Zero-carbon-emission coal power generation system capable of automatically generating CO2 working medium and power generation method

Abstract

The invention relates to the technical field of power generation, in particular to a zero-carbon-emission coal power generation system and method capable of automatically generating a CO2 working medium. The power generation system comprises a coal gasification reaction furnace, a desulfurization absorption tower, a condensation tank, a pressure swing adsorption device, a CO storage tank, a battery device and a first connecting pipeline; a pulverized coal inlet and a CO2 inlet are formed in the coal gasification reaction furnace; the battery device comprises a load, a cathode chamber, an anode chamber and an electrolyte layer arranged between the cathode chamber and the anode chamber, and an air inlet and a tail gas outlet are formed in the battery device; the first connecting pipeline is communicated with the coal gasification reaction furnace and the tail gas outlet of the battery device and is used for circulating tail gas generated in the battery device into the coal gasification reaction furnace. The power generation system not only has very high power generation efficiency and good power generation stability, but also avoids subsequent CO2 capture and storage through system self-circulation, realizes near-zero emission of CO2, and co-produces an additional value chemical product CO at the same time.

Description

Technical Field

[0001] The present invention relates to the technical field of power generation, and particularly relates to a zero-carbon emission coal power generation system and power generation method using self-generated CO 2 working medium. Background Art

[0002] The general process of IGFC (Integrated Gasification Fuel Cell) is that coal (or natural gas, biomass, etc.) is gasified to generate syngas, and the fuel gas and the oxidation gas undergo an electrochemical reaction in the cell to generate electricity. During the reaction process, most of the combustible components are converted into electricity and heat. However, the unreacted combustible components are discharged with the anode tail gas of the cell and still need to enter the combustion chamber for catalytic combustion. This not only increases the complexity of system operation and causes additional economic burden, but also fails to avoid the subsequent CO 2 emission problem well, and still needs to capture and store CO 2 .

[0003] Therefore, the existing technology still needs to be improved and developed. Summary of the Invention

[0004] In view of the above deficiencies of the prior art, the purpose of the present invention is to provide a zero-carbon emission coal power generation system and power generation method using self-generated CO 2 working medium, aiming to solve the problem that in the prior art, the unreacted combustible components of IGFC are discharged with the anode tail gas of the cell and still need to enter the combustion chamber for catalytic combustion, which not only increases the complexity of system operation and causes additional economic burden, but also fails to avoid the subsequent CO 2 emission well, and still needs to capture and store CO 2 .

[0005] The technical solution of the present invention is as follows: In the first aspect of the present invention, there is provided a zero-carbon emission coal power generation system using self-generated CO 2 working medium, which includes: a coal gasification reactor, a desulfurization absorption tower, a condensation tank, a pressure swing adsorption device, a CO storage tank, a cell device, and a first connecting pipeline; Wherein, the coal gasification reactor is connected to the desulfurization absorption tower, the desulfurization absorption tower is connected to the condensation tank, the condensation tank is connected to the pressure swing adsorption device, and the pressure swing adsorption device is respectively connected to the CO storage tank and the cell device; The coal gasification reactor is provided with a pulverized coal inlet and a CO 2 inlet; The cell device includes a load, a cathode chamber, an anode chamber, and an electrolyte layer disposed between the cathode chamber and the anode chamber, and the cell device is provided with an air inlet and a tail gas outlet; The first connecting pipe communicates with the tail gas outlet of the coal gasification reactor and the battery device, and the first connecting pipe is used to circulate the tail gas generated in the battery device into the coal gasification reactor.

[0006] Optionally, a waste heat recovery device is further provided between the coal gasification reactor and the battery device, and the waste heat recovery device is used to supply the waste heat of the gas flowing out of the battery device to the coal gasification reactor.

[0007] Optionally, the self-generated CO 2 The zero-carbon emission coal power generation system with working medium further includes a second connecting pipe connecting the coal gasification reactor and the pressure swing adsorption device, and the second connecting pipe is used to return the CO separated by the pressure swing adsorption device 2 back into the coal gasification reactor.

[0008] Optionally, an air outlet is further provided on the battery device, and the air outlet is used to discharge the oxygen-depleted air generated by the battery device.

[0009] Optionally, the self-generated CO 2 The zero-carbon emission coal power generation system with working medium further includes a residue storage tank, a dust discharge valve is arranged at the lower end of the coal gasification reactor, and the residue storage tank is communicated with the dust discharge valve.

[0010] Optionally, the self-generated CO 2 The zero-carbon emission coal power generation system with working medium further includes a preheating tank, the preheating tank is communicated with the CO 2 inlet arranged on the coal gasification reactor, and the preheating tank is used to preheat CO 2 .

[0011] Optionally, the working temperature of the coal gasification reactor is 720 - 1000 °C, the working temperature of the battery device is 720 - 1000 °C, and the working temperature of the battery device is 20 - 50 °C higher than that of the coal gasification reactor.

[0012] Optionally, the working temperature of the condensation tank is 30 - 60 °C.

[0013] In the second aspect of the present invention, a power generation method for the zero-carbon emission coal power generation system with self-generated CO 2 working medium as described in the present invention is provided, and the method includes the steps: Adding coal and introducing CO 2 into the coal gasification reactor through the pulverized coal inlet and the CO 2 inlet respectively, and a reaction occurs in the coal gasification reactor to generate a gas containing CO; The generated gas containing CO is desulfurized in a desulfurization absorption tower, then condensed in a condensation tank, and then separated into two parts by a pressure swing adsorption device. One part of the CO is introduced into a CO storage tank for storage, and the other part of the CO is introduced into the interior of the battery device; Connect the load of the battery device, and introduce air into the battery device through the air inlet. The oxygen in the air gains electrons in the cathode chamber to generate O 2- , and the generated O 2- is conducted from the cathode chamber to the anode chamber through the electrolyte layer. The O 2- undergoes an electrochemical reaction with CO in the anode chamber to generate CO 2 and simultaneously releases electrons, thus forming a closed circuit to generate current. And the generated CO 2 circulates back into the coal gasification reactor through the first connecting pipe.

[0014] Optionally, the operating parameters of the load include: the voltage of a single cell is 0.6 - 0.9 V, and the current density is 500 - 900 mA / cm 2 .

[0015] Beneficial effects: The zero-carbon emission coal power generation system with self-generated CO 2 working medium provided by the present invention is provided with a desulfurization absorption tower for desulfurizing the CO generated by coal gasification between the coal gasification reactor and the battery device, which can avoid the poisoning effect of a small amount of sulfur-containing gas contained in the gasified solid carbon on the anode catalyst; a condensation tank is provided to condense the desulfurized CO to a suitable temperature, which can ensure the separation of impurities such as moisture and light hydrocarbons, and at the same time keep the CO in a gaseous state; a pressure swing adsorption device is provided to separate the CO. Part of the CO is recovered and stored in the CO storage tank after pressure swing separation to obtain high-purity and high-value CO chemical products, and part enters the interior of the battery device to undergo an electrochemical reaction to generate CO 2 and releases electrons to generate current. And the CO 2 generated in the battery device and the unreacted CO, etc. can re-enter the coal gasification reactor through the first connecting pipe to participate in the coal gasification reaction. The power generation system of the present invention not only has high power generation efficiency and good power generation stability, but also avoids subsequent CO 2 capture and storage through the system self-circulation, realizes near-zero emission of CO 2 , and simultaneously co-produces chemical products with added value, CO. Description of the Drawings

[0016] Figure 1 is a schematic structural diagram of a zero-carbon emission coal power generation system with self-generated CO 2 working medium provided by the present invention.

[0017] Figure 2 is a zero-carbon emission coal power generation system with self-generated CO2 Working principle diagram of a zero-carbon emission coal power generation system with a working medium

[0018] Figure 3 A self-generated CO provided by the present invention 2 Flow chart of the power generation method of a zero-carbon emission coal power generation system with a working medium

[0019] Figure 4 For the power generation system provided in Example 1, under the condition that the current density is 687 mA / cm 2 , and the working temperature of the battery device is 850 °C, the power generation durability test curve graph

[0020] Among them, 1 - coal gasification reactor, 2 - desulfurization absorption tower, 3 - condensation tank, 4 - pressure swing adsorption device, 5 - CO storage tank, 6 - battery device, 7 - first connection pipeline, 8 - load, 9 - anode chamber, 10 - electrolyte layer, 11 - cathode chamber, 12 - air source, 13 - pulverized coal source, 14 - CO 2 source, 15 - preheating tank, 16 - waste heat recovery device, 17 - second connection pipeline, 18 - residue storage tank Specific implementation manners

[0021] The present invention provides a self-generated CO 2 Zero-carbon emission coal power generation system and power generation method with a working medium. To make the purpose, technical solution and effect of the present invention clearer and more definite, the present invention is further described in detail below. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention

[0022] Since in the prior art, the unreacted combustible components of IGFC are discharged with the anode tail gas of the battery and still need to enter the combustion chamber for catalytic combustion, which not only increases the complexity of system operation, causing an additional economic burden, but also fails to avoid the subsequent CO 2 emission problem well, and still needs to capture and store CO 2 and other problems. To solve the above problems, the present invention provides a self-generated CO 2 Zero-carbon emission coal power generation system with a working medium

[0023] As Figure 1 shown, the embodiment of the present invention provides a self-generated CO 2 Zero-carbon emission coal power generation system with a working medium, including: coal gasification reactor 1, desulfurization absorption tower 2, condensation tank 3, pressure swing adsorption device 4, CO storage tank 5, battery device 6 and first connection pipeline 7 Among them, the coal gasification reactor 1 is connected to the desulfurization absorption tower 2, the desulfurization absorption tower 2 is connected to the condensation tank 3, the condensation tank 3 is connected to the pressure swing adsorption device 4, and the pressure swing adsorption device 4 is respectively connected to the CO storage tank 5 and the battery device 6; A coal powder inlet and a CO 2 inlet are provided on the coal gasification reactor 1. The coal powder inlet is used to add coal powder into the coal gasification reactor 1, and the coal powder is provided by the coal powder source 13; the CO 2 inlet is used to introduce CO 2 into the coal gasification reactor 1, and the CO 2 is provided by the CO 2 source 14; The battery device 6 includes a load 8, a cathode chamber 11, an anode chamber 9, and an electrolyte layer 10 provided between the cathode chamber and the anode chamber. An air inlet and a tail gas outlet are provided on the battery device 6; the air inlet is used to introduce air into the battery device 6, and the air is provided by the air source 12; The first connecting pipe 7 connects the tail gas outlets of the coal gasification reactor 1 and the battery device 6, and the first connecting pipe 7 is used to circulate the tail gas generated in the battery device 6 back into the coal gasification reactor 1.

[0024] The zero-carbon emission coal power generation system with self-generated CO 2 working medium provided by the embodiment of the present invention is provided with a desulfurization absorption tower 2 for desulfurizing the CO generated by coal gasification between the coal gasification reactor 1 and the battery device 6, which can avoid the poisoning effect of a small amount of sulfur-containing gas contained in the gasified solid carbon on the anode catalyst; a condensation tank 3 is provided to condense the desulfurized CO to a suitable temperature, which can ensure the separation of impurities such as moisture and light hydrocarbons, and at the same time keep the CO in a gaseous state; a pressure swing adsorption device 4 is provided to separate the CO. Part of the CO is recovered and stored in the CO storage tank 5 after pressure swing separation to obtain high-purity and high-value CO chemical products, and part enters the battery device 6 to undergo an electrochemical reaction to generate CO 2 and release electrons to generate current, and the CO 2 generated in the battery device 6 and the unreacted CO, etc. can re-enter the coal gasification reactor 1 through the first connecting pipe 7 to participate in the coal gasification reaction. The power generation system of the present invention not only has high power generation efficiency and good power generation stability, but also avoids subsequent CO 2 capture and storage through system self-circulation, realizing nearly zero emission of CO 2 and co-producing value-added chemical product CO at the same time.

[0025] The zero-carbon emission coal power generation system with self-generated CO 2The zero-carbon emission coal power generation system with working medium is compact in structure, has small pipeline losses in gas transmission, and the heat generated by the electrochemical reaction in the battery device can heat the coal gasification reaction device through cavity heat conduction, thermal radiation, etc., supplementing the heat required for the reverse Boudouard reaction, without external heating, and can improve the power generation efficiency of the equipment.

[0026] The self-generated CO provided by the embodiment of the present invention 2 The zero-carbon emission coal power generation system with working medium adopts the method of self-catalytic carbon-oxygen decoupling to realize power generation and CO co-production. The CO generated in the anode chamber 2 circulates to the inside of the coal gasification reactor outside the battery device, and spontaneously reduces and regenerates the oxidized reactants in the anode through the Boudouard reaction. This system decouples the electrochemical oxidation reaction of CO from the 2 non-electrochemical reduction reaction of CO to realize the continuous and stable circulation of reactants, and at the same time collect high-value CO accessories.

[0027] The self-generated CO provided by the embodiment of the present invention 2 The working principle of the zero-carbon emission coal power generation system with working medium is: combined with Figure 1 and Figure 2 as shown, pulverized coal is added to the coal gasification reactor 1 through the pulverized coal source 13, and CO 2 gas is introduced into the coal gasification reactor 1 through the CO 2 source 14. Coal and CO in the coal gasification reactor 1 2 undergo the reverse Boudouard reaction (Boudouard reaction): C + CO 2 = 2CO, thereby generating a large amount of CO fuel gas; the generated CO is desulfurized by the desulfurization absorption tower 2, and the CO generated by the coal gasification reactor can be desulfurized, which can avoid the poisoning effect of a small amount of sulfur-containing gas contained in the pulverized coal gasification on the anode catalyst and the blockage of the pipeline after low-temperature solidification; all the desulfurized CO is condensed to a suitable temperature by the condensation tank 3, which can ensure the separation of impurities such as moisture and light hydrocarbons, and at the same time keep the CO in a gaseous state; all the condensed CO, part of the CO is recycled and stored in the CO storage tank 5 with high purity through the pressure swing adsorption device 4 by pressure swing separation, and part of the CO enters the inside of the battery device 6; O 2 in the air introduced by the air source 12 enters the cathode chamber 11 in the battery device 6 to obtain electrons and generate O 2- , O 2- passes through the electrolyte layer 10 and enters the anode chamber 9, and undergoes an electrochemical reaction with the CO inside the anode chamber 9, discharging electrons to the external circuit and generating CO 2 at the same time. The generated CO 2 circulates back to the coal gasification reactor 1 through the first connecting pipe 7. The power generation system of the present invention avoids subsequent CO through system self-circulation2 Capture and storage to achieve near-zero emissions of CO 2 .

[0028] In some embodiments, fuel gas is generated through a coal gasification reaction in the coal gasification reactor 1. The main component of the fuel gas is CO, and it also includes CO 2 , N 2 , H 2 , CH 4 , C 2 H 6 and C 2 H 4 etc. Specifically, the components in the fuel gas are CO: 70%, CO 2 : 10%, N 2 : 5%, H 2 : 6%, CH 4 : 3%, C 2 H 6 : 3%, C 2 H 4 : 3%.

[0029] In some embodiments, the zero-carbon emission coal power generation system with the self-generated CO 2 working medium is provided with a CO 2 source 14 connected to the coal gasification reactor 1 for introducing CO 2 into the coal gasification reactor 1, so as to achieve the supply of CO 2 .

[0030] In some embodiments, the zero-carbon emission coal power generation system with the self-generated CO 2 working medium further includes a preheating tank 15. The preheating tank 15 is connected to the CO 2 inlet provided on the coal gasification reactor 1. The preheating tank 15 is used to preheat the CO 2 provided by the CO 2 source 14. After preheating the CO 2 through the preheating tank 15 and then introducing it into the coal gasification reactor 1, the reaction process between coal and CO 2 in the coal gasification reactor can be accelerated.

[0031] In some preferred embodiments, the operating temperature of the preheating tank 15 is 500°C to 750°C, and for example, it can be 500°C, 550°C, 600°C, 650°C, 700°C, 750°C, etc.

[0032] In some embodiments, the self-generated CO 2The zero-carbon emission coal power generation system with working medium is provided with a pulverized coal source 13 connected to the coal gasification reactor 1 for adding pulverized coal into the coal gasification reactor 1, so as to realize the circulation and continuous supply of coal. When the power generation system is working, the power generation amount of the battery device can be controlled by controlling the adding rate and adding amount of pulverized coal. When the power demand is small, the battery device will work at a lower current. At this time, the CO generation rate can be controlled by reducing the adding rate or amount of pulverized coal to reduce the electrochemical reaction rate and decrease the output power. On the contrary, when the power demand is large, the adding amount or adding rate of pulverized coal can be increased. Since the CO generation rate is determined by both the pulverized coal and the CO 2 feed-through amount at the same time, similarly, the electrochemical reaction rate can be reduced by decreasing the flow rate of the recycled tail gas CO 2 or increased by increasing the flow rate of the recycled tail gas CO 2 flow rate.

[0033] In some preferred embodiments, the zero-carbon emission coal power generation system with self-generated CO 2 working medium is further provided with a residue storage tank 18 connected to the coal gasification reactor 1. A dust discharging valve is arranged at the lower end of the coal gasification reactor 1, and the residue storage tank 18 is connected to the dust discharging valve. The incombustible coal ash particles and unburned coal particles in the coal gasification reactor 1 settle in the residue storage tank 18 through the dust discharging valve.

[0034] In some preferred embodiments, the pulverized coal source 13 in the zero-carbon emission coal power generation system with self-generated CO 2 working medium is arranged at the upper end of the coal gasification reactor 1, and the residue storage tank 18 is arranged at the lower end of the coal gasification reactor 1. By arranging the pulverized coal source at the upper end of the coal gasification reactor and the residue storage tank at the lower end of the coal gasification reactor, the top-down pulverized coal supply mode and the design of the ash discharge port at the lower part (dust discharging valve) ensure the rapid and continuous supply of coal fuel, can increase the CO supply amount, reduce the CO concentration loss of the stack, and avoid the mechanical damage that may be caused by the direct contact between the battery anode and coal particles.

[0035] In some embodiments, the adding rate and adding amount of pulverized coal in the coal gasification reactor 1 can be determined according to the power demand of the battery device and the CO 2 circulation amount. Preferably, the adding rate of pulverized coal is 0.05 - 0.5 kg / min.

[0036] In some embodiments, the desulfurization absorption tower 2 is connected to the coal gasification reactor 1 and the condensation tank 3, and granular desulfurizing agents such as limestone, dolomite or slaked lime can be filled therein to complete the desulfurization process, which can avoid the poisoning effect of a small amount of sulfur-containing gas in CO after coal gasification on the anode catalyst. For example, when the anode catalyst is Ni particles, it can prevent the sulfur-containing gas from sulfiding the catalyst Ni particles to form low-catalytic-activity substances such as NiS and Ni 3 S x etc. Preferably, the desulfurization absorption tower 2 can adopt a fixed-bed adsorption structure, and zinc oxide (ZnO) and iron oxide (Fe 2 O 3 ) are filled in the tower as the main adsorption materials and operate in the temperature range of 300-500 °C, which can effectively remove sulfides such as H 2 S and SO 2 generated by coal gasification. Among them, ZnO is mainly used to adsorb H 2 S to form ZnS, while Fe 2 O 3 can react with H 2 S to form Fe 2 S 3 and regenerate under certain conditions.

[0037] In some embodiments, the condensation tank 3 is connected to the desulfurization absorption tower 2 and the pressure swing adsorption device 4, and condensation can be achieved by means such as shell-and-tube water cooling condensation and plate heat exchangers. The working temperature of the condensation tank 3 is 30-60 °C (for example, it can be 30 °C, 35 °C, 40 °C, 45 °C, 50 °C, 55 °C, 60 °C, etc.), to ensure the separation of a small amount of impurities such as moisture and light hydrocarbons contained in CO, while keeping CO in a gaseous state for subsequent further treatment by the pressure swing adsorption device to recover high-purity CO. The working temperature range can remove water vapor and other impurities in the gas without condensing carbon monoxide itself, which can ensure the subsequent separation and recovery of the gas and ensure the efficient operation of the system.

[0038] In some embodiments, the pressure swing adsorption (PSA) device 4 is connected to the condensation tank 3 and is respectively connected to the CO storage tank 5 and the battery device 6. Pressure swing adsorption is a technology for separating gases by periodically changing the pressure based on the difference in the adsorption capacity of different components in a gas mixture on an adsorbent. In the embodiment of the present invention, the pressure swing adsorption device 4 separates and recovers and stores high-purity CO in the CO storage tank 5 after pressure swing separation of a part of the condensed CO, and a part of the CO enters the interior of the battery device 6 and reacts with O in the anode chamber 2-An electrochemical reaction occurs. Preferably, 50% to 70% of the CO is introduced into the CO storage tank 5 for recovery and storage, and the remaining CO (30% to 50%) is introduced into the battery device to undergo an electrochemical reaction.

[0039] In some embodiments, the self-generated CO 2 The zero-carbon emission coal power generation system of the working medium further includes a second connecting pipe 17 connecting the coal gasification reactor 1 and the pressure swing adsorption device 4. The second connecting pipe 17 is used to return the CO separated by the pressure swing adsorption device 4 2 back to the coal gasification reactor 1 to continue participating in the coal gasification reaction, further improving the utilization rate of CO 2 and achieving nearly zero emission of CO. 2

[0040] In some embodiments, the battery device 6 includes a load 8, a cathode chamber 11, an anode chamber 9, and an electrolyte layer 10 disposed between the cathode chamber and the anode chamber. The anode of the battery device is a Ni and electrolyte powder composite porous anode used in traditional solid oxide fuel cells. The electrolyte layer uses common cationic electrolytes such as 8mol% Y 2 O 3 -ZrO 2 , Ce 0.8 Sm 0.2 O 1.9 , Ce 0.8 Gd 0.2 O 1.9 . The cathode uses a composite porous electrode mainly composed of the above electrolyte materials and common classical cathode materials of solid oxide batteries, such as (La 0.8 Sr 0.2 ) 0.95 MnO 3 , (La 0.6 Sr 0.4 ) 0.95 Co 0.2 Fe 0.8 O 3 , etc.

[0041] In this embodiment, the working principle of the battery device 6 is as follows: When the external load is connected, air is provided by the air source 12. The oxygen in the air entering the battery device 6 obtains electrons from the cathode chamber 11 of the battery to become O 2- , and O 2- passes through the electrolyte layer 10 (preferably an oxygen ion conducting electrolyte) under the drive of the concentration difference and potential difference to reach the anode chamber 9 of the battery. O 2- contacts with the carbon monoxide gas in the anode chamber to undergo an electrochemical reaction, releasing electrons and generating CO 2, thus completing power generation. The coal gasification reaction and the electrochemical reaction are carried out in the coal gasification reactor 1 and the battery device 6 respectively, which can realize the recycling and continuous supply of coal. The pulverized coal does not come into direct contact with the battery, avoiding the contact between coal particles, ash and the anode, and improving the long-term stability of the battery.

[0042] In some embodiments, the battery device 6 is further provided with an air outlet for discharging the oxygen-depleted air generated by the battery device. Preferably, the oxygen-depleted air in the battery device can be discharged to the outside by providing devices such as an exhaust valve or a gas diverter in the battery device. More preferably, the air inlet and the air outlet on the battery device 6 are arranged on the cathode chamber side. The oxygen in the air introduced through the air inlet obtains electrons in the cathode chamber and becomes O 2- , and the oxygen-depleted air can be discharged into the air through the air outlet, thereby increasing the air circulation in the battery device and being beneficial to accelerating the electrochemical reaction.

[0043] In some embodiments, the ratio of the CO flow rate to the air flow rate introduced into the battery device 6 is generally controlled between 1:1 and 1:3 to ensure the reaction efficiency and avoid catalyst poisoning.

[0044] In some embodiments, the operating voltage of the battery device 6 is 0.7 - 0.9 V.

[0045] In some embodiments, the working temperature of the coal gasification reactor is 720 - 1000 °C (for example, it can be 720 °C, 750 °C, 800 °C, 827 °C, 850 °C, 900 °C, 950 °C, 1000 °C, etc.), and the working temperature of the battery device is 720 - 1000 °C (for example, it can be 720 °C, 750 °C, 800 °C, 850 °C, 900 °C, 950 °C, 1000 °C, etc.) to avoid affecting the long-term stability of the entire power generation system due to too high temperature; and the working temperature of the battery device is 20 - 50 °C higher than the working temperature of the coal gasification reactor (preferably 23 °C), so that the CO production rate of the coal gasification reactor 1 matches the CO consumption rate of the battery device 6, and the heat generated by the battery device 6 can be conducted to the coal gasification reactor 1 through the waste heat recovery device 16 to maintain its working temperature.

[0046] In some embodiments, the self-generated CO 2Between the coal gasification reactor 1 and the battery device 6 in the zero-carbon emission coal power generation system of the working medium, there is also a waste heat recovery device 16 (which can generally be a tubular heat exchanger). The waste heat recovery device 16 is used to supply the waste heat of the outflow gas of the battery device 6 to the coal gasification reactor. Preferably, the waste heat recovery device 16 is connected to the anode chamber 9 side of the battery device 6 through a pipeline. Since in this embodiment, the anode chamber 9 of the battery device 6 is enriched with CO 2 tail gas. This tail gas is rich in CO 2 and has a relatively high temperature. In this way, not only can CO be recycled 2 but also its waste heat can be used to maintain the working temperature of the coal gasification reactor 1, improving the energy utilization rate.

[0047] In some embodiments, the temperature at the outlet of the pipeline connecting the anode chamber 9 side of the battery device 6 to the waste heat recovery device 16 is 700 - 900°C. The waste heat recovery device 16 can conduct the heat to the coal gasification reactor 1 to maintain its working temperature.

[0048] In some embodiments, in order to ensure that the CO generated in the coal gasification reactor 1 only flows into the battery device and does not flow into other places causing energy waste, in the embodiments of the present invention, the coal gasification reactor 1, the desulfurization absorption tower 2, the condensation tank 3, the pressure swing adsorption device 4, the CO storage tank 5, the battery device 6, and the first connection pipeline 7, as well as the connection points of each device, are all sealed and connected through a high-temperature sealant. And the working temperature of the high-temperature sealant must be higher than the working temperature of the battery device. Preferably, the high-temperature sealant is a high-temperature glass sealant resistant to 1250°C.

[0049] As Figure 3 shown, the embodiments of the present invention provide a power generation method for the zero-carbon emission coal power generation system with the self-generated CO 2 working medium as described in any of the foregoing embodiments. Among them, the method includes the steps: S1. Add coal and introduce CO 2 into the coal gasification reactor through the coal powder inlet and the CO 2 inlet respectively. A reaction occurs in the coal gasification reactor to generate a gas containing CO; S2. The generated gas containing CO is desulfurized by the desulfurization absorption tower, then condensed by the condensation tank, and then the CO is separated into two parts by the pressure swing adsorption device. One part of the CO is introduced into the CO storage tank for storage, and the other part of the CO is introduced into the battery device; S3. Connect the load of the battery device, and introduce air into the battery device through the air inlet. Among them, the oxygen in the air obtains electrons in the cathode chamber to generate O 2- , and the generated O 2- is conducted from the cathode chamber to the anode chamber through the electrolyte layer. The O 2-In the anode chamber, an electrochemical reaction occurs between CO and CO to generate CO 2 and at the same time, electrons are released, thus forming a closed circuit to generate current, and the generated CO 2 circulates back to the gasification reactor through the first connecting pipe.

[0050] In this embodiment, coal is added to the gasification reactor through the pulverized coal inlet and CO 2 is introduced into the gasification reactor through the CO inlet. The gasification reaction takes place in an independent gasification reactor. The coal and CO in the gasification reactor 2 undergo an inverse Boudouard reaction to generate CO. Then, a gas containing CO is produced in the gasification reactor 1. The gas containing CO is desulfurized by a desulfurization absorption tower, then condensed by a condensation tank, and then the CO is separated into two parts by a pressure swing adsorption device. One part of the CO is introduced into a CO storage tank for storage to obtain a high-purity and high-value CO chemical product, and the other part of the CO is introduced into the battery device. Then, the load of the battery device is connected, and air is introduced into the battery device through the air inlet. The oxygen in the air obtains electrons in the cathode chamber to generate O 2 The generated O 2- is conducted from the cathode chamber to the anode chamber through the electrolyte layer. The O 2- undergoes an electrochemical reaction with the introduced CO gas in the anode chamber to generate CO 2- and releases electrons, forming a closed circuit to generate current, that is, power generation is completed, and the generated CO 2 circulates to the gasification reactor through the first connecting pipe for further recycling. 2

[0051] In some embodiments, the operating parameters of the load include: the voltage of a single cell is 0.6 - 0.9 V, and the current density is 500 - 900 mA / cm 2 2 .

[0052] In some embodiments, the pressure in the battery device is 1 - 100 atm.

[0053] In some embodiments, the reaction pressure of the gasification reactor is 1 - 100 atm.

[0054] In some embodiments, the CO 2 conversion rate in the gasification reactor is 71.8% - 98%.

[0055] In some embodiments, the CO conversion rate in the zero-carbon emission coal power generation system with self-generated CO 2 working medium is 70% - 95%.

[0056] In some embodiments, in step S2, the pressure swing adsorption device separates CO into two parts, where 50% - 70% of the CO is introduced into the CO storage tank for storage, and the remaining CO is introduced into the interior of the battery device.

[0057] The present invention will be further described below through specific embodiments.

[0058] Example 1 This example provides a zero-carbon emission coal power generation system using self-generated CO 2 working medium and its power generation method, specifically as follows: As Figure 1 shown, CO 2 gas is introduced from the CO 3 source 14 at a rate of 0.1 m 2 / s. The CO 2 gas is preheated to 650 °C in the preheating tank 15 and then introduced into the coal gasification reactor 1 through the CO 2 inlet. Pulverized coal is provided by the pulverized coal source 13 and added to the coal gasification reactor 1 through the pulverized coal inlet at a speed of 0.2 kg / min. The pulverized coal and CO 2 gas in the coal gasification reactor 1 undergo the reverse Boudouard reaction at 800 °C: C + CO 2 = 2CO, and then a gas containing CO is generated in the coal gasification reactor 1. In addition, the incombustible coal ash particles and unburned pulverized coal particles in the coal gasification reactor 1 settle in the residue storage tank 18 through the ash discharge valve provided at the lower end of the coal gasification reactor 1.

[0059] Subsequently, the gas containing CO generated in the coal gasification reactor 1 undergoes desulfurization treatment in the desulfurization absorption tower 2. The desulfurization absorption tower 2 adopts a fixed-bed adsorption structure, and ZnO and Fe 2 O 3 are filled in the tower as the main adsorption materials and operate in the temperature range of 300 - 500 °C to effectively remove sulfides such as H 2 S and SO 2 generated by coal gasification. The gas after desulfurization treatment enters the shell-and-tube water-cooled condensation tank 3 (steam flows inside the tube and cooling water flows outside the tube) through the outlet and is condensed to 50 °C to ensure the purity of the CO gas and improve the stability and service life of the subsequent battery device 6. Then the gas is introduced into the pressure swing adsorption device 4, where an activated carbon-based adsorbent is used. CO 2 is selectively adsorbed under high pressure by PSA and desorbed and regenerated under low pressure to achieve the separation of CO 2 and obtain high-purity CO gas. 70% of the CO is recovered and stored in the CO storage tank 5 after pressure swing separation by the pressure swing adsorption device 4, and 30% of the CO enters the interior of the battery device 6. At the same time, the CO separated by the pressure swing adsorption device 42 It flows back into the coal gasification reactor 1 through the second connecting pipeline 17 to continue participating in the coal gasification reaction.

[0060] Connect the load 8 of the battery device 6. At a current density of 687 mA / cm 2 , the output voltage of the battery is stable at 0.78 V. Air is introduced into the battery device 6 (operating temperature is 850 °C) through the air source 12. The introduced air enters the cathode chamber 11, and the oxygen in the air gains electrons to generate O 2- , O 2- conducts from the cathode chamber 11 to the anode chamber 9 through the electrolyte layer 10. O 2- undergoes an electrochemical reaction with the CO introduced into the anode chamber 9 to generate CO 2 and simultaneously releases electrons to the external circuit, thus forming a closed loop to generate current. And the generated CO 2 circulates back into the coal gasification reactor 1 through the first connecting pipeline 7. At the same time, the waste heat of the 750 °C gas flowing out of the battery device 6 is recovered by the waste heat recovery device 16 and supplied to the coal gasification reactor 1 to provide the temperature required for operation.

[0061] Figure 4 is the power generation durability test curve of the power generation system provided in Example 1 under the conditions of a current density of 687 mA / cm 2 , and the operating temperature of the battery device is 850 °C. According to this figure, it can be seen that the voltage of the power generation system does not have obvious fluctuations during power generation, showing good power generation stability, and can stably generate electricity for more than 80 hours.

[0062] In summary, a zero-carbon emission coal power generation system with self-generated CO 2 working medium provided by the present invention is provided. By arranging a desulfurization absorption tower for desulfurizing the CO generated by coal gasification between the coal gasification reactor and the battery device, the poisoning effect of a small amount of sulfur-containing gas contained in the gasified solid carbon on the anode catalyst can be avoided; a condensation tank is arranged to condense the desulfurized CO to a suitable temperature, which can ensure the separation of impurities such as moisture and light hydrocarbons, and at the same time keep the CO in a gaseous state; a pressure swing adsorption device is arranged to separate the CO. Part of it is recovered and stored in the CO storage tank through pressure swing separation to obtain high-purity and high-value CO chemical products. Part of it enters the battery device to undergo an electrochemical reaction to generate CO 2 and releases electrons to generate current. And the CO 2 generated in the battery device and the unreacted CO, etc. can re-enter the coal gasification reactor through the first connecting pipeline to participate in the coal gasification reaction. The power generation system of the present invention not only has high power generation efficiency and good power generation stability, but also avoids subsequent CO 2 capture and storage through system self-circulation, realizing CO 2near-zero emissions, while co-producing chemical products with added value, such as CO.

[0063] It should be understood that the application of the present invention is not limited to the above examples. For those of ordinary skill in the art, improvements or modifications can be made according to the above description, and all such improvements and modifications shall fall within the protection scope of the appended claims of the present invention.

Claims

1. A zero-carbon emission coal power generation system with self-generated CO2 working fluid, characterized in that: include: Coal gasification reactor, desulfurization absorption tower, condensation tank, pressure swing adsorption device, CO storage tank, battery device and first connecting pipeline; The coal gasification reactor is connected to the desulfurization absorption tower, the desulfurization absorption tower is connected to the condensation tank, the condensation tank is connected to the pressure swing adsorption device, and the pressure swing adsorption device is respectively connected to the CO storage tank and the battery device; The coal gasification reactor is provided with a coal powder inlet and a CO2 inlet; The battery device comprises a load, a cathode chamber, an anode chamber, and an electrolyte layer arranged between the cathode chamber and the anode chamber, and the battery device is provided with an air inlet and an exhaust gas outlet; The first connecting pipe connects the tail gas outlet of the coal gasification reactor and the battery device, and the first connecting pipe is used to circulate the tail gas generated in the battery device to the coal gasification reactor.

2. The zero-carbon emission coal power generation system with self-generated CO2 working fluid according to claim 1 is characterized in that: A waste heat recovery device is further provided between the coal gasification reactor and the battery device, and the waste heat recovery device is used to supply waste heat of outflow gas of the battery device to the coal gasification reactor.

3. The zero-carbon emission coal power generation system with self-generated CO2 working fluid according to claim 1 is characterized in that: The zero-carbon emission coal power generation system with self-generated CO2 working fluid also includes a second connecting pipeline connecting the coal gasification reactor and the pressure swing adsorption device, and the second connecting pipeline is used to return the CO2 separated by the pressure swing adsorption device to the coal gasification reactor.

4. The zero-carbon emission coal power generation system with self-generated CO2 working fluid according to claim 1 is characterized in that: The battery device is also provided with an air outlet, which is used to discharge oxygen-depleted air generated by the battery device.

5. The zero-carbon emission coal power generation system with self-generated CO2 working fluid according to claim 1 is characterized in that: The zero-carbon emission coal power generation system with self-generated CO2 working fluid also includes a residue storage tank. An ash discharge valve is provided at the lower end of the coal gasification reactor, and the residue storage tank is connected to the ash discharge valve.

6. The zero-carbon emission coal power generation system with self-generated CO2 working fluid according to claim 1 is characterized in that: The zero-carbon emission coal power generation system with self-generated CO2 working fluid also includes a preheating tank, which is connected to the CO2 inlet provided on the coal gasification reactor, and is used to preheat CO2.

7. The zero-carbon emission coal power generation system with self-generated CO2 working fluid according to claim 1 is characterized in that: The working temperature of the coal gasification reactor is 720-1000° C., the working temperature of the battery device is 720-1000° C., and the working temperature of the battery device is 20-50° C. higher than the working temperature of the coal gasification reactor.

8. The zero-carbon emission coal power generation system with self-generated CO2 working fluid according to claim 1 is characterized in that: The working temperature of the condensation tank is 30-60°C.

9. A method for generating electricity using a zero-carbon emission coal-fired power generation system with self-generated CO2 as a working medium according to any one of claims 1 to 8, characterized in that: Includes steps: Coal is added into the coal gasification reactor through the coal powder inlet and the CO2 inlet respectively, and CO2 is introduced into the coal gasification reactor, and a reaction occurs in the coal gasification reactor to generate a gas containing CO; The generated gas containing CO is desulfurized by a desulfurization absorption tower, condensed by a condensation tank, and then separated into two parts by a pressure swing adsorption device, one part of which is passed into a CO storage tank for storage, and the other part of CO is passed into the battery device; The load of the battery device is turned on, and air is introduced into the battery device through the air inlet, wherein the oxygen in the air obtains electrons in the cathode chamber to generate O 2- , the generated O 2- The O is conducted from the cathode chamber to the anode chamber through the electrolyte layer. 2- In the anode chamber, an electrochemical reaction occurs with CO to generate CO2 and release electrons at the same time, thereby forming a closed loop to generate current, and the generated CO2 circulates back into the coal gasification reactor through the first connecting pipeline.

10. The power generation method of the zero-carbon emission coal power generation system with self-generated CO2 working medium according to claim 9 is characterized in that: The working parameters of the load include: the voltage of the single cell is 0.6-0.9 V, the current density is 500-900 mA / cm 2 .

Images