherein the immersion fluid comprises up to 50 weight % of particulate carbon.

14. A process as claimed in Claim 1, wherein the quench zone contains 30 to 60 gallons of immersion fluid maintained at a temperature of 300 to 850°F for each 1000 Standard Cubic Feet of effluent gas from the gas generator that is directly quenched therein.

15. A process as claimed in Claim 1, wherein the cooling of the hot immersion fluid is effected by indirect heat exchange with H2O thereby producing steam.

16. A process as claimed in Claim 1, wherein the clean gaseous stream from the quench zone contains from nil to 40 mole % of C1 - C10 hydrocarbons.