KR102052311B1 - Apparatus for fuel cell power generation using stnthetic gas and method for generating fuel cell thereof - Google Patents

Abstract

The present invention relates to a fuel cell power generation apparatus using the synthesis gas and a fuel cell power generation method using the same. A fuel cell power generation apparatus using the synthesis gas includes: a water gas conversion reactor configured to transfer a synthesis gas including carbon monoxide and steam to generate a first gas mixture including carbon dioxide and hydrogen; A selective methanation reactor wherein the first gas mixture is conveyed to produce a second gas mixture comprising methane and water; A pressure circulation adsorption tower for transporting the second gas mixture to separate hydrogen to generate a third gas mixture; Phosphoric acid fuel cell into which the hydrogen separated in the pressure circulation adsorption column is introduced; A membrane separator for transferring the third gas mixture to separate carbon dioxide and methane; And a molten carbonate fuel cell in which carbon dioxide and methane separated through the membrane separator are introduced into the cathode and the anode, respectively.

Description

Fuel cell power generation apparatus using synthetic gas and fuel cell power generation method using same {APPARATUS FOR FUEL CELL POWER GENERATION USING STNTHETIC GAS AND METHOD FOR GENERATING FUEL CELL THEREOF}

The present invention relates to a fuel cell power generation apparatus using the synthesis gas and a fuel cell power generation method using the same.

Fuel cell (FC) is a device that directly utilizes the transfer of electrons from the redox reaction to the production of electrical energy. It has high efficiency and clean energy with relatively low greenhouse gas emission and the theoretical energy production efficiency of 83%. One of the circles. It is also a relatively widely used renewable energy source in Korea, thanks to the high weight (2.0) on the Renewable Energy Certificate (REC) and financial support from the government.

Despite the various advantages of fuel cells, there are some obstacles to their commercialization. Therefore, there is no economic plan for securing high purity hydrogen (H ₂ ) used as fuel for fuel cells. To date, various technologies have been developed and tried to produce high purity hydrogen, which is used as fuel for fuel cells, but the development of groundbreaking technologies to lead the expansion of fuel cells has not been made yet. Methanol (CH ₃ OH), ethanol (C ₂ H ₅ OH), gasoline, natural gas, propane (C ₃ H ₈ ), etc. are used as precursors for hydrogen production. There was a problem that it was difficult and economical.

One solution to this problem is the Integrated Gasification-Fuel Cell (IGFC) technology, which converts and refines coal and combines it with a fuel cell. It is a technology that pretreats synthetic gas produced by coal gasification to make high purity hydrogen or methane (CH ₄ ) and uses it as fuel of fuel cell. It is one of the next generation power generation systems combined with efficiency.

Prior art related to the present invention is Republic of Korea Patent Publication No. 2011-0136197 (published Dec. 21, 2011, the name of the invention: a fuel cell system using waste hydrogen generated in seawater electrolysis facility). Said document is a seawater electrolysis facility for generating chlorine material by electrolyzing seawater used as cooling water in nuclear power and thermal power generation systems; A hydrogen storage transfer pipe connected to one side of the seawater electrolysis facility to transfer waste hydrogen generated in the electrolysis process; A fuel cell connected to the hydrogen transfer pipe and generating electricity using a portion of waste hydrogen supplied therefrom as a fuel; A hydrogen reservoir connected to the hydrogen storage transfer pipe to fill the remaining portion of the waste hydrogen supplied therefrom; A hydrogen charger connected to the hydrogen storage to charge hydrogen in a fuel cell vehicle or a fuel cell hybrid vehicle; And an electric charger connected to a rear end of the fuel cell to charge an electric vehicle or an electric hybrid vehicle.

The coal gasification fuel cell (IGFC) has a problem in that a lot of energy is consumed in the process of obtaining high purity hydrogen from fuels other than hydrogen, and the economical efficiency is lowered. In addition, since the fuel cell and the operating conditions are different depending on the type of fuel cell, selecting a suitable pretreatment process and the type of fuel cell according to the characteristics of the fuel serves as a key to improving the economic efficiency.

One object of the present invention is to provide a fuel cell power generation apparatus using a syngas having excellent conversion efficiency from syngas to hydrogen.

Another object of the present invention is to provide a fuel cell power generation apparatus using a syngas having excellent energy efficiency, economical efficiency, and process stability in fuel cell power generation.

Still another object of the present invention is to provide a fuel cell power generation method using a fuel cell power generation apparatus using the syngas.

One aspect of the present invention relates to a fuel cell power generation apparatus using syngas. In one embodiment, the fuel cell power generation apparatus using the syngas may include: a water gas conversion reactor configured to transfer a syngas including carbon monoxide and steam to generate a first gas mixture including carbon dioxide and hydrogen; A selective methanation reactor wherein the first gas mixture is conveyed to produce a second gas mixture comprising methane and water; A pressure circulation adsorption tower for transporting the second gas mixture to separate hydrogen to generate a third gas mixture; Phosphoric acid fuel cell into which the hydrogen separated in the pressure circulation adsorption column is introduced; A membrane separator for transferring the third gas mixture to separate carbon dioxide and methane; And a molten carbonate fuel cell in which carbon dioxide and methane separated through the membrane separator are introduced into the cathode and the anode, respectively.

In one embodiment, a first heat exchanger is provided at the front end of the water gas conversion reactor, a second heat exchanger is provided at the front end of the selective methanation reactor, and the syngas and steam are exchanged with the first gas mixture in the first heat exchanger. Is heated to the water gas conversion reactor, the first gas mixture is heat-exchanged with the third gas mixture in the second heat exchanger and cooled to the selective methanation reactor, and the third gas mixture is 2 Heat exchanger in the heat exchanger can be heated up and transferred to the membrane separator.

In one embodiment, the synthesis gas may be heated to 250 ~ 300 ℃ by heat exchange with the first gas mixture in a first heat exchanger.

In one embodiment, the first gas mixture is cooled to 350 to 420 ° C. by heat exchange with the syngas in a first heat exchanger, and is cooled to 200 to 250 ° C. by heat exchange with the third gas mixture in the second heat exchanger. Can be.

In one embodiment the third gas mixture may be heated to 180 ~ 220 ℃ by heat exchange with the first gas mixture in the second heat exchanger.

In one embodiment further comprises a third heat exchanger provided in front of the pressure circulation adsorption tower, the second gas mixture may be cooled by heat exchange with the cooling water in the third heat exchanger may be transferred to the pressure circulation adsorption tower.

In one embodiment the second gas mixture may be cooled to 30 ~ 60 ℃ by heat exchange with the cooling water in the third heat exchanger.

In one embodiment the membrane separator may comprise a polymer membrane having a molecular chain spacing greater than 0.33 nm and less than 0.38 nm.

In one embodiment, the first gas mixture includes carbon monoxide, hydrogen, and carbon dioxide in a volume ratio of 1: 3 to 5: 1 to 3, and the second gas mixture includes carbon monoxide, methane, hydrogen, and carbon dioxide 1:18 to 22 1: 15 to 18: 38 to 45 by volume, and the third gas mixture may include carbon monoxide, methane and carbon dioxide in a volume ratio of 1:18 to 22:38 to 45.

Another aspect of the present invention relates to a fuel cell power generation method using a fuel cell power generation apparatus using the syngas. In one embodiment, the fuel cell power generation method includes the steps of: generating a first gas mixture including carbon dioxide and hydrogen by transferring syngas and steam including carbon monoxide to a water gas conversion reactor; Transferring the first gas mixture to a selective methanation reactor to produce a second gas mixture comprising methane and water; Transferring the second gas mixture to a pressure circulating adsorption tower to separate hydrogen to generate a third gas mixture; And separating carbon dioxide and methane by transferring the third gas mixture to a membrane separator, wherein the hydrogen separated from the pressure circulation adsorption column is introduced into a phosphate fuel cell, and the carbon dioxide and methane separated through the membrane separator. Are respectively introduced into the cathode and the anode of the molten carbonate fuel cell.

When the fuel cell power generation apparatus using the synthesis gas according to the present invention is applied, hydrogen and methane are generated from the synthesis gas using coal, and these are used as fuels of two types of fuel cells, thereby simplifying the coal gas pretreatment process and energy loss. Since the fuel cell power generation apparatus of the present invention does not require a single component of fuel, the process can be simplified, and carbon dioxide (CO ₂ ) generated and separated in the middle of the process can be used as an electron carrier of the fuel cell. This can simplify the construction of the fuel cell and reduce the power consumption.

1 illustrates a fuel cell generator according to an embodiment of the present invention.
Figure 2 shows a specific example of the water gas conversion process combined with a conventional high temperature reactor and low temperature reactor.
3 shows a membrane separator according to one embodiment of the invention.
4 shows the dynamic molecular diameter of the molecules.
5 shows a phosphate fuel cell according to one embodiment of the present invention.
6 shows a molten carbonate fuel cell according to one embodiment of the invention.
Figure 7 shows the composition of the synthesis gas and steam, the first gas mixture, the second gas mixture and the third gas mixture produced in accordance with the present invention.
8 is a graph showing a gas composition prediction result of the rear stage of the water gas conversion reactor of the present invention.
9 is a graph showing a temperature distribution prediction result in the water gas conversion reactor of the present invention.

In the following description of the present invention, when it is determined that detailed descriptions of related well-known technologies or configurations may unnecessarily obscure the subject matter of the present invention, the detailed description will be omitted.

The terms to be described below are terms defined in consideration of functions in the present invention, and may be changed according to intentions or customs of users or operators, and the definitions should be made based on the contents throughout the present specification for describing the present invention.

Hereinafter, the present invention will be described in detail with reference to the accompanying drawings.

Fuel Cell Generator Using Syngas

One aspect of the present invention relates to a fuel cell power generation apparatus using syngas. 1 shows a fuel cell power generation apparatus according to an embodiment of the present invention. Referring to FIG. 1, the fuel cell power generation apparatus 1000 using the synthesis gas is a water gas conversion reactor 100 in which a synthesis gas including carbon monoxide and steam are transferred to generate a first gas mixture including carbon dioxide and hydrogen. ); A selective methanation reactor (110) for transporting the first gas mixture to produce a second gas mixture comprising methane and water; A pressure circulating adsorption tower 120 for transferring the second gas mixture to separate hydrogen to generate a third gas mixture; Phosphoric acid fuel cell 500 in which hydrogen separated from the pressure circulation adsorption tower 120 is introduced; A membrane separator 300 for transferring the third gas mixture to separate carbon dioxide and methane; And a molten carbonate fuel cell 400 in which carbon dioxide and methane separated through the membrane separator 300 flow into the cathode and the anode, respectively.

In one embodiment, a first heat exchanger 201 is provided in front of the water gas conversion reactor 100, and a second heat exchanger 202 is provided in front of the selective methanation reactor 110, and the syngas and steam are Heat exchanged with the first gas mixture in the first heat exchanger 201 and the temperature is increased to be transferred to the water gas conversion reactor 100, the first gas mixture is cooled by heat exchange with the third gas mixture in the second heat exchanger (202) And the third gas mixture may be heated by heat exchange in the second heat exchanger 202 to be heated to the membrane separator 300.

In one embodiment, the syngas may be supplied from the coal gas supply unit 10, and the steam may be supplied from the steam supply unit 20. In one embodiment, the synthesis gas is generated by gasifying coal, and the volume ratio (or molar ratio) of carbon monoxide (CO) and hydrogen (H ₂ ) may be 1.5: 1 to 3: 1. For example, 2: 1. Under the above conditions, the process efficiency of the present invention can be excellent.

The syngas is mixed with steam and then transferred to the water gas conversion reactor 100 via a first heat exchanger. In one embodiment, the syngas may be heat-exchanged with the first gas mixture in the first heat exchanger 201 to 250-300 ° C. at room temperature, and may be transferred to the water gas conversion reactor 100. As described above, when heat-exchanging the syngas, the vapor, and the first gas mixture through the first heat exchanger 201, energy efficiency may be excellent and economical may be excellent. For example, the syngas may be heated up to 280 ° C. and then transferred to the water gas conversion reactor 100.

In the water gas conversion reactor 100, a reaction comprising Scheme 1 occurs to produce a first gas mixture comprising carbon dioxide and hydrogen:

Scheme 1

CO + H ₂ O → CO ₂ + H ₂

Scheme 1 is known as a water gas shift (WGS) reaction. In the water gas conversion reaction, the reaction heat is about -41 kJ / mol, the temperature of the first gas mixture by the reaction may be 500 ~ 550 ℃. For example, it may be 530 ~ 540 ℃.

In one embodiment, the first gas mixture generated in the water gas conversion reactor may include carbon monoxide (CO), hydrogen (H ₂ ), and carbon dioxide (CO ₂ ) in a volume ratio of 1: 3 to 5: 1 to 3. . For example, carbon monoxide, hydrogen, and carbon dioxide may be included in a volume ratio of 1: 3.7: 2.1. Under the above conditions, fuel cell operation efficiency may be excellent.

In the case of gasification of coal to produce syngas, the volume ratio of carbon monoxide and hydrogen in the syngas produced may vary from time to time depending on the type of coal or the operating conditions of the gasifier. It is technically difficult to control the reactivity of the water gas shift reactor to be 1: 3.

In the case of driving a fuel cell using methane as an existing synthesis gas, the role of the water gas conversion reactor is to adjust the volume ratio of carbon monoxide and hydrogen to an equivalent ratio of 1: 3, which is suitable for the methanation reaction. Control was required. However, in the present invention, since the role of the water gas shift reaction is not an exact equivalent ratio adjustment, precise reactivity control is not required.

On the other hand, the water gas conversion process used to obtain a high hydrogen yield is a polygeneration process (Polygeneration Process). 2 shows a specific example of a water gas conversion process combining a high temperature reactor and a low temperature reactor.

Referring to FIG. 2, in the case of applying a fuel cell using hydrogen as a fuel, the role of the water gas conversion reaction is to convert all carbon monoxide in the synthesis gas into hydrogen, so that the reaction rate is increased to improve the reaction rate and yield. The process must be constructed by combining a high temperature reactor with a high yield of hydrogen.

However, in the case of the present invention, it is not necessary to increase the yield of hydrogen by combining a high temperature reactor with a low temperature reactor because it allows a certain amount of carbon monoxide to remain after the water gas conversion reaction. The high temperature water gas conversion reactor and the low temperature water gas conversion reactor have different operating temperatures and require heat exchange to cool the gas between the two reactors, which complicates the process configuration. Cumbersome.

In one embodiment, the first gas mixture may be cooled to 350 to 420 ° C. by heat exchange with the syngas in the first heat exchanger 201. For example, it may be cooled to 400 ℃ through the heat exchange.

In addition, the first gas mixture is heat-exchanged with the third gas mixture, which is generated and discharged from the pressure circulation adsorption tower 120 in the second heat exchanger 202, is cooled to 200 to 250 ° C., and is selectively methanated reactor 110. Can be introduced into.

In the selective methanation reactor 110, a reaction comprising Scheme 2 occurs, producing a second gas mixture comprising methane and water:

Scheme 2

CO + 3H ₂ → CH ₄ + H ₂ O

The reaction heat generated in Scheme 2 is about -206 kJ / mol, and the temperature of the second gas mixture may be 280 to 350 ° C by the reaction. For example, it may be 300 ℃.

In one embodiment, the second gas mixture produced in the selective methanation reactor 110 includes carbon monoxide (CO), methane (CH ₄ ), hydrogen (H ₂ ), and carbon dioxide (CO ₂ ) in a range of 1:18 to 22:15. 18 to 38 to 45 by volume. For example, the second gas mixture may include carbon monoxide, methane, hydrogen, and carbon dioxide in a volume ratio of 1: 19: 16: 42. Under the above conditions, fuel cell operation efficiency may be excellent.

The second gas mixture is transferred to the pressure circulation adsorption tower 120 to separate hydrogen to generate a third gas mixture.

Referring to FIG. 1, the fuel cell generator 1000 may further include a third heat exchanger 203 provided between the rear end of the selective methanation reactor 110 and the front end of the pressure circulation adsorption tower 120. . In one embodiment, the second gas mixture may be cooled by heat exchange with cooling water in the third heat exchanger 203 and then transferred to the pressure circulating adsorption tower 120.

Referring to FIG. 1, the coolant may be supplied from the coolant supply unit 30. In one embodiment the temperature of the cooling water may be 0 ~ 70 ℃. In the above range, the second gas mixture may be easily cooled, and process efficiency may be excellent when the pressure circulation adsorption tower 120 is introduced.

In one embodiment, the second gas mixture may be heat-exchanged with the cooling water in the third heat exchanger 203, cooled to 30 to 60 ° C, and then transferred to the pressure circulation adsorption tower 120.

The second gas mixture produced by the selective methanation reaction as in Scheme 2 generates water (H ₂ O) of the same volume as methane, and is cooled by heat exchange with cooling water through the third heat exchanger 203. In which the water is condensed and removed from the gas. In the heat exchange under the above conditions, the process efficiency during the hydrogen separation is excellent, it is possible to reduce the process time and energy. For example, it may be cooled to 40 ° C.

In one embodiment, the third gas mixture generated in the pressure circulation adsorption tower 120 may include carbon monoxide (CO), methane (CH ₄ ), and carbon dioxide (CO ₂ ) in a volume ratio of 1:18 to 22:38 to 45. . For example, the ratio may be 1:19:42.

In one embodiment, the third gas mixture may be heat-exchanged with the first gas mixture in the second heat exchanger 202 to be heated to 180 to 220 ° C., and then transferred to the membrane separator 300.

On the other hand, the operating temperature of the molten carbonate fuel cell 400 is higher than 600 ℃ and thus preheating the third gas mixture in which hydrogen is separated in the pressure circulation adsorption tower 120 through heat exchange in the second heat exchanger 202, When the carbonate fuel cell 400 is driven, energy consumed for preheating the fuel may be reduced.

Figure 3 shows a membrane separator according to one embodiment of the invention, Figure 4 shows the dynamic molecular diameter of the molecules. Referring to FIG. 4, the membrane separator 300 may include a polymer membrane having a molecular chain spacing greater than 0.33 nm and less than 0.38 nm. Including the polymer membrane under the above conditions, carbon dioxide and methane molecules can be easily separated. In an embodiment, water in the third gas mixture may be separated together with carbon dioxide and carbon monoxide may be separated together with methane through the membrane separator 300.

In one embodiment, the hydrogen separated in the pressure circulation adsorption tower 120 is introduced into the phosphate fuel cell 500 is used as fuel.

5 shows a phosphate fuel cell according to one embodiment of the present invention. Referring to FIG. 5, the phosphate fuel cell uses liquid high concentration phosphoric acid (H ₃ PO ₄ ) as an electrolyte, and is a thin silicon carbide (SiC) structure disposed between two porous graphite electrodes coated with platinum (Pt) catalyst. It may include. In the phosphate fuel cell, hydrogen is used as a fuel and air or oxygen is used as an oxidizing agent, and the reaction of the phosphate fuel cell at the anode and the cathode is as shown in Scheme 3:

Scheme 3

Phosphoric acid fuel cell the oxidation ^{_{electrode: H 2 → 2H + + 2e}} -

Phosphoric acid fuel cell electrode ^{_{reduction: 0.5O 2 + 2H + + 2e}} - → H 2 O

Referring to FIG. 1, the carbon dioxide separated through the membrane separator 300 is introduced into the cathode of the molten carbonate fuel cell 400, and the methane separated through the membrane separator 300 is the molten carbonate fuel cell 400. May be introduced into the anode. For example, the methane may be introduced into the anode of the molten carbonate fuel cell 400 together with the methane introduced from the methane supply unit 40.

6 shows a molten carbonate fuel cell according to one embodiment of the invention. Referring to FIG. 6, a molten carbonate fuel cell uses a mixture of lithium carbonate (Li ₂ CO ₃ ) and potassium carbonate (K ₂ CO ₃ ) fixed inside a LiOAlO ₂ structure as an electrolyte. Carbonate ions act as charge carriers in molten carbonate fuel cells, and the reaction between the anode and the cathode is shown in Scheme 4:

Scheme 4

MCFC oxide ^{_{electrode: H 2 + CO 3 2- →}} CO 2 + H 2 O + 2e -

A molten carbonate fuel cell electrode _{reduction: 0.5O 2 + CO 2 + 2e} - → CO 3 2-

Referring to FIG. 6, in the molten carbonate fuel cell, carbon dioxide is generated at the anode and is consumed at the cathode. Therefore, the molten carbonate fuel cell system must circulate carbon dioxide from the anode to the cathode. However, according to the present invention, by injecting a high concentration of carbon dioxide separated from the membrane separator 300 into the cathode, such a need for carbon dioxide recycling is eliminated, thereby simplifying the structure of the fuel cell system.

When the carbon dioxide of the molten carbonate fuel cell is circulated to the cathode, the concentration of carbon dioxide produced by the anode changes according to the operating state of the fuel cell, so that the operation state of the fuel cell is changed to supply a certain amount of carbon dioxide to the cathode. Flow rate control considering the change in the concentration of carbon dioxide is required. In addition, since the gas generated in the anode has not only carbon dioxide but also unreacted methane or hydrogen, the concentration of carbon dioxide is low and a large amount of gas must be circulated toward the cathode.

However, the present invention has the advantage that it is easy to adjust the flow rate injected into the molten carbonate fuel cell cathode because the carbon dioxide is separated and introduced in the membrane separator 300 has a high concentration and relatively uniform, and also uses the pressure of the system itself It does not require a separate gas circulation pump. At this time, since the molten carbonate fuel cell has a high operating temperature of about 650 ° C., even if a small amount of carbon monoxide is present in the cathode, no carbon monoxide removal process is required between the gas separation membrane and the cathode.

Fuel cell power generation method using fuel cell power generation device using synthetic gas

Another aspect of the present invention relates to a fuel cell power generation method using a fuel cell power generation apparatus using the syngas. In one embodiment, the fuel cell power generation method includes the steps of: generating a first gas mixture including carbon dioxide and hydrogen by transferring syngas and steam including carbon monoxide to a water gas conversion reactor; Transferring the first gas mixture to a selective methanation reactor to produce a second gas mixture comprising methane and water; Transferring the second gas mixture to a pressure circulating adsorption tower to separate hydrogen to generate a third gas mixture; And separating carbon dioxide and methane by transferring the third gas mixture to a membrane separator, wherein the hydrogen separated from the pressure circulation adsorption column is introduced into a phosphate fuel cell, and the carbon dioxide and methane separated through the membrane separator. Are respectively introduced into the cathode and the anode of the molten carbonate fuel cell.

A first heat exchanger is provided in front of the water gas conversion reactor, and a second heat exchanger is provided in front of the methanation reactor, and the syngas and vapor are heated in heat exchange with the first gas mixture in the first heat exchanger to form the aqueous phase. Is transferred to a gas conversion reactor, the first gas mixture is cooled by heat exchange with a third gas mixture in the second heat exchanger, and is transferred to the selective methanation reactor, and the third gas mixture is heat exchanged in the second heat exchanger. The temperature is raised to the membrane separator.

In one embodiment, the synthesis gas may be heated to 250 ~ 300 ℃ by heat exchange with the first gas mixture in a first heat exchanger.

In one embodiment, the first gas mixture is cooled to 350 to 420 ° C. by heat exchange with the syngas in a first heat exchanger, and is cooled to 200 to 250 ° C. by heat exchange with the third gas mixture in the second heat exchanger. Can be.

In one embodiment the third gas mixture may be heated to 180 ~ 220 ℃ by heat exchange with the first gas mixture in the second heat exchanger.

In one embodiment further comprises a third heat exchanger provided in front of the pressure circulation adsorption tower, the second gas mixture may be cooled by heat exchange with the cooling water in the third heat exchanger may be transferred to the pressure circulation adsorption tower.

In one embodiment the second gas mixture may be cooled to 30 ~ 60 ℃ by heat exchange with the cooling water in the third heat exchanger.

In one embodiment the membrane separator may comprise a polymer membrane having a molecular chain spacing greater than 0.33 nm and less than 0.38 nm.

In one embodiment, the first gas mixture includes carbon monoxide, hydrogen, and carbon dioxide in a volume ratio of 1: 3 to 5: 1 to 3, and the second gas mixture includes carbon monoxide, methane, hydrogen, and carbon dioxide 1:18 to 22 1: 15 to 18: 38 to 45 by volume, and the third gas mixture may include carbon monoxide, methane and carbon dioxide in a volume ratio of 1:18 to 22:38 to 45.

The fuel cell power generation apparatus using the syngas according to the present invention and the fuel cell power generation method using the same produce hydrogen and methane from coal-derived syngas, and use it as fuel for two fuel cells, thereby simplifying the pretreatment process of coal gas. It has the advantage of low energy loss. In order to obtain fuel cell fuel from coal synthesis gas, coal synthesis gas was converted into hydrogen or methane and used as fuel of a single type of fuel cell using these fuels. In the process, a lot of energy and operating costs were consumed.

However, since the present invention does not require a single component fuel, the process can be simplified, and carbon dioxide (CO ₂ ) generated and separated in the process can be used as an electron carrier of the fuel cell, thereby simplifying the construction of the fuel cell and driving power. There is an advantage that the consumption is reduced.

Hereinafter, the configuration and operation of the present invention through the preferred embodiment of the present invention will be described in more detail. However, this is presented as a preferred example of the present invention and in no sense can be construed as limiting the present invention.

Example

Using the fuel cell generator 1000 as shown in FIG. 1, a fuel cell was generated using syngas. Specifically, the synthesis gas including carbon monoxide and hydrogen in a 2: 1 volume ratio (molar ratio) is supplied from the coal gas supply unit 10, steam is supplied from the steam supply unit 20, and transferred to the water gas conversion reactor 100. To generate a first gas mixture including carbon dioxide and hydrogen, and transfer the first gas mixture to the selective methanation reactor 110 to produce a second gas mixture including methane and water, and the second gas mixture. This was transferred to the pressure circulation adsorption tower 120 to separate hydrogen to produce a third gas mixture. In this case, the composition of the synthesis gas and steam, the first gas mixture after the water gas conversion reactor, the second gas mixture after the selective methanation reactor and the third gas mixture after the pressure circulation adsorption column is shown in Figure 7 below.

The syngas and steam were heat-exchanged with the first gas mixture in the first heat exchanger 201 provided in front of the water gas conversion reactor 100 and heated to 280 ° C., and then transferred to the water gas conversion reactor 100. The temperature of the first gas mixture produced in the water gas conversion reactor 100 was 537 ° C., and included carbon monoxide, hydrogen, and carbon dioxide in a volume ratio of about 1: 3.7: 2.1.

The first gas mixture is cooled to 400 ° C. by heat exchange with the syngas in the first heat exchanger 201, and then the third gas mixture in the second heat exchanger 202 provided in front of the selective methanation reactor 110. Heat exchange with and cooled to 200 ℃ was transferred to the selective methanation reactor (110). The temperature of the second gas mixture produced in the selective methanation reactor 110 was about 300 ° C. and included carbon monoxide, methane, hydrogen, and carbon dioxide in a volume ratio of about 1: 19: 16: 42.

The second gas mixture is heat-exchanged with the cooling water supplied from the cooling water supply unit 30 in the third heat exchanger 203 provided in front of the pressure circulation adsorption tower 120 and cooled to about 40 ° C. to the pressure circulation adsorption tower 120. Transferred. The third gas mixture produced by separating hydrogen from the pressure circulation adsorption column 120 had a temperature of about 50 ° C. and included carbon monoxide, methane, and carbon dioxide in a volume ratio of about 1:19:42.

The third gas mixture was heat-exchanged in the second heat exchanger, heated up to about 200 ° C., and transferred to the membrane separator 300. Membrane separator 300 includes a polymer membrane having a molecular chain spacing greater than 0.33 nm and less than 0.38 nm, and separated carbon dioxide and methane. At this time, carbon dioxide in the third gas mixture was separated together with water, and methane was separated together with carbon monoxide.

Carbon dioxide separated through the membrane separator 300 was introduced into the cathode of the molten carbonate fuel cell 400, and the methane separated through the membrane separator 300, together with the methane introduced through the methane supply unit 40, It was introduced into the anode of the molten carbonate fuel cell 400. In addition, hydrogen separated in the pressure circulation adsorption tower 120 was introduced into the phosphate fuel cell 500.

On the other hand, through the computational modeling of the reactor predicted the performance of the water gas conversion reactor 100 of the fuel cell generator of the embodiment. Assuming that the water gas conversion reactor 100 is a one-dimensional packed bed tubular reactor (1-D Packed Bed Reactor), the numerical analysis was performed. The components of the synthesis gas and steam, measured at the inlet of the water gas conversion reactor 100, are shown in Table 1 below.

The numerical analysis conditions of the water gas conversion reactor are shown in Table 2 below, and it is assumed that the equilibrium constant K _eq of the water gas conversion reaction changes with temperature as shown in Equation 1 below.

[Relationship 1]

The reaction rate r of the water gas conversion reactor under atmospheric pressure is shown in the following relation 2, and the constants used in the following relation 2 are shown in Table 3 below:

[Relationship 2]

In addition, the numerical analysis was conducted under normal pressure conditions, the reaction rate in the pressurized state can be corrected by applying the effective pressure (F) instead of the pressure (P) as shown in Equation 1 below:

[Equation 1]

8 and 9 show the results of calculating the temperature and gas composition inside the water gas conversion reactor in the same manner as described above. 8 is a graph illustrating a gas composition prediction result at the rear of the water gas conversion reactor of the present invention, and FIG. 9 is a graph showing a temperature distribution prediction result inside the water gas conversion reactor of the present invention. Referring to FIGS. 8 and 9, the temperature of the syngas is increased from about 280 ° C. to about 537 ° C., and after the water gas conversion reactor is started, the steady state is reached in about 4,000 seconds. . At this time, the mole fraction of each component at the rear end of the water gas conversion reactor is shown in Table 4.

Simple modifications or changes of the present invention can be easily carried out by those skilled in the art, and all such modifications or changes can be seen to be included in the scope of the present invention.

10: coal gas supply unit 20: steam supply unit
30: cooling water supply 40: methane supply
100: water gas conversion reactor 110: selective methanation reactor
120: pressure circulation adsorption tower 201: first heat exchanger
202: second heat exchanger 203: third heat exchanger
300: membrane separator 400: molten carbonate fuel cell
500: phosphate fuel cell 1000: fuel cell generator

Claims (17)

A water gas conversion reactor wherein the synthesis gas and carbon vapor containing carbon monoxide are transferred to produce a first gas mixture including carbon dioxide and hydrogen;
A selective methanation reactor wherein the first gas mixture is conveyed to produce a second gas mixture comprising methane and water;
A pressure circulation adsorption tower for transporting the second gas mixture to separate hydrogen to generate a third gas mixture;
Phosphoric acid fuel cell into which the hydrogen separated in the pressure circulation adsorption column is introduced;
A membrane separator for transferring the third gas mixture to separate carbon dioxide and methane; And
And a molten carbonate fuel cell in which carbon dioxide and methane separated through the membrane separator are introduced into the cathode and the anode, respectively.
A first heat exchanger is provided in front of the water gas conversion reactor,
A second heat exchanger is provided in front of the selective methanation reactor,
The syngas and steam are heated by heat exchange with the first gas mixture in the first heat exchanger is transferred to the water gas conversion reactor,
The synthesis gas is heated to 250 ~ 300 ℃ by heat exchange with the first gas mixture,
The first gas mixture is cooled to 350 to 420 ° C. by heat exchange with the syngas in a first heat exchanger, and is cooled to 200 to 250 ° C. by heat exchange with the third gas mixture in the second heat exchanger to form the selective methane. Is transferred to the reactor
The third gas mixture is heat exchanged with the first gas mixture in the second heat exchanger is heated to 180 ~ 220 ℃ is transferred to the membrane separator, characterized in that the fuel cell power generation apparatus using.
delete delete delete delete According to claim 1, further comprising a third heat exchanger provided in front of the pressure circulation adsorption tower,
The second gas mixture is cooled by heat-exchanging with the cooling water in the third heat exchanger is transferred to the pressure circulating adsorption tower characterized in that the fuel cell power generation using the synthesis gas.
The fuel cell generator of claim 6, wherein the second gas mixture is cooled to 30 ° C. to 60 ° C. by heat exchange with cooling water in the third heat exchanger.
The fuel cell generator of claim 1, wherein the membrane separator comprises a polymer membrane having a molecular chain spacing greater than 0.33 nm and less than 0.38 nm.
The method of claim 1, wherein the first gas mixture comprises carbon monoxide, hydrogen and carbon dioxide in a volume ratio of 1: 3 to 5: 1 to 3,
The second gas mixture includes carbon monoxide, methane, hydrogen, and carbon dioxide in a volume ratio of 1:18 to 22:15 to 18:38 to 45,
The third gas mixture is a fuel cell power generation device using a synthesis gas, characterized in that containing carbon monoxide, methane and carbon dioxide in a volume ratio of 1:18 to 22:38 to 45.
Transferring the syngas and steam including carbon monoxide to a water gas conversion reactor to generate a first gas mixture including carbon dioxide and hydrogen;
Transferring the first gas mixture to a selective methanation reactor to produce a second gas mixture comprising methane and water;
Transferring the second gas mixture to a pressure circulating adsorption tower to separate hydrogen to generate a third gas mixture; And
And transporting the third gas mixture to a membrane separator to separate carbon dioxide and methane.
Hydrogen separated from the pressure circulation adsorption tower is introduced into the phosphate fuel cell,
Carbon dioxide and methane separated through the membrane separator are respectively introduced into the cathode and the anode of the molten carbonate fuel cell is a fuel cell power generation method using a fuel cell power generation device,
A first heat exchanger is provided in front of the water gas conversion reactor,
A second heat exchanger is provided in front of the selective methanation reactor,
The syngas and steam are heated by heat exchange with the first gas mixture in the first heat exchanger is transferred to the water gas conversion reactor,
The synthesis gas is heated to 250 ~ 300 ℃ by heat exchange with the first gas mixture,
The first gas mixture is cooled to 350 to 420 ° C. by exchanging heat with the syngas in a first heat exchanger, and is cooled to 200 to 250 ° C. by heat exchange with the third gas mixture in the second heat exchanger to form the selective methane. Is transferred to the reactor
The third gas mixture is heat exchanged with the first gas mixture in the second heat exchanger is heated to 180 ~ 220 ℃ and transported to the membrane separator, characterized in that the fuel cell power generation method using a fuel cell power generation device.
delete delete delete The method of claim 10, wherein the first gas mixture comprises carbon monoxide, hydrogen and carbon dioxide in a volume ratio of 1: 3 to 5: 1 to 3,
The second gas mixture includes carbon monoxide, methane, hydrogen, and carbon dioxide in a volume ratio of 1:18 to 22:15 to 18:38 to 45,
The third gas mixture includes carbon monoxide, methane and carbon dioxide in a volume ratio of 1:18 to 22:38 to 45.
delete The fuel cell generator of claim 10, further comprising a third heat exchanger provided at a front end of the pressure circulation adsorption tower.
And the second gas mixture is cooled by heat exchange with cooling water in the third heat exchanger and then transferred to the pressure circulating adsorption tower.
11. The method of claim 10, wherein the membrane separator comprises a polymer membrane having a molecular chain spacing greater than 0.33 nm and less than 0.38 nm.

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