CA1126031A - Coal gasification process - Google Patents

Coal gasification process

Info

Publication number
CA1126031A
CA1126031A CA354,223A CA354223A CA1126031A CA 1126031 A CA1126031 A CA 1126031A CA 354223 A CA354223 A CA 354223A CA 1126031 A CA1126031 A CA 1126031A
Authority
CA
Canada
Prior art keywords
gas
gas stream
stream
tube
quench
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired
Application number
CA354,223A
Other languages
French (fr)
Inventor
Paul N. Woldy
James F. Beall
Michael M. Dach
Harold C. Kaufman
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Texaco Development Corp
Original Assignee
Texaco Development Corp
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Texaco Development Corp filed Critical Texaco Development Corp
Application granted granted Critical
Publication of CA1126031A publication Critical patent/CA1126031A/en
Expired legal-status Critical Current

Links

Classifications

    • CCHEMISTRY; METALLURGY
    • C10PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
    • C10JPRODUCTION OF PRODUCER GAS, WATER-GAS, SYNTHESIS GAS FROM SOLID CARBONACEOUS MATERIAL, OR MIXTURES CONTAINING THESE GASES; CARBURETTING AIR OR OTHER GASES
    • C10J3/00Production of combustible gases containing carbon monoxide from solid carbonaceous fuels
    • C10J3/02Fixed-bed gasification of lump fuel
    • C10J3/06Continuous processes
    • C10J3/08Continuous processes with ash-removal in liquid state
    • CCHEMISTRY; METALLURGY
    • C10PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
    • C10JPRODUCTION OF PRODUCER GAS, WATER-GAS, SYNTHESIS GAS FROM SOLID CARBONACEOUS MATERIAL, OR MIXTURES CONTAINING THESE GASES; CARBURETTING AIR OR OTHER GASES
    • C10J3/00Production of combustible gases containing carbon monoxide from solid carbonaceous fuels
    • C10J3/46Gasification of granular or pulverulent flues in suspension
    • C10J3/48Apparatus; Plants
    • C10J3/485Entrained flow gasifiers
    • CCHEMISTRY; METALLURGY
    • C10PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
    • C10JPRODUCTION OF PRODUCER GAS, WATER-GAS, SYNTHESIS GAS FROM SOLID CARBONACEOUS MATERIAL, OR MIXTURES CONTAINING THESE GASES; CARBURETTING AIR OR OTHER GASES
    • C10J3/00Production of combustible gases containing carbon monoxide from solid carbonaceous fuels
    • C10J3/72Other features
    • C10J3/74Construction of shells or jackets
    • CCHEMISTRY; METALLURGY
    • C10PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
    • C10JPRODUCTION OF PRODUCER GAS, WATER-GAS, SYNTHESIS GAS FROM SOLID CARBONACEOUS MATERIAL, OR MIXTURES CONTAINING THESE GASES; CARBURETTING AIR OR OTHER GASES
    • C10J3/00Production of combustible gases containing carbon monoxide from solid carbonaceous fuels
    • C10J3/72Other features
    • C10J3/78High-pressure apparatus
    • CCHEMISTRY; METALLURGY
    • C10PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
    • C10JPRODUCTION OF PRODUCER GAS, WATER-GAS, SYNTHESIS GAS FROM SOLID CARBONACEOUS MATERIAL, OR MIXTURES CONTAINING THESE GASES; CARBURETTING AIR OR OTHER GASES
    • C10J3/00Production of combustible gases containing carbon monoxide from solid carbonaceous fuels
    • C10J3/72Other features
    • C10J3/82Gas withdrawal means
    • C10J3/84Gas withdrawal means with means for removing dust or tar from the gas
    • CCHEMISTRY; METALLURGY
    • C10PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
    • C10JPRODUCTION OF PRODUCER GAS, WATER-GAS, SYNTHESIS GAS FROM SOLID CARBONACEOUS MATERIAL, OR MIXTURES CONTAINING THESE GASES; CARBURETTING AIR OR OTHER GASES
    • C10J3/00Production of combustible gases containing carbon monoxide from solid carbonaceous fuels
    • C10J3/72Other features
    • C10J3/82Gas withdrawal means
    • C10J3/84Gas withdrawal means with means for removing dust or tar from the gas
    • C10J3/845Quench rings
    • CCHEMISTRY; METALLURGY
    • C10PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
    • C10JPRODUCTION OF PRODUCER GAS, WATER-GAS, SYNTHESIS GAS FROM SOLID CARBONACEOUS MATERIAL, OR MIXTURES CONTAINING THESE GASES; CARBURETTING AIR OR OTHER GASES
    • C10J3/00Production of combustible gases containing carbon monoxide from solid carbonaceous fuels
    • C10J3/72Other features
    • C10J3/86Other features combined with waste-heat boilers
    • CCHEMISTRY; METALLURGY
    • C10PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
    • C10KPURIFYING OR MODIFYING THE CHEMICAL COMPOSITION OF COMBUSTIBLE GASES CONTAINING CARBON MONOXIDE
    • C10K1/00Purifying combustible gases containing carbon monoxide
    • C10K1/02Dust removal
    • CCHEMISTRY; METALLURGY
    • C10PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
    • C10KPURIFYING OR MODIFYING THE CHEMICAL COMPOSITION OF COMBUSTIBLE GASES CONTAINING CARBON MONOXIDE
    • C10K1/00Purifying combustible gases containing carbon monoxide
    • C10K1/02Dust removal
    • C10K1/026Dust removal by centrifugal forces
    • CCHEMISTRY; METALLURGY
    • C10PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
    • C10KPURIFYING OR MODIFYING THE CHEMICAL COMPOSITION OF COMBUSTIBLE GASES CONTAINING CARBON MONOXIDE
    • C10K1/00Purifying combustible gases containing carbon monoxide
    • C10K1/04Purifying combustible gases containing carbon monoxide by cooling to condense non-gaseous materials
    • CCHEMISTRY; METALLURGY
    • C10PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
    • C10JPRODUCTION OF PRODUCER GAS, WATER-GAS, SYNTHESIS GAS FROM SOLID CARBONACEOUS MATERIAL, OR MIXTURES CONTAINING THESE GASES; CARBURETTING AIR OR OTHER GASES
    • C10J2300/00Details of gasification processes
    • C10J2300/09Details of the feed, e.g. feeding of spent catalyst, inert gas or halogens
    • C10J2300/0913Carbonaceous raw material
    • C10J2300/093Coal
    • CCHEMISTRY; METALLURGY
    • C10PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
    • C10JPRODUCTION OF PRODUCER GAS, WATER-GAS, SYNTHESIS GAS FROM SOLID CARBONACEOUS MATERIAL, OR MIXTURES CONTAINING THESE GASES; CARBURETTING AIR OR OTHER GASES
    • C10J2300/00Details of gasification processes
    • C10J2300/09Details of the feed, e.g. feeding of spent catalyst, inert gas or halogens
    • C10J2300/0913Carbonaceous raw material
    • C10J2300/0943Coke
    • CCHEMISTRY; METALLURGY
    • C10PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
    • C10JPRODUCTION OF PRODUCER GAS, WATER-GAS, SYNTHESIS GAS FROM SOLID CARBONACEOUS MATERIAL, OR MIXTURES CONTAINING THESE GASES; CARBURETTING AIR OR OTHER GASES
    • C10J2300/00Details of gasification processes
    • C10J2300/09Details of the feed, e.g. feeding of spent catalyst, inert gas or halogens
    • C10J2300/0913Carbonaceous raw material
    • C10J2300/0946Waste, e.g. MSW, tires, glass, tar sand, peat, paper, lignite, oil shale
    • CCHEMISTRY; METALLURGY
    • C10PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
    • C10JPRODUCTION OF PRODUCER GAS, WATER-GAS, SYNTHESIS GAS FROM SOLID CARBONACEOUS MATERIAL, OR MIXTURES CONTAINING THESE GASES; CARBURETTING AIR OR OTHER GASES
    • C10J2300/00Details of gasification processes
    • C10J2300/09Details of the feed, e.g. feeding of spent catalyst, inert gas or halogens
    • C10J2300/0953Gasifying agents
    • C10J2300/0956Air or oxygen enriched air
    • CCHEMISTRY; METALLURGY
    • C10PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
    • C10JPRODUCTION OF PRODUCER GAS, WATER-GAS, SYNTHESIS GAS FROM SOLID CARBONACEOUS MATERIAL, OR MIXTURES CONTAINING THESE GASES; CARBURETTING AIR OR OTHER GASES
    • C10J2300/00Details of gasification processes
    • C10J2300/09Details of the feed, e.g. feeding of spent catalyst, inert gas or halogens
    • C10J2300/0953Gasifying agents
    • C10J2300/0959Oxygen
    • CCHEMISTRY; METALLURGY
    • C10PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
    • C10JPRODUCTION OF PRODUCER GAS, WATER-GAS, SYNTHESIS GAS FROM SOLID CARBONACEOUS MATERIAL, OR MIXTURES CONTAINING THESE GASES; CARBURETTING AIR OR OTHER GASES
    • C10J2300/00Details of gasification processes
    • C10J2300/09Details of the feed, e.g. feeding of spent catalyst, inert gas or halogens
    • C10J2300/0953Gasifying agents
    • C10J2300/0969Carbon dioxide
    • CCHEMISTRY; METALLURGY
    • C10PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
    • C10JPRODUCTION OF PRODUCER GAS, WATER-GAS, SYNTHESIS GAS FROM SOLID CARBONACEOUS MATERIAL, OR MIXTURES CONTAINING THESE GASES; CARBURETTING AIR OR OTHER GASES
    • C10J2300/00Details of gasification processes
    • C10J2300/09Details of the feed, e.g. feeding of spent catalyst, inert gas or halogens
    • C10J2300/0953Gasifying agents
    • C10J2300/0973Water
    • CCHEMISTRY; METALLURGY
    • C10PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
    • C10JPRODUCTION OF PRODUCER GAS, WATER-GAS, SYNTHESIS GAS FROM SOLID CARBONACEOUS MATERIAL, OR MIXTURES CONTAINING THESE GASES; CARBURETTING AIR OR OTHER GASES
    • C10J2300/00Details of gasification processes
    • C10J2300/09Details of the feed, e.g. feeding of spent catalyst, inert gas or halogens
    • C10J2300/0953Gasifying agents
    • C10J2300/0973Water
    • C10J2300/0976Water as steam
    • CCHEMISTRY; METALLURGY
    • C10PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
    • C10JPRODUCTION OF PRODUCER GAS, WATER-GAS, SYNTHESIS GAS FROM SOLID CARBONACEOUS MATERIAL, OR MIXTURES CONTAINING THESE GASES; CARBURETTING AIR OR OTHER GASES
    • C10J2300/00Details of gasification processes
    • C10J2300/16Integration of gasification processes with another plant or parts within the plant
    • C10J2300/1671Integration of gasification processes with another plant or parts within the plant with the production of electricity
    • C10J2300/1675Integration of gasification processes with another plant or parts within the plant with the production of electricity making use of a steam turbine
    • CCHEMISTRY; METALLURGY
    • C10PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
    • C10JPRODUCTION OF PRODUCER GAS, WATER-GAS, SYNTHESIS GAS FROM SOLID CARBONACEOUS MATERIAL, OR MIXTURES CONTAINING THESE GASES; CARBURETTING AIR OR OTHER GASES
    • C10J2300/00Details of gasification processes
    • C10J2300/18Details of the gasification process, e.g. loops, autothermal operation
    • C10J2300/1807Recycle loops, e.g. gas, solids, heating medium, water
    • CCHEMISTRY; METALLURGY
    • C10PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
    • C10JPRODUCTION OF PRODUCER GAS, WATER-GAS, SYNTHESIS GAS FROM SOLID CARBONACEOUS MATERIAL, OR MIXTURES CONTAINING THESE GASES; CARBURETTING AIR OR OTHER GASES
    • C10J2300/00Details of gasification processes
    • C10J2300/18Details of the gasification process, e.g. loops, autothermal operation
    • C10J2300/1807Recycle loops, e.g. gas, solids, heating medium, water
    • C10J2300/1823Recycle loops, e.g. gas, solids, heating medium, water for synthesis gas
    • CCHEMISTRY; METALLURGY
    • C10PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
    • C10JPRODUCTION OF PRODUCER GAS, WATER-GAS, SYNTHESIS GAS FROM SOLID CARBONACEOUS MATERIAL, OR MIXTURES CONTAINING THESE GASES; CARBURETTING AIR OR OTHER GASES
    • C10J2300/00Details of gasification processes
    • C10J2300/18Details of the gasification process, e.g. loops, autothermal operation
    • C10J2300/1846Partial oxidation, i.e. injection of air or oxygen only

Abstract

COAL GASIFICATION PROCESS
(D#76,476 -F) ABSTRACT
Coal or other high ash containing carbonaceous solid fuel is reacted with a free-oxygen containing gas, with or without a temperature moderator, in a down-flow partial oxidation gas generator to produce a stream of raw synthesis gas, fuel gas, or reducing gas. A large portion of the combustion residue, i.e., molten slag and/or particulate solids that is entrained in the down-flowing generated gas stream is removed by gravity when the gas stream is passed through a diversion chamber where the velocity of the gas stream is reduced and its direction is diverted. The separated solid material and molten slag pass down through an outlet in the bottom of the diversion chamber and into a pool of quench water below. Preferably, a small portion of the hot gas stream is passed through the bottom outlet of the diversion chamber to prevent plugging. The main gas stream leaving the diversion chamber through the side outlet passes upward through a solids separation zone, optionally including gas-gas quench cooling, cyclones, filters, im-pingement separators, or combinations thereof, where ad-ditional entrained solids are removed and where some cooling of the gas stream may be effected by impingement with a cooled cleaned recycle portion of the gas stream. Next, most of the sensible heat in the gas stream is recovered by the production of steam. The gas stream, with a substantially reduced solids content, is passed through the tubes of one or more shell-and-straight fire tube gas coolers. Each gas cooler has one or more passes on the shell and tube sides and is preferably in an upright position with fixed tube sheets.

Description

3~L

BACKGROUN~ OF THE rN~ENTION
.
Field of the invention This invention relates to the manufacture of cooled and cleaned gaseous mixtures comprising ~2 and CO.
More particularly lt pertains to a process ~or the manufac-ture of a cooled and cleaned s~ream of synthesis gas, ~uel gas, or reducing gas by the partial oxidation of ash con-taining solid carbonaceous ~uels.
Description of the Prior Art The hot raw gas stream leaving a gas generator in which an ash containing solid fuel is burned will contain various amount~ of molten slag and/or solid material such a~
soot and ash. It will often be necessary, depending on the intended use for the gas, to reduce the concentration of these e~trained solid materials. By removing solids from the gas stream, one may increase the life of apparatus located downstream that is contacted by the raw gas stream. For example, the life of such equipment as gas coolers, com-pressors, and turbin2s, may be increased.
In co-assigned U.S. Patent 2,871,114-Du ~oi:s Eastman, the hot raw gas stream leaving ~he gas generator is direeted into a slag pot and then into a quench accumulator vessel where all of the ash is iIltimately contacted with water. All of the sensible heat in the gas stream is there-by dissipated in the quench water at a comparatively low temperature level; and the gas stream leaving the quench tank is saturated with H2O. U.S. Patent 3,988,123 provides for a vertical 3-stage gasifier including a combustio~
~tage, an intermeaiate cooling stage, and a heat recovery stage. In such a scheme not only-is a portion o the sensible (33'1 heat in the hat gases leaving the combustion stage lost in the cooling stage but small partioles of solidi~ied ash tend to plug the tubes in the boiler located under the gas generator. Other waste heak boilers have been proposed for use in recovering heat ~rom gases, for example, the apparatus described in U.S. Patent 2,967,515 in which helically coiled tubes are employed. Waste-heat boilers containing a com-bination o straight and helical, spiral, and surpe~tine coiled heat exchange tubes are also used. Boilers of such general design are high in cost. Further, the sharp bends in such coils make the tubes vulnerable to plugging, dif~i-cult to remove and replace, and expensive to clean and maintain.

SIJMMARY OF THE IN~IENTION
This invention pertains to a cantinuGus ~rocess for the partial oxidation of an ash containing solid carbonaceous fuel for producing a cool clean stream of synthesis gas, uel gas, or reducing gas. Particles of solid carbonaceous fuel are reacted with a free-oxygen containing gas, with or without a temperature moderator, i~ a down-flow refractory lined noncatalytic free-flow gas generator at a temperature in the range of about 1700 to 3100F and a pressure in the range of about 10 to 200 atmospheres to produce a raw gas stream comprising ~2' CO, CO2, and one or more materials g P ~2' ~2S, C~S~ ~4~ ~3, N2, A, and con-taining molten slag and/or particulate matter. The direction of flow of the hot raw gas stream leaving the gas generator is diverted ir. a gas diversion chamber so that a large portion of the slag and/or particulate matter is separated from the gas stream by gravity. The separated slag and/or particulate matter passes through an outlet in the bottom of the diversion chamber into a quench chamber located below.
About 0 to 20 vol. % of the hot gas stream may be passed through the bottom outlet of the gas diversion cham~er as a bleedstream to prevent bridging of the opening with solids and plugging. The remainder of the gas stream is passed upward through an antechamber where solids separation and, optionally, guench cooling takes place. In the lower section of th~ antechamber, the gas stream may be directly Lmpi~ged wi~h a recycle portion of coaled and cleaned product gas.
The gas stream is thereby partial~y cooled, partially solidifying any molten slag, and a portion of the entrained solids settle out. In the upper saction of the antechamber, additional entrained solids are removed from the gas stream.
While the upper chamber may be empty, preferably, one or more of the following gas-solids separation means may be located there: cyclone, impingement separator, filter, and combinations thereof.
The hot gas stream leaving the antachamber may be passed through additional gas-solids separation means located downstream from the antechamber. The cleaned gas stream is cooled by indirect heat exchange with a coolant, i.e., boiler feed water in a main cooling zoneO Most of ~he sensible heat in the hot raw gas stream may be there~y used to produce high pressure steam. The main gas cooling zone comprises one or more shell-and-straight fire tube gas coolers. Each gas cooler has one or more passes on the shell and tube sides, and preferably is in an upright position with ~ixed tube sheet~

3~

-3a-In one aspect the invention provides a process for the partial oxidation of an ash-containing solid carbon-aceous fuel for producing a cooled cleaned product gas stream of synthesis gas, fuel gas or reducing gas and by-product steam comprising:
(1) reacting particles of said solid fuel with a free-oxygen containing gas and with or without a temperature moderator in a down~flow refractory lined gas generator at a temperature in the range of about 1700 to 3100F. and a pressure in the range of about lO to 200 atmospheres to produce a raw gas stream comprising H2, C0, CO2, and one or more materials selected from the group consisting of H2O, H2S, COS, CH4, NH3, N2, and A, and containing molten slag and/or particulate matter;
(2) passing the gas stream from (l) down through the central outlet in the bottom of the reaction zone and into a thermally insulated diversion chamber provided with a side outlet and a bottom outlet; separating by gravity molten slag and/or particulate matter from said gas stream;
passing from about 0 to 20 vol. g~ of said gas stream as bleed gas along with said separated material through the bottom outlet of said diversion chamber and into a pool of quench water in a quench chamber located below said diversion chamber; and passing the remainder of said gas stream through a side exit passage in said divers;`Qn chambex directly through a thermally insulated tran$fer line and inlet passage of a separate thexmally insulated gas-ga$ quench cooling and solids separation:zone at substantially the same -3a~

~,~
3~

-3b-temperature and pressure a$ produced in s.tep (11 less ordinary pressure drop in the lines;
(3) impinging the gas stream from (2) in said gas-gas ~uench cooling and solids separation ~one with a stream of recycle quench gas comprising cooled cleaned and compressed product gas from (7), thereby partially cooling the gas stream from (2) partially solidifying entrained molten slag, and separating from the gas stream a portion of the slag and particulate matter; and passing the partially cooled gas stream up through a separate thermally insulated upper chamber located above and communicating with said gas-gas quench cooling and solids separation zone and removing additional entrained solids from the gas stream;
(4) cooling the gas stream from (3) in a main gas cooling zone and producing by-product steam by passing said gas stream in indirect heat exchange wlth preheated boiler feed water first upward through the tubes of a verti~al high temperature shell-and-straight fire tube gas cooler having refractory lined inlet and outlet sections, one pass on the shell and tube sides and having fixed tube sheets, then passing the gas stream down through the tubes in the first tube-side pass o~ a vertical low temperature shell-and-straight fire tube gas cooler having two passes on the tube-side and one pass on the shell-side and having ~ixed tube sheets, and then upward through the tubes in the second tube-side pass o~ said second gas cooleri and wherein by-product s:team..~$ ~emoyed ~o~ t~ s.hell-s.ides of $aid fi.~st and second gas coolers; and preheating boile~ feed water for use in (4) by indirect heat exchange ~ith the gas - -3b-~., -3c-stream leaving said second gas cooler;
(5) cooling, and scrubbing the gas stream from ~4) wi.th water in ~as cooling and scrubbing zones producing a carbon-water dispersion;
(6) cooling the gas stream from (5) below the dew point and separating condensed water to produce said cooled, cleaned stream of product gas; and
(7) compressing a portion of said product gas stream from (6) and introducing same into said gas-gas quench cooling and solids separation zone in (3) as said stream of recycle quench gas.
In another aspect the invention provides a process for the partial oxidation of an ash-containing solid carbonaceous fuel for producing a cooled cleaned product gas stream of synthesis gas, fuel gas or reducing gas and by-product steam comprising:
(1) reacting particles of said solid fuel with a free-oxygen containing gas and with or without a temperature moderator in a down-flow refractory lined gas generator at a temperature in the range of about 1700 to 3100F. and a pressure in the range of about 10 to 200 a~mospheres to produce a raw gas stream comprising H2, CO, CO2, and one or more materials selected from the group consisting of H2O, H2S, COS, CH4, NK3, N2, and A, and containing molten slag and/or particulate matter;
(2) passing the gas stream ~rom (lL do~n through the central outlet in the bcttom of the: ~eacti.on zone and into a separ~te thermally ~ns.ulated di.~e.rs~on chamber provided with bottom and side outlets; separating ~y graV~ty molten -3c-7~

2 ~ 3' -3d-slag and~or particulate matter fro~ said gas stream; passing from about ~ to 20 vol. ~ of said gas stream as bleed gas along with said separated material through the bottom outlet of said diversion chamber and into a pool of quench water in a quench chamber located below said diversion chamber; and passing the remainder o~ said gas stream throuyh a side exit passage in said diversion chamber directly through a thermally insulated vertical gas-solids separation zone comprising upper and lower communicating chambers, at substantially the same temperature and pressure as produced in step (1) less ordinary pressure drop in the lines;
(3) passing the gas stream from (2) up through said gas-solids separation zone separating from the gas stream by gravity in said lower chamber a portion of -the slag and/or particulate matter; removing additional entrained solids from the gas stream in said upper chamber with or without one or more solids separation means selected from the group consisting of cyclone, impingement separator, filter and combinations thexeof;
(4) cooling the gas stream from (3~ in a main gas cooling zone and producing by-product steam by passing said gas stream in indirect heat exchange with preheated boiler feed water first upward through the tubes of a vertical high temperature shell~and-stxaight first-tube gas cooler having refractory lined i,nlet and outlet sections, one pass on the shell and tu~e s~des~and hav~,ng f~xed tube sheets, then pas.s~ng the gas s,tre.am down through the tubes in the first tube-si:de pass of a verti`cal low temperature shell-and-straight ~re tube gas cooler hav~ng two passes -3d-~i. . ~a 3'~

-3e-on the tube-side and one pass on the shell-side and having fixed tube sheets, and then upward through the tubes in the second tube-side pass of said second gas cooler; and wherein by-product steam is removed from the shell-sides of said first and second gas coolers; and preheating boiler feed water for use in (4) by indirec-t heat exchange with the gas stream leaving said second gas cooleri (5) cooling and scrubbing the gas stream from ~4) with water in gas cooling and scrubbing zones producing a carbon-water dispersion; and (6) cooling the gas stream from (5) below the dew point and separating condensed water to product said cooler, cleaned stream of product gas.

~ 3 ~
In a preferrad embodiment, the hot gas stream is cooled by being passed serially through two such vertical gas coolers connected in series. By-product steam is there~y produced in the tt~o gas coolers which may be used elsewhere in the process or exported. The fir~t gas cooler comprises a shell-and-~traight fire tube heat exchanger with fixed tube sheets and one pass on the shell and tube sides.
The design o the second gas cooler is si~ilar to that of the first. ~wever, the second gas cooler is provided with 1~ two passe~ on the tube-side and one pass on the ~hell-side.
The hot gases flow up through the single bundle a tubes in the first gas cooler and then pass out of the first gas cooler and in~o the lef~ side of the top head of the second gas cooler. ~he gas stream then passes down through the tubes in the first tube-side pass of the second gas cooler, and then up through the tubes in the second tube-side p~ss.
The cooled ga~ stream then passes out through the right side of the top head of the second gas cooler. After leaving the main gas cooling zone, further cleaning and cooling of the gas stream with water is ef~ected in a downst~eam cooling and scrubbing zona. A car~on-water dispersion and a clean product ga~ stream is ther~by produced. ~rom abaut 0 to 80 mol percent of the clean product gas stream may be recycled to the antechambex for gas-gas quench cooling.

BRIEF DESCRIPTION OF T~E DRAWING
The invention will be ~urther understood by re-ference to the accompanying drawing in which:
Fig. 1 is a schematic drawing which shows the subject proc~ss in detail.

6U3~

DESC~IPTION OF THE INVENTION
The present invention pertains t~ an Lmproved con~in~
process for cooling and cleaning a hot raw gas stream principally comprising H2, CO, CO2, and one or more materials from the group H20, H2S, COS, CH4, NH3, N2, A and containing molten slag and/or entrained solid matter. The hot raw gas stream is made by the partial oxidation of an ash containing solid car~onaceQus fuel, such as coal. By means of the -ubjest invention the combustion residues entrained in the raw gas stream from the gas generator may be partially solidified and reduced to acceptable levels of conoentration and particle size. This gas may be used as synthesis gas, fuel ga~, or reducing gas.
The thermal efficiency of the partial oxidation gassification proce3s i9 increased by recovering energv from the hot raw gas stream. Thus, by-product steam for use in the process or for export may be produced by heat exchange of the hot gas stream with water in a gas cooler. Energy recovery, however, is made dif ficult by the presence in the generator e~haust gases of droplets of molten slag and/or particulate solids. In the instant inventi~n; the molten slag droplets are partially solidified and removed before they encounter heat exchange surfaces. By partially solidi-fying the slag particles before they impinge on solid sur-faces, and/or by removing particulate solids entrained in the gas stream common problems with fouling of gas coolers are avoided. Solid surfac2s are removed from the point of inception of slag cooling. Comparatively, sLmple low cost gas coolers are employed _or heat exchange. By means of the subject invention, the reoovery of thermal energy from the hot gases is simplified.

_5 ~ ?~3~
i~ile the subject invention may be used to process the hot raw ef~luent gas stream from almost any type of gas generator, it is particularly suîtable for use downstream of a partial oxidation gas generator. An example of such a gas generator is shown and described in coassigned United States Patent No. 2,871,11~. A burner ls located in the upper portion of the gas generator for introducillg the ~eedstreams. A typic~l annulus type burner is shown in coassigned United States Patent No.
2,928,460.
The free-flow unobstructed reaction zone of the gas generator is contained in a vertical cylindrical steel pressure vessel lined on the inside with a thermal refractory material. Preferably, the pressure vessel may comprise the following three communicating sections: (1) reaction zone, (2) gas diversion chamber, and (3) quench chamber. The central vertical axes of the three sections are preferably coaxial. Alternately, said three sections may be contained in two or three separate pressure vessels connected in series. In the main embodiment, ths reaction zone is located in the upper portion of a pressure vessel; the gas diversion chamber is located about in the center p~rtion of the same vessel; and, the quench chamber is located in the bottom portion of the same vessel below the gas diversion chamber.
In the gas diversion chamber, a portion of the molten slag and/or particulate matter, separate out by gravity from the hot gas stream and pass through a bottom outlet into the quench chamber. The main gas stream is diverted away from the inlet to the quench chamber which is located below the gas diversion chamber and into a side exit passage. The quench chamber contains water for quench cooling the slag ~.1 1 ~J~'~ 3~

and/or particulate matter i.e., unconverted carbon, ash.
51ag, particulate matter, and water are removed from the bot~om of the ~uench chamber by way of an outlet in the bottom o the vessel.
In operation, the hot raw gas stream produced in the reaction zone, leaves the reaction zone by way of a ce~ centrally located outle~ in the bottom of the reaction zone which is coaxial wi~h the centxal longitudinal axis of the g~s generator. The hot gas ~tream pa~ses through said bottom outlet and expands directly in~o the diversion chamber which is preferably located directly below the reaction zone.
The velocity of the hot gas stream is reduced and molten slag and/or particulate matter drop out o the gas stream.
This solid matter and/or molten slag move by gravity through an outlet located in the bottom of the diversion chamber into the pool of water contained in the quench chamber located below. From about 0 to 20 vol. %, such as 0.5 to 15 Yol. ~, of the raw gas stream may be drawn through the bottom outlet in the diversion chamber as a st~eam of bleed gas, thereby carrying said separated portion of molti~n slag and/or particulate matter with it. The partia}ly cooled bleed gas stream is removed ~rom the quench chamber by way of a side outlet and a cooled control valve. The hot hleed ga~ stream pa~ing through the bottom outlet in the gas diversion chamber prevents solids from building up and thereby bridging and plugging the bottom outlet. Preferably, said bottom outlet in the diversion chamber is centrally - located and coaxial with the vertical axis of the diversion chamber. Preferably, the quench chamber is located directly below the bottom outlet in the diversion chamber. -The .

~ 3~

shape of the diversion chambex may be cylindrical, or it may be outwardly diverging or expanding conically from the en-trance to an enlarged cen~ral portion followed by an inwardly converging or converging conically portion to th2 bottom and side outlets.
At least a por~ion i.e. about 80~0 to 100 vol. %
of the hot gas stream e~tering the diversion chamber is directed by the internal configuration of the diversion chamber, which may op~ionally include baffles, into a refractory lined side exit passage that is connected to an antechamber. The angle between this side exit passage and the longitudinal axis of the antechamber is in the range of about 30 to 135, such as about 45 to 105, say about 60, measured clockwise ~rom the central vertical axis o~ said antechamber starting in the third quadrant. There is substantially no drop in tempexature or pressure of the gas stream as it pa~ses through the gas diversion chamber.
The hot raw gas ~tream leaving the diversion cha~ber by way of the refrac ory llned passage enter~
directly into the inlet ~o the an~echamber where additional entrained slag and~or particulate ma~ter are removed, and, ' optionally the gas stream is partially cooled. ~ouling of the boiler tubes in the main gas cooling sec~ion is thereby reduced, minimizing maintenance problems. The antPchamber precedes the main gas cooling section, to be further descrihed.

~ 3~

While any ~uitable equipment may be used for the ante-chamb~r, a preferred arrangement comprisec a closed cylin-drical vertical pressure vessel whose inside walls are thermally insulated with high temperature resistant re-fractory. Within the vessel are two cylindrical vertical refractory lined ch~mbers that are coaxial with the central vertical axis of the ve~sel. An in~ermediate coaxial choke-ring passage connects the upper outlet of the lower chamber with the lower inle~ of the upper chamber. In one embodi-ment in which the hot raw gas stream entering the lower chamber is partially cooled by impingement with a portion of the cooled and cleaned recycle stream of product gas, the longitudinal axis o~ at least one pair o opposed coaxial internally insulated inlet nozzles passes thro~gh the walls of the lower chamber. The inlet nozzles are spaced 180~
apart and are located on opposite sides o~ the chamber. The hot raw gas stream is passed through one inlet nozzle at substantially the same temperature and pressure as that in the rsaction zone of the gas generator, less ordinary pressure drop in the lines. That is the t mperature may be in the range of about 1700 to 3100F., say about 2300 to 2800F., and typically about 2500F. The pr~ssure in the antechamber is in the range of about lO to 200 atmospheres, say about 25 to 85 atmospheres, and ~ypically about 40 atmosphexes. The inlet velocity is in the ran~e of about 10 to 100 feet per second, say about 20 to 50 feet per second, and typically about 30 feet per - second. The concentration of the solids ln the entering hot raw gas stream is in the range o~ about 0.1 to 4.0 grams (gms.) per ~tandard cubic ~oo~ (SCF3, say about _g_ 3~

O.25 to 2.0 gms pex SCF . T~e particle size may be in the range of about 40 to 1000 mlcrometers, or roughly equivalent to Stair~and's Coarse dust-Filtration and Separatlon Vol. 7, No. 1 page 53, 1970 Uplands Press Ltd., Croydon, England.
~ot raw synthesis gas containing entrained solids is passed through the inlet nozzle of the lower ~uench chamber and a comparatively cooler and cleaner recycle stream of ~uench gas produced downstream and recycled bac~ to the antechamber is passed through the opposite inlet nozzle. The two streams impinge each other within the lower chamber and the head-on collision produces a turbulent mi~ture of gases. The high turbulence re~ults in rapid mixing of the opposed ~as streams and paxticles entrained in the gas stream drop out and are removed by way o~ an outlet at the bottom of the lower ~uench chamber.
While the previous discussion pertained to a single pair of inlet nozzles, which is the usual design, a plurality of pairs of inlet nozæles, say 2 to 10, of similar description, may be employed. The pairs of nozzles may be evenly spaced around the vessela Preferably, the longi-tudinal axis of the inlet for the hot raw gas stream i5 inclined upward as shown in the drawing or downward. How-ever, depending on the nature and concentration o~ entrained solids, the longitudinaL axis for the inlet nozzle through whlch the hot raw gas pas es may be horizontal or inclined downward. Thus, the longitudinal axis of each pair of inlet nozzles is in the plane of and may be at an angle in the range of about 30 to 135 with and measured clockwise, starting in the third quadrant, from the central vertical axis of the antechamber. Suitably, this angle may be in the range of 45 to 105, say about 60; as shown in the drawing.

~ 3~

Th~ actual angle is a function of such factor~ as temp-erature and velocity of the gas streams, and the compo~ition, concentration and characteristics of the entrained matt~r to be removed. For example, when the raw gas stream contains liquid ~lag of high fluidity, the longitudinal axis of the raw ga~ inlet nozzle is pointed.upwardly at a 60 angle measured clockwise from the central vertical axis-of the antechamber. By this means, much of the slag would then run down the feed pipe and be collected in the quench chamber as previously described located below the diversion chamber.
On the other hand, when the liquid slag is viscous, the flow of the slag may be. helped by pointing the raw gas inlet nozzle downward at a small angle with the ver~ical axis o~ -the antechamber, say at about 135 with and measured cloc~-wise from the central vertical axis. The high velocity of the ho~ raw gas stream passi~g through the lnlet nozzle and the force of gravity would then help to move the viscous liquid slag into the lower chamber, where it solidifies and is separated from the gas stream by gravity.
When employed, ~he cooled cl2an recycle stream of quench gas enters through the opposite inlet nozzle and is obtained from at least a portion i.e. about 20 to 80 mol %, say about 30 to 60 mol % and typically about 50 mol ~ of cooled and cleaned product gas produced downstream. The temperature of the recycle quench gas is in the range of about 275 to 800F., say about 300 to 600F., and typically about 37QF. The mass flow rate and~or the velocity of the hot raw gas stream and the cooled cleaned recycled stream of quench gas are adjusted so that the momentum of.the two opposed ~ 3~

inlet gas streams is about the same.
The e~d~ of each pair of opposed inlet nozzles pre-ferably do not extend significantly into the chamber.
Preferably, the opposed inlet nozzles terminate in planes normal to their centerline. ~y this means, deviation of these streams from concentricity is minimized. The jets o~ gas which l~ave from the oppo~ed nozzles ~ravel about 5 to 10 ~eet, ~ay about 8 feet, bef~re they directly impinge wi~h each other. The high turbulence that ~esults in the lower chamber promotes rapid mixing o~ the gas streams. This promotes gas to particle heat trans~er. Thus, through turbulent mixing of the cooled and cooling streams o~ gas, solidification of the outer layer of the slag particles takes place before the slag can impinge on solid surfaces. A gas mixture is produced having a temperature below the initial deformation temperature of the slag entering with the ga.~ stream i.e., about 1200 to 1800F., typically about 1400F. The entrained slag is cooled and a solidified shell is formed o~ the slag particles which prevent them from sticking to th~ inside walls of the apparatus, or to any solid structural member contained therein.
In another embodiment r the amount of slag en-trained in the hot raw gas stream entering the lower chamber of the antechamber is minlmized or eliminated by control of the composition of the solid carbonaceous fuel and the temperature in the gasifier. In such case, the element of gas-gas impingement and quench cooling of the entering hot raw gas stre~m with a cooled and cleaned recycle gas stream may be advantageously minimized or 6~ 3~

completely elimlnated. In such case the gas s~ream leaves the ante~hamber at substantially the sam~ temperature as tha~ of the entering hot raw gas stream, less ordinary thermal losses. All other aspects of the antechamber are the same as that ~or the mode employing gas-gas quenching.
In one embodiment, from about 1 to 50 vol. ~ of the recycle quench gaq s~ream is introduced into the subject ga3-gas quench cooling and solids separation ~e~el by way of a plurality o~ tangential nozzles located at the top o~
the lower chamber and/or the bottom o the upper chamber. By this mean~, a swirl is imparted to the upward flowing gases which helps to direct the upwardly flowing gas stream into an additional, but op~ional, qoli~ sepaxation means, such as one or more cyclones, located in the upper solid separa~ing chamber of the ant~chamber. Additionally, this will provide a protective belt of cooler gas along the inside wall of the choke ring and above.
The bottom of the presQure vessel has a low point that is connected to the bottom outlet in the lower gas-gas quench chamber. For example, the shape o~ the bottom o~ the pressure vessel may be truncated cone, or spherically, or elliptically shaped. Solid mattPr i.e. un onverted coal, car~on particlesj carbon containing particula~e ~olids, mineral matter inclu~ing slag particles, ash, and bits of ~e~racto~y separate from the raw gas stream and fall to the bottom of the lower chamber where they are removed through an outlet at the bottom of the antechamber.
A lock-hopper system for maintaining the pressure in~the vessel is connected to the bottom outlet.

~-13-, 3~

The cho~e ring corridor joining the lower and upper chamber~ is used to dampen out the turbulence of the gas ~tream rising up in the vessel from the lower chamber.
By this means the upward flow of the gas stream i~ made orderly. In compari~on with the turbulence in the bottom chamber, the gas stream pas~ing up into the upper cha~ber is relati~ely calm. This promotes gravity settling o~ salid particles which fall down through the ~hoke ring and into the ~ottom of the lower chamber. The choke ring is pre-ferably made from a thermally resista~t refractory. Its diameter is ~maller than either the diameter o the upper or the lower chamber. The diameters of the upper and lower chamber depend on such factors as the velocity of the gas stream flowing therein and the size of the entrained par-ticles. The ratio of ~he diameter of the upper chamber (du) to the diameter of the lower chamber (dl) is in the range of about 1.0 to 1.$, such as about 1Ø The ratio of the diameter of the choke ring (dc) to the diameter o~ the lower chamber (dl) is in the range of about O . S to O . 9 such as about 0.6 to 0.8 , say 0~75, While the upper chamb~r may be empty, preferably there may be mounted within the upper chamber at l~ast one, such as 2-12, say 2 gas-solid separation means for removing at least a portion of the solid parti les remaining in the gas stream. The actua? number of such additional gas-solid separation means will depend on such factors as the dimen-sions of the upper chamber and the actual volumetric rate of the gas stream approaching the entrance to the gas-solid separation means at the top of the upper chamber. At this point, the conce~tration o~ solids is in the range of about ~ ~ 6~3'1 O.005 to 2 grams per SCF. The particle size is in the range of about 40 to 200 micrometexs. Any conventional co~-tinuous ga~-solid separation means may be employed in the uppex chamber that will remove over about 65 wt.~ of thee solid particles in the gas ~tream and which will withstand the operating conditions in the upper chamber. The pressure drop through the gas-solid separation means is preferably less than about 20 inlet velocity heads. Further, the sclids separation means should withstand hot abrasive gas streams at a temperature up to about 3000F.
Typical gas-solids separation means that may be used in the upper chamber may be selected from the group:
single-stage cyclone separator, impingement gas-solid se-para~or, filter, and combinations thereo~.
The gas-solids separators are prefera~ly of the cyclone type. A cyclone is essentially a settling cha~ber in which the force of gravity is replaced by centrifugal acceleration.
In the dry type cyclone separator, the stream of raw gas laden with particulate solids enters the cylindrical conical ~hamber tangentially at one or more entrances at the upper end. The gas path involves a double vortex with the raw gas stream spiraling downward at the outside and the clsan gas stream spiraling upward on the inside to a ¢~n~al,:or.~
concentric gas outlet tube. The clean gas stream leaves the cyclone and then passes out of the vessel through an outlet at the top. The solid particles, by virtue of their inertia, will tend to move in the cyclone toward the separator wall from which they are led into a discharye pipe by way of a central outlet at the bottom of the cyclone. The discharge pipe or dipleg extends downward within the pressure vessel 3'~

~rom the bottom of the cyclone to preferably below the longi~udinal axes of the inlet nozzles in the bottom chamber, and below the highly turbulent area. Particulate solids that are separated in the cyclone may be thereby pas~ed through the dipleg and discharged through a check valve into the bottom of the lower chamber below the ~one af vigorous mixing. The dipleg may be removed rom the path of the slag droplets by one or more o~ the following ways: keeping the dipleg close to the walls of the vessel, stxaddling the axis of the hot gas and quench gas inlet nozzles, or by putting ceramic dipless in the re~ractory wall. Alternately, the diplegs may be shor~ened to terminate anyplace above .he top of the lower chamber.
Single stage or multiple cyclone units may be em-ployed. For example, one or more single stage cyclones may be mounted in parallel within the upper chamber. The inlets to the cyclone are located in the upper por~ion of the upper cham~er, and face the stream of qas flowing therethrough.
In such case the gas outlet tubes of each cyclon2 may discharge into a common internal plenum chamber that is supported within ~he upper chamber. The cleaned gas stream exits the plenum through the gas outlet at the top o~ the upper chamber. In another embodiment, at least one multiple cyclone unit is supported within the upper chamber. In such case, the partially clean gas stream that is discharged from a first internal cyclone is passed into a second internal cyclone that is supported within the upper chamber. The gas stream from each second cyclone is discharged into a common internal plenum chamber that is supported at the top of the upper chamber. From there the clean gas is aischarged to an 3~L
outlet at the top of the upper chamber. In still other embodiments, one and two stage cyclones are arran~ed ex-ternal to the upper chamber, either separately or in addition to the internal cyclones. ~or a more detailed description of cyclone separators, and impingen)ent gas-solids separators, reference is made to CHEMICAL F.NGINFERS HANDBOOK - Perry ~
Chilton, 5th edition, 1973 McGraw-Hill Book Company, pages 20-80 to 20-87.
The velocity of the gas stream through the choke ring ~y vary in the range of about 2 to 5 ft. per sec. The velocity of the gas stream through the upper chamber basis nct cross section may vary in the range of about 1 to 3 ft. per sec. The upward superficial velocity of the gas stream in the upper chamber and the diameter and height of the upper chamber, preferably may be such that the inlet to the cyclone separator (or separators) is above the choke ring by a distance at least equal to the Transport Disen-gaging Height (TDH), also referred to as the equilibrium disengaging height. Above the TDH, the rate of decrease in entrainment of the solid particles in the gas stream approaches zero. Particle entrainment varies with such factors as viscosity, density and velocity of the gas stream, specific gravity and size distribution of the solid particles, and height above the choke ring. The Transport Disengaging Height may vary in the range of about 10 to 25 ft. Thus, for example, if ~he velocity of the gas stream is about 3.5 ft./sec. through the choke ring and about 2 ft./sec. basis total cross section of the upper chamber or 2.5 ft./sec. basis net cross section of ~he upper chamber, then, the Transport Disengaging Height may be about 15 to 20 ~ 17 -~f' ~6~i31 ft. in an upper chamber having an inside diameter of about 10 to 15 feet. The pxessure drop of the gas stream passing through the antechamber is less than about 5 psi.
In one embodiment, in place of or in addition to the gas-solids separation means located inside of the upper chamber o~ the antechamber, outside gas-solids separation means may be located downstream rom the antechamber and prior to the main gas cooling zone. The gas-solidq separation means located outside o~ the antechamber means may be selected from the group: single or mul.iple cyclone separators, gas-solids impingement separators, filters, electrostatic precipitators, and combinations thereof.
The main gas cooling zone, is located directl~
downstream from the antechamber or any solids separation means located after the antechamber. The. temperature of the gas stream entering the main gas cooling zone is in the range of about 1200 to 3000P., such as about 1200 to 1800~., say about l600F. The concentration of solids in this gas stream is in t~e ra~ge of about 10 to 700 Mgr. per SCF. Next, most of the sensible heat in the gas stream is r~moved in the main gas cooling zone comprising one or more interconnected shell-and-straight fire tube gas coolers i.e.
heat exchangers. Each gas cooIer ha~ one or more passes on the shell and tube sides, and preferably has fixed tube sheets. In comparison, with the gas coolers employed in the su~ject process, the conventional synthesis gas coolers for producing high pressure steam are of a spiral-tube, helical-tube, or serpentine-coil design. Gas coolers with such coils of tubes are difficult to clean and maintain; they are relatively expensive; and they tend to plug if the solids ~ 1 ~ 6~ 3~

loading in the gas i~ significant. Costly down-time resulks when boilers with such coils r~quire ser~icing. Advan-tageou~ly, these problems are avoided in the subject process which employs one or mors qas coolers each compri~ing a shell-and-a plurality of parallel straight fire tubes.
Tha gas co~lers are preferably arranged in the subject process to provide two stages of cooling - a first or high tempexature stage, and a second or low temperature stage. In the first or high tempera~ure stage a preferred embodiment comprises one shell-and-straight fire tube heat exchanger with fixed tube sheets, and with one pass on the tube and shell sides. The raw gas is on the tube-side and the coolant in on the shell-side. Inlet and outlat ends of the plurality o straight parallel tubes in the tube bundle contained in the pressure shell are supported on each end by a t~be sheet. The tube end~ are in communication with respective inlet and outle~ i.e. front end and rear end, stationary heads. The inlet and outlet sections and inlet tube sheet are refractory l1ned. Metal or ceramic ferrels may also be used in the inlet tube sheet to provid~ additional thermal protection for the tubes. The first heat exchanger is sized as short as possible to facilitate cleaning the tube~ and to minLmize the thermal expansion str~ s imposed on the fixed tube sheets. The tube sheets themselves are designed to ~ex slightly to eliminate excessive thermal stress. The tube O.D. is in the range of l.5 to 2.0 times the tube O.D. of the second stage cooler. This is done to minimize the possibility o~ plugging the exchanger. The gas veloci~y is set high~enough to keep the fouling problems within an acceptable range. For further details 3~
of tube~side and shell-side construction of flxed-tube-~heet heat exchangers, see pages ll-S to 11-6, Fig. 11-2 (b), and pages ll-10 to 11-18 o~ Chemical Engineer~' Handbook-Perry and Chilton-Fith Edition, McGraw-Hill Book Co., New York.
The second or low temperature stage o~ the gas cooler may preferably have two tube-~ide passes and one shell-side pas~. Thi~ exchanger i5 designed s.imilarly to the first ~tage gas coolar. Howe~er, in this exchanger smaller ~ube. may be used due to fewer plugging problems at l~wer temperatures. By this means, the surface area avail-able ~or a given shell diameter may be increased. For example, ~he tube diameters in the first stage gas cooler may be 3 inch O.D. while the second s~age gas cooler may be 2 inch O.D.
The direction of the longitudinal axes of ~he straight fire tube heat exchangers may be hori7ontal, vertical, or a combination o both directions. However, preferably as ~hown i~ the drawing, the longitudinal axes o~
the shell-and-~traight tube heat exchanger~ are vertical.
20~ This permits separating by gravity of entrained particulate ~olid.~ from the gas stream, and easy removal of particulate matter from an outlet in the lower end of the gas cooler.
Further, the inlet o the first stage gas cooler is pre-ferably located directly above the antechamber, or any additional entrained solids removal means following the antechamber.
The prefered combination of shell-and-straight - vertical fire tube heat exchangers with one and two tube-side passes and ~ixed tu~e sheets is shown in the drawing and will be described later in greater detail. In said embodiment, the hot gas stream is cooled in the first stage gas cooler to a temperature in the range af about 800 to 1200F., such as 90~ to 1100~., say about 1000~., by indir~ct heat exchange with a coolant i.e. boiler feed water or steam. The hot gas qtream passes through a bundle of parallel straight tu~es. The singLe pass of straight tubes will distribute th~ thermal stre~ses equally over the fixed tube sheets. Next, in the second stage gas cooler, the temperature o~ the gas stream is reduced to within about 15 to 90F., say to about 20F. o~ the chosen steam temperature.
For example, the temperature of the gas stream leaving ths second stage gas cooler is in the range o about 450 to 5900F., sa~ about 550F. In the secand stage gas cooler, by employing two passes on the tube~-side, the length of the tubes i5 effectively increased ~or a giVQn shell size.
Savings in construction are thereby achieved. Multiple passes on the tube-side are used to reduce thermal stresses on the fixed tube sheets due to expansion. Also, muItiple tube passes will reduce p~t area or elevations depending on the orientation of the exchanger.
In the subject process, the term "~ire tube" means that the hot gas always passes through the bank of parallel straight tubes of the gas cooler. ~he coolant passes on the shell-side. The inte~nal flow of the coolant within the gas cooler is controlled by uch elements as: one or more inlet and exit nozzles and their location; and the number, lo-cations, and design of transverse baf f les, partitions, and weirs. Besides directing the shelI-side coolant through a prescribed path, baffles are commonly used to support the 6~ 3'1 ~traight tube~ within the tube bundle.
Small diameter tubes (1 to 4 inch O.D.) may be u~ed in the con~truction o~ the ~ubject gas coolers. The tube diameter is chosen baqi~ economic analysis of its e~fect on heat transfer, pressure drup, fouling and plugging tendencies~ Long tubes a~ford potential savings in con-struc~ion at higher pressures a~ the in~estment per unit area of heat tran~er Rervic~ is le~s for longer heat exchangers. The gas a~d coolant flow ~elocities within the heat exchanger are limlted so as to a~oid destructive mechanical da~age by vibration or erosion, to maintain an allowable pres~ure drop, and to control the buildup of deposi~s. For example, the velocity of the hot gas through the straigh~ tubes may be in the range of about 40 to 55 ~t.~sec. or a 2 inch ~.D. tube depending on the temperature and pressure at any given point in the exchanger. Larger diameter tubes are u~ed when heavy fouling is expected, and to facilitate the me~hanical cleaning of khe inside of the tubes. Tube-to-tube sheet attachment may be accomplished by the combination of tube end welding and rolled expansion.
The tube may be arranged on a triangular, square, or rotated-sguare pitch. Cen~er-to-center spacings tube pitch, baffle type and spacing are chosen to provide good coolant circulation avoiding hot spots on the inlet tube sheet. The heat exchanger's shell size is directly related to the number of tube3 and to the tube pitch. Generally, the shell of the heat exchanger used in the ~ubject process is con-structed from high grade carbon-steel. When high pressure steam is being generated or superheated, alloy steels may be employed to reduce the re~uired shell thickness and to lower the equipment cos~

~ 3~

The inlet and outlet ~ections of the gas coolex will normally be made of alloy steels due to the temperature and hydrogen partial pressure in the raw gas. Tube m~teria~ 5 will genesally be alloy ~teel by similar reasoning; however, the last pass(es) of the second stage ga~ coolor may be carbon steel in ~ome cases. Flow pat~erns between the shell and tube-side fluids include counter-current flow, co-current flow and combinations thereof.
- Rolevant factors affecting the size of the heat exchanger, and ther~fore the cost, include: pre~sure drop, gas compo~ition, gas and coolant flow rates, log-mean-- temperature difference, and fouling factors. An optimum heat-exchanger design is the function o many of the pre-viously discus~ed interacting parameters.
While any suitable liquid or gaseous coolant may be passed on the sheIl-side of the gas coolers, boiler feed water (BFW) or steam are the preferred coolants. By this means, by-product ~aturated or superheated steam a~ a temp-erature in th~ range of about s2no to 900F., at pressures approaching lO0 atm may be produced for use ~lsewhere in the system or for export.
The followi~g advantages are achieved by passing the hot solids containing gas stream through the straight tubes of the subject gas cooler vs. conventional coiled tube synthesis ga~ coolers: (1) Heat.Transfer-higher heat-transfer rates are obtained due to less fouling, (2) Fouling-velocities of ~he hot gases through the tubes tend to reduce fouling; straight tubes allow mechanical clea~ing, (3) Pressure drop-lower pressure drop due to fewer bends ~ 3~
and reduced pos~ibility for plugging, and (4) Cost-lower fabrica~ion cost due to a less complex design.
The stream of ga~ leaving the main cooling zone may be used as synthe~i~ ga~, reducing g~s, or fuel gas.
Alternately, the sensibLe heat remaining in the gas stream may be extracted in one or more economizers i.e. heat ex-changers by preheating bailer feed wa~er. Additional entxained particulate matter may be then remo~ed from the gas stream by scrubbing the gas stream with water in a carbo~ scrubbQr. By this means the concentration of en-trained solids may b~ further reduced to less ~han 2 Mgs per : normal cubic meter. The clea~ gas stream leaving the carbon scrubber saturated with water may be then dewatered~ Thus, ~he ga~ stream is cooled below the dew point by indirect heat exchange with boiler feed water or clean ~uel gas.
Condensed water is separated from the gas stream in a knockout drum. The condensate, optionally in admixture with makeup water, is returned to the carbon ~crubber for use as the final stage scrubbing agent. The clean gas stream leaving from the top of the knockout drum is at a ~emp-` erature in t~e range of about 2Q0 to 600F., such as about 275 to 400F., say about 340F. A portion of this clean gas stream in the range of about 0 to 80 vol. % , such as : about 30 to 60 vol. %, say about S0 vol. % may be compressed to a pressure greater than th~t in the antechamber. The compressed gas stream may be recycl d to the antechamber wher~ it is introduced into ~he lswex quench chamber as said - recycle gas. The remainder of the cooled clean gas stream is removed from the top of the knockou~ drum as the product gas.

When a bleed gas streæm is employed in the gas diversion chamber, it is also cooled and cleaned in th~ gas scrubbing zone along with the main ga~ s~ream. The bleed ga~ strea~, which is split from the main ga~ stream in the gas di~ersion chamb~r, is passed ~hrough the bot~om outlet of the gas diversion chamber, and then through a communicating dip tube which discharg~ under water. By ~his means the bleed gas stream and separated molten slag and/or particulate solids are quenched in a pool of water contained in the bottom of the quench chamber. The quench water may be at a temperature in the range o~ about 50 to 600F. Optionally, the hot quench wa~er on the way to a carbon recovery facility may be used to prehea~ one or Moxe of the feed streams to the gas generator by indirect heat exchange. The bleed gas stream, ater being quenched, is at a temperature in the range of about 200 to 600F.
A wide range o~ ash con~aining combustible car-bonaceous solid fuels may be used in the subject process.
The term solid carbonaceous fuel as used herein to describe various suitable feed stocks is intended to include (1):
pumpable slurries of ~olid carbonacevus fuels; (2~ gas-solid suspensions, such as finely ground solid carbonaceous fuels disper~ed in either a temperature moderating gas, a gaseous hydrocarbon, or a free-oxygen containing gas, and ~3) gas-liquid-solid dispersions, such as atomized liquid hydrocarbon fuel or water and solid caxbonaceous fuel dis-persed in a temperature-moderating gas, or a free-oxygen containing gas~ The solid carbonaceous fuel may be subjected to partial oxidation either alone or in the presence of a thermally liquefiable or vaporizable hydrocarbon or;carbonaceous ~ 3~

materials and/or water. Alternately, the solid carbonacsous fuel free from the surface moisture may be introduced into the ga~ generator entrained in a ga~eous medium from the group steam, C02, N~, synthesis gas, and a free-oxygen containing ga~. The term solid carbonaceous fuels include~
coal, ~uch as anthracite, bituminou~, sub-bituminous, coke, ~rom coal and lignite; oil ~hale; tar sands; pe~roleum ~oke;
asphalt; pitch: particulate carbon (soo~); concentrated sewer sludge; and mixture~ thereo. The solid carbonaceous fuel may be ground to a particle size in the range of ASTM
E11-70 Sieve Designatisn Standard ~S~S) 12.5 mm (Alternative 1/2 in.) to 75 mm (A?ternative No.200). Pumpable slurries of solid carbonaceous fuels may have a solids content in the range of about 25-65 weight percent (wt. ~), such as 45-60 wt. ~, depending on the characteris~ics of the fuel and the sh~rying medium. The ~lurrying medium may be water, liquid hydrocarbon, or both.
The term liquid hydrocarbon, as used herei~, is intended to include various materials, such as liquified petroleum ga~, petroleum distillates and residues, gasoline, naphtha, k~rosene, crude petroleum~ asphal~, gas oil, residual oil, tar~sand and shal~ oil, oil derived from coal, aromatic hydroc~rbons (such as benzene, toluen~, and xylene ~ractions), coal tar, cycl~ gas oil from fluid-catalytic-cracking opera~ion, furfural extract of cokex gas oil, and mixtures thereof. Also included within the definition of liquid hydrocarbons are oxygenated hydrocarbonaceous organic mat rials including carbohydrates, cellulosic materials, aldehydes, organic acids, alcohols, ketones, oxygenated fuel oil, waste liquids and by-produc~s from chemical processes ~ 3~

containing oxygenated hydrocarbonaceous organic materials, and mixtures th~reof.
The use o~ a temperature modera~or to moderate the temperature in the reaction zone of the gas ~enerator is optional and depends in generaL on the carbon to hydrogen ratio of the feed stoc~ and the oxygen content o~ the oxidant stream. Suitable temperature moderators include H20, C02 rich gas, liquid C02, a portion of the cooled clean exhaust gas from a gas turhine employed downstream.in the process with or without admix~ure with air, by-product nitrogen from the air separation unit used to produce substantially pure oxygen, and mixtures o~ the afore~aid temperature moderatorq. ~ temperature modexator may not be required with feed slurries of water and solid carbonaceous fuel. However, steam may be the tempexature m~derator with slurries of liquid hydrocarbon fuels and solid car~onaceous fuel. Generally, a temperature moderator is used with liquid hydrocarbon fuels and with sub~tantially pure oxygen.
The tempera~ure moderator may be introduced into the gas 20 generator i~ admix~ure with either the solid carbonaceous fuel fe~d, the free-oxygen containing stream, or both.
Alternatively, the temp~rature moderator may be introduced i~o the reac~ion zone of the gas generator by way of a separate conduit in the fuel burner. When supplemental H20 is introduced into the gas generator either as a temperature moderator, a slurrying medium, or both, the weight ratio of supplemental water to the solid carbonaceous fuel plus liquid hydrocarbon fuel if any, is pre~erably in the range of about 0.2 to 0.50.

, .

~ J~ 3'~
The term ~ree-oxygen containin~ gas, as used herei~ is intended to include air, oxygen enriched air, i.e., greater than 21 mol % oxygen, and substantially pure axygen , i.e., greater ~han 95 m~l % oxygen, (the remainder comprising N2 and rare gases). Free-o~ygen containing gas may be introduced into the burner at a temperature in the range o~ about ambient to 1200F. ~he atomic ra~io of free oxygen in the oxidant to carbon in the feed ~tock (0/C, atom/atom) is pre~erably in the range of about 0.7 to 1.5, such as about 0.85 to 1.2.
The relative proportions of ~olid carbonaceous fuel, liquid hydrocarbon fuel if any, water or other temp-erature moderator, and oxygen in ~he feed streams to the gas generator are careully regulated to convert a substantial partion af the carhon, e.g. at ~east 80 wt% to carbon oxides e.g. C0 and C02: and to maintain an autogenous raaction zone temperature i~ the range of about 1700~ to 3100~. For example, in one e~bodiment employing a coal-water slurry ~eed, a slagging-mode gasifier may be operated at a temper-: 20 ature in the range of about 2300 to 2800F. For the same fuel, a fly-ash mode coal gasifier may be opexated at a low~r temperature in the range o~ about 1700 to 2100'F.
The pre~sure in thP reaction zone is in the range of about 10 to 200 a~mospheres. The time in the reaction zo~e in seconds is in the range of about 0.5 to 50, such as about 1.0 to 10.
The effluent gas stream leaving the partial oxidation gas generator has t~e following composition in mol %: ~2
8.0 to 60.0, CO 8.0 to 70.0, CO2 1.0 to 50.0, H20 2.0 to 50.0, CH4 0 to 30.0, H2S 0.0 to 2.0, COS 0.0 to 1.0, N2 0.0 to 85.0, and A 0.0 to 2Ø Entrained in the e~fluent 3~

gas ~tream is about 0.5 to 20 wt% of particulate carbon (basis weight of carbon in the feed ~o the gas generator).
Molten slag resulting from the fusion of the ash content of the coal, and/or fly-ash, bits of refractory from the walls o~ the gas generator, and other bits of solia~ may also be entrained in the gas stream leaving the generator.
By means of the subject process the following advantages are achievad~ A~ut 90-99.9 wt.~ of the entrained molten slag and~or particulate matter in the hot raw gas stream leaving the partial oxidation gas gen-erator may be removed. (2) Substantially all of the sensible heat in th~ hot r~w gas stream leaving the partial oxidation gas generator i~ utilized thereby increasing the thermal efficiency o~ the process. ~3) ~y product steam is produced at a high temperature level. The steam may be used else-where in th~ process i.e., for heating purposes, for producing power, or in the gas generator. Alternately, a portion of the by product steam may be exported. (43 MoLtan slag and/or particulate matter from the solid carbonaceous fuel may be readily removed upstream from the gas cooler~ Fouling of hea~ exchange suraces is thereby prevented. (53 One or more comparatively low cost shell-and-straight fire-tube gas coolers are employed. The design of such gas coolers allows thermal stresses to be equally dis~ributed over the tube ~heets, ~implifies tube cleaning and maintenance operations, and minimizes plot area and elevation.

--2g--~26~3~L
0~ O- r~ A~IYG
A more complete understanding of the invention may be had hy re~erence to the accompanying schematic drawing which show~ the previously described proces~ in detail.
Although the drawing illu3trates a preferred embodiment of the process of this invention, it i~ not intended to lLmit the continuous process illustrated to the particuLar ap-paratus or materials described.
With referenc~ to the drawing, in line 1 a slurry comprising 1/4 inch diameter bituminous coal in water having a solids content of 40 wt~ is pumped by mean~ of pump ~ through line 3 into heat exchanger 4. The temperature of the coal slurry is increased in heat exchanger 4 from room temperature to 200F. by indirect heat exchange with quench water. The quench water entexs heat exchanger 4 by way of line 5 and leaves by way o~ line 6 aftex giving up heat to the coal ~lurry. The heated coal slurry is then pa~sad through line 7 and into the annulus passage 8 of burner 9.
Burner 9 is mounted in upper inlet 10 of synthesis gas generator 11. SLmultaneously, a straam of free-oxygen containing gas, such as substantially pure oxygen from line 12, is heated by indirect heat exchange wi~h steam in heat exchanger 13, and passed into gas generator 11 by way of line 14 and the central conduit 15 of burner 9.
Synthesis gas generator 11 is a free-flow steel pressure ve~sel compri~ing the following principle sections; reaction zone 16, gas diversion chamber 17, and quench chamber 18.
Reaction zone 16 and gas diversio~ chamber 17 are lined on the inside with a thermally resistan~ refractory material.
~lternately, these thre~ sections may comprise two or more distinct and interconnected c~mmunicating u~its.

3~L

The vertical central axis of upper inlet 10 is aligned with the central vertical axis of the gas generator 11. The reactant streams impinge on each other and partial oxidation takes place in reaction zone 16. A hot raw gas stream containing entrained molten slag and/or particulate matter including unconverted carbon and bits of reractory pa~ses thxough the axially aligned opening 19 located in the bot~om of reaction zone 16 and enters into an enlarged gas diversion chamber 17. The velocity and direction o~ the hot .ga~ ~tream are suddenly changed in di~ersion chamber 17.
A ~mall porti~n i.e. bleed~ream of the xaw gas is, op-tionally, drawn through the bottom thxoat ZO of the gas diversion chamber 17, dip leg 21, and into water 22 con-tained in the bottom of quench chamber 18. By this means outlet 20 is kept open, a portion of the mol~en 31ag and/or particulate matter is qu~nch cooled, and the slag may be solidified. Periodically, s~lid particles and ash are removed from quench chamber 18 by way of lower axially aligned ou~let 23, line 24, valve 25, line 26, lock hopper 2~ 27, line 28, valve 29, and line 30. :Ash and other solid are separated from the quench water by maans:of ash conveyor 31 and sump 32. Th~ ash is removed through line 33 for use as fill. Quench water i~ removed frsm ~he sump by way of line 34. pump 35 and line 36 and may be recycled to the quench chamber. A portion of the quench water is removed from the bottom of the quench chamber through outlet 37 and is intxoduced ~y way of line 5 into heat exchanger 4, as previously described. The cooled quench water containing carbon in line 6 is introduced into a conventional carbon removal facility (not shown) for reclaiming the quench water ~ 3~1 by way of line 38. The recovered carbon i5 then added to the coal slurry as a portion of the feed to the gas generator.
Any ~leed gas is removed from quench chamber la through side outlet 3g, line 40, valve 41, and line 42.
The hot raw gas stream leaving diversion chamber 17 with a portion of the molten ~lag and/or particula~e matter removed is dl~erted through refractory lined side exit passage 43 and is then upwardly directed through refractory lined transfer line 44, and in~o inlet 45 of antechamber 46. Antechamber 45 is a closed cylindrical vertical steel pressure vessel lined on the inside through-: out with refractory 47 and includes coaxial lower solids separati~g chamber 48, coaxial upper solids separating chamber 49, and coaxial re~ractory choke ring 50. Choke ring 50 forms a cylindrically shaped passage o~ reduced diameter between lower chamber 48 and upper cham~er 49.
Antechamber 46 has a conical shaped bottom Sl that converges into refractory line~ coaxial bottom outlet 52. Hemi-spherical dome 53 at the top of vessel 46:is equippea with refractory li~ed top outlet 54. Outlet 54 is coaxial with : the vertical axis of vessel 46. A pair of refractory lined : opposed coaxial inlet nozzles ~5 and 55~ex~end through the vessel wall and are d~rected into lower cham~er 46. ~Th~
longitudinal axis o~ inlet nozzles 45 and 55 makes an angle of about 60 with the ~ertical central axis of ve~sel 46 and li2s in the same plane. Inlet nozzle 45, for introducing a hot raw gas stream, is pcinted upward. Inlet nozzle 55, for introducing a stream of clean and comparatively coolex recycle quench gas, is pointed downwardO While only one pair of inlet nozzles is shown in-the drawing, additional pairs may be included in .the àppara~us. ~-- -32 "

~ 3 ~

In the preferred embodiment, at least one cyclone 56, with its longitudinal vertical axiq parallel or coaxial with the vertical axis of vessel 46, is supported within upper chamber 49. Each cyclone is resistant to heat and abrasion and has a gas inlet 57 near the upper portion of the upper chamber. When multiple cyclones are employed, they may be unifonmly spaced within the chamber. The ~ace of rectangular inlet 57 of cyclone 56 is preferably parallel to the vertical axis of vessel 46. The inlet is oriented to ~ace the direction of the incoming gas stream. Thus, the cyclone inlet or inlets may be oriented to continue the direction o swirl.
Cyclone 56 is of conventional deqign including a cylindrical body, a converging conical shaped bottom portion, ~everse ch~mber, outlet plenum which connects into upper outlet 54, dipleg 58, an~ a check valve near the bottom end of th~ dipleg. Dipleg 53 may be o~-set to pass close to the walLs o vessel ~ and thereby avoid intersecting the common longitudinal axis o~ inlets 4S and S5. By this means contact and build-up on the dipleg of uncooled sl~g particles are avoided. Cooled clean syn hesis gas is discharged .
through top outlet 54. Particulate solids are discharged through bot~om outlet 52 by way of line 59, valve 60, a~d line 61 and pass into a lock-hopp2r, not shown.
Optionally, from about 1 to 4 tangential quench gas inlets 62 are evenly spaced around the circumference of ~essel 46, for example, near the top of the lower chamber 48 and/or the bottom of the upper chamber 49. ~y this means, a supplemental amount of cooled clean recycle quench gas may be introduced into vessel 46. The spiraling .. .

~ 3 ~
clockwis~ direction of thP ~tream of recycled gas h~lps to direct all of the gases in the vess~l upwardly. It also maintains a cool gas stream along the wall of vessel 46 which protects the refrac~ory lining. The cooled clean recycled gas ~tream that may be introduced into inlet 55 and optionally into ~aid tangential inlets 62 comprises at least a portion of the cooled clean. ga~ stream from line 63.
If it is desired to further reduce the ~olids concentration or the ~ize o~ the particulate solids in the gas ~tream leaving antechamber 46 by way of top outlet 54, then th~ gas -qtream in line 64 may be optionally introduced into a conventional solids separation zone Inot 3hown) which may be located outside of antechamber 46. Cyclones, im-pingemen separators, bag filters, electrostatic precipitators, or combinatj,ons thereof may be used for ~his purpose. These are located downs~ream from the antechamber and prior to the main gas cooling zone.
Most of the sensible heat in the gas stream leaving th~ antechamber is xemoved in the main gas cooling zone which in the pre~erxed embodiment:comprises two vertlcally dispo ed shell-and-straigh~ fire tube heat exchangers 65 and 66 which are connected in series. Both gas cooLers 65 and 66 have fixed tube sheets i.e. lower tube sheet 67 and upper tube sheet 68. While both gas coolers 65 and 66 have one-pass on the shell-side, gas cooler 65 has one-pass on the tube-siae and gas cool~r 66 has two-passes on the tube-side.
The hot gas stream from antechamber 46, or op-tionally from a supplemental solidq removal facility (not shown) located downstream ~rom antechamber 46, is cooled ~ ~f>~ ~3~
by b~ing pa~sed upwardly through low~r inlet nozzle 6g into refractory lined lower ~tationary-head bonnet 70, past lower fixed tube sheet 67, through tube bundle 71 comprising a plurality of parallel straight vertical tube~ located within shell 72, past upper fixed tube sheet 68, into upper sta-tionary-head bonnet 73, through connecting passage 74 and i.n~o the left side 75 of upper stationary-head bonnet 76 o~
the second gas cooler 66. Central bafle 77 separates upper bonnet 76 into le~t ~ide 75 and right side 78. The gas stream on th~ left side 75 is passed by upper fixed tube sheet 68, down through the left bank of parallel straight tubes 79, through lower fixed tube sheet 67, into the bottom stationary-head bonnet 80, up through ~he righ~ bank of .
parallel straight vertical tubes 81, into ~he right section 78 o~ upper ~tationary-head bonne~ 76, and out through upper stationary head exit noz~le 82 and line 83. Particulate solids that ~all into the bottom heads 70 and 80 respec~ively o~ gas coolers 65 and 66, are removed by way of bottom out-lets, such as flanged noz71e 84 for gas cooler 66. A
suitable arrangement for i~troducing a coolant, in this case boiler feed water, into each of ~he two gas coalers 65 and 66 is shown in the drawing. By-product s~eam is produced in gas coolers 65 and 66 and is collected in steam drum 90.
Boiler feed water from drum 90 is passed through line 91 and inlet nozzle 92 into the shell-side of gas cooler 65. Steam is removed from gas cooler 65 through outlet nozzle 93, and passed into steam drum 90 by way of line 94. Similarly, boiler feed water from steam drum 90 is passed through line 95 and inlet nozzle 96 into the shell-side o~ gas cooler 66.
Steam is remo~ed from gas cooler 66 through outlet nozzle 97 ~ 6~3~

and i~ pas~ed into 3~eam drum 90 by way of line 98. Pr~-heat~d boiler feed water is introduced into steam drum 90 through line 99. Saturated steam is removed rom ste~m drum 90 by way of line 100. This steam may be used elsewhere in the process, for example, as the hea~ing medium in heat exchanger 13, or as the temperature-moderator in ga~ gener-ator 11, or as the worki~g fluid in a steam turbine (not shown) for the production of mechanical and/or electrical power. Alternately, the saturated steam may be superheated.
~dditional entrained solids and sensible heat are removed from the gas stream leaving the second gas cooler by way of outlet 82 and line 83, by passing tha gas stream through economizer 101, line 102, and into carbon scrubber 103. Carbon scrubber 103 comprises a two section vertical ve~sel including upper chamber 104, and lower chamb~r 105.
The gas stream in line 102 is passed through inlet 106 in lower chamber 105, and then through diptube 107 into wa~er-bath 108 contained in the bottom of lower chamber 105. The once-washed gas stream leaves lower chamber 105 by way of outle~ 109, and is passed through lines 110 and 111 into .
venturi scrubber 112. There ~h~ gas ~tream is scrubbed with wa~er from line 116. The scrubbed gas stream from venturi scrubber 112 is passed into upp~r chamber 104 by way of line 117 and inlet 118. By way of diptube 119, the gas stream is next introduced ~nto and washed in waterbath 120. Before leaving upper chamber 104 by way of upper outlet 121 in the top of chamber 78, the gas stream may be given a fi~al rinse by mean-c of water spray 122 or by,a wash tray (not shown).
~or example, condensate 123 from the bottom of knock-out drum 124 ma~ ~e passed through line 125 and introduced 3~

through inlet 126 into spray 122. Water from pool 120 is passed through pipe 1~7, outlet 128, line 129, pump 130, lines 131 and 132, inlet 133, and pipe 13~ into quench cham~er 18. A portion of the water in line 131 may be recycled to lower chamber 105 of gas scrubber 103 by way of line 13S, valve 136, lines 137 and 138, and inlet 139.
Another portion o water in line 137 is passed through line 140 a~d mlxed in line 116 with maXe-up water from line 141, valve 142, and line 143. The wa~er in line 116 is introduced into venturi 112 as previously described~ Water containing dispersed solids 108 from the bottom of chamber 105 is passed through outlet 144, line 145, valve 146, line 147, and mixad in line 38 with the water dispersion from line 6.
The water dispersion in line 38 is sent to a conventional carbon recovery facility (not shown) where water is separated from the entrained solids. The recovered water is returned to the system as make-up. The make-up water may be intro-duced at various locations, for example through line 141 as previously described.
The cleaned gas stream leaving upper chamber 104 of carbon scrubber 103 by way of upper outlet 121 and line 155 is pa~sed through economizer 156 where it is cooled below the dew point. The wet gas stream passes through line 157 into knockout drum 124 where separation of the condensed water from the gas stream takes place. A cooled and cleaned stream of product gas leaves the top of knockout drum~124 by way of lines 158 and 159. Optionally bu~ preferabiy when gasifier 11 is opexated in the slagging mode, a portion of this cooled and cleaned product gas stream is passed through line 160, valve 161, line 162, gas compressor 163, and -37- .

~ 1 2 ~ 3 ~

recycled a~ the stream of quench gas to lower chamber 48 of antechamber 46 ~y way of line 63 and inlet passage 55, and optionally through tangential gas inlets 62.
Make-up boiler feed water (BFW) for cooling shell-and-straight tube heat exchangers 65 and 66 is prPheated by b~ing passed through line 164, economizer 156 as the coolant, line 165, economizer 101 as the coolant, line 99, and into steam drum 90. From there the BFW i5 distributed to gas coolers 65 and 66, as previously described.

2~

Other modifications and variations of the in-vention as hereinbefore se~ forth may be made withou~
departing from the spirit and scope thereof, and therefore only such limitations should be imposed o~ the in~ention as are indicated in the appended claims.

30.

Claims (15)

The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows:
1. A process for the partial oxidation of an ash-containing solid carbonaceous fuel for producing a cooled cleaned product gas stream of synthesis gas, fuel gas or reducing gas and by-product steam comprising:
(1) reacting particles of said solid fuel with a free-oxygen containing gas and with or without a temperature moderator in a down-flow refractory lined gas generator at a temperature in the range of about 1700° to 3100°F. and a pressure in the range of about 10 to 200 atmospheres to produce a raw gas stream comprising H2, CO, CO2, and one or more materials selected from the group consisting of H2O, H2S, COS, CH4, NH3, N2, and Ar, and containing molten slag and/or particulate matter;
(2) passing the gas stream from (1) down through the central outlet in the bottom of the reaction zone and into a thermally insulated diversion chamber provided with a side outlet and a bottom outlet; separating by gravity molten slag and/or particulate matter from said gas stream; passing from about 0 to 20 vol. % of said gas stream as bleed gas along with said separated material through the bottom outlet of said diversion chamber and into a pool of quench water in a quench chamber located below said diversion chamber; and passing the remainder of said gas stream through a side exit passage in said diversion chamber directly through a thermally insulated transfer line and inlet passage of a separate thermally insulated gas-gas quench cooling and solids separation zone at substantially the same temperature and pressure as produced in step (1) less ordinary pressure drop in the lines;
(3) impinging the gas stream from (2) in said gas-gas quench cooling and solids separation zone with a stream of recycle quench gas comprising cooled cleaned and compressed product gas from (7), thereby partially cooling the gas stream from (2) partially solidifying entrained molten slag, and separating from the gas stream a portion of the slag and particulate matter; and passing the partially cooled gas stream up through a separate thermally insulated upper chamber located above and communicating with said gas-gas quench cooling and solids separation zone and removing additional entrained solids from the gas stream;
(4) cooling the gas stream from (3) in a main gas cooling zone and producing by-product steam by passing said gas stream in indirect heat exchange with preheated boiler feed water first upward through the tubes of a vertical high temperature shell-and-straight fire tube gas cooler having refractory lined inlet and outlet sections, one pass on the shell and tube sides and having fixed tube sheets, then passing the gas stream down through the tubes in the first tube-side pass of a vertical low temperature shell-and-straight fire tube gas cooler having two passes on the tube-side and one pass on the shell-side and having fixed tube sheets, and then upward through the tubes in the second tube-side pass of said second gas cooler; and wherein by-product steam is removed from the shell-sides of said first and second gas coolers; and preheating boiler feed water for use in (4) by indirect heat exchange with the gas stream leaving said second gas cooler;

(5) cooling, and scrubbing the gas stream from (4) with water in gas cooling and scrubbing zones producing a carbon-water dispersion;
(6) cooling the gas stream from (5) below the dew point and separating condensed water to produce said cooled, cleaned stream of product gas; and (7) compressing a portion of said product gas stream from (6) and introducing same into said gas-gas quench cooling and solids separation zone in (3) as said stream of recycle quench gas.
2. The process of Claim 1 provided with the added step of separating additional solid matter from the gas stream leaving step (3) by introducing said gas stream into one or more solids separation means located before said main gas cooling zone in step (4) and selected from the group consisting of single or multiple cyclones, impingement separator, filter, electrostatic precipitator, and combinations thereof.
3 The process according to Claim 1 where in (2) said stream of bleed gas and separated material are passed through dip tube means into said quench water.
4. The process according to Claim 1 provided with the steps of producing said preheated boiler feed water for use in (4) by serially passing fresh boiler feed water in indirect heat exchange first with the gas stream from (5) and then with the gas stream leaving the second gas cooler in (4).
5. The process according to Claim 1 further comprising the step of passing the gas stream in step (2) into said gas-gas quench cooling and solids separation zone by way of said transfer line and inlet conduit whose longi-tudinal axis is at an angle in the range of about 30° to 135° with and measured clockwise starting in the third quadrant from the central vertical axis of said solids separation zone.
6. The process according to Claim 1 provided with the steps of simultaneously passing separate portions of preheated boiler feed water from a steam drum through the shell-sides of said first and second gas coolers in (4) and passing the steam produced thereby into said steam drum;
and removing by-product saturated steam from said steam drum.
7. The process according to Claim 1 wherein the upper chamber in step (3) contains one or more gas-solids separation means selected from the group consisting of cyclone, gas-solids, impingement separators, filter, and combinations thereof.
8. The process of Claim 1 wherein said solid carbonaceous fuel is selected from the group consisting of particulate carbon, coal, coke from coal, lignite, petroleum coke, oil shale, tar sands, asphalt, pitch, concentrated sewer sludge, and mixtures thereof.
9. The process of Claim 1 wherein said free-oxygen containing gas is selected from the group consisting of air, oxygen-enriched air, i.e. greater than 21 mol % oxygen, and substantially pure oxygen, i.e. greater than 95 mol % oxygen.
10. The process of Claim 1 wherein said temperature moderator is selected from the group consisting of H2O, CO2-rich gas, liquid CO2, a portion of the cooled clean exhaust gas from a gas turbine with or without admixture with air, nitrogen, and mixtures thereof.
11. The process according to Claim 1 further comprising the steps of mixing together at least a portion of said carbon-water dispersion from (5) with or without concentration and solid fuel to produce a solid fuel slurry, and gasifying said solid fuel slurry in the gas generator in step (1).
12. The process of Claim 1 wherein said solid carbonaceous fuel is subjected to partial oxidation either alone or in the presence of substantially thermally liquefiable or vaporizable hydrocarbon and/or water.
13. The process according to Claim 11 further comprising the step of preheating said solid fuel slurry feed to the gas generator with a portion of the quench water from said quench chamber in (2).
14. The process according to Claim 1 wherein about 0.5 to 15 vol. % of the raw gas stream from (1) is introduced into said quench water along with said slag and/or particulate matter.
15. A process for the partial oxidation of an ash-containing solid carbonaceous fuel for producing a cooled cleaned product gas stream of synthesis gas, fuel gas or reducing gas and by-product steam comprising:
(1) reacting particles of said solid fuel with a free-oxygen containing gas and with or without a temperature moderator in a down-flow refractory lined gas generator at a temperature in the range of about 1700° to 3100°F. and a pressure in the range of about 10 to 200 atmospheres to produce a raw gas stream comprising H2, CO, CO2, and one or more materials selected from the group consisting of H2O, H2S, COS, CH4, NH3, N2, and Ar, and containing molten slag and/or particulate matter;

(2) passing the gas stream from (1) down through the central outlet in the bottom of the reaction zone and into a separate thermally insulated diversion chamber provided with bottom and side outlets; separating by gravity molten slag and/or particulate matter from said gas stream; passing from about 0 to 20 vol. % of said gas stream as bleed gas along with said separated material through the bottom outlet of said diversion chamber and into a pool of quench water in a quench chamber located below said diversion chamber;
and passing the remainder of said gas stream through a side exit passage in said diversion chamber directly through a thermally insulated vertical gas-solids separation zone comprising upper and lower communicating chambers, at substantially the same temperature and pressure as produced in step (1) less ordinary pressure drop in the lines;
(3) passing the gas stream from (2) up through said gas-solids separation zone separating from the gas stream by gravity in said lower chamber a portion of the slag and/or particulate matter; removing additional entrained solids from the gas stream in said upper chamber with or without one or more solids separation means selected from the group consisting of cyclone, impingement separator, filter and combinations thereof;
(4) cooling the gas stream from (3) in a main gas cooling zone and producing by-product steam by passing said gas stream in indirect heat exchange with preheated boiler feed water first upward through the tubes of a vertical high temperature shell-and-straight first tube gas, cooler having refractory lined inlet and outlet sections, one pass on the shell and tube sides and having fixed tube sheets, then passing the gas stream down through the tubes in the first tube-side pass of a vertical low temperature shell-and-straight fire tube gas cooler having two passes on the tube-side and one pass on the shell-side and having fixed tube sheets, and then upward through the tubes in the second tube-side pass of said second gas cooler; and wherein by-product steam is removed from the shell-sides of said first and second gas coolers; and preheating boiler feed water for use in (4) by indirect heat exchange with the gas stream leaving said second gas cooler;
(5) cooling, and scrubbing the gas stream from (4) with water in gas cooling and scrubbing zones producing a carbon-water dispersion; and (6) cooling the gas stream from (5) below the dew point and separating condensed water to produce said cooled, cleaned stream of product gas.
CA354,223A 1979-07-13 1980-06-17 Coal gasification process Expired CA1126031A (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
US06/057,226 US4248604A (en) 1979-07-13 1979-07-13 Gasification process
US057,226 1979-07-13

Publications (1)

Publication Number Publication Date
CA1126031A true CA1126031A (en) 1982-06-22

Family

ID=22009279

Family Applications (1)

Application Number Title Priority Date Filing Date
CA354,223A Expired CA1126031A (en) 1979-07-13 1980-06-17 Coal gasification process

Country Status (2)

Country Link
US (1) US4248604A (en)
CA (1) CA1126031A (en)

Families Citing this family (32)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE2951153C2 (en) * 1979-12-19 1981-11-12 M.A.N. Maschinenfabrik Augsburg-Nürnberg AG, 4200 Oberhausen Device for cleaning and synthesis gas produced by coal gasification
DE3137576C2 (en) * 1981-09-22 1985-02-28 L. & C. Steinmüller GmbH, 5270 Gummersbach Device for cooling process gas originating from a gasification process
DE3137586A1 (en) * 1981-09-22 1983-04-07 L. & C. Steinmüller GmbH, 5270 Gummersbach "METHOD FOR TREATING PROCESS GASES COMING FROM A GASIFICATION REACTOR"
US4436530A (en) 1982-07-02 1984-03-13 Texaco Development Corporation Process for gasifying solid carbon containing materials
US4559061A (en) * 1983-07-05 1985-12-17 Texaco Inc. Means for synthesis gas generation with control of ratio of steam to dry gas
US4502869A (en) * 1983-07-05 1985-03-05 Texaco Inc. Synthesis gas generation process with control of ratio of steam to dry gas
US4548162A (en) * 1984-10-22 1985-10-22 Combustion Engineering, Inc. Slagging heat recovery unit with potassium seed recovery
US4569680A (en) * 1984-12-26 1986-02-11 Combustion Engineering Gasifier with economizer gas exit temperature control
US4969933A (en) * 1986-12-22 1990-11-13 Shell Oil Company Process for flyslag treatment utilizing a solids-containing concentrated aqueous stream
US4857077A (en) * 1986-12-22 1989-08-15 Shell Oil Company Process for removing flyslag from gas
US4969932A (en) * 1986-12-22 1990-11-13 Shell Oil Company Flyslag treatment utilizing a solids-containing concentrated aqueous stream and a cementitious material
GB2199842A (en) * 1986-12-30 1988-07-20 Us Energy Power generating system and method utilizing hydropyrolysis
DE3922612C2 (en) * 1989-07-10 1998-07-02 Krupp Koppers Gmbh Process for the production of methanol synthesis gas
US7694523B2 (en) * 2004-07-19 2010-04-13 Earthrenew, Inc. Control system for gas turbine in material treatment unit
US20070084077A1 (en) * 2004-07-19 2007-04-19 Gorbell Brian N Control system for gas turbine in material treatment unit
US7024800B2 (en) * 2004-07-19 2006-04-11 Earthrenew, Inc. Process and system for drying and heat treating materials
US7685737B2 (en) * 2004-07-19 2010-03-30 Earthrenew, Inc. Process and system for drying and heat treating materials
US7024796B2 (en) * 2004-07-19 2006-04-11 Earthrenew, Inc. Process and apparatus for manufacture of fertilizer products from manure and sewage
US20070163316A1 (en) * 2006-01-18 2007-07-19 Earthrenew Organics Ltd. High organic matter products and related systems for restoring organic matter and nutrients in soil
US7610692B2 (en) * 2006-01-18 2009-11-03 Earthrenew, Inc. Systems for prevention of HAP emissions and for efficient drying/dehydration processes
US8211191B2 (en) * 2007-08-07 2012-07-03 Phillips 66 Company Upright gasifier
US20100139581A1 (en) * 2008-12-04 2010-06-10 Thomas Ebner Vessel for cooling syngas
US8357216B2 (en) 2009-04-01 2013-01-22 Phillips 66 Company Two stage dry feed gasification system and process
CN101929672B (en) * 2009-06-24 2012-10-24 中国科学院工程热物理研究所 U-shaped water-cooling material returner
US9611437B2 (en) * 2010-01-12 2017-04-04 Lummus Technology Inc. Producing low methane syngas from a two-stage gasifier
US9028571B2 (en) * 2011-04-06 2015-05-12 Ineos Bio Sa Syngas cooler system and method of operation
US9410097B2 (en) 2013-03-15 2016-08-09 General Electric Company Methods and systems of producing a particulate free, cooled syngas product
CN104650988A (en) * 2013-11-25 2015-05-27 航天长征化学工程股份有限公司 Carbon-containing substance reaction system and method
US10899967B2 (en) * 2015-04-30 2021-01-26 Domenico Tanfoglio Molecular pyrodisaggregator
JP6804200B2 (en) * 2016-02-08 2020-12-23 三菱パワー株式会社 Slag cyclone, gasification equipment, gasification combined power generation equipment, slag cyclone operation method and slag cyclone maintenance method
CN106765209A (en) * 2017-03-03 2017-05-31 中国人民解放军63729部队 The processing unit and method of a kind of dinitrogen tetroxide spent liquor
CN108998103B (en) * 2018-08-08 2020-10-27 鞍钢股份有限公司 Method and device for improving quality of condensate circulating of horizontal pipe primary cooler

Family Cites Families (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB673164A (en) * 1948-12-07 1952-06-04 Koppers Co Inc Improvements in the production of gases containing carbon monoxide and hydrogen from finely divided solid fuels
US2699384A (en) * 1949-12-20 1955-01-11 Du Pont Preparation of carbon monoxide and hydrogen from carbonaceous solids
US3963457A (en) * 1974-11-08 1976-06-15 Koppers Company, Inc. Coal gasification process
DE2650512B2 (en) * 1976-11-04 1980-03-20 Gutehoffnungshuette Sterkrade Ag, 4200 Oberhausen Device for cleaning synthesis gas produced by chemical coal gasification
US4074981A (en) * 1976-12-10 1978-02-21 Texaco Inc. Partial oxidation process
US4121912A (en) * 1977-05-02 1978-10-24 Texaco Inc. Partial oxidation process with production of power

Also Published As

Publication number Publication date
US4248604A (en) 1981-02-03

Similar Documents

Publication Publication Date Title
CA1126031A (en) Coal gasification process
CA1126030A (en) Coal gasification and production of by-product superheated steam
CA1131026A (en) Production of cleaned and cooled synthesis gas
US4328008A (en) Method for the production of cleaned and cooled synthesis gas
EP0423401B1 (en) Two-stage coal gasification process
US4328006A (en) Apparatus for the production of cleaned and cooled synthesis gas
US9890341B2 (en) Gasification reactor and process for entrained-flow gasification
US4436531A (en) Synthesis gas from slurries of solid carbonaceous fuels
US4289502A (en) Apparatus for the production of cleaned and cooled synthesis gas
US4377394A (en) Apparatus for the production of cleaned and cooled synthesis gas
AU2007245732B2 (en) Gasification reactor and its use
EP2013317A1 (en) Gasification system and its use
US4326856A (en) Production of cleaned and cooled synthesis gas
US4279622A (en) Gas-gas quench cooling and solids separation process
CA1128315A (en) Gas-gas quench cooling and solids separation
GB2053262A (en) Process and Apparatus for Producing Gaseous Mixtures including H2 and CO
US4778485A (en) POX process with high temperature desulfurization of syngas
US4880439A (en) High temperature desulfurization of synthesis gas
EP0305047B1 (en) High temperature desulfurization of synthesis gas
EP0148542B1 (en) Synthesis gas from slurries of solid, carbonaceous fuels
JPH04503526A (en) Coal gasification method and equipment
GB2050198A (en) Production of cleaned and cooled synthesis gas
AU638424B2 (en) Coal gasification process and apparatus
Najjar et al. High temperature desulfurization of synthesis gas
NZ231018A (en) Two-stage coal gasification process and apparatus

Legal Events

Date Code Title Description
MKEX Expiry