JP5407358B2 - Gasification gas purification method and apparatus - Google Patents

Description

  The present invention relates to a gasification gas purification method and apparatus.

In general, a gasification gas refining apparatus for coal or the like includes a gasification furnace 1 that generates coal gas by supplying coal and water vapor as gasification raw materials as shown in FIG. 3, and a gasification gas from the gasification furnace 1. The oxidation reforming furnace 2 for oxidizing and reforming the gas at high temperature, the water cooling wall 3 for cooling the gasification gas reformed in the oxidation reforming furnace 2, the gasification gas cooled by the water cooling wall 3 is further cooled and heated A heat exchanger 4 to be recovered, a direct cooler 5 for cooling the gasification gas after being cooled by the heat exchanger 4, an indirect cooler 6 for further indirectly cooling the gasification gas cooled by the direct cooler 5, A booster 7 that pressurizes the gasified gas indirectly cooled by the indirect cooler 6, and a desulfurizer / denitrogenator / desorber that removes sulfur, nitrogen, CO _2, etc. from the gasified gas pressurized by the booster 7. and CO ₂ unit 8, directly cooler 5, indirect cooler 6, waste water treatment for processing the waste water generated in the booster 7 And a 9.

  The gasification furnace 1 is set to gasify coal at a temperature of 700 ° C. to 900 ° C. Further, the gasification furnace 1 includes not only coal and water vapor but also tar content from the waste water treatment device 9. Gas, gas, and other gasification gas remaining after circulation are supplied.

  The oxidation reforming furnace 2 is set so that oxygen and air are introduced and hydrogen is burned to reach a high temperature of about 1100 ° C to 1300 ° C.

  The water cooling wall 3 includes a configuration having piping such as cooling water, and the heat exchanger 4 is configured by a heat recovery structure such as a boiler.

  The direct cooler 5 includes cooling means such as water spray spray, and the indirect cooler 6 includes indirect cooling means such as heat exchange pipes.

  The booster 7 is a gas compressor that pressurizes the gasified gas to about 1 MPa to 5 MPa, and lowers the saturated vapor concentration of tar in the gasified gas.

The desulfurizer / denitrogenator / deCO ₂ unit 8 is configured to separate sulfur (H ₂ S, COS, CS ₂ ), nitrogen (NH ₃ , HCN) and CO ₂ from the gasification gas. Yes.

  The waste water treatment device 9 is configured to treat waste water generated in the direct cooler 5, the indirect cooler 6, and the booster 7, and to separate the tar content and char of the combustible material from the treated water.

When the gasification gas is processed, coal or the like is gasified in the gasification furnace 1, and the gasification gas from the gasification furnace 1 is oxidized and steam reformed in the oxidation reforming furnace 2 to be included in the gasification gas. The reformed gasification gas is cooled by the water cooling wall 3 and further cooled by the heat exchanger 4 to recover the heat, and the cooled gasification gas is directly cooled by the cooler 5 and the indirect cooler 6. Then, the water vapor remaining in the gasified gas is condensed, and the cooled gasified gas is pressurized by the booster 7, and the pressurized gasified gas is cooled by the desulfurizer / denitrogenator / deCO ₂ unit 8. Then, the sulfur content, the nitrogen content, and CO ₂ are separated, and the gasified gas containing CO is used as synthesis gas for power generation and chemical raw material synthesis.

  Here, at the outlet side of the oxidation reforming furnace 2, the gas temperature is lowered to about 1100 ° C. by the water cooling wall 3 to ensure the durability of the heat exchanger 4 on the downstream side, but about 20% of the gasification gas. The cooling water (quenching water) of (molar flow ratio) may be sprayed to lower the gas temperature to about 1100 ° C. to ensure the durability of the downstream heat exchanger 4 and the like. Further, the steam introduced into the gasification furnace 1 and the sprayed cooling water are condensed as the temperature decreases in the downstream direct cooler 5, indirect cooler 6, and booster 7, and sent to the wastewater treatment device 9. Yes.

  The waste water treatment device 9 separates the combustible material tar and char from the waste water and supplies them to the gasifier 1.

For example, Patent Documents 1 and 2 show the general technical level of the gasification gas purification method and the fuel gas reforming apparatus.
JP 2007-45857 A JP 2005-60533 A

  However, when a large amount of gasification gas is processed in such a gasification gas purification method and apparatus, the direct cooler 5, the indirect cooler 6, the booster 7, etc. are increased in size, and the manufacturing cost and the operating cost are increased. There was a problem to do. In the case of patent literature, the same problem has occurred.

  In view of such circumstances, the present invention intends to provide a gasification gas purification method and apparatus capable of downsizing an apparatus and easily using hydrogen.

The gasification gas purification method of the present invention supplies coal and steam as gasification raw materials to a gasification furnace to form gasification gas, and oxidizes and reforms the gasification gas from the gasification furnace in an oxidation reforming furnace. The tar content in the gasified gas is removed, and the reformed gasified gas is cooled with a heat exchanger to recover heat, and the cooled gasified gas is cooled with a cooler and remains in the gasified gas. steam to condense, a said the cooled gasification gas pressurized by the booster, the pressurized pressurized gasification gas purification method of the gasification gas is treated with CO ₂ absorber to separate the CO _2, the A hydrogen separation membrane is disposed downstream of the oxidation reforming furnace between the oxidation reforming furnace and the heat exchanger , and the gasification gas is passed through the hydrogen separation membrane at 1000 ° C. or more to separate hydrogen from the gasification gas. This is to reduce the volume of the chemical gas.

In the gasification gas purification method of the present invention, it is preferable to pass the cooled gasification gas through a hydrogen separation membrane at a temperature of 1000 ° C. to 1100 ° C. to prevent clogging of the hydrogen separation membrane due to tar content .

  In the gasification gas purification method of the present invention, it is preferable that a shift reaction is performed on the gasification gas by an acid gas shift reactor between the heat exchanger and the cooler, and further hydrogen is separated by a hydrogen separation membrane. .

  Moreover, in the gasification gas purification method of this invention, it is preferable to cool the hydrogen isolate | separated with the hydrogen separation membrane with an indirect cooler.

The gasification gas purification apparatus of the present invention supplies a coal and water vapor as gasification raw materials to generate gasification gas,
And oxidation reforming furnace gasification gas oxidizing reforming from the gasifier,
A heat exchanger for recovering heat by cooling the gasified gas reformed in the oxidation reforming furnace;
A cooler for condensing water vapor by cooling the gasification gas after cooling by the heat exchanger;
A booster for pressurizing the gasified gas cooled by the cooler;
And CO ₂ absorbing apparatus for separating CO ₂ by cooling the pressurized gasification gas by said booster,
A separator for a hydrogen separation membrane, which is located between an oxidation reforming furnace and a heat exchanger downstream of the oxidation reforming furnace and separates hydrogen from the gasification gas by passing the gasification gas through the hydrogen separation membrane at 1000 ° C. or higher . Are provided.

In the gasification gas purification apparatus of the present invention, the cooled gasification gas is passed through the hydrogen separation membrane at a temperature of 1000 ° C. to 1100 ° C. to prevent clogging of the hydrogen separation membrane due to tar content . Is a thing

  In the gasification gas purification apparatus of the present invention, an acid gas shift reactor for performing a shift reaction on the gasification gas is provided between the heat exchanger and the cooler, and hydrogen gas is provided downstream of the acid gas shift reactor. The separator of the hydrogen separation membrane which isolate | separates is equipped.

  In addition, the gasification gas purification apparatus of the present invention includes an indirect cooler that cools the hydrogen separated by the hydrogen separation membrane.

According to the gasification gas purification method and apparatus of the present invention, hydrogen is separated from the gasification gas on the downstream side of the oxidation reforming furnace to reduce the volume of the gasification gas. Therefore, the heat exchanger, the cooler, and the booster The processing capacity of the CO ₂ absorber can be reduced, and therefore the heat exchanger, cooler, booster, and CO ₂ absorber can be miniaturized to reduce manufacturing costs and operating costs. Moreover, the outstanding effect that the isolate | separated hydrogen can be utilized easily can be show | played.

  Hereinafter, a first example of an embodiment of the present invention will be described with reference to FIG.

  FIG. 1 is a first example of an embodiment for carrying out a gasification gas purification method and apparatus. In the figure, the same reference numerals as those in FIG. 3 denote the same parts.

The gasification gas purification apparatus of the first example includes a gasification furnace 1 that supplies coal and steam as gasification raw materials to generate gasification gas, and gasification gas from the gasification furnace 1 is oxidized and modified at a high temperature. Oxidation reforming furnace 2 for cooling, water cooling wall 3 for cooling the gasification gas reformed in oxidation reforming furnace 2, and heat exchanger 10 for further cooling and recovering the gasification gas cooled by water cooling wall 3 A direct cooler (cooler) 11 that cools the gasified gas after cooling by the heat exchanger 10, an indirect cooler 12 that further indirectly cools the gasified gas cooled by the direct cooler 11, and indirect cooling A pressure booster 13 that pressurizes the gasified gas indirectly cooled by the pressure vessel 12, a CO ₂ absorber 14 that separates CO ₂ from the gasified gas pressure boosted by the pressure booster 13, a direct cooler 11, an indirect cooler 12, And a waste water treatment device 9 for treating the waste water generated by the booster 13.

  Here, the heat exchanger 10, the direct cooler 11, the indirect cooler 12, and the booster 13 have substantially the same configuration as the conventional example, but are reduced in size by reducing the volume of gasified gas that can be processed. ing.

The CO ₂ absorber 14 is composed of a CO ₂ absorption tower using an absorbing liquid such as amine, methanol, polyethylene glycol, and the like, and is similarly miniaturized by reducing the volume of gasification gas that can be processed.

  A separator 15 having a hydrogen separation membrane is disposed between the water cooling wall 3 located on the downstream side of the oxidation reforming furnace 2 and the heat exchanger 10 so as to separate hydrogen. The hydrogen separation membrane of the separator 15 is composed of a silica-based or alumina-based ceramic separation membrane or a palladium membrane reinforced with ceramic. Here, the hydrogen separation membrane may be detachable from the separator 15 or may be fixed, and the shape and installation structure are not particularly limited as long as the gasification gas can pass therethrough.

  The separator 15 having a hydrogen separation membrane is connected to a supply line 16 for supplying the separated hydrogen to the user in the product state. The supply line 16 includes an indirect cooler 17 having a cold water pipe or the like. Has been placed.

  The operation of the first embodiment of the present invention will be described below.

When the gasification gas is treated, coal or the like is gasified in the gasification furnace 1, and the gas contained in the gasification gas is oxidized and reformed in the oxidation reforming furnace 2 from the gasification furnace 1. The reformed gasification gas is cooled by the water cooling wall 3 and the cooled gasification gas is passed through the separator 15 of the hydrogen separation membrane at a temperature of about 1000 ° C. to 1100 ° C. to separate the hydrogen. The main components of the gasification gas are CO, CO ₂ and water vapor, and the trace components are sulfur (H ₂ S, COS, CS ₂ ) and nitrogen (NH ₃ , HCN).

Subsequently, after cooling by the heat exchanger 10 and recovering heat, the gasified gas after cooling is directly cooled by the cooler 11 and the indirect cooler 12 to condense and separate water vapor remaining in the gasified gas, The pressurized gasification gas is pressurized by the booster 13, and the pressurized gasification gas is cooled by the CO ₂ absorber 14 to separate sulfur, nitrogen, and CO ₂ , and the CO gasification gas is generated by power generation or steam. Used for shift reaction.

  At the same time, in the separator 15, the gasified gas is passed through the hydrogen separation membrane at 1000 ° C. or higher to prevent clogging of tars and the like into the hydrogen separation membrane, and the separated hydrogen is supplied to the supply line 16. The product is cooled and supplied to the user in the product state.

The separator 15 of the hydrogen separation membrane separates hydrogen from the gasification gas to reduce the volume of the gasification gas, and reduces the cooling capacity of the gasification gas in the heat exchanger 10, the direct cooler 11, and the indirect cooler 12. At the same time, the amount of gasification gas to be processed by the CO ₂ absorber 14 is reduced to about half, and the processing capacity of the equipment downstream of the hydrogen separation membrane separator 15 is reduced.

Thus, according to the first example of the embodiment as described above, since the hydrogen is separated from the gasification gas on the downstream side of the oxidation reforming furnace 2, the volume of the gasification gas is reduced. , The processing capacity of the direct cooler 11, the indirect cooler 12, the booster 13, and the CO ₂ absorber 14 can be reduced, so that the heat exchanger 10, the direct cooler 11, the indirect cooler 12, the booster 13, The CO ₂ absorber 14 can be downsized to reduce manufacturing costs and operating costs. Moreover, the separated hydrogen can be easily used.

In the first example of the embodiment, when hydrogen is separated by the hydrogen separation membrane between the oxidation reforming furnace 2 and the heat exchanger 10, the heat exchanger 10 and the direct cooler 11 which are devices downstream from the hydrogen separation membrane are used. , The processing capacity in the indirect cooler 12, the booster 13, and the CO ₂ absorber 14 can be easily reduced, so that the heat exchanger 10, the direct cooler 11, the indirect cooler 12, the booster 13, the CO ₂ absorption The device 14 can be appropriately downsized to further reduce manufacturing costs and operating costs.

  In the first example of the embodiment, when the hydrogen separated by the hydrogen separation membrane is cooled by the indirect cooler 17, the separated hydrogen can be supplied to the user in a product state, so that hydrogen can be used more easily. it can.

  Hereinafter, a second example of the embodiment of the present invention will be described with reference to FIG. In the figure, the same reference numerals as those in FIG. 1 denote the same parts.

  The second example of the gasification gas purification method and apparatus of the present invention is a configuration in which hydrogen is separated and the separation position is changed, and the other configurations are substantially the same as the first example.

Similarly to the first example, the direct cooler 11, the indirect cooler 12, the booster 13, and the CO ₂ absorber 14 of the second example are reduced in size by reducing the volume of gasification gas that can be processed.

  Between the heat exchanger 4 and the direct cooler 11 (cooler), an acid gas shift reactor 18 for performing a shift reaction on the gasification gas is disposed, and the acid gas shift reactor 18 and the direct cooler are disposed. 11, a hydrogen separation membrane separator 19 for separating hydrogen is disposed.

  The acid gas shift reactor 18 includes a catalyst that causes a shift reaction, and the catalyst is an acid gas shift catalyst so as to avoid poisoning due to sulfur in the gasification gas.

  Similarly to the first example, the hydrogen separation membrane of the separator 19 is composed of a silica-based or alumina-based ceramic separation membrane or a palladium membrane reinforced with ceramic. Here, the hydrogen separation membrane may be detachable from the separator 19 or may be fixed, and the shape and installation structure are not particularly limited as long as the gasification gas can pass therethrough.

  In addition, a separator 19 having a hydrogen separation membrane is connected to a supply line 20 for supplying the separated hydrogen to a user in a product state. The supply line 20 includes an indirect cooler 21 having a cold water pipe or the like. Has been placed.

  The operation of the second embodiment of the present invention will be described below.

When the gasification gas is treated, coal or the like is gasified in the gasification furnace 1, and the gas contained in the gasification gas is oxidized and reformed in the oxidation reforming furnace 2 from the gasification furnace 1. The reformed gasification gas is cooled by the water-cooled wall 3 and further cooled by the heat exchanger 4 to recover the heat. The cooled gasification gas is acidic at a temperature of about 400 ° C to 500 ° C. The gas shift reactor 18 is used to increase the proportion of hydrogen in the gasification gas, and the gasification gas is passed through the separator 19 of the hydrogen separation membrane to separate the hydrogen, and the main components of the gasification gas are CO, CO ₂ , sulfur trace components as well as water vapor _{(H 2 S, COS, CS} 2), to nitrogen partial _(NH 3, HCN).

Subsequently, the gasified gas is cooled by the direct cooler 11 and the indirect cooler 12 to condense and separate the water vapor remaining in the gasified gas, and the cooled gasified gas is pressurized by the booster 13 and then pressurized. The gasified gas is cooled by the CO ₂ absorber 14 to separate sulfur, nitrogen, and CO _2, and the gasified CO gas is used for power generation and shift reaction with water vapor.

  At the same time, in the separator 19, the separated hydrogen is supplied to the supply line 20, cooled by the indirect cooler 21, and supplied to the user in the product state.

The hydrogen separation membrane separator 19 separates hydrogen from the gasification gas to reduce the volume of the gasification gas, to reduce the cooling capacity of the gasification gas in the direct cooler 11 and the indirect cooler 12, and to reduce the CO ₂ absorption device. 14 greatly reduces the amount of gasification gas to be processed, and reduces the processing capacity of equipment downstream of the hydrogen separation membrane separator 19.

Thus, according to the second example of the embodiment, hydrogen is separated from the gasification gas on the downstream side of the heat exchanger 4 to reduce the volume of the gasification gas. The processing capacity of the indirect cooler 12, the booster 13, and the CO ₂ absorber 14 can be reduced, and thus the direct cooler 11, the indirect cooler 12, the booster 13, and the CO ₂ absorber 14 can be reduced in size and manufacturing cost. And operating costs can be reduced. Moreover, the separated hydrogen can be easily used.

In the second example of the embodiment, a shift reaction is performed on the gasification gas by the acidic gas shift reactor 18 between the heat exchanger 4 and the direct cooler (cooler) 11, and hydrogen is further removed by the hydrogen separation membrane. When separated, the processing capacity in the direct cooler 11, the indirect cooler 12, the booster 13, and the CO ₂ absorber 14 which are devices downstream from the hydrogen separation membrane can be easily reduced, and thus the direct cooler 11, The indirect cooler 12, the booster 13, and the CO ₂ absorber 14 can be appropriately downsized to further reduce manufacturing costs and operating costs.

  In the second example of the embodiment, when the hydrogen separated by the hydrogen separation membrane is cooled by the indirect cooler 21, the separated hydrogen can be supplied to the user in a product state, so that the hydrogen can be used more easily. it can.

  Note that the gasification gas purification method and apparatus of the present invention are not limited to the illustrated examples described above, and it is needless to say that various modifications can be made without departing from the scope of the present invention.

1 is an overall schematic configuration diagram showing a first example of an embodiment for carrying out the present invention. It is a whole schematic block diagram which shows the 2nd example of embodiment which implements this invention. It is a whole schematic block diagram which shows the conventional gasification gas refinement | purification apparatus.

DESCRIPTION OF SYMBOLS 1 Gasification furnace 2 Oxidation reforming furnace 4 Heat exchanger 10 Heat exchanger 11 Direct cooler (cooler)
12 indirect cooler 13 booster 14 CO ₂ absorber 15 hydrogen separation membrane separator 17 indirect cooler 18 the acidic gas shift reactor 19 the hydrogen separation membrane separator 21 indirect cooler

Claims (8)

Coal and water vapor are supplied to the gasification furnace as gasification raw materials to form gasification gas. The gasification gas from the gasification furnace is oxidized and reformed in the oxidation reforming furnace to remove the tar content in the gasification gas. The reformed gasification gas is cooled by a heat exchanger to recover heat, the cooled gasification gas is cooled by a cooler to condense water vapor remaining in the gasification gas, and the cooled gas gases was pressurized with booster, the the pressurized pressure gasification gas to a gasification gas purification method of separating CO ₂ is treated with CO ₂ absorber, oxidation reforming in the downstream side of the oxidation reformer A hydrogen separation membrane is placed between the heat treatment furnace and the heat exchanger , and the gasification gas is passed through the hydrogen separation membrane at 1000 ° C. or higher to separate hydrogen from the gasification gas, thereby reducing the volume of the gasification gas. Gasification gas purification method. The gasified gas purification method according to claim 1, wherein the gasified gas after cooling is passed through the hydrogen separation membrane at a temperature of 1000 ° C to 1100 ° C to prevent clogging of the hydrogen separation membrane due to tar content.   The gasification gas purification according to claim 1, wherein a shift reaction is performed on the gasification gas by an acid gas shift reactor between the heat exchanger and the cooler, and further hydrogen is separated by a hydrogen separation membrane. Method.   The gasified gas purification method according to any one of claims 1 to 3, wherein the hydrogen separated by the hydrogen separation membrane is cooled by an indirect cooler. A gasification furnace for supplying gas and steam as gasification raw materials to generate gasification gas;
And oxidation reforming furnace gasification gas oxidizing reforming from the gasifier,
A heat exchanger for recovering heat by cooling the gasified gas reformed in the oxidation reforming furnace;
A cooler for condensing water vapor by cooling the gasification gas after cooling by the heat exchanger;
A booster for pressurizing the gasified gas cooled by the cooler;
And CO ₂ absorbing apparatus for separating CO ₂ by cooling the pressurized gasification gas by said booster,
A separator for a hydrogen separation membrane, which is located between an oxidation reforming furnace and a heat exchanger downstream of the oxidation reforming furnace and separates hydrogen from the gasification gas by passing the gasification gas through the hydrogen separation membrane at 1000 ° C. or higher . A gasification gas purification apparatus comprising: 6. The gas according to claim 5 , wherein the gasified gas after cooling is passed through a hydrogen separation membrane at a temperature of 1000 ° C. to 1100 ° C. to prevent clogging of the hydrogen separation membrane due to tar content. Gas purification equipment.   Between the heat exchanger and the cooler, an acid gas shift reactor that performs a shift reaction on the gasification gas is provided, and a hydrogen separation membrane separator that separates hydrogen is provided downstream of the acid gas shift reactor. The gasification gas purification apparatus of Claim 5 characterized by the above-mentioned.   The gasification gas purification apparatus according to any one of claims 5 to 7, further comprising an indirect cooler for cooling hydrogen separated by the hydrogen separation membrane.

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