JP4107869B2 - Desulfurization equipment operation device incorporated in coal gasification system and its operation method - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a method and system for operating a desulfurization facility incorporated in a coal gasification system, and in particular, a CH solid organic matter generated in a liquid circulation line in the desulfurization facility of the coal gasification system is treated in the system. The present invention relates to a method and a system for operating the desulfurization facility that reduce the amount of waste generated during plant operation.
[0002]
[Prior art]
Conventionally, an apparatus shown in FIG. 2 has been proposed as a coal gasification system.
In the figure, 1 is an air-blown pressurized two-stage entrained bed gasification furnace comprising a combustor 1a and a reductor 1b. After combusting high-temperature combustion by putting pulverized coal (coal), char and air into the combustor 1a, Pulverized coal (coal) is further introduced into the upper reductor 1b, and dry distillation gasification is performed using high-temperature combustion of the combustor 1a. Gasified CO, H _{2 and} other generated gases are cooled by a water-cooled wall boiler (heat recovery boiler) 12 and then a porous filter (dust removal device) 13, a gas heat exchanger 21, a COS converter 22, gas heat after removal of the ammonia in the ammonia removal device comprising a gas cooling tower 14 and the gas washing column 15 via exchanger 23, it is sent to the H ₂ S absorption tower 16, to remove the H ₂ S.
Strainers 8 and 9 are provided in a cooling water return line 31 from the gas cleaning tower 15 to the gas cooling tower 14 and a line 32 from the gas cooling tower 14 to the cooling water storage tank 26, respectively. A solid organic substance mainly composed of benzene-based hydrocarbons precipitated is separated.
In the H ₂ S absorption tower 16, sulfur compounds such as H ₂ S, COS and the like in the crude product gas are removed by the absorption liquid to an allowable concentration of the gas turbine 17 or less.
[0003]
The purified gas is sequentially heated in the steam heat exchanger 24, the gas heat exchanger 23 and the gas heat exchanger 21 and sent to the gas turbine 17 for power generation, while the combustion exhaust gas from the gas turbine 17 is generated. Is recovered by high-pressure steam heated by the steam heat exchanger 24 at the same time as it is cooled by a waste heat recovery boiler (not shown), and the steam obtained here is sent to a steam turbine (not shown) for power generation. Is called.
[0004]
The absorbent that has absorbed the sulfur compounds such as H ₂ S in H ₂ S absorption tower 16 is sent to an absorption regeneration tower 18, the H ₂ S which is absorbed by heating the absorption liquid regeneration heater 19 desorbed Played.
[0005]
[Problems to be solved by the invention]
In the desulfurization facility incorporated in such a coal gasification system, a cooling water return line 31 to the gas cooling tower 14 for removing the ammonia gas and a line 32 from the gas cooling tower 14 to the cooling water storage tank 26 are provided. The strainers 8 and 9 are respectively provided on the extraction lines from the H ₂ S absorption tower 16 to the heat exchanger 25, and the strainers 10 are provided to precipitate benzene hydrocarbon solids generated by cooling the product gas.
In such a coal gasification combined power generation desulfurization apparatus, solid matter generated in a liquid circulation line in the facility has been recovered by a foreign matter removing apparatus such as a strainer and discarded as industrial waste.
[0006]
However, it is very difficult to dispose of solids in order to prevent pollution.
Therefore, in recent years, it has been studied to burn the solid matter, but not only the precipitation point is originally high and the combustion is difficult, but also it tends to adhere to the furnace wall as tar or the like.
An object of the present invention is to reduce the amount of waste generated during plant operation by treating CH solid organic matter generated in a liquid circulation line in a desulfurization facility of a coal gasification system in the system in view of the problems of the conventional technology. An object of the present invention is to provide a method and system for operating the desulfurization facility.
Another object of the present invention is to provide a method for operating the desulfurization facility capable of treating the CH-based solid organic matter in a closed cycle and more efficiently recovering heat.
[0007]
[Means for Solving the Problems]
The present invention solves such a problem. In the desulfurization equipment section of the coal gasification system, the solid organic matter recovered by the solid matter removing device provided in the liquid circulation line in the equipment is either light oil, kerosene, or acetone. less becomes dissolved in an organic solvent, the lysate, as well as used as a part of the pulverized coal to be charged into the hot combustion to coal gasification furnace to produce a product gas fuel, the lysate hydrogen sulfide Operation of a desulfurization facility built in a coal gasification system, characterized in that steam is generated by combustion exhaust gas generated by burning in an off-gas combustion furnace that burns off stripper gas, and this steam is used to drive a steam turbine. Suggest a method.
According to this invention, the CH solid organic matter generated in the liquid circulation line in the desulfurization facility has a size from 5 mm to an egg size, and if it is retained, it grows from an irregular sludge to a size larger than the egg size. Since this is dissolved in an organic solvent and used as part of the fuel, reliable combustion is possible, and the CH solid organic matter is processed in a closed cycle, and more efficient heat recovery is possible.
Further, the combustion furnace is composed of an off-gas combustion furnace that burns off the hydrogen sulfide stripper off-gas, thereby realizing effective combustion of the hydrogen sulfide stripper off-gas, and a heat exchanger is disposed downstream of the off-gas combustion furnace. By installing and generating steam for steam turbine power generation, it becomes possible to generate steam at a high temperature, and efficient heat recovery is possible.
Furthermore, according to this invention, the said solid substance is processed within a closed cycle system, and the reduction of the waste generation amount at the time of plant operation can be aimed at.
[0008]
In this case, in order to promote the dissolution of the solid organic substance, it is preferable that the solid substance is dissolved after being atomized.
In addition, light oil or kerosene is inexpensive as a solvent for dissolving the solid matter, but by using acetone in combination, it is reasonable in price and promotes dissolution.
[0009]
In a coal gasification system configured to be recoverable by a solids removal device provided in a liquid circulation line in a desulfurization facility part of the coal gasification system, as a suitable system for achieving the invention of such an operation method,
A dissolving means for dissolving the solid organic matter in an organic solvent composed of either light oil, kerosene or acetone, two combustion furnaces for burning the dissolved substance by the dissolution, and combustion exhaust gas generated in one of the combustion furnaces Rutotomoni a heat exchanger to generate steam,
Of the two combustion furnaces, one combustion furnace is a coal gasification furnace that generates pulverized coal at a high temperature to generate product gas, and the other combustion furnace is an off-gas combustion furnace that burns hydrogen sulfide stripper off-gas. Suggest coal gasification system, characterized in that it.
[0010]
As a result, the hydrogen sulfide stripper off-gas is effectively burned, and as described above, a heat exchanger is disposed downstream of the off-gas combustion furnace to generate steam for steam turbine power generation. It becomes possible and efficient heat recovery becomes possible.
[0011]
The combustion furnace may be a coal gasification furnace that generates pulverized coal by high-temperature combustion. In this case, the product gas can be regenerated as well as reused as fuel. Further, as described above, it is preferable to dispose means for pulverizing the solid matter upstream of the means for dissolving the solid organic matter.
[0012]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, the present invention will be described in detail with reference to the embodiments shown in the drawings. However, unless otherwise specified, the dimensions, shapes, relative arrangements, and the like of the components described in this embodiment are merely illustrative examples and not intended to limit the scope of the present invention.
[0013]
FIG. 1 shows an embodiment of the present invention in which CH solid organic matter generated in a liquid circulation line in a desulfurization facility of a coal gasification combined power generation system is processed in the system to reduce the amount of waste generated during plant operation. 1 is an overall view of a combined coal gasification combined power generation system, in which 1 is an air blown pressurized two-stage entrained bed gasification furnace composed of a combustor 1a and a reductor 1b, 12 is a water-cooled wall boiler (heat recovery boiler), 13 Is a porous filter (dust removing device), 21 and 23 are gas heat exchangers, 22 is a COS converter, 17 is a gas turbine, and the configuration up to this point is as described in the prior art.
The product gas heat-exchanged with the refined gas in the gas heat exchanger 23 is cooled and washed by gas-liquid contact with cooling water in the gas cooling tower 14 and the gas washing tower 15 to remove ammonia. That is, strainers 8 and 9 are provided in the return line 31 of the cooling water from the gas cleaning tower 15 to the gas cooling tower 14 and the line 32 from the gas cooling tower 14 to the cooling water storage tank 26, respectively. Solid organic substances mainly composed of benzene hydrocarbons precipitated in cooling water are separated. The installation position of the strainers 8 and 9 may be a circulation line.
[0014]
Then, the product gas from which ammonia has been removed by the ammonia removing device is sent to the H ₂ S absorption tower 16 and H ₂ S is removed by spraying a hydrogen sulfide absorbent.
In the H ₂ S absorption tower 16, sulfur compounds such as H ₂ S, COS and the like in the crude product gas are removed by the absorption liquid to an allowable concentration of the gas turbine 17 or less.
The purified gas is sequentially heated in the steam heat exchanger 24, the gas heat exchanger 23 and the gas heat exchanger 21 and sent to the gas turbine 17 for power generation, while the combustion exhaust gas from the gas turbine 17 is generated. Is recovered by high-pressure steam heated by the steam heat exchanger 24 at the same time as it is cooled by a waste heat recovery boiler (not shown), and the steam obtained here is sent to a steam turbine (not shown) for power generation. Is called.
[0015]
The absorption liquid that has absorbed sulfur compounds such as H ₂ S and COS in the H ₂ S absorption tower 16 is sent to the absorption regeneration tower 18 after the solid organic matter is removed by the strainer 10, and is absorbed by the absorption liquid regeneration heater 19. Heated H ₂ S is desorbed and regenerated.
The absorption liquid regenerated in the absorption regeneration tower 18 is sent to the H ₂ S absorption tower 16 via the heat exchanger 25, and H ₂ S is removed by spraying the hydrogen sulfide absorption liquid as described above. .
Further, the H ₂ S stripper off-gas separated in the absorption regeneration tower 18 is introduced into the off-gas combustion furnace 5 through the line 6 and burned.
[0016]
On the other hand, the solid organic matter separated by the three strainers 8, 9, and 10 is collected by the solid matter collecting device 2 and then pulverized into a fine powder by the solid matter pulverizing device 3 such as a roller mill or a ball mill to dissolve the solid matter. Sent to device 4.
In the solid material dissolution apparatus 4, a first solvent composed of light oil or kerosene and a second solvent composed of acetone are combined and dissolved by stirring as a solvent for dissolving the solid material.
Of course, the cost is lower when only the first solvent made of light oil or kerosene is used as the solvent, and the dissolving power is higher when the second solvent made of acetone is used. Therefore, it is better to stir and dissolve them in combination.
[0017]
Since the dissolved solid / solvent can be used as a liquid fuel, it is introduced into the off-gas combustion furnace 5 through the line 7 together with air and burned together with the H ₂ S stripper off-gas.
In this case, the off-gas combustion furnace 5 has a cylindrical shape, and air and the liquid fuel are introduced into the inlet side thereof, and an H ₂ S stripper is provided at a midway position of the cylindrical off-gas combustion furnace 5 where the combustion zone becomes high temperature. It is better to introduce off-gas and burn.
The high-temperature exhaust gas combusted in the off-gas combustion furnace 5 is provided with a heat exchanger 29 on the downstream side of the off-gas combustion furnace 5 to generate steam for steam turbine power generation. Be sent.
This enables generation of high temperature steam and efficient heat recovery.
[0018]
The liquid fuel may be introduced into the combustor 1a of the coal gasification furnace 1 that generates pulverized coal by high-temperature combustion via the line 11, and in this case, the fuel is reused as the fuel. Since the liquid fuel contains benzene-based hydrocarbons, product gas can be generated again.
[0019]
【The invention's effect】
As described above, according to the present invention, the CH-based solid organic matter generated in the liquid circulation line in the desulfurization facility of the coal gasification system can be processed in the system to reduce the amount of waste generated during plant operation. In addition, the CH-based solid organic matter can be processed in a closed cycle, and more efficient heat recovery can be achieved.
[Brief description of the drawings]
FIG. 1 shows an embodiment of the present invention in which CH solid organic matter generated in a liquid circulation line in a desulfurization facility of a coal gasification combined power generation system is processed in the system to reduce the amount of waste generated during plant operation. 1 is an overall view of a combined coal gasification combined power generation system according to FIG.
FIG. 2 is an overall view of a combined coal gasification combined power generation system corresponding to FIG. 1 according to the prior art.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Gasification furnace 1a Combustor 1b Reductor 2 Solid matter collection device 3 Solid matter grinding device 4 Solid matter dissolution device 5 Off-gas combustion furnaces 6, 7, 11 Lines 8, 9, 10 Strainer

Claims (5)

In the desulfurization equipment section of the coal gasification system, the solid organic matter recovered by the solid matter removal device provided in the liquid circulation line in the equipment is dissolved in an organic solvent consisting of either light oil, kerosene, or acetone, and the dissolution is performed. The product is put into a coal gasification furnace that generates pulverized coal at a high temperature and used as part of the fuel, and the melt is burned in an off-gas combustion furnace that burns off hydrogen sulfide stripper off-gas. A method for operating a desulfurization facility incorporated in a coal gasification system, characterized in that steam is generated by combustion exhaust gas generated and used to drive a steam turbine. The method for operating a desulfurization facility for a coal gasification combined cycle power generation according to claim 1 , wherein the solid matter is atomized and then dissolved in order to promote dissolution of the solid organic matter.   2. The coal gasification system according to claim 1, wherein a first solvent composed of light oil or kerosene and a second solvent composed of acetone are used in combination as a solvent for dissolving the solid matter. Desulfurization equipment operation method. In the coal gasification system configured to be recoverable by the solids removal device provided in the liquid circulation line in the desulfurization facility of the coal gasification system,
A dissolving means for dissolving the solid organic matter in an organic solvent composed of either light oil, kerosene or acetone, two combustion furnaces for burning the dissolved substance, and combustion exhaust gas generated in one of the combustion furnaces Rutotomoni a heat exchanger to generate steam,
Of the two combustion furnaces, one combustion furnace is a coal gasification furnace that generates pulverized coal at a high temperature to generate product gas, and the other combustion furnace is an off-gas combustion furnace that burns hydrogen sulfide stripper off-gas. coal gasification system, characterized in that it.   5. The coal gasification system according to claim 4, wherein means for pulverizing the solid matter is disposed upstream of the means for dissolving the solid organic matter.

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