阅读说明：本技术 发电并捕集二氧化碳的系统及方法 (System and method for generating power and capturing carbon dioxide ) 是由 苏林德·辛格 顾佑宗 徐文强 于 2020-06-08 设计创作，主要内容包括：本发明实施例公开了一种发电并捕集二氧化碳的系统及方法,涉及固体电池技术领域,用于在发电的同时,实现对二氧化碳的捕集。所述发电并捕集二氧化碳的系统,包括气化炉,用于将第一燃料转化为合成气。固体氧化物燃料电池,与气化炉连通,用于将合成气转化为电能和第一废气。燃烧器,用于将第二燃料转化为电能和烟道气体。熔融碳酸盐燃料电池,与固体氧化物燃料电池和燃烧器连通,用于将烟道气体和第一废气转化为电能和第二废气。压缩纯化装置,与熔融碳酸盐燃料电池连通,用于对第二废气中的二氧化碳进行捕集。上述发电并捕集二氧化碳的系统及方法用于发电并捕集二氧化碳。(The embodiment of the invention discloses a system and a method for generating power and capturing carbon dioxide, relates to the technical field of solid batteries, and is used for capturing carbon dioxide while generating power. The system for generating power and capturing carbon dioxide includes a gasifier for converting a first fuel into syngas. And the solid oxide fuel cell is communicated with the gasification furnace and is used for converting the synthesis gas into electric energy and first waste gas. A combustor for converting the second fuel into electrical energy and flue gas. A molten carbonate fuel cell in communication with the solid oxide fuel cell and the burner for converting the flue gas and the first exhaust gas to electrical energy and a second exhaust gas. And a compression purification device in communication with the molten carbonate fuel cell for capturing carbon dioxide in the second exhaust gas. The system and the method for generating power and capturing carbon dioxide are used for generating power and capturing carbon dioxide.)

1. A system for generating electricity and capturing carbon dioxide, comprising:

a gasification furnace for converting a first fuel into syngas;

a solid oxide fuel cell in communication with the gasifier for converting the syngas into electrical energy and a first exhaust gas;

a burner for converting the second fuel into electrical energy and flue gas;

a molten carbonate fuel cell in communication with the burner and the solid oxide fuel cell for converting the flue gas and the first exhaust gas to electrical energy and a second exhaust gas;

a compression purification device in communication with the molten carbonate fuel cell for capturing carbon dioxide in the second exhaust gas.

2. The system for generating power and capturing carbon dioxide as claimed in claim 1, wherein the gasifier is in communication with an anode of the solid oxide fuel cell;

the anode of the solid oxide fuel cell is in communication with the anode of the molten carbonate fuel cell;

the burner is in communication with a cathode of the molten carbonate fuel cell and the compression purification device is in communication with an anode of the molten carbonate fuel cell.

3. The system for generating power and capturing carbon dioxide as claimed in claim 1, further comprising a first condensing device connected between the solid oxide fuel cell and the molten carbonate fuel cell for condensing the first exhaust gas, removing water and carbon dioxide from the first exhaust gas, and delivering the first exhaust gas from which water and carbon dioxide are removed to the molten carbonate fuel cell.

4. The system for generating power and capturing carbon dioxide as claimed in claim 1, further comprising a second condensing unit connected between the molten carbonate fuel cell and the compression purification unit, for condensing a second exhaust gas generated from the molten carbonate fuel cell, removing water from the second exhaust gas, and delivering the water-removed second exhaust gas to the compression purification unit.

5. The system for generating power and capturing carbon dioxide as claimed in claim 1, further comprising at least one first purification device connected between the gasification furnace and the solid oxide fuel cell for purifying the syngas generated from the gasification furnace and delivering the purified syngas to the solid oxide fuel cell.

6. A method for generating power and capturing carbon dioxide, which is applied to the system for generating power and capturing carbon dioxide according to any one of claims 1 to 5, the method for generating power and capturing carbon dioxide comprising:

adding a first fuel into a gasification furnace of the system for generating power and capturing carbon dioxide to obtain synthesis gas;

conveying the synthesis gas to a solid oxide fuel cell of the system for generating power and capturing carbon dioxide for reaction to obtain electric energy and first waste gas;

adding a second fuel to a burner of the system for generating electricity and capturing carbon dioxide to obtain electrical energy and flue gas;

conveying the flue gas and the first waste gas to a molten carbonate fuel cell of the system for generating power and capturing carbon dioxide for reaction to obtain electric energy and second waste gas;

and conveying the second exhaust gas to a compression purification device of the system for generating power and capturing carbon dioxide, and capturing the carbon dioxide in the second exhaust gas.

7. The method of generating power and capturing carbon dioxide as claimed in claim 6, further comprising, prior to delivering the syngas to the solid oxide fuel cell: purifying the synthesis gas.

8. The method for generating power and capturing carbon dioxide as claimed in claim 7, wherein the volume of the gas reacted in the purified synthesis gas is 50 to 70% of the volume of the whole gas after the purified synthesis gas is fed to the solid oxide fuel cell.

9. The method of generating power and capturing carbon dioxide as claimed in claim 6, wherein the ratio of the electrical energy obtained in the solid oxide fuel cell to the electrical energy obtained in the molten carbonate fuel cell is 2:5 to 4: 5.

10. The method of generating power and capturing carbon dioxide as claimed in claim 6, further comprising, prior to delivering the first exhaust gas to the molten carbonate fuel cell: and condensing the first waste gas, and removing water and carbon dioxide in the first waste gas.

Technical Field

The invention relates to the technical field of solid batteries, in particular to a system and a method for generating power and capturing carbon dioxide.

Background

At present, coal-fired power generation is mainly used for power generation. In the process of generating electricity by burning coal, a large amount of carbon dioxide is generated and is discharged into the atmosphere, which easily affects the heat balance of the atmosphere and aggravates climate warming.

Disclosure of Invention

An object of an embodiment of the present invention is to provide a system and a method for generating power and capturing carbon dioxide, so as to capture carbon dioxide while generating power.

In order to achieve the above purpose, the embodiment of the present invention provides the following technical solutions:

a first aspect of embodiments of the present invention provides a system for generating electricity and capturing carbon dioxide, comprising: the gasification furnace is used for converting the first fuel into the synthetic gas. And the solid oxide fuel cell is communicated with the gasification furnace and is used for converting the synthesis gas into electric energy and first waste gas. A combustor for converting the second fuel into electrical energy and flue gas. A molten carbonate fuel cell in communication with the burner and the solid oxide fuel cell for converting the flue gas and the first exhaust gas to electrical energy and a second exhaust gas. And a compression purification device in communication with the molten carbonate fuel cell for capturing carbon dioxide in the second exhaust gas.

According to the system for generating power and capturing carbon dioxide, the solid oxide fuel cell communicated with the gasification furnace is arranged, the molten carbonate fuel cell communicated with the combustor is arranged, and the solid oxide fuel cell is communicated with the molten carbonate fuel cell, so that first waste gas mainly comprising hydrogen, carbon monoxide and water vapor and flue gas mainly comprising carbon dioxide can be conveyed to the molten carbonate fuel cell, the first waste gas and the flue gas are enabled to react in the molten carbonate fuel cell, and the carbon dioxide is transferred and gathered to one end of the molten carbonate fuel cell to obtain second waste gas mainly comprising carbon dioxide. In this way, the second exhaust gas can be compressed and purified by a compression and purification device communicating with the molten carbonate fuel cell, and carbon dioxide in the second exhaust gas can be captured and obtained. Furthermore, electrical energy is generated during the conversion of the syngas and electrical energy is also generated during the conversion of the first exhaust gas and the flue gas into the second exhaust gas. That is, the system for generating power and capturing carbon dioxide according to the embodiment of the present invention can generate power and capture carbon dioxide.

In addition, the anode of the solid oxide fuel cell is communicated with the anode of the molten carbonate fuel cell, and the first exhaust gas generated from the anode of the solid oxide fuel cell may be returned to the solid oxide fuel cell without circulating and continuing the reaction, and the first exhaust gas may be used as a fuel source for the anode of the molten carbonate fuel cell, be sent to the anode of the molten carbonate fuel cell, and pass H in the synthesis gas that is not completely reacted therein₂Removing CO from flue gas₂Converging to the anode of the solid oxide fuel cell 102. That is, by the cooperation between the solid oxide fuel cell 102 and the molten carbonate fuel cell 202, on the one hand, the molten carbonate fuel cell 202 can be prevented from being restricted by an external fuel source, and on the other hand, the H in the first exhaust gas can be effectively utilized₂And the utilization rate of the synthesis gas is improved.

In some embodiments, the gasifier is in communication with an anode of the solid oxide fuel cell. The anode of the solid oxide fuel cell is in communication with the anode of the molten carbonate fuel cell. The burner is in communication with the cathode of the molten carbonate fuel cell and the compression purification apparatus is in communication with the anode of the molten carbonate fuel cell.

In some embodiments, the system for generating power and capturing carbon dioxide further comprises a first condensing device connected between the solid oxide fuel cell and the molten carbonate fuel cell, and configured to condense the first exhaust gas, remove water and carbon dioxide from the first exhaust gas, and deliver the first exhaust gas after removing water and carbon dioxide to the molten carbonate fuel cell.

In some embodiments, the system for generating power and capturing carbon dioxide further includes a second condensing device connected between the molten carbonate fuel cell and the compression and purification device, for condensing a second exhaust gas generated by the molten carbonate fuel cell, removing water from the second exhaust gas, and delivering the second exhaust gas with water removed to the compression and purification device.

In some embodiments, the system for generating power and capturing carbon dioxide further includes at least one first purification device connected between the gasification furnace and the solid oxide fuel cell, and configured to purify the syngas generated by the gasification furnace and deliver the purified syngas to the solid oxide fuel cell.

A second aspect of an embodiment of the present invention provides a method for generating power and capturing carbon dioxide, which is applied to the system for generating power and capturing carbon dioxide provided in the above embodiment, and the method for generating power and capturing carbon dioxide includes: the first fuel is added to a gasifier of a system for generating electricity and capturing carbon dioxide to obtain a syngas. The synthesis gas is conveyed to a solid oxide fuel cell of a system for generating electricity and capturing carbon dioxide to react, and electric energy and first waste gas are obtained. A second fuel is added to the burner of the system for generating electricity and capturing carbon dioxide to obtain electrical energy and flue gas. The flue gas and the first exhaust gas are conveyed to a molten carbonate fuel cell of a system for generating electricity and capturing carbon dioxide for reaction to obtain electric energy and a second exhaust gas. And conveying the second exhaust gas to a compression and purification device of a system for generating power and capturing carbon dioxide, and compressing, purifying and capturing the carbon dioxide in the second exhaust gas.

The beneficial effects that can be achieved by the method for generating power and capturing carbon dioxide provided by the embodiment of the invention are the same as those that can be achieved by the system for generating power and capturing carbon dioxide provided by the embodiment, and are not described herein again.

In some embodiments, prior to delivering the syngas to the solid oxide fuel cell, the method further comprises: the synthesis gas is purified.

In some embodiments, after the purified syngas is delivered to the solid oxide fuel cell, the volume of the gas reacted in the purified syngas is 50% to 70% of the volume of the total gas.

In some embodiments, the ratio of electrical energy obtained in the solid oxide fuel cell to electrical energy obtained in the molten carbonate fuel cell is from 2:5 to 4: 5.

In some embodiments, prior to delivering the first off-gas to the molten carbonate fuel cell, the method further comprises: and condensing the first waste gas, and removing water and carbon dioxide in the first waste gas.

Drawings

The accompanying drawings, which are included to provide a further understanding of the embodiments of the invention and are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and together with the description serve to explain the embodiments of the invention and not to limit the embodiments of the invention unduly. In the drawings:

FIG. 1 is a schematic diagram of a system for generating electricity and capturing carbon dioxide according to an embodiment of the present invention;

FIG. 2 is a schematic diagram of another system for generating power and capturing carbon dioxide according to an embodiment of the present invention;

FIG. 3 is a schematic flow diagram of a method for generating electricity and capturing carbon dioxide according to an embodiment of the present invention;

fig. 4 is a schematic flow chart of another method for generating power and capturing carbon dioxide according to an embodiment of the present invention.

Detailed Description

For the convenience of understanding, the technical solutions provided by the embodiments of the present invention are described in detail below with reference to the drawings of the specification. It is obvious that the described embodiments are only some, not all embodiments of the proposed solution.

Referring to fig. 1, a system for generating power and capturing carbon dioxide according to an embodiment of the present invention includes a gasification furnace 101, a solid oxide fuel cell 102 in communication with the gasification furnace 101, a burner 201, a molten carbonate fuel cell 202 in communication with the burner 201, and a compression purification apparatus 203 in communication with the molten carbonate fuel cell 202.

The gasification furnace 101 is configured to perform coal gasification processing on the first fuel and convert the first fuel into syngas. Wherein the first fuel comprises a solid fuel or natural gas containing coal, coke or semicoke, etc., and water vapor (H)₂O) and/or oxygen (O)₂) The gasifying agent of (1). The synthesis gas generated after the coal gasification of the first fuel mainly comprises hydrogen (H)₂) Carbon monoxide (CO), H₂O, and the like. The gasification furnace 101 may be selected from various types of gasification furnaces, and for example, a fixed bed gasification furnace, a fluidized bed gasification furnace, an entrained flow gasification furnace, or the like may be selected.

The solid oxide fuel cell 102 is a power generation device that converts a fuel, which may be natural gas or syngas, etc., and an oxidant, which may be air or O, into electrical energy₂And the like.

The gasification furnace 101 is in communication with the solid oxide fuel cell 102, and when in particular communication, the gasification furnace 101 may be in communication with the anode of the solid oxide fuel cell 102. Thus, the synthesis gas in the gasification furnace 101 can be supplied as fuel to the anode of the solid oxide fuel cell 102, and the synthesis gas and the oxidant supplied to the cathode of the solid oxide fuel cell 102 can undergo oxidation-reduction reaction to generate electric energy, and at the same time, the first exhaust gas is also generated. In the process of the reaction, the anode of the solid oxide fuel cell 102 undergoes an oxidation reaction, and the cathode of the solid oxide fuel cell 102 undergoes a reduction reaction.

In the case of converting fuel into electric energy by using the solid oxide fuel cell 102, only a portion of the fuel is reacted each time the fuel is delivered to the solid oxide fuel cell 102, which means that the first exhaust gas includes not only syngas and oxidantCarbon dioxide (CO) formed by the reaction₂) And H₂O, and the like, and also comprises unreacted synthesis gas. Wherein, in a single reaction process, the volumetric ratio of fuel reacted to fuel delivered is referred to as single pass fuel utilization.

The burner 201 is used for burning the second fuel to obtain electric energy and flue gas. The combustor 201 includes a supercritical pulverized coal boiler, a hydraulic fluidized bed, and other power generation equipment, and the combustor 201 is generally provided in a coal-fired power plant. Wherein the second fuel comprises coal and an oxidant, and flue gas generated after the second fuel is combusted to generate electricity mainly comprises CO₂And the like.

Molten carbonate fuel cell 202 is a type of fuel cell that can internally reform and transfer fuel. The molten carbonate fuel cell 202 is in communication with the burner 201, and the cathode of the molten carbonate fuel cell 202 may be in communication with the burner 201, so that the flue gas generated in the burner 201 may be delivered to the cathode of the molten carbonate fuel cell 202, so that CO in the flue gas may be transported₂Reacts with the oxidant delivered to the cathode of the molten carbonate fuel cell 202 and converts it to carbonate ions (CO)₃ ^2-) And reacting the CO₃ ^2-Gradually transferred to the anode of the molten carbonate fuel cell 202. The molten carbonate fuel cell 202 is in communication with the solid oxide fuel cell 102, and may be in communication with the anode of the molten carbonate fuel cell 202 and the anode of the solid oxide fuel cell 102, such that the first exhaust gas generated in the solid oxide fuel cell 102 can be transported to the anode of the molten carbonate fuel cell 202 through the anode of the solid oxide fuel cell 102, such that H in the first exhaust gas₂With CO₃ ^2-React and convert into CO₂And H₂O, also realizes CO₂The transfer from the cathode of the molten carbonate fuel cell 202 to the anode of the molten carbonate fuel cell 202 converges.

The flue gas and the first exhaust gas react in the molten carbonate fuel cell 202 to generate electricity and a second exhaust gas including the molten carbonate fuel cell 2 during the reforming and transferring processes02 CO produced at the anode₂And H₂O, and the like. The process of reforming and transferring the first off-gas and the flue gas in the molten carbonate fuel cell 202 is as follows:

reaction of the cathode of the molten carbonate fuel cell 202: 2CO₂+O₂→2CO₃ ^2-

Reaction of the anode of molten carbonate fuel cell 202: h₂+CO₃ ^2-→CO₂+H₂O

The compressing and purifying device 203 is in communication with the molten carbonate fuel cell 202, and specifically can be in communication with the anode of the molten carbonate fuel cell 202, so that the second exhaust gas generated by the anode of the molten carbonate fuel cell 202 can be sent to the compressing and purifying device 203 for compressing and purifying to obtain CO in the second exhaust gas₂Then realize CO₂And (4) trapping.

The system for generating power and capturing carbon dioxide according to the embodiment of the present invention can mainly include H by providing the solid oxide fuel cell 102 communicating with the gasification furnace 101, providing the molten carbonate fuel cell 202 communicating with the burner 201, and communicating the solid oxide fuel cell 102 with the molten carbonate fuel cell 202₂、CO、H₂A first exhaust gas of O, and mainly comprising CO₂Is fed to the molten carbonate fuel cell 202, the first exhaust gas and the flue gas are caused to react in the molten carbonate fuel cell 202, and CO is generated₂Is diverted to converge to one end of the molten carbonate fuel cell 202 to obtain a fuel cell comprising primarily CO₂The second exhaust gas of (2) can be compressed and purified by the compression and purification device 203 communicating with the molten carbonate fuel cell 202, and CO in the second exhaust gas can be captured and obtained₂. Furthermore, electrical energy is generated during the conversion of the syngas and electrical energy is also generated during the conversion of the first exhaust gas and the flue gas into the second exhaust gas. That is to say, the system for generating power and capturing carbon dioxide provided by the embodiment of the invention can realize power generation and CO capture₂And (4) trapping.

Prior ArtIn the case of power generation using a solid oxide fuel cell, the off-gas generated at the anode is generally circulated and returned to the solid oxide fuel cell, and the unreacted synthesis gas in the first off-gas is allowed to continue to react. CO in molten carbonate fuel cells₂The method generally needs to additionally provide natural gas and water vapor, and the natural gas and the water vapor are used as fuel sources of an anode of the molten carbonate fuel cell, so that the natural gas and the water vapor are reformed at the anode of the molten carbonate fuel cell to obtain H required by the reaction₂This in turn leads to CO in molten carbonate fuel cells₂The capture process is limited by the fuel source and the absence of a fuel source does not allow the use of molten carbonate fuel cells for CO₂And (4) trapping.

In the embodiment of the present invention, the anode of the solid oxide fuel cell 102 is connected to the anode of the molten carbonate fuel cell 202, so that the first exhaust gas generated by the anode of the solid oxide fuel cell can be returned to the solid oxide fuel cell to continue the reaction without circulating the first exhaust gas, and the first exhaust gas can be used as a fuel source for the anode of the molten carbonate fuel cell 202 to pass H in the syngas which is not completely reacted in the first exhaust gas₂Removing CO from flue gas₂Converging to the anode of the solid oxide fuel cell 102. That is, by the cooperation between the solid oxide fuel cell 102 and the molten carbonate fuel cell 202, on the one hand, the molten carbonate fuel cell 202 can be prevented from being restricted by an external fuel source, and on the other hand, the H in the first exhaust gas can be effectively utilized₂And the utilization rate of the synthesis gas is improved.

In some embodiments, referring to fig. 1, the system for generating power and capturing carbon dioxide further comprises a first condensing device 104, wherein the first condensing device 104 is connected between the solid oxide fuel cell 102 and the molten carbonate fuel cell 202, and is used for condensing the first exhaust gas and removing H in the first exhaust gas₂O and CO₂And will remove H₂O and CO₂The latter first off-gas is delivered to the molten carbonate fuel cell 202.

Illustratively, the first condensing device 104 is provided with a first gas inlet and a first gas outlet, the first condensing device 104 is communicated with the anode of the solid oxide fuel cell 102 through the first gas inlet and is communicated with the anode of the molten carbonate fuel cell 202 through the first gas outlet, so that the first waste gas generated by the solid oxide fuel cell 102 can enter the first condensing device 104 through the first gas inlet, and the first waste gas is condensed by the first condensing device 104, so that H is generated by H₂O and CO₂Changing from gas state to liquid state, and changing liquid state of H₂O and liquid CO₂Removal, after which H can be removed via the first gas outlet₂O and CO₂The latter first off-gas is delivered to the anode of the molten carbonate fuel cell 202.

It will be appreciated that in the anode of the molten carbonate fuel cell 202, H₂O and CO₂Not participating as a reactant, but H₂And CO₃ ^2-Will generate H₂O and CO₂. The above-described embodiment can reduce the amount of H in the first off-gas delivered to the molten carbonate fuel cell 202 by providing the first condensing unit 104₂O and CO₂In the first exhaust gas, H in the first exhaust gas is reduced₂O and CO₂Increasing the volume ratio of H for reaction in the first exhaust gas₂Can further increase the reaction rate in the anode of the molten carbonate fuel cell 202 and increase CO₂The collection efficiency of (1).

In some embodiments, referring to fig. 1, the system for generating power and capturing carbon dioxide further comprises a second condensing device 204, wherein the second condensing device 204 is connected between the molten carbonate fuel cell 202 and the compressing and purifying device 203, and is used for condensing the second exhaust gas generated by the molten carbonate fuel cell 202 and removing H in the second exhaust gas₂O, and H is to be removed₂The second exhaust gas after O is sent to the compression purification apparatus 203.

It should be noted that the second condensing device 204 is provided with a second gas inlet and a second gas outlet, and the second condensing device 204 is communicated with the anode of the molten carbonate fuel cell 202 through the second gas inlet and is communicated with the anode through the second gas outletThe gas port communicates with the compression purification apparatus 203. Therefore, the second exhaust gas conveyed to the second condensing device 204 can be subjected to temperature reduction and cooling treatment by using the second condensing device, so that H in the second exhaust gas₂O changes from gas to liquid and for H in liquid state₂O is removed and recovered, and then H can be removed₂The second exhaust gas after O is delivered to the compression and purification device 203 for subsequent treatment, so that CO can be effectively increased₂The collection efficiency of (1).

In some embodiments, referring to fig. 1, the system for generating power and capturing carbon dioxide further includes at least one first purification device 103, wherein the at least one first purification device 103 is connected between the gasification furnace 101 and the solid oxide fuel cell 102, and is used for purifying the syngas generated by the gasification furnace 101 and delivering the purified syngas to the solid oxide fuel cell 102. It can be understood that, in the synthesis gas obtained after gasifying the first fuel, the first fuel further comprises impurities including sulfide and particles, and through the arrangement of the first purifying device 103, the synthesis gas can be purified, the impurities including sulfide and particles in the synthesis gas can be removed, and a relatively pure synthesis gas is obtained, so that the H content in the synthesis gas can be increased₂、CO、H₂The volume ratio of the gas such as O, and the like, further improves the one-way fuel utilization rate of the synthesis gas in the solid oxide fuel cell 102, and improves the power generation efficiency of the solid oxide fuel cell 102.

Each of the at least one first purification apparatus 103 is provided with an air inlet end and an air outlet end. When the at least one first purification apparatus 103 includes one first purification apparatus 103, the first purification apparatus 103 may communicate with the gasification furnace 101 through an inlet end and communicate with the anode of the solid oxide fuel cell 102 through an outlet end. When the at least one first purification apparatus 103 includes a plurality of first purification apparatuses 103, each first purification apparatus 103 may be connected in series between the gasification furnace 101 and the solid oxide fuel cell 102, i.e., the gas inlet and outlet of each first purification apparatus 103 are connected in series. Each first purification device 103 can also be connected in parallel between the gasification furnace 101 and the solid oxide fuel cell 102, that is, the gas inlet end of each first purification device 103 is communicated with the gasification furnace 101, and the gas outlet end is communicated with the anode of the solid oxide fuel cell 102.

In some embodiments, referring to fig. 2, the system for generating power and capturing carbon dioxide further comprises a first expansion device 105, wherein one end of the first expansion device 105 is communicated with the first purification device 103, and the other end is communicated with the solid oxide fuel cell 102, and particularly can be communicated with the anode of the solid oxide fuel cell 102. By providing the first expansion device 105, the synthesis gas can be expanded before being sent to the solid oxide fuel cell 102, so that the pressure of the synthesis gas is reduced, the pressure of the synthesis gas is substantially balanced with the pressure in the solid oxide fuel cell 102, a safety hazard caused by a too large pressure difference between the synthesis gas and the pressure in the solid oxide fuel cell 102 is avoided, and the use safety of the solid oxide fuel cell 102 can be improved. Alternatively, the first expansion device 105 may be a turbine.

With continued reference to fig. 2, in other embodiments, the system for generating electricity and capturing carbon dioxide further comprises a second expansion device 106, a first heat recovery device 107, and a first stack device 108, the second expansion device 106, the first heat recovery device 107, and the first stack device 108 are in serial communication, and the second expansion device 106 is also in communication with the cathode of the solid oxide fuel cell 102. The second expansion device 106 may be a turbine. When the synthesis gas supplied to the anode of the solid oxide fuel cell 102 and the oxidant supplied to the cathode of the solid oxide fuel cell 102 are subjected to oxidation-reduction reaction, a mixed gas (if the oxidant is air, the mixed gas contains nitrogen) is also generated at the cathode of the solid oxide fuel cell 102, and the mixed gas has a high pressure and carries a large amount of heat. The second expansion device 106 can expand the mixed gas generated at the cathode of the solid oxide fuel cell 102, thereby reducing the gas pressure of the mixed gas and improving the safety of the mixed gas treatment. Utilize first heat reclamation device 107 can carry out heat recovery to the mist after the inflation is handled, after carrying out heat recovery to the mist, alright discharge in carrying out first stack device 108 with the mist, retrieve through the heat to the mist, can avoid it to give off in the atmosphere, form a large amount of heat waste and the temperature rise of corresponding region, improve thermal utilization ratio, reduce the cost of the system of electricity generation and entrapment carbon dioxide.

It will be appreciated that the combustor 201 is typically a power generation facility located in a coal fired power plant that produces flue gas including, in addition to CO, during the coal fired power generation process₂In addition, the material also comprises substances containing sulfide, particles and the like. In some embodiments, at least one second purification device 205 is further connected between the burner 201 and the cathode of the molten carbonate fuel cell 202, and the at least one second purification device 205 can be used to purify the flue gas, remove substances such as sulfides and particulate matters in the flue gas, and obtain a relatively pure flue gas, so that the reaction rate of the flue gas in the molten carbonate fuel cell 202 can be improved. In the at least one second purification apparatus 205, the number and connection mode of the second purification apparatus 205 may be set according to actual conditions.

Referring to fig. 2, a preheating device 206 may be further communicated between the at least one second purification device 205 and the molten carbonate fuel cell 202. By providing the preheating device 206, the flue gas can be heated before being delivered to the cathode of the molten carbonate fuel cell 202, so that the temperature of the flue gas can be substantially the same as the temperature in the molten carbonate fuel cell 202, and thus, when the flue gas having a large difference from the temperature in the molten carbonate fuel cell 202 is delivered to the cathode of the molten carbonate fuel cell 202, the temperature in the molten carbonate fuel cell 202 can be prevented from being lowered, and the reaction rate in the molten carbonate fuel cell 202 can be prevented from being affected.

It should be noted that during the reaction between the flue gas and the first exhaust gas in the molten carbonate fuel cell 202, a gas is generated at the cathode of the molten carbonate fuel cell 202, and the gas carries a large amount of heat. In some embodiments, the system for generating electricity and capturing carbon dioxide further comprises a second heat recovery device 207 and a second stack device 208 in serial communication, wherein the second heat recovery device 207 is further in communication with the cathode of the molten carbonate fuel cell 202. Utilize second heat reclamation device 207 can carry out heat recovery to this gas, after carrying out heat recovery, can carry this gas to second stack device 208 and discharge, retrieve through the heat to gas, can avoid it to give off and cause a large amount of heat waste in the atmosphere, improve thermal utilization ratio, reduce the cost of the system of electricity generation and entrapment carbon dioxide.

It is worth mentioning that the first heat recovery device 207 and the second heat recovery device 207 may be a set of heat recovery devices, and the first stack device 108 and the second stack device 208 may be a set of stack devices.

An embodiment of the present invention further provides a method for generating power and capturing carbon dioxide, which is applied to the system for generating power and capturing carbon dioxide provided in the above embodiment, with reference to fig. 3 to 4, the method for generating power and capturing carbon dioxide includes:

s1: the first fuel is added to a gasifier of a system for generating electricity and capturing carbon dioxide to obtain a syngas.

The first fuel comprises solid fuel or natural gas containing coal, coke or semicoke, and gasifying agent containing water vapor and/or oxygen, wherein the solid fuel and the gasifying agent are subjected to coal gasification reaction in a gasification furnace to obtain synthesis gas mainly containing H for combustion₂And CO, etc.

S2: the synthesis gas is conveyed to a solid oxide fuel cell of a system for generating electricity and capturing carbon dioxide to react, and electric energy and first waste gas are obtained.

It is understood that the syngas generated by gasifying the first fuel may also include sulfur compounds, particulate matters, and the like.

In some embodiments, before the syngas is delivered to the solid oxide fuel cell, further comprising: the synthesis gas is purified. Through purifying the synthetic gas, can get rid of the material such as sulphide and particulate matter that contains in the synthetic gas, obtain comparatively pure synthetic gas, can make the volume proportion of the component that can be used for burning in the synthetic gas like this and promote, and then can improve the one-way fuel utilization ratio of synthetic gas in solid oxide fuel cell, improve solid oxide fuel cell's generating efficiency. Where single pass fuel utilization refers to the volumetric ratio of fuel reacted to fuel delivered in a single reaction.

It should be noted that the pressure of the synthesis gas generated in the gasification furnace is greater than the pressure in the solid oxide fuel cell, so that before the purified synthesis gas is delivered to the solid oxide fuel cell, the method further comprises: the purified synthesis gas is expanded, i.e. the pressure of the synthesis gas is reduced, so that the pressure of the synthesis gas is substantially the same as the pressure in the solid oxide fuel cell. By carrying out expansion treatment on the purified synthesis gas, potential safety hazards caused by large difference between the gas pressure of the synthesis gas and the gas pressure in the solid oxide fuel cell can be avoided, and the use safety of the solid oxide fuel cell is improved.

After the syngas is sequentially purged and expanded, the syngas can be delivered to the anode of the solid oxide fuel cell, with an oxidant (e.g., O) delivered to the cathode of the solid oxide fuel cell₂Or air, etc.) to generate a redox reaction, and generating electric energy and a first exhaust gas in the process of generating the redox reaction. The first exhaust gas is present at the anode of the solid oxide fuel cell.

Since only part of the synthesis gas in the solid oxide fuel cell will react, i.e. the single pass fuel utilization of the solid oxide fuel cell is less than 100%, the first exhaust gas not only includes CO generated by the oxidation-reduction reaction₂And H₂O, and the like, and also comprises unreacted synthesis gas.

It should be noted that, at the cathode of the solid oxide fuel cell, a mixed gas is generated, which has a high gas pressure and carries a large amount of heat. In some embodiments, the mixed gas generated at the cathode of the solid oxide fuel cell is further processed in the process of obtaining the first exhaust gas, and the specific processing process includes: the mixed gas is subjected to expansion treatment to reduce the gas pressure of the mixed gas, then the mixed gas subjected to expansion treatment is subjected to heat recovery treatment, and then the mixed gas subjected to heat recovery can be subjected to stack discharge. By performing the expansion treatment on the mixed gas, the safety of the treatment on the mixed gas can be improved. By recovering the heat of the mixed gas, a large amount of heat waste can be avoided, and the cost of the process of generating power and capturing carbon dioxide is reduced.

S3: a second fuel is added to the burner of the system for generating electricity and capturing carbon dioxide to obtain electrical energy and flue gas.

The second fuel comprises coal and oxidant, and the coal and oxidant generate electric energy and flue gas during combustion in the combustor, wherein the flue gas mainly comprises CO₂And the like.

S4: the flue gas and the first exhaust gas are conveyed to a molten carbonate fuel cell of a system for generating electricity and capturing carbon dioxide for reaction to obtain electric energy and a second exhaust gas.

The flue gas generated by combustion of coal and an oxidizing agent to generate electricity includes not only CO₂Also, the material includes sulfide and particulate matter.

In some embodiments, prior to delivering the flue gas to the molten carbonate fuel cell, further comprising: the flue gas is purified. By purifying the flue gas, substances such as sulfide and particulate matters in the flue gas can be removed, and the purer flue gas is obtained, so that the reaction rate of the flue gas in the molten carbonate fuel cell can be improved.

It is worth mentioning that before the purified flue gas is delivered to the molten carbonate fuel cell, the method further comprises: and preheating the purified flue gas. By preheating the flue gas, the temperature of the flue gas can be heated to the temperature basically same as that of the molten carbonate fuel cell, so that the temperature in the molten carbonate fuel cell can be prevented from being reduced when the purified flue gas is conveyed to the molten carbonate fuel cell, and the influence on the reaction rate in the molten carbonate fuel cell can be avoided.

When the flue gas and the first off-gas are supplied to the molten carbonate fuel cell, the flue gas may be supplied to the cathode of the molten carbonate fuel cell, and the first off-gas may be supplied to the anode of the molten carbonate fuel cell. The flue gas is delivered to the cathode of the molten carbonate fuel cell while an oxidant is also delivered at the cathode of the molten carbonate fuel cell. After the flue gas, the oxidant and the first exhaust gas are respectively delivered to the corresponding positions of the molten carbonate fuel cell, the reaction process in the molten carbonate fuel cell is as follows:

reaction of the cathode of a molten carbonate fuel cell: 2CO₂+O₂→2CO₃ ^2-

Reaction of the anode of molten carbonate fuel cells: h₂+CO₃ ^2-→CO₂+H₂O

CO in flue gas₂With O in the oxidant₂Reaction to CO at the anode of a molten carbonate fuel cell₃ ^2-The CO is₃ ^2-Gradually transferred to the anode of the molten carbonate fuel cell. H in the first exhaust gas₂With CO transferred to the anode of a molten carbonate fuel cell₃ ^2-React to generate CO₂And H₂And O. That is, CO in the flue gas₂Can be gradually converged from the cathode of the molten carbonate fuel cell to the anode of the molten carbonate fuel cell through the processes of reforming, transferring and the like in the molten carbonate fuel cell to obtain the fuel cell mainly comprising CO₂Of the second exhaust gas. Meanwhile, in the process of reaction, electric energy can be generated.

It can be understood that H contained in the first exhaust gas₂O and CO₂Do not participate as reactants in the redox reaction, and the redox reaction occurring in molten carbonate fuel cells can also generate H₂O and CO₂。

In some embodiments, prior to delivering the first off-gas to the molten carbonate fuel cell, further comprising: condensing the first waste gas to remove H in the first waste gas₂O and CO₂. H in the first waste gas can be condensed by the first waste gas₂O and CO₂From the gaseous state to the liquid state, followed by the liquid H₂O and CO₂Removing and recovering to make the first waste gas mainly comprise H₂The first exhaust gas of (1). This can increase H₂The volume ratio of the first waste gas in the first waste gas can further improve the reaction rate of the first waste gas in the molten carbonate fuel cell and improve the CO reaction rate₂The collection efficiency.

S5: and conveying the second exhaust gas to a compression and purification device of a system for generating power and capturing carbon dioxide, and compressing, purifying and capturing the carbon dioxide in the second exhaust gas.

According to the reaction process in the molten carbonate fuel cell, H is also included in the second exhaust gas₂And O. In some embodiments, before the delivering the second exhaust gas to the compression purification apparatus, further comprises: and condensing the second waste gas to remove water in the second waste gas. H in the second exhaust gas can be condensed by the second exhaust gas₂O is converted from gas to liquid and is added to H in liquid state₂Removing O to make the component in the second waste gas mainly be CO₂So that CO in the second exhaust gas can be increased₂The purity of (2). And, the above liquid H₂The O can be recovered and reused after being removed, which can reduce the process cost of the method of generating electricity and capturing carbon dioxide.

After condensing the second off-gas, H may be removed₂The second waste gas of O is conveyed to a compression and purification device to compress and purify the second waste gas so as to reduce the volume occupied by the second waste gas and further improve the CO in the second waste gas₂So as to facilitate capture and storage of more CO₂。

It is noted that gases are also generated at the cathode of molten carbonate fuel cells, which carry a significant amount of heat. In some embodiments, the gas generated at the cathode of the solid oxide fuel cell is also treated during the treatment of the second exhaust gas, and the treatment process includes: the gas is subjected to heat recovery treatment, and then the mixed gas subjected to heat recovery can be discharged in a stack. Through retrieving the heat to gaseous, can avoid causing a large amount of heat extravagants, improve thermal utilization ratio.

The reference numerals "S1", "S2", "S3", "S4" and "S5" are for descriptive purposes only and are not to be construed as limiting the order in which the steps of the method of generating electricity and capturing carbon dioxide are performed.

It is understood that when the single-pass fuel utilization in the solid oxide fuel cell is high, i.e. a large portion of the syngas delivered to the solid oxide fuel cell can be reacted, the solid oxide fuel cell has high power generation efficiency. However, this also results in a smaller volume of unreacted synthesis gas in the synthesis gas, and a smaller volume of unreacted synthesis gas contained in the first exhaust gas, which in turn is available for CO₂H undergoing reforming₂The volume of (a) is relatively small.

In some embodiments, the single pass fuel utilization in the solid oxide fuel cell can be set (e.g., the setting of the single pass fuel utilization in the solid oxide fuel cell can be achieved based on the VI performance curve of the solid oxide fuel cell and controlling the flow of syngas delivered to the solid oxide fuel cell) to enable the solid oxide fuel cell to have a higher power generation efficiency while also enabling the molten carbonate fuel cell to have a higher reaction efficiency. Optionally, after the purified syngas is conveyed to the solid oxide fuel cell, the volume of the gas that reacts in the purified syngas accounts for 50% to 70% of the volume of all the gases, that is, in a single reaction process in the solid oxide fuel cell, 50 to 70 parts by volume of the purified syngas may be conveyed for every 100 parts by volume of the purified syngas, and the purified syngas reacts to generate electric energy and a first waste gas, where the first waste gas includes 30 to 50 parts by volume of the syngas that does not react. H in the unreacted synthesis gas in the first exhaust gas₂With CO in the flue gas₂Reaction in molten carbonate fuel cells, capture during the production of electrical energyCollect more CO₂. By setting the volume ratio of the synthesis gas to be reacted, the reaction efficiency between the solid oxide fuel cell and the molten carbonate fuel cell can be balanced, so that the solid oxide fuel cell has higher power generation efficiency and the molten carbonate fuel cell has higher CO₂Transfer of the efficiency of concentration and thus higher CO₂The collection rate of (1).

In other embodiments, the ratio of electrical energy obtained in the solid oxide fuel cell to electrical energy obtained in the molten carbonate fuel cell is from 2:5 to 4: 5. By setting the ratio of the electric energy obtained in the solid oxide fuel cell to the electric energy obtained in the molten carbonate fuel cell, that is, setting the ratio of the volume of the synthesis gas delivered to the solid oxide fuel cell for generating electric energy to the volume of the flue gas delivered to the molten carbonate fuel cell for generating electric energy, and combining the ratio of the volume of the synthesis gas subjected to the reaction in the solid oxide fuel cell to the volume of the whole synthesis gas, the volume of the synthesis gas delivered to the solid oxide fuel cell and the volume of the flue gas delivered to the molten carbonate fuel cell can be respectively controlled to match the two, and further, the mass ratio of the first fuel delivered to the gasification furnace and the second fuel delivered to the combustor can be controlled, so that the reactions in the solid oxide fuel cell and the molten carbonate fuel cell can be more optimally regulated and controlled, balancing power generation efficiency and CO of an overall system₂The capture rate of the system ensures the economic benefit of the whole system.

The above description is only for the specific embodiments of the present invention, but the scope of the present invention is not limited thereto, and any person skilled in the art can easily conceive of the changes or substitutions within the technical scope of the present invention, and the present invention shall be covered thereby. Therefore, the protection scope of the present invention shall be subject to the protection scope of the appended claims.