US2931715A

US2931715A - Apparatus for the gasification of solid fuels

Info

Publication number: US2931715A
Application number: US618082A
Authority: US
Inventors: Eastman Du Bois
Original assignee: Texaco Inc
Current assignee: Texaco Inc
Priority date: 1956-10-24
Filing date: 1956-10-24
Publication date: 1960-04-05
Anticipated expiration: 1977-04-05

Description

April 5, 1960 nu Bols EAsTMAN 2,931,715

APPARATUS FOR THE GASIFICATION OF SOLID FUELS Filed oct. 24, 195e 3 Sheets-Sheet 1 April 5, 1960 nu Bols EASTMAN 2,931,715

APPARATUS FOR THE GASIFICATION OF SOLID FUELS April 5, 1960 Du Bols EAsTMAN 2,931,715

APPARATUS FOR THE GASIF'ICATION OF SOLID FUELS Filed Oct. 24, 1956 3 Sheets-Sheet 3 APPARATUS FOR THE GASIFICATION 0F SOLID FUELS Dn Bois Eastman, Whittier, Calif., assigner to Texaco Inc., a corporation of VDelaware This inventionrelates toa process for themanufacture .of'valuable gaseous productsfromra solid carbonaceous fuel. :In one of its more .specific aspects, this invention relates to a process 'for the production `of carbon monoxide and hydrogen from a solid carbonaceous fuel by the interaction of said fuel with a mixture of oxygen and steam. ACoke and :various coals, including lignite, anthracite, `and bituminous coals, are suitable as feed materials `for the process of this invention.

The gasification of solid fuels by simultaneous reaction avith oxygen and steam atelevated. temperatures is lfairly yvelLknown. .This Atype .o-f gasification has been .previously carried out successfully at temperatures above abouti2000 F. n reactors containing a large excess of carbon. The solid fuel is generally maintained in a stationary, moving, or dense phase fluidizedbed. Due to previous heat treatment, the solid fuel undergoing reac- :tion is substantially completely, if Ynot entirely, in the :form of coke or char, and consists essentially of carbon and ash. Thus, the steam and oxygen are reactedwith coke or char, rather than with raw coal. A number of the commercially attractive fuels are coals containing volatile matter and often having caking tendencies. v Caking coals imposeV a problem in gasification and severely llimit the lie'ld to which many processes may be applied. vCaking tendencies may be eliminated by various Vtreatments. Removal of the volatilizable constituents by distillation, or coking, is generally most satisfactory but costly. The process of the present invention may lbe -used for the gasification of caking type coals without previous coking or pretreating of the coal.

This application is a continuation-impart ofmy copending application SerialNo. 525,240, filed `luly 29, '1955, 110W Patent No. 2,871,1l4.

In accordance with theL present invention, solid fuel in powder ,form is reacted under pressure with relatively pure oxygen and steam in a flow type reaction zone. Pulverized solid fuel is dispersed in steam and reacted in .dilute phase with an oxygen-containing gas, preferably commercial oxygen of above about 90 percent purity by volume. The gasification reaction is carried out in an unobstructed reaction zone at a pressure in excess of about 100 pounds per square inch gauge. Free heat `transfer by radiation is achieved so that the entire reaction zone operates essentially at a single uniform temperature. The quantity of solid fuel supplied to the generator is just `suiicient to react with the gases. Ash Yis withdrawn from the generator as a fluid slag.

vContrary to previous reports to the effect thatl particles smaller than about 0.05 mm. (50 microns) in diameter tend `to'escape gasification because of insufficient motion brelative to the gaseous reactants, I have found that an impalpable powder is preferred for the present process.

.Particles of solid fuel on the order of 40 microns and smaller. are very suitable as feed; advantageously the largest particles should not exceed 4150 microns in aver- .,ageidiameter. Furthermore, I have found,.unexpectedly,

fhasrrsssurestimetable@ thesascatoafreactiog even 2,931,715 Patented A-pr. 5, 1960` though theoretically, from the consideration ofthe voliune increase upon gasification, lpressure 'should be detrimental. I have also found, contrary to general opinion, that elevated pressures do not result in the production of methane to any appreciable extent. Another nding not supported by previous reports is that a residence time of at least one second is required for effective carbon utilization at these temperatures. Theoretically much longer times could be used but substantially complete carbon consumption has been obtained with 2 seconds reaction time at pressures Vranging from to 500 pounds per square inch vand temperatures of 2200 lto 2600 F.l At the higher temperatures, the reaction time is less than at the lower temperatures.

`For effective gasification of powdered fuel and successful operation of the gas generator, the operating temperature must be maintained above about 2200" rF. While there may be a limited zone at the point of maximum heat release, due to the highly exothermic reaction between carbon and oxygen, where the temperature is considerably higher, heat is distributed very rapidly and uniformly throughout the gasification zone. The measured temperature is very close to that obtained by thermo dynamic calculations.

The temperature of the stream of eflluent gases from the generator is preferably quenched by direct contact with water. 'Y The pressure must be vabove about 100 pounds per lsquareinch gauge and may range as high as 1000 pounds per square inch; preferably a pressure within the range of 200 to 500 pounds per square inch gauge is used.

Mixing of the reactants in the gas generator may lbe effectively accomplished by introducing a stream of oxygen and a stream of steam containing powdered coal into contact with one another at relatively high velocity. Inlet velocities of 100 to 200 feet per second give satisfactory mixing with the streams introduced through concentric tubes. It is preferable to preheat the reactants to a temperature aboveV about 600 F. The oxygen Ais preferably preheated to a temperature of 600 to 800 F. and the steam and coal, to 800 to 1200 F. or higher.V

In a copending application of Du Bois Eastman and Leon P. Gaucher; Serial No. 490,214, tiled February 24, 1955, now U.S. Patent 2,864,677, a novel process for heating and pulverizing carbonaceous solids is disclosed. In accordance with the method disclosed in said application, particles of a solid carbonaceous material, for example coal, are admixed with a liquid to form a suspension and the suspension passed as a continuous conned stream in turbulent ilow through a heating zone comprising an externally heated conduit. The slurry is heated inthe heating zone to an elevated temperature sufficient to vaporize the liquid, thereby suspending the solid particles in vapor and preheating the solid. The solid particles are pulverized by turbulent ow at relatively highvelocity through a grinding zone. This novel step of heating and pulverizing solid carbonaceous material is preferably employed in connection with the present process for gasiiica` tion of the resulting powder with oxygen and steam. The solid fuel particles used for making up the slurry need be only moderately pulverized. Particles having average diameters less than 40 microns, and even less than yone micron, may be economically produced by this method. In a preferred embodiment of this invention, coal in particle form is mixed with sufficient water to form a fluid suspension or slurry. The particles may range from vabout onelquarter inch in average diameter to powder; generally a moderatelypulverized coal containing random sizes below about one-eighth inch is readily obtainable and suitable as feed. The slurry preferably contains only as much Water as is required to make it readily pumpable. The slurry is passed through a tubularv heating Vzone where- ICC in it is heated to a temperature at least sufcient to vaporize the water. The heating step produces a dispersion of powdered coal in steam which is fed into the gas generator. Suicient oxygen is suppliedV to the generator into intimate admixture with the steam and solid fuel to maintain the temperature of the generator within the range of from about 2200 to about 3200 F.

A flux may be used to reduce the fusion temperature of the slag or to render it more uid. The ux may be admixed with the coal and water during the preparation of the slurry. Alternatively, a separate slurry of the flux may be prepared and injected into the coal feed stream either before or after the slurry of coal and water is passed through the heating zone.

Lime is generally required as the iiux, where one is indicated, although with some coals it may be desirable to add uorite, silica or alumina together with lime to increase the quantity of fluidity of the slag. The addition of lime to the generator not only increases fluidity of the slag and decreases the uxing temperature but also effects removal of at least a portion of the hydrogen sulfide from the product gas stream. The amount of lime required as flux may be determined from the composition of the coal ash. In general, the most satisfactory fusion is obtained when the sum of the lime and magnesia in the feed is approximately equal in weight to the sum of the silica and alumina. The lime and magnesia may be in the form of the carbonates, but should be converted to equivalent quantities of the oxides in determining the quantity of ilux required.

Part of the vapors may be separated from the powdered solid in the effluent from the heating step before the stream is fed into the generator.

Some coals require substantial theoretical amounts of steam for the production of hydrogen and carbon monoxide by reaction with steam and oxygen. Others contain water in suicient quantity or even in excess of the theoretical requirements. Anthracite is an example of the former, requiring a considerable quantity of steam, for example 30 percent by weight based on the weight of the anthracite fed. Lignite is an example of the latter and contains more than the theoretical requirement of Water.

Water in excess of the theoretical requirement is not detrimental to the gasification reaction.

The total oxygen requirements for the generator, that is, oxygen from the steam as well as free oxygen, must be at least 10 percent in excess of the amount theoretically required to convert the carbon content of the solid fuel to carbon monoxide. v In general, satisfactory operation may be obtained with a total oxygen supply of l0 to 200 percent in excess of the theoretical requirements. As the steam preheat temperature is increased, the free oxygen requirements decrease. In general, however, it is necessary to use from about 0.4 to about 1.0 pound free oxygen per pound of coal. From about 0.3 to about 2.0 pounds of steam per pound of coal may be used.

Preferably the ratio of area of the internal surface of the generator to the surface of a sphere of equal volume is less than about 1.5. A cylindrical reaction zone having a lengthLto-diameter ratio not above about 3:1 or below about 1:1n is generally preferred.

The reaction mixture should be directed away from the wall of the reactor. The path of flow and volume of reactants should be such that the proper residence time, as defined above, is obtained. In a preferred embodiment, the reactants are introduced axially into one end of a cylindrical reaction space and the product gases discharged from the opposite end.

The reactor is preferably constructed with an outer steel shell capable of withstanding an internal pressure considerably in excess of the operating pressure and provided with a high temperature refractory lining.

' Figure l is a diagrammatic view illustrating one arrangement of apparatus for carrying out the process of the present invention.

Figure 2 is a diagrammatic view illustrating a preferred arrangement of apparatus for the gasification of coal in accordance with the present invention.

Figure 3 is an elevational view in cross section of a preferred form of gas generator and for carrying out the process of this invention.

Figure 4 is a elevational view partly in cross section and partly diagrammatic illustrating a preferred form of gas generation and gas scrubbing apparatus suitable for carrying out the process of this invention.

With reference to Figure 1 of the drawings, crushed coal is admitted through valve 6 into a charging hopper 7. An inert gas is admitted to the charging hopper through valve 8 to build up pressure in the hopper equivalent to the desired feed pressure. Gas may be vented from the charging hopper through valve 9. From the charging hopper the coal is admitted through valve 11 into a feed hopper 12. Provision is made for the addition of a pres surizing gas to the feed hopper through line 13. From the feed hopper powdered coal passes through a feed rate controller 14 into a jet type mixing device 15. For the sake of simplicity in the figure, the feed rate controller is indicated simply as a valve. Suitable rate of feed controllers, e.g., feed screws and toothed wheels, are well known. Steam under pressure is admitted through line 16 to the jet mixer 15 which introduces the coal particles into a stream of steam.

The resulting mixture of steam and coal particles is passed at relatively high velocity through a conduit 18, which may be externally heated, for example by a heater 17, wherein the coal is preheated and subjected to further disintegration. Heat may be supplied by external heating or all of the heat required for preheating the coal may be supplied by the steam. A dispersion of powdered coal in the steam is discharged into generator 19 through a suitable burner 20. Sufficient oxygen is admitted into the generator 19 through line 21 to maintain the temperature in the generator within the range of 2200 to 3500 F., preferably in the range of 2200 to 2800 F. Product gas and slag are discharged from the generator directly into a slag pot 22 placed directly below the generator as illustrated in Figure 3. The slag pot and generator may be conveniently contained in a single pressure vessel, as illustrated. It will be evident, however, that separate pressure vessels may be employed for the generator and slag pot, respectively. Water is supplied to the slag pot to collect and solidify the slag. The product gas from the slag pot, together with some of the quench water, is passedinto quench accumulator 23 where the gas is intimately contacted ,with water. Figure 3 illustrates a preferred method of effecting intimate contact between the gas and water. The cooled product gas is discharged through line 24.

The operation of the charging hopper and feed hopper is as follows. With valves I8 and 11 closed and valve 9 open, the charging hopper is at atmospheric pressure. Coal is then admitted through valve 6 until the desired amount enters the charging hopper. Valves 6 and 9 are then closed and pressurizing gas admitted through valve 8 until the pressure in the charging hopper is equal to the pressure in the feed hopper 12. Valve 11 is then opened and the charge transferred from the charging hopper 7 into feed hopper 12. The cycle is then repeated. By this means, coal may be fed continuously at an elevated pressure and at a constant rate and an adequate supply of coal maintained at all times in the feed hopper 12.

With reference to Figure 2 of the drawings, a preferred feeding system is illustrated. Crushed coal is fed into a mixer 26 operated at atmospheric pressure wherein it is admixed with sufficient water to form a fluid slurry. From the mixer 26 of the slurry is passed through line 28 into a thickener 29. Excess water is eliminated from the slurry in the thickener 29 and recycled to the mixer through line 31. The resulting slurry, containing only sufficient water to render it tuid,

is :withdrawn from the thckener 2.9 through line 32arldv charged by means of a pump 33 through-line 34V into a heater 36 operated at an elevated pressure.

The water is vaporized in the heater dispersing the powdered coal in steam. The dispersion is passed through line 1S into the gasy generator 19 as invFigure 1. Oxygen under pressure is admitted through line 21 into admixture with the reactants from line 18 at or near the point of introduction of the reactions to the generator. The generator is operated at a suitable'temperature, for example at a temperature within the range of 2200 to 2500 F. Product gas and slag are discharged from the generator into a slag pot 22. Slag produced in the generator is quenched with water as described in more detail in connection with .Figure 3.` Gas and quench water pass from slag pot 22 into quench accumulator 23. Lime in an amount sufficient for llux in the subsequent gasification step is admixed with water in a mixer l37V to form a slurry and this slurry charged by pump 38A into line 34 where it is admixed` with the coal slurry and passed through the heater 36. Alternatively, thelimev' 6 latorby sl'aacer bars78 ex ending from the shield 74m the wall of the quench accumulator.

f l An outlet 81 at Vthe bottom of the quench accumulator water slurry may be injected into the coal-steam stream following vaporization of the water from the coal-water slurry, or lime may be mixed Awith the coaly before or during the preparation` of the coal slurry.

Figure 3 illustrates a preferred embodiment of the gas generation, slag collection, and gas cooling apparatus for carrying out the processof this invention. The gas generator and slag pot are contained in a pressure vessel having an outer c ylindricalsteel shell 51 designed to withstand the internal operating pressure. The gasrgenerator section is provided withV a liner 52 of suitableA refractory'and insulating materials to withstand the high temperature generated within the gas generation zonel and to protect the shell`from overheating. Burner 20 v introduces reactants into the upper end of the gas generation zone. A partition 53 divides the vessel into two separate zones, the gas generation zone, or gas generator 19, and the slag quench zone, or slag pot 22. Partition 53 is supported by suitable support'members 54. vAn opening 55 through the liner and partition permits passage of dieproducts of reaction from the gas generation zone directly itno the slag quench zone 22.

. The internal surface of vessel 51 and the bottom surface of partition 53 are provided with cooling tubes 56. Cooling water is circulated through the tubes to vprevent overheating of the walls, partition 53, and structural supports 5,4. A metal jacket 57 prevents direct contact of the hot gases with the wall ofthe pressure vessel. -In addition, spray nozzles 58 may be provided in the upper section of the slag pot for'further cooling of the elluent from the gas generator. L Y

Directly beneath the slag pot is a lock hopper 61 provided with

valves

62 and 63 to permit removal of slagy vfrom the slag quench zone. Y

Water may' be supplied to slag pot through line 66. Water may be withdrawn from'the slag pot through line 67 or through water-jacketed product gas lineV 25, or. both.

Product gas is discharged from the slag pot through line into quench accumulator '23.' The quenchV accumulator is provided with a dip leg or pipe 71 thelower end of which is provided with a serrated edge. Pipe 71 is` supported from angev73 and-directly. connected toline 25. A section of pipe 71' adjacent its lower end is provided with 'perforations 72p A cylindrical shieldA 74, open at both ends, surrounds pipe 71 from a point below the 4lower end of pipe 71r to a point near the upper end ofthe quench accumulator. Cylindrical shield 74 extends above outlet 24 for theproduct gas. A cylindrical splash guard 7S` surrounds shield 74 and extends from the top of quench accumulator 23 to a point below product gas outlet 2.4. -Shield`- 74 is supported from pipe Y71 by lugs 77 and is spaced from pipe 71 and from thewall ofthe quench accumupermits withdrawal of quench water therefrom.Y A level controller 82, indicated diagrammatically, may be used to control the liquid level within the quench accumulator by Acontrolling the operation of valve 33.

In operation, steam and coal in highly dispersed con@ dition, prepared for example, as described in connection with either Figure 1 or Figure 2, is introduced into the gas generator through burner 20. The dispersion of coal in steam preferably is discharged directly into the gas generator through a burner of the type illustrated in Figure 3. The steam and co'al liow through the inner pipe 87 while oxygen ows through the annular passageway between

pipes

87 and 88. The outer pipe 88 converges slightly at the burner tip so that the oxygen stream is directed into the stream of coal and steam issuing from the inner pipe 87 providing immediate and complete mixing of the oxygenwith the stream of coal and steam. Means preferably are provided, not killustrated in the drawing, to protect the burner from overheating at the high temperatures prevailing in the combustion chamber by circulation of cooling uid about the burner tip. Preferably, the velocity at the point of discharge of the steam and coal from conduit 87 into the gas generator is above about 30 feet per second. The velocity of the oxygen from the annular passageway at the point of discharge into the gas generator is at least 20 feet per second and preferably in excess of 30 feet per second.

Products of reaction discharged from the gas generator through outlet 5S pass directly into the upper portion of the slag pot. Slag produced during the operationis discharged directly into the slag pot with the hot product gas. The slag drops into a body of water maintained in the slag pot Iwhere it is immediately chilled and solidified. Quick cooling of the vslag in thisl mannerv causes it to form small beads and granular pieces which are easily removed through the lock hopper 61 as de.- scribed below.

Spray nozzles 58, arranged just below the outlet from the gas generator, may be employed to contact the hot gases and slag with a spray of water immediately upon their discharge from the gas generator effecting a partial cooling of the product gas and slag. The spray nozzles may be used to cool the gases to a safe temperature for handling in steel under pressure. Generally the nozzles are not necessary. I Water is admitted to the slag pot through line 66. The water level may be controlled by means of line 67 through which water may be withdrawn into quench accumulator 23 or the water may be permitted to kliow 'through the gas discharge line 25 (as illustrated in FigureA 3) with the product gases into the quench accumulator. y Slag is removed periodically from the slag pot through lock hopper 61. Removal of slag is accomplishedby opening valve 62 with valve 63 in closed position, permitting slag and some water, from the slag pot to enter lock hopper61. Valve 62 is then closed and valve 63 opened, discharging the slag and water from lock hopper 61.

Product gas, together with steam formed by vaporiza- Y tion of water in the slag pot, are discharged throughl line 25 into the quench accumulator. This gas stream also carries some small solid particles of unconsumed fuel or ash (slag)` entrained therein. A body of water is maintained in the quench accumulator the level of, which may be controlled in any suitable manner, for example by means of a liquid controller as indicated diagrammatically. Pipe 71 conducts the gases below the level of the water contained nV the quench accumulator. The gases escape through openings 72, resulting in intimate` contact of the gases with the water, trapping solid particlesfronithe4 gas stream in the water, and cooling: thegases to a temperature well below reaction tempera assiste Theproduct gas is discharged from the quench accumulator through line 24. Water, drawn from the quench accumulator through line 81, may be recycled to the slurry feed preparation step (Figure 2) or to slag pot 22.

With reference to Figure 4 of the drawing, the gas generation chamber and slag quench zone are contained in a pressure vessel (as in Figure 3) having an outer cylindrical steel shell 151 designed to withstand the internal operating pressure. The gas generation section is provided with an insulated lining 152 of suitable refractory and insulating materials to withstand the high temperatures generated therewithin during operation.

The refractory insulating lining 152 in the gas generation section is supported by suitable support members 154,. The lower portion of the gas generation reaction cham'- ber opens directly into the slag quench zone, or slag pot, 22. v

Cooling of the shell 151 of the pressure vesselis provided by a metal jacket 156 spaced from the wall of the vessel to form an annular space through which cooling water may be circulated. Metal jacket 156 encloses support members 154 surrounding them with cooling water. Bafiie 155 deliects the cooling water away from the wall of the vessel to ensure adequate cooling of the members and the shelf portion of jacket 156 supporting the lining 152. c Lock hopper 61 directly below vessel 151 permits removal of slag from the slag quench zone. Water may be introduced into the slag quench zone through nozzle 157. Product gas and water are drawn froml slag quench zone through oiftake pipe 160 preferably provided with serrations 161 and passed through Va water jacketed transfer line 162 to a gas cooling and scrubbing tower 163. The gas from the transfer line 162 is dischargedrthrough a vertically disposed dip leg 164 in the. lowerportion of tower 163. Dip leg 164 is preferably provided with serrations 165 and, optionally, also with perforations 166. An opening 167 (not visible in the drawing) is preferably provided in the dip leg 164` to act as a vacuum breaker to prevent drawing of water from the tower to the slag quench zone when the flow of feed gases tothe generator 19 is interrupted. The gases are discharged below the surface of a pool of water maintained in thetower by liquid level controller 168. Water is withdrawn `from` the tower through line 169 in response to the level control.. This water may be returned, with suitable make-up water, to the slag quench zone. A i

The upper portion of tower 163 is providedy with a` packed section 176, suitably containing Raschg` rings, to provide intimate contact between the gases and a' scrubbing liquid. Water is preferablyemployed vas the scrubbing liquid. Water is supplied to the tower as required through line 177 and is distributed over the packing by a suitable spray distributor 178. Scrubbing of the gas with water in the tower not*V only cools the gas to a uniform temperature approximately the *boiling point of water at the existing pressure but also, at the same time, cleanses the gas stream, effecting'rernoval of ash, carbon, or other solid material carriedoverY from the gas generator. Water from packed section 176 is collected in a water trap-out'tray 179, having`a chimney 181 to permit the gas to pass upwardly through the tray into the packed section ofthe columnfV ,A pump 182 draws water from trayV 179 and recircula'tes Vitrto the top of the tower where it is reintroduced through spray distributor 178. 'i t v The scrubbed product gas leaves the column through line 183. A back pressure regulator 184 in ther'gas discharge line controls the pressure in the tower `which in` turn ndetermines the pressure in the gas generation chamber 19. Y

Cooling water is introduced throughline I186 into jacketed transfer line 162.. Upon leavingthe jacket, the water is transferred by line 187 to the cooling space iss formed by jacket 156 through which the water circulates about the jacketed portion of the slag quench chamber and the gas generator reaction chamber. Cooling water is discharged from the generator jacket through line 188, together with any steam generated therein, into an accumulator and steam separator 189. Accumulator 189 is provided with float control 191 to maintain a substantially constant level of liquid therein. Water is withdrawn from the accumulator 189 through line 192 from which it may be introduced, as required, to tower 163 or to the slag quench zone. Steam passes through line 193 to the top of tower 163. Line 193 thereby provides a pressure balance between the internal pressure in the gas generation and slag quench zones and the pressure in the cooling space provided by water jacket 156. This results in a negligible pressure difference at all times between the cooling water in the jacket and the gas in the generator and slag-quench zone and makes possible the use of a relatively thin walled or exible jacket 156. This construction permits complete protection of the wall of the gas generation section and the exposed portion of the quench section of the pressure vessel by providing a sheath of cooling water along the internal surface thereof. This construction is less costly than conventional cooling tubes which generally do not provide complete wall coverage.

Operation of the apparatus of Figure 4 is very much like that of Figure 3, described above. As illustrated in Figure 4, the oxygen is fed through the inner pipe of the burner, which is essentially a concentric double pipe burner, while the steam and coal ow through the annulus.

In the apparatus illustrated in Figure 4, the lower portion of the reaction zone is fully open to the slag-quench zone. Slag which tends to run down the wall of the reaction zone ows freely to the slag-quench zone without forming restrictions or plugs. Contrary to expectations, itis found that heat loss from the reaction chamber is not excessive with this arrangement even though the end of the reaction chamber is completely open to the slagquench zone. Apparently, the products from the reaction zone are substantially opaque to radiation, since no appreciable increase in radiation loss is observed in comparison with the closed end reaction chamber illustrated in Figure 3. I For the sake of simplifying the description, various elements of a conventional nature, such as pressure control valves and the ilke, have been omitted from the foregoing detailed description of the invention.

Example A No. 4 Buckwheat Pennsylvania anthracite was ground to a size such that percent was finer than 100 mesh and mixed with water to form a slurry. The slurry was thickened in a Dorr thickener to approximately equal parts water and coal by weight. The slurry was fed at the rate of 388 pounds of coal and 357 pounds of water per hour through about 225 feet of 1/2 inch extra heavy steel pipe in a gas fired preheater wherein it was preheated to 650 F.

The resulting dispersion of powdered coal in steam was discharged into the upper end of a vertical cylindrical gas generator having a reaction space 22 inches in diameter and 30 inches in length. Unpreheated oxygen was fed at the rate of 3550 standard cubic feet per hour and admixed withthe coal and steam at the point of introduction to the generator. The mixture of reactants was introduced at the center of the end wall and directed into the generator along its axis. A pressure of pounds per square inch gauge was maintained in the generator. Thermocouples placed at two points along the wall of the generator, one about 7 inches from the upper end and the other about 14 inches from the upper end, indicated. a uniform reaction temperature of 2350". F. Molten slag and product gas were discharged through an opening at the lopposite end of the reaction space, or the bottom of lthef-"generaton into arslagi quenchv zone in which the slag collected iu water. The product gas was quenched by direct contact with Acooling water.

*"Product gas of the" following compositionj waslv produced at the rate of 12,935standard,"y cubic feetv per'hour:

Moly percent Carbon monoxide 47.11 Carbon dioxide 18.23 Hydrogen 33.51 Nitrogen 1.07 Methane 0.08

`port in its lower portion disposed at a point intermediate said reaction chamber and the lowermost portion of said shell an inlet for reactants in the upper portion of said reaction chamber, means for maintaining a body of cooling liquid in the lower portion of said shell, a thermal shield comprising a water jacket internally of said shell surrounding said reaction chamber and extending to a point below the level of said liquid, and means associated with said gas outlet port for discharging product gas from said reaction chamber into intimate contact with water, said contact means being in communication with said water jacket whereby the perssure within said reac- Vtion chamber and the pressure within said water jacket are equalized.

2. Apparatus for conducting a chemical reaction at elevated pressure and temperature comprising a verticaly extending cylindrical pressure vessel shell having a reaction chamber in its upper portion and a gas outlet port in its lower portion disposed at a point intermediate said reaction chamber and the lowermost portion of said shell an inlet for reactants in the upper portion of said reaction chamber, means for maintaining a body of cooling liquid in the lower portion of said shell, a thermal shield comprising a water jacket internally of said shell surrounding said reaction chamber and extending to apoint below the level of said liquid, a second vertically extending pressure vessel spaced from said irst vessel, a water jacketed transfer line connected with said outlet port and with said second vessel, means for supplying Water to said water jacketed transfer line and for discharging water from said jacketed transfer line directly into said internal water jacket within said pressure vessel shell, and means `for equalzing the pressure between said internal water jacket and said second pressure vessel.

3. Apparatus for-conducting a chemical reaction at elevated pressure and temperature comprising a vertically extending cylindrical pressure vessel shell having a reaction chamber in its upper portion and a gas outlet port in its lower portion, said reaction chamber having a refractory heat insulating wall defining a cylindrical reaction space therewithin and having an axially disposed inlet for reactants at the upper end thereof and an outlet at the lower end thereof, a slag quench zone in the lower portion of said vessel, means for maintaining a body of cooling liquid in said slag quench zone, a thermal shield comprising a water jacket internally of said shell surrounding said reaction chamber and said slag quench zone and extending to a point below the level of said liquid, and means for equalzing pressure between the interior of said gas generation zone and said water jacket.

4. Apparatus for'conducting: a chemical reactiony at elevated pressure and temperature comprising a verticallyY extending cylindrical pressure vessel shell having areaction chamber in its upper portion and a gas outlet port in its'lower portion, said reaction chamber having a re'- fractory heat insulating wall defining a cylindrical reaction space therewithin and having an axially disposed inlet for reactants at the upper end thereof and an outlet at the lower end thereof, a slag quench zone in the lower portion of said vessel, means for maintaining a body of cooling liquid in said slag quench zone, a thermal'shield comprising a water jacket internally of said shell surrounding said reaction chamber and said slag quench zone and extending to a point below the level of said liquid, vertical support members spaced peripherally around the inner wall of said pressure vessel shell and within said water jacket below said heat insulating wall in supporting relationship thereto, and means for circulating cooling liquid through said water jacket.

5. Apparatus for conducting a chemical reaction at elevated pressure and temperature comprising a vertically extending cylindrical pressure vessel shell having a reaction chamber in its upper portion and a gas outlet port in its lower portion, said reaction chamber having a refractory heat insulating wall defining a cylindrical reaction space therewithn and having an axially disposed inlet for reactants at the upper end thereof and an outlet at the lower end thereof, a slag quench zone in the lower portion of said vessel, means for maintaining a body of cooling liquid in said slag quench zone, a thermal shield comprising a water jacket internally of said shell surrounding said reaction chamber and extending to a point below the level of said liquid, vertical support members spaced peripherally around the inner wall of said pressure vessel shell and within said water jacket below said heat insulating wall in supporting relationship thereto, and dellectng means associated with said support members for directing coolant away from said shell to accomplish cooling of said members.

6. Apparatus for the gasication of solid carbonaceous material by direct oxidation with oxygen and steam at an elevated pressure and a temperature above the fusion point of incombustible residue or ash contained in said fuel, which comprises a vertical cylindrical pressure vessel shell having a refractory lined reaction chamber in its upper portion; a quench chamber in the lower portion of said shell adapted to contain a body of water therein; an inlet for reactants in the upper portion of said reaction chamber an outlet port from said reaction chamber directly into said quench chamber, said outlet port being disposed centrally of said pressure vessel; a gas outlet port in said quench chamber intermediate said reaction chamber and the lowermost portion of said shell; means for maintaining a body of cooling liquid in said quench chamber; a thermal shield comprising a water jacket internally of said shell extending from said reaction chamber to a point below the level of said liquid; and means for equalzing pressure between the interior of said gas generation chamber and said water jacket.

7. Apparatus for conducting a chemical reaction at elevated pressure and temperature comprising a vertically extending cylindrical pressure vessel shell having a reacf tion chamber in its upper portion and a slag quench zone in its lower portion, an inlet'for reactants in the upper portion of said reaction chamber, a gas outlet port in the lower portion of said shell disposed at a point intermediate said reaction chamber and the lowermost portion of said slag quench zone, means for maintaining a body of cooling liquid in said slag quench zone, a thermal shield internally of said shell extending from said reaction chamber to a point below the level of said liquid, and means for circulating cooling liquid through said thermal shield.

8. Apparatus as defined in claim 7 wherein said thermal shield comprises a metal jacket.

9. Apparatus` for conducting a chemical reaction at elevated pressure and temperature comprising a vertically extending cylindrical pressure vessel shell having' a reaction chamber in its upper portion and a slag quench zone in its lower portion, an inlet for reactants in the upper portion of said reaction chamber, a gas outlet port in the lower portion of said shell disposed at a point intermediate said reaction chamber and the lower most portion of said slag quench zone, means for maintaining a body of cooling liquid in said slag quench zone, a thermal'shield internally of said shell surrounding said reaction chamber and extending to a point below the level of said liquid, and means for circulating cooling liquid through said thermal shield.

12 ReferencesA Cited in thele of this-patent UNITED STATES PATENTS s :2,177,665 Loughrey Oct. 31, 1939 2,558,746 Gaucher July 3, 1951 2,701,755 Strasser Feb. 8, 1955 2,702,744

Totzek Feb. 22, 1,955

Y, V OTHER REFERENCES 'Y Ser. No. 303,852, Szigeth (A.P.C.), published April 27, 1943, now abandoned.

v Odell: Bureau of Mines Information Circulator No. 7415, November 1947. i Y p

Claims

1. APPARATUS FOR CONDUCTING A CHEMICAL REACTION AT ELEVATED PRESSURE AND TEMPERATURE COMPRISING A VERTICALLY EXTENDING CYLINDRICAL PRESSURE VESSEL SHELL HAVING A REACTION CHAMBER IN IS UPPER PORTION AND A GAS OUTLET PORT IN ITS LOWER PORTION DISPOSED AT A POINT INTERMEDIATE SAID REACTION CHAMBER AND THE LOWERMOST PORTION OF SAID SHELL AND INLET FOR REACTANTS IN THE UPPER PORTION OF SAID REACTION CHAMBER, MEANS FOR MAINTAINING A BODY OF COOLING LIQUID IN THE LOWER PORTION OF SAID SHELL, A THERMAL SHIELD COMPRISING A WATER JACKET INTERNALLY OF SAID SHELL SURROUNDING SAID REACTION CHAMBER AND EXTENDING TO A POINT BELOW THE LEVEL OF SAID LIQUID, AND MEANS ASSOCIATED WITH SAID GAS OUTLET PORT FOR DISCHARGING PRODUCT GAS FROM SAID REACTION CHAMBER INTO INITIMATE CONTACT WITH WATER, SAID CONTACT MEANS BEING IN COMMUNICATION WITH SAID WATER JACKET WHEREBY THE PRESSURE WITHIN SAID REACTION CHAMBER AND THE PRESSURE WITHIN SAID WATER JACKET ARE EQUALIZED.