JP2719424B2 - Coal gasification method and apparatus - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to the gasification of carbonaceous materials, and more particularly to the conversion of solid carbon fuels into high fuel value gas products.

Regarding gasification of carbon materials such as coal, the following three processes have been developed. (1) solid bed gasification, (2) fluidized bed gasification and (3) suspension gasification or entrainment gasification.

An inherent disadvantage of entrainment gasifiers is that they generate hot product gases. Hent valu of coal
To use e) fully, the heat must be recovered from the gas. Direct quenching of the gasification reaction by partial oxidation with water or steam (US Pat. Nos. 2,957,387, 3,000,711 and 3,723,345), or partial cooling of the effluent gas by indirect heat exchange (US Pat. No. 3,025,149). Is known. However, a large amount of high-temperature heat is lost when quenching the effluent gas, and the fuel value of the produced syngas does not increase.

Another disadvantage of the entrainment gasifier is that the temperature of the gaseous product is too high, so that it must be quenched or cooled in order to continue to recover heat in a conventional radiant hot water boiler. That is, the product gas must be cooled considerably before being introduced into the heat recovery boiler. As such, a significant amount of the high temperature heat that would be useful is lost. Moreover, the equipment cost of the radiant heat recovery boiler is extremely high. Therefore, another heat recovery boiler is economically necessary for the entrainment gasification method.

A further disadvantage of the entrainment gasification method is that sticky slag particles are carried through the partial gasification reactor and do not tend to foul the heat transfer surfaces of the heat recovery unit.

The reaction in the coal gasifier includes an exothermic reaction and an endothermic reaction. It is highly desirable if there is a coal gasification method that uses the heat generated by the exothermic reaction as heat required for the endothermic reaction,
Energy efficiency will be good. That is, an object of the present invention is to combine an exothermic reactor for partially oxidizing a carbon material with an oxygen-containing gas with an unfired second reactor, and reacting the additional carbonaceous material with water to obtain high quality. An object of the present invention is to provide a reactor for efficiently proceeding an endothermic reaction for producing a synthesis gas. These and other objects are achieved in accordance with the invention described below.

In general, the present invention provides a non-catalytic two-stage upward flow process for gasifying carbonaceous materials, which process produces a non-polluting gas product that can use a combustion tube waste heat unit. I do. The first or first step of the process is a first increment of a slurry of carbonaceous solid particles dispersed in a stream of oxygen-containing gas and a carrier liquid in a horizontal slag production reaction zone or combustion reactor that is heated and heated. (Increment) and burning. The solids concentration of the slurry is between 30 and 70 weight percent. Combustion was performed at 1300 to 1650 ° C (2400 to 1400 ° C) using a horizontal burner nozzle facing in the horizontal reactor zone.
Occurs at a temperature of 3000 ゜ F). Preferably, the horizontal burner nozzle is also coaxial, but not required. This oxygen, the carbonaceous solids and the carrier liquid are steam, the vapor of the carrier liquid,
Converts to slag, char, and combustion products.
The slag generated in the reactor flows down to the bottom of the reactor due to gravity, and is discharged from the reactor via a tap hole. In the second stage, the second step, it is burned (fire
d) contacting the steam from the horizontal reactor, the vapor of the carrier liquid, the char and the gaseous product with a second increment of the solid carbon particle slurry in the carrier liquid in an unburned vertical second stage reactor; , Water vapor, carrier liquid vapor, syngas and char, which are entrained in the effluent gas. As used herein, the term "unfired" means that the addition of a second oxygen-containing gas does not further promote combustion. This vertical second stage reactor does not further promote the combustion or exothermic reactions that occur in the burning horizontal reactor. In a vertical second stage reactor, an endothermic reaction exclusively using the heat generated by the combustion in the burned horizontal reactor occurs. A second increment of the carbonaceous solid particles in the carrier liquid is injected into a vertical second reactor along with steam or other atomizing gas that sprays the carbonaceous solid particle slurry to improve the reaction. Injecting a second increment of slurry at a point downstream from the initial injection point lowers the temperature of the gas leaving the horizontal reactor being burned and more efficiently uses the heat generated in the process. That is,
The horizontal reactor being burned is primarily a combustion reactor, while the vertical second stage reactor is primarily a quench reactor, which increases the value of the heat source of the gas. The solids concentration of the second incremental slurry is between 30 and 70 weight percent. The temperature of the second vertical reactor is 870 to 1100 ° C (1600 to 2000
゜ F). In one preferred embodiment of the process of the present invention, an unburned vertical second stage reactor is connected directly to the top of a burned horizontal reactor, and hot reaction products are transferred from the horizontal reactor to the second stage. It is carried directly to the reactor to minimize heat loss of the reaction product gas and associated solids. The direct connection also has the advantage of maintaining a temperature that prevents the slag formed from being cooled in the first stage horizontal reactor to form solid deposits.

The char associated with the syngas and effluent gas from the unburned vertical second stage reactor exits at the top and is separated by a cyclone separator. The char exiting the cyclone separator is mixed with the carrier liquid to form a dilute slurry. Thereafter, the slurry is solidified in the settling tank at a solid content of 10 to
Concentrated to 30 weight percent. Next, 5 to 20 percent of the concentrated recycle char slurry, based on the total amount of solid carbon fuel fed to the first stage, is fed to a preferably horizontal burned slag production reactor. After mixing with one or more streams of carbonaceous solids containing one increment, it is added to the first stage horizontal slag production reactor zone.

After leaving the cyclone, the product gas enters the high temperature heat recovery system. Usually, such a device will be a radiant heat boiler or a water tube boiler, in which case such a boiler is very expensive to install. Thus, a fire-tube-boiler is suitable, which provides the necessary heat exchange capacity, is simple to operate and has low equipment costs,
It well meets the requirements of the heat recovery operation. This operation can be enhanced by adding additional steam heaters.

However, this additional equipment is only practical when the burned combustion reaction step and the unburned second-stage reaction step provide a non-polluting gas stream. That is, it is not possible when the synthesis gas contains aromatic compounds or tar-like heavy hydrocarbons, but these heavy hydrocarbons do not pose a problem in high-temperature heat recovery. The synthesis gas also contains small particles of molten slag, up to 5 micrometers in diameter, which tend to attach the slightly lower melting alkaline surface to the internal heat transfer surface, and thus the boiler heat transfer surface rapidly. They become dirty and inefficient, and sometimes block. That is, it is essential that the method of the present invention provide a non-polluting product gas stream and sufficiently cool the sticky slag granules to be harder and less sticky. Therefore, in the present invention, it is necessary to cool the product gas stream to a temperature lower than the initial deformation temperature of the accompanying slag particles in the presence of a carbonaceous particulate material capable of absorbing the sticky slag to the upper part.

The drawings are an overview of a preferred apparatus useful in the method of the present invention and a process flow diagram for implementing one preferred embodiment of the method of the present invention.

The following description illustrates how to apply the principles of the present invention and should not be construed as limiting the scope of the invention in any way.

More specifically, as shown in FIG. 1, first and second streams of oxygen or an oxygen-containing gas such as air or oxygen-enriched air, and a first increment of slurry of carbonaceous solid particles and a carrier liquid are provided. Enters the apparatus 1 via the mixing nozzles 6 and 6a, respectively. The mixing nozzles 6 and 6a are arranged facing each other in the horizontal burned slag production reactor 3,
It extends via respective end portions 10 and 11 of the reactor 3.
Inside the burned horizontal slag production reactor 3, the feed streams are steam, slag, char, carrier liquid vapor, hydrogen,
Exothermically converted to carbon monoxide, carbon dioxide, small amounts of methane, other gases including ammonia and hydrogen sulfide, and small accompanying grains of cohesive slag. The slag mass generated as a by-product is discharged from the bottom of the reactor 3 through the tap hole 2 to the slag quenching unit 9 and a continuous pressure reducing system (not shown). After leaving the reactor 3, the steam, char, intermediate gas and the products associated with the product flow into the upper unburned second stage reactor 4 where the slurry of carbonaceous solid particles and the carrier liquid forms a slurry. A second increment is injected via the nozzle 8. The heat generated in the reactor 3 and transferred upward is
Used to perform endothermic processes. The endothermic process occurs in the unburned second stage reactor 4 and includes feed water evaporation, carbon-steam reaction and water gas reaction of CO with water. Carbon - steam reaction generates CO and H _2, thus increasing the yield of these usable gases. In the water gas reaction, carbon monoxide reacts with water or steam to produce carbon dioxide and additional hydrogen. Therefore, the reaction that occurs in the unburned second stage reactor enriches the gas produced by the burning combustion reaction to produce high-grade synthesis gas, while recovering heat from the combustion reactor. The slag is sufficiently cooled to cool the gas, and the resulting slag is transformed to the ash fusion initial deformation temperature (1100
By cooling below 11150 ° C. or 2000-2100 ° F.), the accompanying slag droplets will self-bond or fuse onto the particulate material and will not adhere to the heat transfer surface. The mixing nozzles or two-fluid nozzles 6 and 6a atomize the carbonaceous solid particle slurry material to make combustion of the carbonaceous solid more efficient. The nozzle has a central tube for slurry and an annular space surrounding the central tube and containing the atomized gas, and the atomized gas is internally or externally opened toward a common mixing zone to discharge the slurry. A type that is atomized is preferred. Furthermore, the injection nozzles 8 of the unburned second stage reactor 4 can also be of the type described above. Both mixing nozzles 6 and 6a and injection nozzle 8 may be of the internal mixing type or the external mixing type, as is conventionally known to those skilled in the art. Examples of such nozzles and their use in processes similar to the present invention are described in U.S. Patent Application No. 039,493 to Lipp, pending in the United States.
(Filed April 16, 1987) and U.S. Pat. No. 4,679,733 (1
Published on July 14, 987).

As further shown in FIG. 1, the unburned effluent from the second stage reactor 4 is sent to a cyclone separator 5 where it is separated into a solids stream and a synthesis gas stream. Synthesis gas stream is hydrogen, carbon monoxide, small amounts of methane, H ₂ S, ammonia, water vapor,
It consists of carrier liquid vapor, nitrogen, carbon dioxide and a small amount of char particles. The solids stream consists of solidified ash and char produced in the unburned second reactor 4 or conveyed from the horizontal reactor 3. Next, the synthesis gas is sent to a smoke tube boiler 14, and steam is generated from boiler feed water supplied from a water feed line 15, and is sent to a steam drum 16. The steam generated by the boiler 14 is sent to a steam heater 18 to further recover the heat value, and the synthesis gas, which has now become considerably cold, is sent to a line 20.
And exits the heat recovery system via, for further use as the desired fuel rich gas. The char is reduced to a low-concentration slurry and settled, as described in more detail below.
Reactor 3 with new carbonaceous solid / carrier liquid slurry
Recirculate to

The solid stream consisting of char and ash separated from the gas stream in the cyclone separator 5 contacts the carrier liquid to form a dilute slurry and goes to the settling tank 7 for concentration. The slurry may be further concentrated by including a separating means and an evaporating means (not shown) in the settling tank 7. The stream leaving vessel 7 forms a recirculated slurry stream. A suitable recycle slurry concentration of char and carrier liquid is 20 to 40 weight percent, more preferably 30 to 40 weight percent. The slurry of the char and the carrier liquid has a high solids concentration, but if the solids concentration is too high, the viscosity of the feedstock to the burned horizontal reactor 3 becomes excessive, which makes pumping inconvenient. become. The recirculation slurry of the char and the carrier liquid is mixed with the raw slurry of the carbonaceous solid slurry and the carrier liquid in the mixing tank 7a before being transferred to the burned horizontal reactor 3 via the mixing nozzles 6 and 6a. It is desirable to carry out.

The constituent materials of the burned horizontal slag production reactor 3 and the unburned second stage reactor 4 are not critical. This vessel wall is made of steel and is made of insulating castable or ceramic fibers or high chromium-containing bricks in the first stage reactor, dense media used in blast furnaces and non-slag producing applications in the second stage. It is preferred, but not essential, that the lining be made of refractory bricks. All of the above insulating materials are commercially available from several sources. Using this type of system, a high rate of heat value is recovered from the carbonaceous solids used in the process. Optionally, the burned horizontal reactor 3
And, in some cases, the walls are not lined by employing a "cold wall" system in the unburned second reactor 4. As used herein, the term "cold wall" refers to cooling the wall with an outer cooling jacket, as is conventionally known in prior coal gasification systems. In such a system, the slag freezes on the inner wall and protects the metal wall of the cooling jacket.

Reaction conditions within the process will vary with the type of feed and the type of conversion desired. Generally, the temperature of the burned horizontal slag production reactor 3 is 1300 to 1650 ° C (24 ° C).
00 to 3000 ° F). Below this temperature, the slag tends to become more viscous and can freeze and deposit, sometimes clogging the reactor. 1650 ℃ (30
If the temperature is higher than 00 ° F., the reaction will take place rapidly, but less satisfactory product gas will be produced and the overall thermal efficiency will be reduced, thus reducing the economics of operation. The temperature of the second stage reactor 4 that is not burned is 870 ° C to 1100 ° C (1600 to 2000 ° C).
F) is desirable. If the temperature is lower than that, the rate of addition of the carbonaceous material to the product gas decreases, and the production amount of char that requires reslurry and recirculation increases.
The high temperature of the unburned second stage reactor 4 is mainly related to the temperature of the burned horizontal reactor 3. The hot intermediate product flowing upward from the burned horizontal reactor 3 supplies heat for the endothermic reaction that occurs in the unburned second stage reactor 4. The temperature drop in the smoke tube boiler 14 and the steam superheater 18 is related to the inlet temperature and the heat transfer surface. Generally, the inlet temperature is close to the outlet temperature of the unburned second stage reactor 4, typically 870 to 1100 ° C.
(1600-2000 ° F) and typical outlet temperature of the high temperature heat recovery system is 230-290 ° C (450-550 ° F). Although the temperature of each section of the apparatus is important, the specific reaction conditions themselves are important to the method or apparatus of the present invention, except that the high temperature heat recovery system inlet temperature is lower than the temperature at which the slag particles cause contamination problems. is not.

The method of the present invention is performed at atmospheric pressure or higher. Generally, the pressure of the reactor 3 is set to a gauge pressure of 345 to 41,40.
0 kPa (50-600 psig). Pressure is gauge pressure 4140kPa
(600 psig), the capital cost of the high pressure reactor reduces the economic appeal of the process, while the pressure is 345 kPa gauge
Below 50 psig, the product gas output in reactor 3 and unburned second stage reactor 4 is less than economically attractive. This method has a gauge pressure of 690 to 276
It is preferably carried out at a pressure of 0 kPa (100 to 400 psig), most preferably a gauge pressure of 1725 to 2760 kPa (250 to 400 psig).

This method is applicable to any carbonaceous material.
Furthermore, the quality and concentration of the carbonaceous material in both stages are not the same. However, the carbonaceous material particles are preferably coal, including, without limitation, lignite, bituminous coal, subbituminous coal, or any combination thereof. Furthermore, carbonaceous materials include coal coke, coal char, coal residue, granular carbon, petroleum coke, carbonaceous solids derived from shale, tar sands, pitch, dense sour sludge, bits of garbage, rubber And mixtures thereof. The materials exemplified above can be in the form of finely pulverized solids in order to optimize material handling and reaction characteristics as a transportable slurry in a carrier liquid.

The carrier liquid of the carbonaceous solid material can be any liquid that can evaporate and participate in reactions that produce the desired product gas, especially carbon monoxide and hydrogen. The most likely carrier liquid is water, which produces steam in both the reactor 3 and the unburned second stage reactor 4. Water vapor can react with carbon to form product gas, a component of synthesis gas. In addition, the carbonaceous material can be slurried using a liquid other than water. The carrier liquid is preferably water, but is preferably a hydrocarbon such as fuel oil, petroleum or liquid CO.
_It may be ₂ . When the carrier liquid is a hydrocarbon, additional water or steam is added to supply sufficient water for efficient reaction and reaction temperature mitigation.

As the oxygen-containing gas to be supplied to the burned horizontal reactor 3, any gas containing 20% or more of oxygen is used. Suitable containing gases include oxygen, air and oxygen-enriched air as oxygen-containing gas, wherein the initial atomic ratio of free elemental oxygen to carbon in reactor 3 is 1.
5: 1 to 2.5: 1. For oxygen, the ratio is 1: 1 to 2: 1.

The concentration of the carbonaceous material particles present in the carrier liquid as a slurry need only be a concentration that results in a pumpable mixture. Generally, this concentration will range up to 70 weight percent solids material. The concentration of the carbonaceous material particles in the slurry is determined during both the first and second stages of the process.
It is in the range of 30 to 70 weight percent. More preferably, the coal concentration in the aqueous slurry is between 45 and 55 weight percent.

When coal is the feedstock, it is milled and then mixed with the carrier liquid to form a slurry. In general, any material can be used as long as it is a finely divided carbonaceous material, and any known method for reducing the particle size of solid particles can be used. Examples of such a method include a method using a ball mill, a rod mill, and a hammer mill.
Although the particle size is not critical, finely divided carbon particles are preferred. A typical example is powdered coal used as a fuel for coal-fired power plants. The particle size distribution of such coal is
The distribution is such that 90 weight percent passes through a 200 mesh sieve of the Tyler series.

The present invention is illustrated by the following examples, which should not be construed as limiting the scope of the invention in any way.

Example 1 Crushed subbituminous coal, Western Coal (West
ern Coal) 26.7 ° C with 52% and 48% water
195 liters / minute (5 liters / minute) were applied to each of the two facing bar nozzles of the horizontal reactor 3 where the slurry of (80 ° F) was burned.
21,000 gallons / minute, 41,000 kg / hr (90,000 pounds /
H) with a 500 ° C. (950 ° F.) air flow. The temperature inside the reactor 3 was 1430 ° C. (2600 ° F.), and the pressure was 830 kPa (120 psig). The steam produced in reactor 3 and the hot product gas are passed to an upper, unburned second stage reactor 4 where 75 liter / min containing 52 weight percent of powdered subbituminous coal and 48 weight percent of water. 27 ° C (180) flowing at a rate of (20 gallons / minute)
゜ F) and a first increment of slurry, as well as 240 ° C. (465 ° F.) of atomized steam flowing at a rate of 3200 kg / hr (7,000 lb / hr).

In the unburned second stage reactor 4, the heat generated in the reactor 3 is absorbed in a second increment of the slurry and used to convert the slurry to further steam and product gas.
The temperature inside the second stage reactor 4 that is not burned is 980 ° C (1
800 ゜ F). The water vapor and product gas are discharged from the unburned second stage reactor 4 to a cyclone separator 5, where the mixture is separated into a gas stream and a solids stream.
The effluent from reactor 3 consists on a dry basis of 10.4 percent hydrogen, 10.4 percent carbon monoxide, 15.0 percent carbon dioxide, 0.04 percent methane, and 65.0 percent nitrogen. This gas flow is 45,000kg from cyclone separator 5
/ H (100,000 lb / h) and contained 11.8 percent hydrogen, 8.8 percent carbon monoxide, 15.4, percent carbon dioxide, 0.5 percent methane, and 63.4 percent nitrogen on a dry volume basis. This solid content is 1100
90 to 1 flowing at a rate of 300 l / min (300 gallons / min)
Mix with water at 50 ° C. (200-300 ° F.) to form a slurry, concentrate it to 25 weight percent solids and recycle to the burned reactor 3 if desired, or
Alternatively, it was discharged and disposed of.

Example 2 A slurry containing 50 weight percent of powdered subbituminous coal and 50 weight percent of water at 27 ° C. (180 ° F.) was sprayed at 195 liters / minute (5
21,000 gallons / minute, 41,000 kg / hr (90,000 pounds /
H) with a 500 ° C. (950 ° F.) stream of air flowing into the burned horizontal reactor 3. The temperature inside the reactor 3 is 1450 ° C (2650 ° F), and the pressure is 758.4 gauge pressure.
It was 2 kPa (110 psig). Second stage reactor 4 not burning the steam and hot product gas produced in reactor 3
, Containing 40 weight percent of powdered subbituminous coal and 60 weight percent of water at 106 liters / minute (28 gal /
Min.) And a second increment of 27 ° C. (80 ° F.) slurry and 240 ° C. (465 ° F.) atomized steam flowing at a rate of 3200 kg / hr (7,000 lb / hr). In the unburned second stage reactor 4, the heat generated in the reactor 3 was absorbed in a second increment of the slurry and used to convert the slurry to further steam and product gas. The temperature inside the second stage reactor 4 that is not burned is 980 ° C (1800 ° F)
Met. The water vapor and product gas were discharged from the unburned second stage reactor to cyclone separator 5, where the mixture was separated into a gas stream and a solids stream. The product gas discharged from the upper part of the reactor 3 contains 9.5% of hydrogen, 10.2% of carbon monoxide and 16.5% of carbon dioxide on a dry basis.
Percent, methane 0.07 percent and nitrogen 63.6 percent. 51,000 from the top of cyclone separator 5
The product gas emitted at a rate of 112,000 pounds / hour (112,000 pounds / hour) is 12 percent hydrogen and 10.0 carbon monoxide on a dry basis.
Percent, 11.0 percent carbon dioxide, 0.5 percent methane and 66.4 percent nitrogen. Solids
90 flowing at a rate of 1100 liters / minute (300 gallons / minute)
-200 ° C. (200-3000 ° F.) to form a slurry which is then concentrated to 25 weight percent solids and recycled to the burned reactor 3 if desired, or Discharged and disposed of.

Example 3 In this example, a slurry of powdered lignite and water was used as a feedstock to a reactor similar to that shown as apparatus 1 in FIG. The oxygen-containing gas used 99.6 percent pure oxygen instead of air.

24 ° C (75 ° F) containing 44.5 weight percent dry lignite, with 17 ° C (63 ° F) oxygen flowing at a rate of 740 kg / hr
Was injected into the burned horizontal reactor 3 at a rate of 1330 kg / h. The temperature inside the reactor 3 is 1370 ° C (2500
゜ F) and the pressure was 165 kPa (240 psig) gauge pressure. 45 kg / hr (100 lb / hr) of nitrogen was added to the burned horizontal reactor 3 via a purge device. The steam generated in the burned horizontal reactor 3 and the hot product gas are passed upward into the unburned second stage reactor 4 where 400 kg / h containing 44.5 weight percent dry lignite (87
Contact with a second increment of slurry at 24 ° C (75 ° F) flowing at a rate of 4 pounds / hour and atomized steam at 240 ° C (465 ° F) flowing at a rate of 73 kg / hour (161 pounds / hour). Was. In the unburned second stage reactor 4, the heat generated in the burned horizontal reactor 3 is absorbed in the second slurry increment,
It was used to convert the slurry to additional steam and product gas. The temperature inside the second stage reactor 4 that was not burned was 1000 ° C. (1840 ° F.). The steam and product gas were discharged from the unburned second stage reactor 4 to a cyclone separator 5, where the mixture was separated into a gas stream and a solids stream. This solid stream was added to water and discharged. The effluent from Reactor 3 contained, on a dry volume basis, 43.3 percent hydrogen, 26.6 percent carbon monoxide, 23.3 percent carbon dioxide, 0.8 percent methane, and 5.9 percent nitrogen. The gas stream leaving the cyclone contained, on a dry volume basis, 48.8 percent hydrogen, 22.0 percent carbon monoxide, 23.3 percent carbon dioxide, 2.2 percent methane, and 3.5 percent nitrogen.

Example 4 93 ° C. with 49.5 weight percent powdered sub-bituminous coal and recycle char with a net water flow of 50.5 weight percent, with an oxygen stream flowing at a rate of 13.000 kg / hr (29.200 lb / hr).
(200 ° F) slurry at 325 liters / minute (86 gallons / minute)
Min) into the burned horizontal reactor 3.
The feed slurry was a mixture of 0.92 volume fraction of 51 percent solids subbituminous coal slurry and 0.074 volume fraction of 30 percent solids char slurry. The temperature inside the reactor 3 was 1560 ° C (2840 ° F), and the pressure was 827 gauge pressure.
kPa (120 psig). The steam and hot product gas produced in the reactor 3 are passed from the top through an unburned second stage reactor 4 where 95 liter / min containing 50 weight percent of powdered subbituminous coal and 50 weight percent of water ( Contact with a second increment of slurry at 32 ° C (90 ° F) flowing at a rate of 25 gallons / minute, and atomized steam at 240 ° C (465 ° F) flowing at a rate of 3180 kg / hour (7,000 pounds / hour). Was. In the unburned second stage reactor 4, the heat generated in reactor 3 was absorbed in the second increment of the slurry and used to add the slurry to additional steam and product gas. The temperature inside the heat recovery unit 4 was 1050 ° C. (1920 ° F.). The water vapor and product gas are discharged from the unburned second stage reactor 4 to a cyclone separator 5, where the mixture is separated into a gas stream and a solids stream. The product gas discharged from the top of reactor 3 contained, on a dry basis, 32.7 percent hydrogen, 31.5 percent carbon monoxide, 30.5 percent carbon dioxide, 0 percent methane, and 5.3 percent nitrogen. 23,000 kg / h from the top of cyclone separator 5 (5
The product gas discharged at a rate of 0.504 pounds / hour contained, on a dry basis, 36.1 percent hydrogen, 26.7 percent carbon monoxide, 31.8 percent carbon dioxide, 0.5 percent methane, and 4.9 percent nitrogen. The solids from the bottom of the cyclone are mixed with water at 93-149 ° C. (200-300 ° F.) flowing at a rate of 1135 liters / minute (300 gallons / minute) to form a slurry, which is then reduced to about 25 solids. Recycled to Reactor 3, which was concentrated to weight percent and burned.

Example 5 The following example shows that a smoke tube boiler as shown in FIG. 1 becomes blocked if an unburned second stage reactor 4 is not used in the process of the present invention.

48.7% water and approx.
Percent, hydrogen 4.7%, nitrogen 0.8%,
0.35% sulfur, 19.05% oxygen and 6.6 ash
A 24 ° C. (75 ° F.) slurry containing 51.3 percent of Wyoming subbituminous coal at a rate of 230 gallons at 1050 liters / minute (1.1 kg / kg solids)
1450 ° C (2650 ° F) with 1kg oxygen and gauge pressure 1860
It was fed to an entrained horizontal burned slag production reactor as shown in FIG. 1 operating at 270 psig. This process produced 85,000 kg / hr (187,4000 lb / hr) of syngas, the components of which were 39 percent (volume) hydrogen, 30 percent carbon dioxide, 28 percent carbon monoxide, and 3 percent nitrogen. . The synthesis gas was discharged from the reactor and quenched, and the temperature was lowered using water. The product gas was then directed to a cyclone to remove char and fly ash other than slag particles and tar product particles having a small diameter, ie, less than 5 micrometers. The resulting gas is then led to a long and enlarged tubular vessel to extend the residence time, and then heat recovered at 910 ° C (1670 ° F) in a smoke tube boiler. It was fed to a heat recovery and normal gas scrubber to produce clean product gas for turbine or chemical synthesis.

During operation under the above conditions, the fire tube boiler was closed inoperable after 37 hours of operation. The obstruction was one in which fly ash particles (particle size ≤ 5 micrometers) piled up on one another to form a large sediment that restricted flow.

Example 6 This example demonstrates that the operation of the unburned second stage reactor 4 in the two-stage gasifier shown in FIG. 1 produces non-polluting syngas and thus supports the flue-tube boiler operation. It is shown.

49.5% water and 50.5% Wyoming sub-bituminous coal with an elemental analysis similar to Example 5
Minute (340.2 gal / min), 1.12k / kg solids
With g of oxygen, it was fed to the same horizontal entrained production reactor as in Example 5. This reactor is 1,400 ° C (2
617 ° F) and a gauge pressure of about 2365 kPa (343 psig), 29.4 percent carbon monoxide, 1.9 percent methane, 28.1 percent carbon dioxide, 38.8 percent hydrogen,
11,000 kg / hr of syngas with 1.8% nitrogen (244,900
(Pounds / hour). 125 liters / min (33
Gallon / min) second stage reactor 4 not burned
The gas stream was quenched by the slurry stream injected into the. This slurry also contains 46.9% water and 5 Wyoming sub-bituminous coal.
It was a 3.1% slurry. This product gas is further quenched with water, and then passed through a large-diameter tubular reactor at 955 ° C (751 ° C).
F), passed through a smoke tube boiler at a surface tube speed of 39 meters / second (127 feet / second). The gas exiting the boiler then went to a venturi scrubber, a low temperature heat recovery and normal gas scrubber, to produce clean synthesis gas. This gas did not block the smoke tube boiler even after several hundred hours of operation.

Example 7 This example uses a non-burned second stage reactor to rapidly cool the product gas from the combustion reactor 3 to increase the product gas content and to prevent contamination of the fire tube boiler. Explain effectiveness.

A slurry of 52.1 percent water and 47.9 percent Wyoming sub-bituminous coal of the same analysis as in Example 5 with a flow rate of 1400 liters / minute (373 gallons / minute) along with 1.14 kg of oxygen per kg solids was wake-up horizontal combustion. To the slag production reactor. This gasifier is 1300 ℃ (2467 ゜
F) and operating at a gauge pressure of 2760 kPa (400 psig) and a synthesis gas of 28 percent carbon monoxide, 1.3 percent methane, 30 percent carbon dioxide, 40 percent hydrogen and 2 percent nitrogen (dry mole percent) at 121,000 kg / hr (266,100 (Pounds / hour). This product gas was passed through the unburned second stage reactor 4 and a slurry of 49 percent water and 51 percent Wyoming sub-bituminous coal of the same analytical value as above was injected at a rate of 205 l / min. And rapidly cooled to 925 ° C (1700 ° C). Next, the quenched gas was pumped at 33.0 meters / second (108.36 feet /
S) through the smoke tube boiler, but the smoke tube boiler was not contaminated.

As a further aspect of the present invention, there is provided an apparatus for partially oxidizing a carbonaceous material particle slurry and an oxygen-containing gas, comprising: (a) a burner having both ends closed and facing substantially aligned with a central long axis. A horizontal cylindrical insulated burned slag production reactor having a bottom slag tap hole centrally located between said closed ends and an upper product gas vent; (b) an upper outlet And a transition piece that is a frustoconical insulated portion aligned with and surrounding the upper vent, and (c) closely coupled to the transition piece, A vertical cylindrical insulation having a lower inlet surrounding and communicating with the upper transition piece outlet, an injection nozzle for quenching the product gas from the burned reactor, and an upper product gas outlet. Burned There is provided an encompassing apparatus of the second stage reactor.

While several representative embodiments and details have been set forth for purposes of illustrating the invention, those skilled in the art will appreciate that various modifications and variations can be made without departing from the spirit and scope of the invention. Will be obvious.

Continuing the front page (72) Inventors Peters, Bruce Sea, Pinewood Drive, Midland, 48640, Michigan, USA 6111 (72) Inventors Lafayette, Larry El, 70809, Louisiana, USA Baton Rouge, Kinglet・ Drive 9966 (56) Reference US Pat. No. 2,963,354 (US, A) US Pat. No. 4,568,680 (US, A) US Pat. No. 3,979,725 (US, A) US Pat. No. 4,169,966 (US, A) US Pat. Patent 4247302 (US, A) US Patent 4457203 (US, A) European Publication 225146 (EP, A1)

Claims (11)

(57) [Claims] 1. A stream comprising an oxygen-containing gas and a first increment of a slurry of particulate carbonaceous material in a carrier liquid is burned in a burning horizontal slag production reactor to produce slag, gaseous Forming a product and associated by-products selected from sticky slag granules, vapors from aromatic hydrocarbon compounds and char granules; (b) separating the slag; (c) unburned vertical In the second stage reactor, the steam, the vapor of the carrier liquid, the char particles and the generated gas from the horizontal reactor being burned and the second increment of the slurry in the carrier liquid of the carbonaceous material particles are heated to 870 to 1100 ° C. (1600 to 2000 ° F.), thereby recovering a substantial part of the heat generated in the reactor, and converting the carbonaceous material and the carrier liquid into steam, steam from the carrier liquid, syngas And char, and accompany the generated gas Cooling the viscous slag particles to a temperature lower than the initial deformation temperature and absorbing the slag particles onto the char particles to prevent fouling; (d) differentiating the heat value of the combustion product gas in a high-temperature heat recovery system. Recovering the portion, thereby synthesizing the syngas from about 230 to
A non-catalytic two-stage upward flow gasification method for a carbon material, comprising a step of cooling to a temperature of (450 to 550 ° F). 2. The method of claim 1 further comprising the step of: (e) recycling the char exiting said step (c) to step (a) as a suspension in liquid having a solids concentration of 20 to 40 weight percent. Term method. 3. The step (e) comprises: (e ₁ ) separating the char from the syngas; (e ₂ ) contacting the char with the liquid to form the suspension of the char in the liquid; e ₃₎ the range the second term of the process of the tea suspensions claims further comprising the step of recirculating to the reactor being burned with the. 4. The method according to claim 1, wherein the carrier liquid is water. 5. The method of claim 1 wherein said solids concentration is between 30 and 70 weight percent in both steps (a) and (b). 6. The method according to claim 1, wherein the oxygen-containing gas is air, oxygen-enriched air or oxygen. 7. The oxygen-containing gas is air and the initial atomic ratio of free elemental oxygen to carbon in the reactor is 1.5:
The method of claim 1 wherein the ratio is 1 to 2.5: 1. 8. The method according to claim 1, wherein said carbonaceous material is coal or lignite. 9. The method of claim 1 wherein said unburned vertical heat recovery unit is connected to the top of said burned horizontal reactor. 10. The method of claim 5 wherein the solids content is from about 45 to about 65 weight percent in both step (a) and step (b). 11. An apparatus for partially oxidizing a slurry of particulate carbonaceous material with an oxygen-containing gas, comprising: (a) both ends closed and substantially at the central longitudinal axis of said burned reactor. Horizontal cylindrical insulated burned slag production reaction with aligned facing burners and with a centrally located bottom slag tap hole between the closed ends and an upper product gas vent A transition piece which is an insulated portion of a truncated cone aligned with and surrounding the upper vent, having (b) an upper outlet and a wider lower inlet; And a lower inlet that surrounds and communicates with the upper outlet for the transition piece.
A vertical cylindrical insulated unburned second stage reactor having a product gas outlet above an injector nozzle for quenching the product gas from said burned reactor. Equipment to do.