CO2 capture and dry reforming conversion integrated reaction system and method for coupling biogas and boiler flue gas

Abstract

The invention relates to a CO2 capture and dry reforming conversion integrated reaction system and method for coupling biogas and boiler flue gas. The reaction system mainly comprises a gas mixer, a first heat exchanger, a rotary trapping reaction furnace, a rotary dry reforming reaction furnace, a biogas storage tank and a coal-fired boiler flue gas pipeline, and the gas mixer is used for preliminarily mixing flue gas and biogas to provide stable and continuous reaction gas; the first heat exchanger realizes simultaneous proceeding of trapping and conversion reactions between double reactors of the rotary trapping reaction furnace and the rotary dry reforming reaction furnace, and realizes gas heat exchange; meanwhile, calcium carbonate generated by the rotary trapping reaction furnace and calcium oxide generated by the rotary dry reforming reaction furnace can be mutually utilized; and low-energy-consumption reaction is realized between the two reactors through a heat pump system. According to the invention, CO2-containing coal-fired boiler flue gas is reacted with biogas, the reaction waste heat is fully utilized, and the energy consumption of the calcium cycle carbon dioxide capture and conversion integrated system is reduced.

Description

Technical Field

[0001] The present invention belongs to the technical field of integrated carbon dioxide capture and conversion, and more specifically, relates to a CO2-capturing system that couples biogas and boiler flue gas. 2 Integrated reaction system and method for capture and dry reforming conversion. Background Art

[0004] Calcium oxide carbon capture and methane dry reforming are important technical paths to achieve carbon treatment and efficient utilization of methane. The main reactions include:

[0005] CaO+CO 2 →CaCO 3 ΔH 0 =-178.32 kJ / mol (trapping)

[0006] CO 2 +CH 4 →2CO+2H 2 ΔH 0 = +247 kJ / mol (dry reforming)

[0007] Among them, the Ca-based capture reaction has the characteristics of a wide reaction temperature range, and there are practical cases at present, but the large amount of heat released in the reaction cannot be fully utilized; the dry reforming reaction has a high reaction starting temperature and needs to absorb a large amount of heat, facing problems such as high energy consumption. Therefore, in order to improve the efficiency and low energy consumption of this path, a technical path of integrated carbon capture and dry reforming conversion under calcium circulation is proposed, and the main reactions are as follows:

[0008] CaCO 3 +CH 4 →CaO+2CO+2H 2 ΔH 0 = +425.32 kJ / mol (calcium cycle dry reforming)

[0009] At present, there are relatively few studies on the process flow of the technical path. The Chinese invention patent with publication number CN116062688A discloses a solar-driven biogas dry reforming hydrogen production system and proposes a methane dry reforming system powered by solar energy. It uses a pressure swing separation method to separate biogas from CO in the generated gas. 2 Separation is used to adjust CH 4 / CO 2 The mixed ratio achieves resistance to carbon deposition and utilizes solar energy for heating, providing a new idea for system construction, but its system energy consumption is still relatively high. Summary of the invention

[0010] In view of the above defects or improvement requirements of the prior art, the present invention provides a CO 2 capture and dry reforming integrated reaction system and method for coupling biogas and boiler flue gas, aiming to combine CO 2 capture with CO 2 dry reforming conversion, thereby solving the technical problems of high energy consumption and low energy utilization rate in the carbon dioxide capture and dry reforming conversion system.

[0011] To achieve the above object, according to one aspect of the present invention, there is provided a CO 2 capture and dry reforming integrated reaction system for coupling biogas and boiler flue gas, including a gas mixer, a first heat exchanger, a rotary capture reaction furnace, a rotary dry reforming reaction furnace, a biogas storage tank, and a coal-fired boiler flue gas pipeline; the coal-fired boiler flue gas pipeline and the biogas storage tank are both connected to the air inlet of the gas mixer, the air outlet of the gas mixer is connected to the inlet of the tube layer of the first heat exchanger through a first pipeline, the outlet of the tube layer of the first heat exchanger is connected to the air inlet of the rotary capture reaction furnace, the air outlet of the rotary capture reaction furnace is connected to the air inlet of the rotary dry reforming reaction furnace through a second pipeline, the air outlet of the rotary dry reforming reaction furnace is connected to the inlet of the shell layer of the first heat exchanger, and the outlet of the shell layer of the first heat exchanger is connected to a third pipeline to discharge the gas reaction product.

[0012] Preferably, a mixture of calcium oxide and catalyst pellets is placed in the rotary capture reaction furnace; a mixture of calcium carbonate and catalyst pellets is placed in the rotary dry reforming reaction furnace; preferably, the catalysts are independently selected from one or more of nickel, cobalt, ruthenium, platinum, palladium, and rhodium.

[0013] Preferably, the gas mixer includes a biogas inlet, a flue gas inlet, a mixer cavity, a metal bellows, a base, and a gas distributor; the coal-fired boiler flue gas pipeline is connected to the flue gas inlet, and the biogas storage tank is connected to the biogas inlet; the metal bellows is located on the inner wall of the mixer cavity; the gas distributor is a tubular structure with one end open and the other end closed and is located inside the mixer cavity; the open end of the gas distributor is nested inside the biogas inlet, and slot holes are provided on the tube wall of the gas distributor near the closed end;

[0014] Preferably, the mixer cavity is cylindrical, and the center line of the flue gas inlet is tangent to the cross-sectional circle of the mixer cavity.

[0015] Preferably, the discharge port of the rotary capture reactor is connected to a first powder classifier, and the discharge port of the rotary dry reforming reactor is connected to a second powder classifier; the first powder classifier is connected to a fourth pipeline and a fifth pipeline, and the fourth pipeline and the fifth pipeline are respectively connected to the inlet of the calcium carbonate silo and the powder granulation regeneration device, and the powder granulation regeneration device is connected to the inlet of the calcium carbonate silo; the second powder classifier is connected to a sixth pipeline and a seventh pipeline, and the sixth pipeline and the seventh pipeline are respectively connected to the inlet of the calcium oxide silo and the powder granulation regeneration device, and the powder granulation regeneration device is connected to the calcium oxide silo;

[0016] The outlet of the calcium oxide silo and the outlet of the calcium carbonate silo are both connected to the inlet of the particle suction device, and the outlet of the particle suction device is respectively connected to the feed inlet of the rotary capture reactor and the feed inlet of the rotary dry reforming reactor.

[0017] Preferably, a second heat exchanger is further included, the tube side of the second heat exchanger is communicated with the sixth pipeline, and the shell side of the second heat exchanger is communicated with the second pipeline; a gas analyzer is further connected to the second pipeline.

[0018] Preferably, the rotary capture reactor and the rotary dry reforming reactor are connected by a heat pump.

[0019] According to another aspect of the present invention, there is provided a method for integrated reaction of CO capture and dry reforming conversion of biogas and boiler flue gas, comprising the following steps: 2 The method includes the following steps:

[0020] (1) Both the coal-fired boiler flue gas containing carbon dioxide and methane in the biogas storage tank are transported to a gas mixer for mixing to form a mixed reaction gas;

[0021] (2) The mixed reaction gas is transported through a first pipeline to the inlet of the tube layer of a first heat exchanger, and after heat exchange, it is output from the outlet of the tube layer of the first heat exchanger, and then introduced into a rotary capture reactor to capture carbon dioxide in the mixed gas;

[0022] (3) The mixed gas discharged after the reaction in the rotary capture reactor is introduced into a rotary dry reforming reactor through a second pipeline to perform a dry reforming reaction, so that methane and un-captured carbon dioxide in the mixed gas are converted into a gas reaction product of carbon monoxide and hydrogen; the gas reaction product is input into the inlet of the shell layer of the first heat exchanger, and after being output from the outlet of the shell layer of the first heat exchanger, the gas reaction product is discharged through a third pipeline.

[0023] Preferably, a mixture of calcium oxide and catalyst in the form of granular balls is placed in the rotary capture reactor; a mixture of calcium carbonate and catalyst in the form of granular balls is placed in the rotary dry reforming reactor; preferably, the catalyst is independently selected from one or more of nickel, cobalt, ruthenium, platinum, palladium, and rhodium; in step (1), the volume flow ratio of methane to carbon dioxide is 0.8 to 1.2.

[0024] Preferably, the method further comprises the following steps:

[0025] The solid components after the reaction in the rotary capture reactor are introduced into a first powder sieve. The sieved powder is introduced into a powder granulation and regeneration device through a fifth pipeline, granulated again, and then introduced into a calcium carbonate bin. The mixture of granular balls obtained by sieving is directly introduced into the calcium carbonate bin through a fourth pipeline; the mixture of calcium carbonate and catalyst in the form of granular balls in the calcium carbonate bin is sucked into the rotary dry reforming reactor through a granular suction device for continuous recycling;

[0026] The solid components after the reaction in the rotary dry reforming reactor are introduced into a second powder sieve. The sieved powder is introduced into a powder granulation and regeneration device through a seventh pipeline, granulated again, and then introduced into a calcium oxide bin. The mixture of granular balls obtained by sieving is directly introduced into the calcium oxide bin through a sixth pipeline; the mixture of calcium oxide and catalyst in the form of granular balls in the calcium oxide bin is sucked into the rotary capture reactor through a granular suction device for continuous recycling.

[0027] Preferably, the solid components after the reaction discharged from the sixth pipeline and the gas components discharged from the gas outlet of the rotary capture reactor are heat-exchanged through a second heat exchanger; a gas analyzer is connected to the second pipeline; the rotary capture reactor and the rotary dry reforming reactor are connected through a heat pump.

[0028] Generally speaking, compared with the prior art, the above technical solutions conceived by the present invention can achieve the following beneficial effects:

[0029] 1. The present invention is provided with a rotary capture reactor and a rotary dry reforming reactor. The two reactors work simultaneously, and the carbon capture reaction of CaO-phase particles and the dry reforming reaction of CaCO 3 phase particles proceed synchronously. The particles after each reaction are switched between the two reactors through a particle circulation system. This system can effectively reduce the heat loss caused by the temperature switching of the capture and dry reforming reactions in a single reactor, ensure the continuity and stability of the operation of the system, and can make full use of the heat released by the capture reaction through a heat pump heat exchange device.

[0030] 2. The present invention is additionally provided with CaO phase and CaCO 3The phase particle storage tank plays a buffering role in the particle cyclic transportation. By adjusting the power of the suction and discharge equipment, the mass flow rate of particle transportation can be further adjusted to adapt to the changes in working conditions. On the other hand, the rotary capture reactor converts calcium oxide into calcium carbonate, and the rotary dry reforming reactor converts calcium carbonate into calcium oxide. The products of the two reactions are the reactants of each other, realizing the cyclic regeneration of particles and facilitating the reuse of the regranulated CaO phase and CaCO 3 phase particles by putting them back into the cycle.

[0031] 3. The present invention sets up the first heat exchanger, the second heat exchanger and the heat pump to realize the recovery and reuse of heat. Among them, the first heat exchanger preheats the unreacted mixed reaction gas with the high-temperature syngas generated by the reaction, realizing the waste heat utilization of the syngas; the second heat exchanger heats the captured mixed gas with the high-temperature CaO phase particles output from the rotary dry reforming reactor, realizing the waste heat utilization of the high-temperature materials; the heat pump collects the low-temperature heat released by the capture reaction, and after treatment, it is converted into high-temperature heat to supply energy to the rotary dry reforming reactor, making full use of the heat released by the capture reaction.

[0032] 4. The advantage that the center line of the flue gas inlet in the gas mixer of the present invention is tangent to the cross-sectional circle of the mixer cavity is that tangential entry is more conducive to the formation of eddy currents of the flue gas in the mixer cavity, entraining the biogas entering from the biogas inlet, and increasing the mixing time of the two gases in the cavity, making the gas mixing more sufficient; the advantage of setting the gas distributor is to buffer the axially entering biogas. The biogas escapes from the slots on the gas distributor. Compared with the axial gas inlet mode, it is more easily entrained and mixed by the flue gas, has less damage to the eddy current, prolongs the mixing time, and further improves the mixing sufficiency; the metal bellows is set to guide the eddy current and make the mixing more sufficient.

[0033] 5. The present invention controls the flow rates of the mixed gas and the syngas in the pipeline by setting the mixed gas flow valve and the syngas flow valve, so that the two gases are fully heat-exchanged in the first heat exchanger, reducing the waste heat loss of the syngas, preheating the mixed gas in advance, and reducing energy consumption. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 is a schematic diagram of the integrated reaction system for CO 2 capture and dry reforming conversion based on the coupling of biogas and boiler flue gas of the present invention.

[0035] Figure 2 is a schematic diagram of the structure of the gas mixer of the present invention.

[0036] Figure 3 is a schematic diagram of the structure of the rotary carbon capture reactor of the present invention.

[0037] In all the accompanying drawings, the same reference numerals are used to denote the same elements or structures, where: 1. Gas mixer; 101. Biogas inlet; 102. Flow monitor; 103. Flue gas inlet; 104. Mixer cavity; 105. Metal bellows; 106. Outlet; 107. Base; 108. Gas distributor; 2. First heat exchanger; 3. Rotary capture reactor; 301. Inlet; 302. Outlet; 303. Transmission mechanism; 304. Cylinder; 305. Feed inlet; 306. Outlet; 4. Gas analyzer; 5. Rotary dry reforming reactor; 6. Biogas storage tank; 7. Coal-fired boiler flue gas pipeline; 8. Biogas flow valve; 9. Eighth pipeline; 10. Calcium oxide silo; 11. Calcium carbonate silo; 12. Mixed gas flow valve; 13. Syngas flow valve; 14. Second heat exchanger; 15. Heat pump; 16. First pipeline; 17. Inlet of the tube layer; 18. Outlet of the tube layer; 19. Second pipeline; 20. Inlet of the shell layer; 21. Outlet of the shell layer; 22. Third pipeline; 23. First powder sieve; 24. Second powder sieve; 25. Fourth pipeline; 26. Fifth pipeline; 27. Powder granulation regeneration device; 28. Sixth pipeline; 29. Seventh pipeline; 30. Particle suction device. Detailed implementation mode

[0038] In order to make the objectives, technical solutions and advantages of the present invention clearer, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. 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. In addition, the technical features involved in the various embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0039] The present invention provides a CO 2 Capture dry reforming integrated reaction system coupling biogas and boiler flue gas, including a gas mixer 1, a first heat exchanger 2, a rotary capture reactor 3, a rotary dry reforming reactor 5, a biogas storage tank 6, and a coal-fired boiler flue gas pipeline 7; the coal-fired boiler flue gas pipeline 7 and the biogas storage tank 6 are both connected to the inlet of the gas mixer 1, the outlet 106 of the gas mixer 1 is connected to the inlet 17 of the tube layer of the first heat exchanger 2 through a first pipeline 16, the outlet 18 of the tube layer of the first heat exchanger 2 is connected to the inlet of the rotary capture reactor 3, the outlet of the rotary capture reactor 3 is connected to the inlet of the rotary dry reforming reactor 5 through a second pipeline 19, the outlet of the rotary dry reforming reactor 5 is connected to the inlet 20 of the shell layer of the first heat exchanger 2, and the outlet 21 of the shell layer of the first heat exchanger 2 is connected to a third pipeline 22 to discharge gas reaction products.

[0040] In some embodiments, a mixture of calcium oxide and catalyst particles is placed in the rotary capture reactor 3; a mixture of calcium carbonate and catalyst particles is placed in the rotary dry reforming reactor 5; preferably, the catalyst is selected from one or more of nickel, cobalt, ruthenium, platinum, palladium, and rhodium;

[0041] In some embodiments, the gas mixer 1 includes a biogas inlet 101, a flue gas inlet 103, a mixer cavity 104, a metal bellows 105, a base 107, and a gas distributor 108; the coal-fired boiler flue gas pipeline 7 is connected to the flue gas inlet 103, and the biogas storage tank 6 is connected to the biogas inlet 101; the metal bellows 105 is located on the inner wall of the mixer cavity 104 and is used to guide the eddy current of the preliminarily mixed gas in the mixer cavity 104 to increase the mixing time of the flue gas and biogas; the gas distributor 108 is a tubular structure with one end open and the other end closed and is located inside the mixer cavity 104; the open end of the gas distributor 108 is nested inside the biogas inlet 101, and slot holes 109 are provided on the tube wall of the gas distributor 108 near the closed end;

[0042] In some embodiments, the mixer cavity 104 is cylindrical, and the center line of the flue gas inlet 103 is tangent to the cross-sectional circle of the mixer cavity 104.

[0043] In some embodiments, to avoid flow blockage in the gas mixer 1, the flue gas inlet pipe deviates towards the outlet, and the angle with the vertical direction of the mixer cavity 104 is between 5-15°.

[0044] In some embodiments, the discharge port of the rotary capture reactor 3 is connected to a first powder and granule sieve 23, and the discharge port of the rotary dry reforming reactor 5 is connected to a second powder and granule sieve 24; the first powder and granule sieve 23 is connected to a fourth pipeline 25 and a fifth pipeline 26, and the fourth pipeline 25 and the fifth pipeline 26 are respectively connected to the inlet of the calcium carbonate silo 11 and the powder granulation and regeneration device 27, and the powder granulation and regeneration device 27 is connected to the inlet of the calcium carbonate silo 11; the second powder and granule sieve 24 is connected to a sixth pipeline 28 and a seventh pipeline 29, and the sixth pipeline 28 and the seventh pipeline 29 are respectively connected to the inlet of the calcium oxide silo 10 and the powder granulation and regeneration device 27, and the powder granulation and regeneration device 27 is connected to the calcium oxide silo 10; the outlets of the calcium oxide silo 10 and the calcium carbonate silo 11 are both connected to the inlet of the particle suction device 30, and the outlet of the particle suction device 30 is respectively connected to the feed inlet of the rotary capture reactor 3 and the feed inlet of the rotary dry reforming reactor 5.

[0045] In some embodiments, the first powder and granule sieve 23 and the second powder and granule sieve 24 contain inclined filters inside. Unbroken CaCO 3 particles and spherical CaO particles respectively enter the calcium carbonate silo 11 and the calcium oxide silo 10 from the outlets of the first powder and granule sieve 23 and the second powder and granule sieve 24 along the filter; the broken powder leaks into the powder outlets of the first powder and granule sieve 23 and the second powder and granule sieve 24 from the filter, and after being collected, is regranulated by the powder granulation and regeneration device 27 and then transported to the calcium carbonate silo 11 and the calcium oxide silo 10 respectively, and is respectively re-inhaled into the feed inlets of the rotary dry reforming reactor 5 and the rotary capture reactor 3 to realize material circulation.

[0046] In some embodiments, a second heat exchanger 14 is further included. The tube side of the second heat exchanger 14 is communicated with the sixth pipeline 28, and the shell side of the second heat exchanger 14 is communicated with the second pipeline 19; the CaO solid particles discharged from the dry reforming reactor 5 have a large amount of waste heat, and the gas discharged from the rotary capture reactor 3 and the CaO solid particles exchange heat countercurrently in the second heat exchanger 14 to preheat the gas discharged from the rotary capture reactor 3 and reduce the waste heat loss of the particles.

[0047] In some embodiments, the second pipeline 19 is further connected with a gas analyzer 4. The gas analyzer 4 monitors the CO 2 content in the gas discharged from the outlet of the rotary capture reactor 3 and transmits the information to the particle suction device 30 in real time. The particle suction device 30 adjusts the power of the particle suction device 30 to increase or decrease according to the CO 2 content information, so as to realize continuous capture and regeneration cycle of the system to adapt to the peak fluctuation of boiler operation.

[0048] In some embodiments, the rotary capture reactor 3 and the rotary dry reforming reactor 5 are connected by a heat pump 15 to transfer the large amount of heat released by the CO 2 capture reaction in the rotary capture reactor for the heat required for the dry reforming reaction in the rotary dry reforming reactor, and the stored heat can be converted and utilized by the heat pump 15.

[0049] In some embodiments, the biogas storage tank 6 and the gas mixer 1 are connected by an eighth pipeline 9, and a biogas flow valve 8 is connected to the eighth pipeline 9;

[0050] In some embodiments, a flow monitor 102 is installed on the pipeline of the flue gas inlet 103 to monitor the flue gas flow of the coal-fired boiler and automatically adjust the biogas flow valve 8 to control the biogas inlet flow, so as to realize the mixing ratio of CH 4 and CO 2 at 0.8 - 1.2.

[0051] In some embodiments, a mixed gas flow valve 12 is provided on the first pipeline 16. When the flue gas flow fluctuates, the flow detector 102 can control the opening degree of the mixed gas flow valve 12 to achieve stable operation of the reaction system; a syngas flow valve 13 is provided on the third pipeline 22; by coupling the syngas flow valve 13 with the mixed gas flow valve 12, the residence time of the mixed gas and the syngas in the first heat exchanger can be adjusted, thereby adjusting the heat exchange amount between the mixed gas and the syngas, reducing waste heat loss and realizing preheating of the mixed gas.

[0052] In some embodiments, the structure of the rotary capture reactor 3 is the same as that of the rotary dry reforming reactor 5. The specific structure is as follows:

[0053] It includes an air inlet 301, a discharge port 302, a transmission mechanism 303, a cylinder body 304, a feed inlet 305, and an air outlet 306; the air inlet 301 and the discharge port 302 are located at one end of the cylinder body 304, and the feed inlet 305 and the air outlet 306 are located at the other end of the cylinder body 304; the transmission mechanism 303 is arranged in the middle of the cylinder body 304 to rotate the cylinder body 304, and a stirring plate is also arranged inside the cylinder body 304.

[0054] In some embodiments, both the rotary capture reactor 3 and the rotary dry reforming reactor 5 are inclined towards the discharge port end. Particles are poured from the feed inlet 305, and during the stirring process, the reaction mixture particles slowly move towards the discharge port 302. During the stirring process, the particles after capture reaction or dry reforming conversion are poured out from the discharge port 302.

[0055] According to another aspect of the present invention, there is provided a method for integrated reaction of CO capture and dry reforming of biogas and boiler flue gas, including the following steps: 2 The steps are as follows:

[0056] (1) Both the coal-fired boiler flue gas containing carbon dioxide and methane in the biogas storage tank are transported to a gas mixer for mixing to form a mixed reaction gas;

[0057] (2) The mixed reaction gas is transported through the first pipeline to the inlet of the tube layer of the first heat exchanger, and after heat exchange, it is output from the outlet of the tube layer of the first heat exchanger, and then introduced into the rotary capture reactor to capture and convert carbon dioxide in the mixed gas into calcium carbonate;

[0058] (3) The mixed gas discharged after the reaction in the rotary capture reactor is introduced into the rotary dry reforming reactor through the second pipeline to carry out the dry reforming reaction, so that methane and un-captured carbon dioxide in the mixed gas are converted into a gas reaction product of carbon monoxide and hydrogen; the gas reaction product is input into the shell layer of the first heat exchanger, and the gas reaction product is discharged through the third pipeline at the gas outlet of the shell layer of the first heat exchanger.

[0059] In some embodiments, a mixture of calcium oxide and catalyst pellets is placed in the rotary capture reactor; a mixture of calcium carbonate and catalyst pellets is placed in the rotary dry reforming reactor; preferably, the catalysts are independently selected from nickel, cobalt, ruthenium, platinum, palladium, and rhodium;

[0060] In some embodiments, in step (1), the volume flow ratio of methane to carbon dioxide is 0.8 to 1.2.

[0061] A carbon dioxide capture reaction occurs in the rotary capture reactor 3, and the specific reaction is: CaO + CO 2 →CaCO 3 , and the reaction temperature is 200 to 500 °C;

[0062] A dry reforming reaction occurs in the rotary solar thermal dry reforming reactor 5, and the specific reaction is: CaCO 3 +CH 4 →CaO + 2CO + 2H 2 , and the reaction temperature is 700 to 800 °C;

[0063] In some embodiments, the following steps are further included:

[0064] The solid components after the reaction in the rotary capture reactor are introduced into the first powder sieve, the sieved powder is introduced into the powder granulation and regeneration device through the fifth pipeline, regranulated and then introduced into the calcium carbonate bin, and the sieved mixture of pellets is directly introduced into the calcium carbonate bin through the fourth pipeline; the mixture of calcium carbonate and catalyst pellets in the calcium carbonate bin is sucked into the rotary dry reforming reactor through the pellet suction device for continuous recycling;

[0065] The solid components after the reaction in the rotary dry reforming reactor are introduced into the second powder sieve, the sieved powder is introduced into the powder granulation and regeneration device through the seventh pipeline, regranulated and then introduced into the calcium oxide bin, and the sieved mixture of pellets is directly introduced into the calcium oxide bin through the sixth pipeline; the mixture of calcium oxide and catalyst pellets in the calcium oxide bin is sucked into the rotary capture reactor through the pellet suction device for continuous recycling.

[0066] In some embodiments, the reacted solid components discharged from the sixth pipeline are heat-exchanged with the gas components discharged from the gas outlet of the rotary capture reactor through a second heat exchanger to increase the temperature of the gas components discharged from the gas outlet of the rotary capture reactor; a gas analyzer is connected to the second pipeline to analyze the gas discharged from the rotary capture reactor; the rotary capture reactor is connected to the rotary dry reforming reactor through a heat pump.

[0067] Example 1

[0068] This example provides an integrated reaction system for coupling biogas and boiler flue gas for CO 2 capture and dry reforming conversion, as Figure 1 shown, including a gas mixer 1, a first heat exchanger 2, a rotary capture reactor 3, a rotary dry reforming reactor 5, a biogas storage tank 6, and a coal-fired boiler flue gas pipeline 7; the coal-fired boiler flue gas pipeline 7 and the biogas storage tank 6 are both connected to the air inlet of the gas mixer 1, the air outlet 106 of the gas mixer 1 is connected to the inlet 17 of the tube layer of the first heat exchanger 2 through a first pipeline 16, the outlet 18 of the tube layer of the first heat exchanger 2 is connected to the air inlet of the rotary capture reactor 3, the air outlet of the rotary capture reactor 3 is connected to the inlet 20 of the shell layer of the first heat exchanger 2 through a second pipeline 19, the air outlet of the rotary dry reforming reactor 5 is connected to the inlet 20 of the shell layer of the first heat exchanger 2, and the outlet 21 of the shell layer of the first heat exchanger 2 is connected to a third pipeline 22 to discharge gas reaction products. Calcium oxide and nickel mixture pellet balls are placed in the rotary capture reactor 3; calcium carbonate and nickel mixture pellet balls are placed in the rotary dry reforming reactor 5;

[0069] The gas mixer 1 includes a biogas inlet 101, a flow monitor 102, a flue gas inlet 103, a mixer cavity 104, a metal bellows 105, a base 107, and a gas distributor 108; the coal-fired boiler flue gas pipeline 7 is connected to the flue gas inlet 103, and the biogas storage tank 6 is connected to the biogas inlet 101; the metal bellows 105 is located on the inner wall of the mixer cavity 104; the gas distributor 108 is a tubular structure with one end open and the other end closed and is located inside the mixer cavity 104; the open end of the gas distributor 108 is nested inside the biogas inlet 101, and slot holes 109 are provided on the tube wall of the gas distributor 108 near the closed end; the mixer cavity 104 is cylindrical, and the center line of the flue gas inlet 103 is tangent to the cross-sectional circle of the mixer cavity 104.

[0070] The discharge port of the rotary capture reactor 3 is connected to the first powder classifier 23, and the discharge port of the rotary dry reforming reactor 5 is connected to the second powder classifier 24; the first powder classifier 23 is connected to the fourth pipeline 25 and the fifth pipeline 26, and the fourth pipeline 25 and the fifth pipeline 26 are respectively connected to the inlet of the calcium carbonate bin 11 and the powder granulation regeneration device 27, and the powder granulation regeneration device 27 is connected to the inlet of the calcium carbonate bin 11; the second powder classifier 24 is connected to the sixth pipeline 28 and the seventh pipeline 29, and the sixth pipeline 28 and the seventh pipeline 29 are respectively connected to the inlet of the calcium oxide bin 10 and the powder granulation regeneration device 27, and the powder granulation regeneration device 27 is connected to the calcium oxide bin 10;

[0071] The outlets of the calcium oxide bin 10 and the calcium carbonate bin 11 are both connected to the inlet of the particle suction device 30, and the outlet of the particle suction device 30 is respectively connected to the feed inlet of the rotary capture reactor 3 and the feed inlet of the rotary dry reforming reactor 5. A second heat exchanger 14 is further included, the tube side of the second heat exchanger 14 is communicated with the sixth pipeline 28, and the shell side of the second heat exchanger 14 is communicated with the second pipeline 19; a gas analyzer 4 is also connected to the second pipeline 19. The rotary capture reactor 3 and the rotary dry reforming reactor 5 are connected by a heat pump 15.

[0072] Example 2

[0073] This example is a method for integrated reaction of CO capture and dry reforming conversion of biogas and boiler flue gas using the system, including the following steps: 2 The steps are as follows:

[0074] (1) Both the coal-fired boiler flue gas containing carbon dioxide and methane in the biogas storage tank are transported to a gas mixer for mixing to form a mixed reaction gas; the volume flow ratio of methane to carbon dioxide is 0.8;

[0075] (2) The mixed reaction gas is transported through the first pipeline to the inlet of the tube layer of the first heat exchanger, and after heat exchange, it is output from the outlet of the tube layer of the first heat exchanger, and then introduced into the rotary capture reactor, so that carbon dioxide in the mixed gas is captured and converted into calcium carbonate;

[0076] (3) The mixed gas discharged after the reaction in the rotary capture reactor is introduced into the rotary dry reforming reactor through the second pipeline to carry out the dry reforming reaction, so that methane and un-captured carbon dioxide in the mixed gas are converted into a gas reaction product of carbon monoxide and hydrogen. A gas analyzer is connected to the second pipeline to analyze the content of carbon dioxide in the gas discharged from the rotary capture reactor; the gas reaction product is input into the shell side of the first heat exchanger, and the gas reaction product is discharged through the third pipeline from the outlet of the shell side of the first heat exchanger.

[0077] (4) The solid components after the reaction in the rotary capture reactor are introduced into the first powder sieve. The sieved powder is introduced into the powder granulation and regeneration device through the fifth pipeline, regranulated and then introduced into the calcium carbonate bin. The sieved mixture of granular balls is directly introduced into the calcium carbonate bin through the fourth pipeline; the calcium carbonate and catalyst mixture of granular balls in the calcium carbonate bin are sucked into the rotary dry reforming reactor through the granular suction device for continuous recycling;

[0078] (5) The solid components after the reaction in the rotary dry reforming reactor are introduced into the second powder sieve. The sieved powder is introduced into the powder granulation and regeneration device through the seventh pipeline, regranulated and then introduced into the calcium oxide bin. The sieved mixture of granular balls is directly introduced into the calcium oxide bin through the sixth pipeline; the calcium carbonate and catalyst mixture of granular balls in the calcium oxide bin are sucked into the rotary capture reactor through the granular suction device for continuous recycling.

[0079] (6) The reacted solid components discharged from the sixth pipeline and the gas components discharged from the outlet of the rotary capture reactor are heat-exchanged through the second heat exchanger to increase the temperature of the gas components discharged from the outlet of the rotary capture reactor; the rotary capture reactor and the rotary dry reforming reactor are connected by a heat pump.

[0080] In the rotary capture reactor, a mixture of calcium oxide and nickel in granular balls is placed; in the rotary dry reforming reactor, a mixture of calcium carbonate and nickel in granular balls is placed.

[0081] According to this system, a test bench is constructed, including a rotary capture reactor, a rotary dry reforming reactor, a CaO phase particle storage tank, and a CaCO 3 phase particle storage tank. The cavity size of the rotary reactor is 50 mm in diameter and 1000 mm in length. Each instrument is connected by a material transport pipe. The feeding speeds M 3 of the CaO phase particles and the CaCO gran phase particles are both 1 kg / min; the two reactors are connected by a gas transport pipe. At the beginning of the reaction, a simulated flue gas and biogas mixture (CH 4 with a volume fraction of 12%, CO2 The volume concentration is 15%, and the remaining component is N 2 ), the total flow rate of the mixed gas is 1 L / min, that is, CH 4 The initial volume flow rate V 0,CH4 = 0.12 L / min, V 0，CO2 = 0.15 L / min; the temperature of the capture reaction chamber is 500 °C, and the temperature of the dry reforming reaction chamber is 720 °C. During the reaction process, a CO 2 volume flow meter is installed during the capture reactor and the dry reforming reaction, and the CO 2 volume flow rate V int,CO2 in the mixed gas after capture is measured. The gas outlet of the dry reforming reactor is connected to a flow tester and an infrared analyzer, and the residual CH 4 and CO 2 volume flow rates in the syngas are V 1,CH4 and V 1,CO2 . The CO 2 capture amount m CO2 , CH 4 conversion rate α CH4 , CO 2 conversion rate α CO2 can be calculated by the formula:

[0082]

[0083] In this reaction system, the CO 2 capture rate reaches 12.55 mmol / g, and the CH 4 and CaCO 3 conversion rates can reach approximately 65% and 71% respectively at the highest under the condition of 720 °C.

[0084] It is easy for those skilled in the art to understand that the above is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A CO2 capture and dry reforming conversion integrated reaction system for coupling biogas and boiler flue gas, characterized in that: The invention comprises a gas mixer (1), a first heat exchanger (2), a rotary capture reactor (3), a rotary dry reforming reactor (5), a biogas storage tank (6), and a coal-fired boiler flue gas pipeline (7); the coal-fired boiler flue gas pipeline (7) and the biogas storage tank (6) are both connected to the air inlet of the gas mixer (1); the air outlet (106) of the gas mixer (1) is connected to the inlet (17) of the tube layer of the first heat exchanger (2) through a first pipeline (16); the first heat exchanger (2) is connected to the inlet (17) of the tube layer of the first heat exchanger (2); The outlet (18) of the tube layer of the heat exchanger (2) is connected to the air inlet of the rotary capture reactor (3), the air outlet of the rotary capture reactor (3) is connected to the air inlet of the rotary dry reforming reactor (5) through a second pipe (19), the air outlet of the rotary dry reforming reactor (5) is connected to the inlet (20) of the shell layer of the first heat exchanger (2), and the outlet (21) of the shell layer of the first heat exchanger (2) is connected to a third pipe (22) to discharge the gas reaction products.

2. The CO2 capture and dry reforming conversion integrated reaction system for coupling biogas and boiler flue gas as claimed in claim 1 is characterized in that: Calcium oxide and catalyst mixture granules are placed in the rotary capture reactor (3); calcium carbonate and catalyst mixture granules are placed in the rotary dry reforming reactor (5); preferably, the catalysts are independently selected from one or more of nickel, cobalt, ruthenium, platinum, palladium and rhodium.

3. The CO2 capture and dry reforming conversion integrated reaction system for coupling biogas and boiler flue gas as claimed in claim 1 or 2, characterized in that: The gas mixer (1) comprises a biogas inlet (101), a smoke inlet (103), a mixer cavity (104), a metal bellows (105), a base (107) and a gas distributor (108); the coal-fired boiler smoke pipe (7) is connected to the smoke inlet (103), and the biogas storage tank (6) is connected to the biogas inlet (101); the metal bellows (105) is located on the inner wall of the mixer cavity (104); the gas distributor (108) is a tubular structure with one end open and the other end closed, and is located inside the mixer cavity (104); the open end of the gas distributor (108) is embedded in the biogas inlet (101), and a slot (109) is provided on the tube wall of the gas distributor (108) close to the closed end; Preferably, the mixer cavity (104) is cylindrical, and the center line of the smoke inlet (103) is tangent to the cross-sectional circle of the mixer cavity (104).

4. The CO2 capture and dry reforming conversion integrated reaction system for coupling biogas and boiler flue gas as claimed in claim 2, characterized in that: The discharge port of the rotary capture reactor (3) is connected to a first powder particle sifter (23), and the discharge port of the rotary dry reforming reactor (5) is connected to a second powder particle sifter (24); the first powder particle sifter (23) is connected to a fourth pipeline (25) and a fifth pipeline (26), and the fourth pipeline (25) and the fifth pipeline (26) are respectively connected to the inlet of the calcium carbonate silo (11) and a powder granulation regeneration device (27), and the powder granulation regeneration device (27) is connected to the inlet of the calcium carbonate silo (11); the second powder particle sifter (24) is connected to a sixth pipeline (28) and a seventh pipeline (29), and the sixth pipeline (28) and the seventh pipeline (29) are respectively connected to the inlet of the calcium oxide silo (10) and the powder granulation regeneration device (27), and the powder granulation regeneration device (27) is connected to the calcium oxide silo (10); The outlet of the calcium oxide bin (10) and the outlet of the calcium carbonate bin (11) are both connected to the inlet of the particle suction device (30), and the outlet of the particle suction device (30) is respectively connected to the feed inlet of the rotary capture reactor (3) and the feed inlet of the rotary dry reforming reactor (5).

5. The CO2 capture and dry reforming conversion integrated reaction system for coupling biogas and boiler flue gas as claimed in claim 4, characterized in that: It also comprises a second heat exchanger (14), the tube side of the second heat exchanger (14) being connected to the sixth pipeline (28), and the shell side of the second heat exchanger (14) being connected to the second pipeline (19); the second pipeline (19) is also connected to a gas analyzer (4).

6. The CO2 capture and dry reforming conversion integrated reaction system for coupling biogas and boiler flue gas as claimed in claim 4, characterized in that: The rotary capture reactor (3) and the rotary dry reforming reactor (5) are connected via a heat pump (15).

7. A method for integrated CO2 capture and dry reforming conversion of biogas and boiler flue gas using the system according to any one of claims 1 to 6, characterized in that: The following steps are involved: (1) The flue gas from a coal-fired boiler containing carbon dioxide and the methane in a biogas storage tank are transported to a gas mixer and mixed to form a mixed reaction gas; (2) transporting the mixed reaction gas to the inlet of the tube layer of the first heat exchanger through the first pipeline, outputting from the outlet of the tube layer of the first heat exchanger after heat exchange, and then passing into the rotary capture reactor to capture carbon dioxide in the mixed gas; (3) The mixed gas discharged from the rotary capture reactor after the reaction is introduced into the rotary dry reforming reactor through the second pipeline to carry out a dry reforming reaction, so that the methane and uncaptured carbon dioxide in the mixed gas are converted into gas reaction products of carbon monoxide and hydrogen; the gas reaction products are input into the inlet of the shell of the first heat exchanger, and after being output through the outlet of the shell of the first heat exchanger, the gas reaction products are discharged through the third pipeline.

8. The integrated reaction method for CO2 capture and dry reforming conversion of biogas and boiler flue gas according to claim 7, characterized in that: The rotary capture reactor is filled with calcium oxide and a catalyst mixture granular balls; the rotary dry reforming reactor is filled with calcium carbonate and a catalyst mixture granular balls; preferably, the catalysts are independently selected from one or more of nickel, cobalt, ruthenium, platinum, palladium, and rhodium; in step (1), the volume flow ratio of methane to carbon dioxide is 0.8 to 1.

2.

9. The integrated reaction method for CO2 capture and dry reforming conversion of biogas and boiler flue gas according to claim 8, characterized in that: The following steps are also included: The solid components after the reaction in the rotary capture reactor are passed into the first powder particle sifter, the powder obtained by screening is passed into the powder granulation regeneration device through the fifth pipeline for further granulation and then passed into the calcium carbonate bin, and the mixed granular balls obtained by screening are directly passed into the calcium carbonate bin through the fourth pipeline; the calcium carbonate and catalyst mixture granular balls in the calcium carbonate bin are sucked into the rotary dry reforming reactor through the particle suction device for continuous recycling; The solid components after the reaction in the rotary dry reforming reactor are passed into the second powder particle sifter, the powder obtained by screening is passed into the powder granulation regeneration device through the seventh pipeline for further granulation and then passed into the calcium oxide bin, and the mixture granular balls obtained by screening are directly passed into the calcium oxide bin through the sixth pipeline; the calcium oxide and catalyst mixture granular balls in the calcium oxide bin are sucked into the rotary capture reactor through the particle suction device for continuous recycling.

10. The integrated reaction method for CO2 capture and dry reforming conversion of biogas and boiler flue gas according to claim 9, characterized in that: The reacted solid components discharged from the sixth pipeline are heat exchanged with the gas components discharged from the outlet of the rotary capture reactor through a second heat exchanger; a gas analyzer is connected to the second pipeline; and the rotary capture reactor is connected to the rotary dry reforming reactor through a heat pump.

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