Biomass pyrolysis poly-generation system coupled with carbon capture and formic acid synthesis

Abstract

The invention discloses a biomass pyrolysis poly-generation system coupled with carbon capture and formic acid synthesis, which relates to the technical field of biomass poly-generation and comprises a biomass pyrolysis power generation subsystem, a carbon capture subsystem and a formic acid synthesis subsystem. The biomass pyrolysis power generation subsystem can generate flue gas and biomass carbon, the flue gas contains CO2, and the carbon capture subsystem captures CO2 in the flue gas generated by the biomass pyrolysis power generation subsystem and separates the CO2; the formic acid synthesis subsystem generates reduction reaction by using CO2 captured by the carbon capture subsystem and biomass carbon generated by the biomass pyrolysis power generation subsystem to generate CO, then carbonylation reaction is performed by using CO and methanol to generate methyl formate, and formic acid is generated through hydrolysis of the methyl formate. According to the invention, biomass energy can be fully utilized, and comprehensive utilization of biomass resources is realized.

Description

Technical Field

[0001] This invention relates to the field of biomass polygeneration technology, and in particular to a biomass pyrolysis polygeneration system that couples carbon capture and formic acid synthesis. Background Technology

[0002] Biomass, as a renewable energy source, has many advantages such as large reserves, wide distribution, and low cost.

[0003] Existing solutions lack systematic design for the tiered utilization of biomass energy, resource recycling, and multiple products, resulting in low energy utilization and insufficient economic efficiency. This invention, based on the concept of combined heat and power generation, effectively couples the biomass conversion process with chemical and energy systems to form biomass combined heat and power generation technology, which can realize the comprehensive utilization of biomass resources. Summary of the Invention

[0004] The purpose of this invention is to provide a biomass pyrolysis polygeneration system that couples carbon capture and formic acid synthesis, overcoming the above-mentioned defects, and fully utilizing biomass energy to achieve comprehensive utilization of biomass resources.

[0005] To achieve the above objectives, the solution of the present invention is as follows: A biomass pyrolysis polygeneration system coupling carbon capture and formic acid synthesis includes a biomass pyrolysis electron generation system, a carbon capture subsystem, and a formic acid synthesis subsystem. The biomass pyrolysis power generation system includes a pyrolyzer, a first combustion chamber, and a gas turbine. The pyrolyzer is used to pyrolyze the dried first biomass feedstock to produce pyrolysis gas, gaseous biomass oil, and solid biomass carbon. The first combustion chamber is used to burn the pyrolysis gas to produce flue gas, which includes CO2 and water vapor. The gas turbine is connected to a generator. The gas turbine receives the flue gas and drives the generator to generate electricity. The pyrolysis gas includes H2, CO, CO2, CH4, C2H2, C2H4, and C2H6. The carbon capture subsystem includes an absorption tower, a stripping tower, a first cooler, and a first gas-liquid separator. The absorption tower contains a lean-loaded ethanolamine solution as the absorbent, which absorbs CO2 from the flue gas to form a rich ethanolamine solution. The stripping tower receives the rich ethanolamine solution from the absorption tower and releases the CO2 from the solution, forming a CO2 mixture. The CO2 mixture includes CO2, water vapor, and gaseous ethanolamine. The first cooler cools the water vapor and gaseous ethanolamine in the CO2 mixture into a liquid state. The first gas-liquid separator separates the liquid water, liquid ethanolamine, and CO2. The formic acid synthesis subsystem includes a reduction reactor, a carbonylation reactor, a first distillation column, and a hydrolysis reactor. The reduction reactor is connected to a first gas-liquid separator and is used to reduce CO2 separated from the first gas-liquid separator and biomass carbon produced by the pyrolysis unit to produce CO. The carbonylation reactor is used to carbonylate CO and methanol to produce methyl formate solution. The first distillation column is used to distill the methyl formate solution to obtain methyl formate distillate. The hydrolysis reactor is used to hydrolyze the methyl formate distillate and water to produce formic acid and methanol. Furthermore, the biomass pyrolysis power generation system also includes a first heat exchanger, a second gas-liquid separator, a first compressor, and a second compressor. The first heat exchanger is used to cool the gaseous biomass oil and pyrolysis gas to produce liquid biomass oil. The second gas-liquid separator is used to separate the liquid biomass oil and pyrolysis gas. The first compressor is used to compress the separated pyrolysis gas and send it into the first combustion chamber. The second compressor is used to compress air and send it into the first combustion chamber. The first heat exchanger is connected to the domestic water network. The first heat exchanger absorbs heat from the gaseous biomass oil and pyrolysis gas, thereby cooling the gaseous biomass oil and pyrolysis gas and heating the water flow in the domestic water network.

[0006] Furthermore, the biomass power generation system also includes a second heat exchanger, a steam turbine, and a first condenser. The second heat exchanger contains water and receives flue gas from the gas turbine. The flue gas exchanges heat with the water in the second heat exchanger, vaporizing the water into steam and simultaneously cooling the flue gas. The steam turbine is connected to a generator, receives the steam, and drives the generator to generate electricity. The first condenser is used to condense the steam from the steam turbine into liquid water, which can then flow back into the second heat exchanger. The first condenser is connected to the domestic water network, heating the water flow in the domestic water network by condensing the steam.

[0007] Furthermore, the biomass pyrolysis power generation system also includes a first distributor, a third compressor, a third heat exchanger, and a fourth heat exchanger. The flue gas also contains incompletely combusted pyrolysis gas. The first distributor is used to separate the incompletely combusted pyrolysis gas from the flue gas after heat exchange in the second heat exchanger. The third compressor is used to compress the separated incompletely combusted pyrolysis gas. The third heat exchanger is used to cool the compressed incompletely combusted pyrolysis gas. After cooling, the pyrolysis gas can return to the first combustion chamber. The third heat exchanger is connected to the domestic water network. It cools the compressed incompletely combusted pyrolysis gas by absorbing the heat from it and heats the water flow in the domestic water network. The fourth heat exchanger is used to cool the CO2 and water vapor separated by the first distributor. The fourth heat exchanger is connected to the domestic water network. It cools the CO2 and water vapor by absorbing the heat from them and heats the water flow in the domestic water network. The CO2 cooled by the heat exchange can be absorbed by the absorbent in the absorption tower.

[0008] Furthermore, the carbon capture subsystem also includes a fifth heat exchanger and a second cooler. The fifth heat exchanger is used to heat the rich amine liquid from the absorption tower. The stripping tower can receive the preheated rich amine liquid. A reboiler is provided at the bottom of the stripping tower. The reboiler is used to heat the rich amine liquid to release CO2 from the rich amine liquid, resulting in a CO2 mixture and a lean amine liquid. The reboiler can transfer the CO2 mixture back into the stripping tower. The lean amine liquid can flow back into the fifth heat exchanger to provide heat for heating the rich amine liquid that subsequently enters the fifth heat exchanger. The second cooler is used to receive the lean amine liquid from the fifth heat exchanger and cool it. The cooled lean amine liquid flows back into the absorption tower.

[0009] Furthermore, the first gas-liquid separator is connected to the stripping tower, and the first gas-liquid separator is used to send the separated liquid ethanolamine and water back into the stripping tower for reuse.

[0010] Furthermore, the formic acid synthesis subsystem also includes a sixth heat exchanger, which is used to heat the CO2 separated by the first gas-liquid separator. The heated CO2 can enter the reduction reactor and undergo a reduction reaction with biomass carbon to produce CO. The produced CO can enter the sixth heat exchanger and provide heat for the CO2 that subsequently enters the sixth heat exchanger. The hydroxylation reactor can receive the CO from the sixth heat exchanger.

[0011] Furthermore, the formic acid synthesis subsystem also includes a first pressure reducing valve, a third cooler, and a third gas-liquid separator. The first pressure reducing valve reduces the pressure on the methyl formate solution and unreacted methanol produced by the carbonylation reactor. The third cooler cools the methyl formate solution and unreacted methanol. The third gas-liquid separator allows the methyl formate solution and unreacted methanol to flash evaporate within it, thereby vaporizing the methanol and separating the methyl formate solution and unreacted methanol. The gaseous methanol can be returned to the carbonylation reactor. The first distillation column can receive the methyl formate solution from the third gas-liquid separator and distill it.

[0012] Furthermore, the formic acid synthesis subsystem also includes a second condenser, a first heater, and a second heater. The hydrolysis reactor includes a pre-hydrolysis reactor and a main hydrolysis reactor. The second condenser is used to condense the distilled methyl formate vapor to obtain methyl formate distillate. The first heater is used to heat the mixture of methyl formate distillate and water to promote the hydrolysis of methyl formate. The pre-hydrolysis reactor is used for the initial hydrolysis of methyl formate. The second heater is used to receive and heat the solution in the pre-hydrolysis reactor to promote the hydrolysis of methyl formate. The main hydrolysis reactor is used to receive the solution heated by the second heater and is used for the hydrolysis of methyl formate to produce methanol and formic acid. The produced methanol is refluxed into the carbonylation reactor to continue reacting with CO.

[0013] Furthermore, the formic acid synthesis subsystem also includes a second pressure reducing valve, a fourth gas-liquid separator, a second distillation column, a third distillation column, a fourth distillation column, and a fifth distillation column. The second pressure reducing valve is used to reduce the pressure of formic acid and methanol. The fourth gas-liquid separator is used to separate methanol and formic acid, and methanol can be refluxed back into the carbonylation reactor. The second distillation column is used to receive formic acid and heat it through a reboiler at the bottom of the column to distill off the residual methyl formate and methanol in the formic acid. After condensation, a mixed distillate of methyl formate and methanol is obtained. The third distillation column is used to receive the mixed distillate of methyl formate and methanol, and then heats the mixed distillate of methyl formate and methanol through a reboiler at the bottom of the column to obtain methyl formate vapor. After condensation, it is transferred to the second heater. The remaining methanol can be returned to the carbonylation reactor. The fourth distillation column is used to receive the remaining formic acid in the second distillation column and is connected to the fifth distillation column for distillation purification of formic acid.

[0014] After adopting the above solution, the beneficial effects of the present invention are as follows: This invention relates to a biomass pyrolysis power generation system. The system utilizes a first biomass feedstock for pyrolysis, producing pyrolysis gas, biomass oil, and biomass carbon. The flue gas generated from the combustion of the pyrolysis gas drives a gas turbine to generate electricity. The CO2 in the flue gas is absorbed by the absorption tower of the carbon capture subsystem, and then released through a desorption tower, resulting in a CO2 mixture. After cooling in a first cooler and undergoing first gas-liquid separation, CO2 is obtained. The formic acid synthesis subsystem uses the biomass carbon generated by the biomass pyrolysis power generation system and the CO2 generated by the carbon capture subsystem for a reduction reaction to produce CO. CO and methanol then undergo a carbonylation reaction to produce methyl formate. The hydrolysis of methyl formate produces formic acid and methanol. This invention's system utilizes biomass feedstock to produce biomass carbon, biomass oil, CO2, and formic acid, and can also provide electricity, thus fully utilizing biomass energy and achieving comprehensive utilization of biomass resources. Attached Figure Description

[0015] Figure 1 This is a connection block diagram of the multi-product system of the present invention.

[0016] Label Explanation: 100. Biomass pyrolysis power generation system; 101. Pyrolyzer; 102. First combustion chamber; 103. Second combustion chamber; 104. Gas turbine; 105. First heat exchanger; 106. Second gas-liquid separator; 107. First compressor; 108. Second compressor; 109. Second heat exchanger; 110. Steam turbine; 111. First condenser; 112. First distributor; 113. Third compressor; 114. Third heat exchanger; 115. Fourth heat exchanger; 116. First mixer; 117. Dryer; 200. Carbon capture subsystem; 201. Absorption tower; 202. Desorption tower; 203. First cooler; 204. First gas-liquid separator; 205. Fifth heat exchanger; 206. Second cooler; 207. Second distributor; 300. Formic acid synthesis subsystem; 301. Reduction reactor; 302. Carbonylation reactor; 303. First distillation column; 304. Sixth heat exchanger; 305. Seventh heat exchanger; 306. Fourth compressor; 307. Fourth cooler; 308. Second mixer; 309. First pressure reducing valve; 310. Third cooler; 311. Third gas-liquid separator; 312. Second condenser; 313. Third mixer; 314. First heater; 315. Pre-hydrolysis reactor; 316. Second heater; 317. Main hydrolysis reactor; 318. Second pressure reducing valve; 319. Fourth gas-liquid separator; 320. Second distillation column; 321. Third distillation column; 322. Fourth distillation column; 323. Fifth distillation column; 324. Fourth mixer; 325. Fifth cooler; 400. Reboiler; 500. Pump. Detailed Implementation

[0017] The present invention will now be further described in conjunction with the accompanying drawings and specific embodiments.

[0018] like Figure 1 As shown, this embodiment provides a biomass pyrolysis polygeneration system that couples carbon capture and formic acid synthesis, including a biomass pyrolysis electron generation system 100, a carbon capture subsystem 200, and a formic acid synthesis subsystem 300. The biomass pyrolysis power generation system 100 includes a pyrolyzer 101, a first combustion chamber 102, and a gas turbine 104. The pyrolyzer 101 is used to pyrolyze the dried first biomass raw material to produce pyrolysis gas, gaseous biomass oil, and solid biomass carbon. The first combustion chamber 102 is used to burn the pyrolysis gas to produce flue gas, which includes CO2 and water vapor. The gas turbine 104 is connected to a generator. The gas turbine 104 receives the flue gas and drives the generator to generate electricity. The pyrolysis gas includes H2, CO, CO2, CH4, C2H2, C2H4, and C2H6. The carbon capture subsystem 200 includes an absorption tower 201, a stripping tower 202, a first cooler 203, and a first gas-liquid separator 204. The absorption tower 201 contains a lean-loaded ethanolamine liquid as an absorbent, which absorbs CO2 from the flue gas to form a rich amine liquid. The stripping tower 202 receives the rich amine liquid from the absorption tower 201 and releases the CO2 from the rich amine liquid to form a CO2 mixture. The CO2 mixture includes CO2, water vapor, and gaseous ethanolamine. The first cooler 203 cools the water vapor and gaseous ethanolamine in the CO2 mixture into a liquid state. The first gas-liquid separator 204 separates the liquid water, liquid ethanolamine, and CO2. The formic acid synthesis subsystem 300 includes a reduction reactor 301, a carbonylation reactor 302, a first distillation column 303, and a hydrolysis reactor. The reduction reactor 301 is connected to a first gas-liquid separator 204. The reduction reactor 301 is used to reduce CO2 separated by the first gas-liquid separator 204 and biomass carbon produced by the pyrolysis unit 101 to produce CO. The carbonylation reactor 302 is used to carbonylate CO and methanol to produce a methyl formate solution. The first distillation column 303 is used to distill the methyl formate solution to obtain methyl formate distillate. The hydrolysis reactor is used to hydrolyze the methyl formate distillate and water to produce formic acid and methanol.

[0019] Specifically, the pyrolysis gas contains seven components: H2, CO, CO2, CH4, C2H2, C2H4, and C2H6. The air consists of 21% oxygen (O2) and 79% nitrogen (N2). The main reactions that occur between the two in the combustion chamber are as follows:

[0020] The energy balance equation within the combustion chamber is as follows:

[0021] In the formula, The mass flow rate of the i-th working fluid entering the combustion chamber, ; The specific enthalpy of the i-th working fluid entering the combustion chamber, ; The mass flow rate at the combustion chamber outlet. ; The specific enthalpy at the combustion chamber outlet. .

[0022] Specifically, it also includes a second combustion chamber 103, which can supply the second biomass raw material for combustion to produce tail gas containing CO2. The CO2 in the tail gas is absorbed by the absorbent in the absorption tower 201 to form an amine-rich liquid, which is then sent to the desorption tower 202.

[0023] Specifically, the biomass pyrolysis power generation system 100 also includes a pulverizer and a dryer 117; the pulverizer is used to pulverize the first biomass raw material, the dryer 117 is used to dry the pulverized first biomass raw material, and the pyrolyzer 101 is used to pyrolyze the dried first biomass raw material. The pyrolysis gas and gaseous biomass oil generated by pyrolysis can provide a heat source for the dryer 117, providing heat for the subsequent drying of the first biomass raw material.

[0024] Specifically, the biomass pyrolysis power generation system 100 also includes a first heat exchanger 105, a second gas-liquid separator 106, a first compressor 107, and a second compressor 108. The first heat exchanger 105 is used to cool the gaseous biomass oil and pyrolysis gas to produce liquid biomass oil. The second gas-liquid separator 106 is used to separate the liquid biomass oil and pyrolysis gas. The first compressor 107 is used to compress the separated pyrolysis gas and send it into the first combustion chamber 102. The second compressor 108 is used to compress air and send it into the first combustion chamber 102. The first heat exchanger 105 is connected to the domestic water network. The first heat exchanger 105 absorbs heat from the gaseous biomass oil and pyrolysis gas, thereby cooling the gaseous biomass oil and pyrolysis gas and heating the water flow in the domestic water network.

[0025] Specifically, the biomass pyrolysis power generation system also includes a second heat exchanger 109, a steam turbine 110, and a first condenser 111. The second heat exchanger 109 contains water and receives flue gas from the gas turbine 104. It is understood that the flue gas from the first combustion chamber 102 has a high temperature. The flue gas expands within the gas turbine 104, causing the turbine to perform work and generate electricity. The flue gas exchanges heat with the water in the second heat exchanger 109, vaporizing the water into steam and simultaneously cooling the flue gas. The steam turbine 110 is connected to a generator. The steam turbine 110 receives the steam and uses the steam to drive the generator to generate electricity. The first condenser 111 is used to condense the steam from the steam turbine 110 into liquid water. The liquid water can flow back into the second heat exchanger 109 to absorb heat from the flue gas subsequently entering the second heat exchanger 109. The first condenser 111 is connected to a domestic water network, heating the water flow within the network by condensing the steam.

[0026] Specifically, the biomass pyrolysis power generation system 100 also includes a first distributor 112, a third compressor 113, a third heat exchanger 114, and a fourth heat exchanger 115. The flue gas also contains unburned pyrolysis gas. The first distributor 112 separates the unburned pyrolysis gas from the flue gas after heat exchange in the second heat exchanger 109. The third compressor 113 compresses the separated unburned pyrolysis gas. The third heat exchanger 114 cools the compressed unburned pyrolysis gas. The cooled pyrolysis gas returns to the first combustion chamber 102. The third heat exchanger 114 is connected to the domestic water network. By absorbing the heat from the compressed, incompletely combusted pyrolysis gas, the compressed, incompletely combusted pyrolysis gas is cooled, and the water flow in the domestic water network is heated. The fourth heat exchanger 115 is used to cool the CO2 and water vapor separated by the first distributor 112. The fourth heat exchanger 115 is connected to the domestic water network. By absorbing the heat from the CO2 and water vapor, the CO2 and water vapor are cooled, and the water flow in the domestic water network is heated. The CO2 cooled by the heat exchange can be absorbed by the absorbent in the absorption tower 201. Specifically, the fourth heat exchanger 115 can also cool the tail gas containing CO2 produced by the combustion of the second biomass raw material.

[0027] Specifically, it also includes a first mixer 116, which is used to mix the CO2 and water vapor diverted from the first distributor 112, the CO2-containing exhaust gas generated from the combustion of the second biomass raw material, and after mixing, it is transferred to the fourth heat exchanger 115 for cooling, and then absorbed by the absorption tower 201.

[0028] Specifically, the carbon capture subsystem 200 also includes a fifth heat exchanger 205 and a second cooler 206. The fifth heat exchanger 205 is used to heat the rich amine liquid from the absorption tower 201. The stripping tower 202 can receive the preheated rich amine liquid. The bottom of the stripping tower 202 is equipped with a reboiler 400, which is used to heat the rich amine liquid to release CO2 from the rich amine liquid, resulting in a CO2 mixture and a lean amine liquid. The reboiler 400 can transfer the CO2 mixture back into the stripping tower 202. The lean amine liquid can flow back into the fifth heat exchanger 205 to provide heat for heating the rich amine liquid that subsequently enters the fifth heat exchanger 205. The second cooler 206 is used to receive the lean amine liquid coming out of the fifth heat exchanger 205 and cool the lean amine liquid. The cooled lean amine liquid flows back into the absorption tower 201.

[0029] Specifically, the first gas-liquid separator 204 is also connected to the stripping tower 202. The first gas-liquid separator 204 is used to send the separated liquid ethanolamine and water back into the stripping tower 202 for reuse.

[0030] Specifically, the carbon capture subsystem 200 also includes a second splitter 207, which is connected to the first gas-liquid separator 204. The second splitter 207 is used to divide the CO2 separated by the first gas-liquid separator 204 into two parts, one part of which is retained and the other part is transferred to the reduction reactor 301.

[0031] Specifically, in the packed towers (absorption tower 201 and desorption tower 202), the gas-liquid two-phase countercurrent flow occurs, and the mass balance equation is as follows:

[0032] In the formula, z represents the position that varies along the axial direction of the packed tower; and denoted as , respectively, the mass flow rates of component i at position z in the gas and liquid phases. ; The cross-sectional area of ​​the packed tower. ; and Let be the molar fluxes of component i in the gas phase and liquid phase, respectively. ; Let Z be the wetting specific surface area of ​​the packing at position z. ; Let be the relative molecular mass of component i. ; Let Z be the wetting specific surface area of ​​the packing at position z. ; Let be the relative molecular mass of component i. ; This represents the liquid holdup per unit packing volume at position z. ; Let z be the reaction rate of component i at position z in reaction j. .

[0033] The energy balance equation for a packed tower is as follows:

[0034] In the formula, and denoted as the total mass flow rates of the gas phase and liquid phase at position z, respectively. ; and These are the mass-to-enthalpy ratios of the gas and liquid phases at position z, respectively. ; and Let Z be the energy flux of the gas and liquid phases at position z. .

[0035] The equilibrium equations for the gas-liquid two-phase interface within the packed tower are as follows:

[0036] In the formula, and These are the fugacity coefficients of component i at the gas-liquid interface; and These represent the mole fractions of component i at the gas and liquid phase interfaces, respectively.

[0037] Specifically, in the amine-based carbon capture process, CO2 desorption occurs not only in the desorption column but also in the reboiler. Using a batch reboiler, the cold fluid evaporates on the shell side, while the hot fluid provides heat on the tube side. The mass and energy balance equations are as follows:

[0038] In the formula, This represents the mass flow rate at the reboiler inlet. ; The mass fraction of component i at the reboiler inlet; and These are the mass flow rates of the gas and liquid phases at the reboiler outlet, respectively. ; and These are the mass fractions of component i in the gas phase and liquid phase at the reboiler outlet, respectively. The specific enthalpy at the reboiler inlet. ; and These are the mass specific enthalpy of the gas phase and liquid phase at the reboiler outlet, respectively. ; For the heat consumed by the reboiler, .

[0039] Specifically, the formic acid synthesis subsystem 300 also includes a sixth heat exchanger 304, which is used to heat the CO2 separated by the first gas-liquid separator 204. The heated CO2 can enter the reduction reactor 301 and undergo a reduction reaction with biomass carbon to produce CO. The produced CO can enter the sixth heat exchanger 304 and provide heat for the CO2 that subsequently enters the sixth heat exchanger 304. The hydroxylation reactor can receive the CO from the sixth heat exchanger 304.

[0040] Furthermore, the formic acid synthesis subsystem 300 also includes a seventh heat exchanger 305, a fourth compressor 306, and a fourth cooler 307. The seventh heat exchanger 305 is used to receive CO from the sixth heat exchanger 30 and cool it. The seventh heat exchanger 305 is connected to the domestic water network to heat the water flow of the domestic water network by absorbing the heat of CO. The fourth compressor 306 is used to compress the cooled CO. The fourth cooler 307 is used to cool the compressed CO. The fourth cooler 307 is connected to the domestic water network to heat the water flow of the domestic water network by absorbing the heat of the compressed CO, thereby producing hot water.

[0041] Specifically, it also includes a second mixer 308, which is used to receive CO cooled by the fourth cooler 307 and mix it with methanol, and then transfer it to the carbonylation reactor 302 after mixing.

[0042] Furthermore, the formic acid synthesis subsystem 300 also includes a first pressure reducing valve 309, a third cooler 310, and a third gas-liquid separator 311. The first pressure reducing valve 309 reduces the pressure on the methyl formate solution and unreacted methanol produced by the carbonylation reactor 302. The third cooler 310 cools the methyl formate solution and unreacted methanol. The third gas-liquid separator 311 flashes the methyl formate solution and unreacted methanol within it to vaporize the methanol and separate the methyl formate solution and unreacted methanol. The gaseous methanol can be returned to the carbonylation reactor 302. The first distillation column 303 can receive the methyl formate solution from the third gas-liquid separator 311 and distill it.

[0043] Furthermore, the formic acid synthesis subsystem 300 also includes a second condenser 312, a first heater 314, and a second heater 316. The hydrolysis reactor includes a pre-hydrolysis reactor 315 and a main hydrolysis reactor 317. The second condenser 312 is used to condense the distilled methyl formate vapor to obtain methyl formate distillate. The first heater 314 is used to heat the mixture of methyl formate distillate and water to promote the hydrolysis of methyl formate. The pre-hydrolysis reactor 315 is used for the initial hydrolysis of methyl formate. The second heater 316 is used to receive and heat the solution in the pre-hydrolysis reactor 315 to promote the hydrolysis of methyl formate. The main hydrolysis reactor 317 is used to receive the solution heated by the second heater 316 and is used for the hydrolysis of methyl formate to produce methanol and formic acid. The produced methanol is refluxed into the carbonylation reactor 302 to continue reacting with CO.

[0044] Specifically, a reboiler 400 is provided at the bottom of the first distillation column 303. The reboiler 400 is used to heat the methyl formate solution to obtain methyl formate vapor. Then, the methyl formate vapor is condensed by the second condenser 312 to obtain the methyl formate distillate.

[0045] Specifically, it also includes a third mixer 313, which is used to receive the distillate of methyl formate and mix it with water, and then transfer the mixture to the first heater 314. Furthermore, the formic acid synthesis subsystem 300 also includes a second pressure reducing valve 318, a fourth gas-liquid separator 319, a second distillation column 320, a third distillation column 321, a fourth distillation column 322, and a fifth distillation column 323. The second pressure reducing valve 318 is used to reduce the pressure of formic acid and methanol. The fourth gas-liquid separator 319 is used to separate methanol and formic acid, allowing methanol to be refluxed back into the carbonylation reactor 302. The second distillation column 320 is used to receive formic acid and heat it through a reboiler 400 at the bottom of the column, distilling off the residual methyl formate and methanol from the formic acid. After condensation, a mixed distillate of methyl formate and methanol is obtained. The third distillation column 321 is used to receive the mixed distillate of methyl formate and methanol, and then heats the mixed distillate of methyl formate and methanol through its reboiler 400 to obtain... The vapor from methyl formate is condensed and then transferred to the second heater 316. The remaining methanol can return to the carbonylation reactor 302. The fourth distillation column 322 is used to receive the remaining formic acid in the second distillation column 320 and is connected to the fifth distillation column 323 for distillation purification of formic acid. Specifically, the fourth distillation column 322 and the fifth distillation column 323 distill formic acid through pressure swing distillation. The fourth distillation column 322 is a pressure enrichment column. The top of the fourth distillation column 322 is dehydrated, and the bottom of the column contains formic acid, which is then fed into the fifth distillation column 323. The fifth distillation column 323 is a vacuum distillation column. The top of the column contains 99% formic acid, and the bottom of the column contains low-concentration formic acid, which is returned to the fourth distillation column 322. The formic acid at the top of the fifth distillation column 323 is cooled by the fifth cooler 325 before being output.

[0046] It also includes a fourth mixer 324, which is used to mix the products of the preliminary hydrolysis of methyl formate in the pre-hydrolysis reactor 315, methyl formate from the top of the third distillation column 321, and water from the top of the fourth distillation column 322.

[0047] Specifically, in each subsystem, the liquid is transported using pump 500.

[0048] Specifically, the carbonylation reactor 302 is a continuous stirred tank reactor, and sodium methoxide is used as a catalyst to catalyze the reaction of methanol and CO. The reaction rate equation is as follows:

[0049] In the formula, The reaction rate of the carbonylation reaction, ; This represents the concentration of the sodium methoxide catalyst in the liquid phase. ; , and These represent the concentrations of carbon monoxide, methanol, and methyl formate in the liquid phase, respectively. ; The reaction temperature, ; Let be the ideal gas constant. .

[0050] Specifically, the hydrolysis reaction occurred in a pre-hydrolysis reactor 315 (PRELIM) at 120°C and 18 bar, and in a main hydrolysis reactor 317 (MAIN), both of which are tubular reactors. The concentration of FA (formic acid) in the pre-hydrolysis reactor 315 was low, and its hydrolysis reaction was autocatalyzed by methyl formate. The reaction kinetic equation is as follows:

[0051] In the formula, For the pre-hydrolysis reaction rate, ; The rate constant for the uncatalyzed reaction is... ; Let be the rate constant of the autocatalytic reaction. , and These are the activation energies for non-catalytic and autocatalytic reactions, respectively. ; and These are the reaction temperature and the reference temperature, respectively. ; and These are the concentrations of MF (methyl formate) and water, respectively. ; and These represent the concentrations of FA (formic acid) and MA (methanol), respectively. ; The equilibrium constant is shown in Table 1. Table 1. Kinetic parameters of hydrolysis reaction

[0052] The concentration of FA (formic acid) in the main hydrolysis reactor 317 is relatively high. The hydrolysis reaction is catalyzed by FA (formic acid), and its reaction kinetic equation is as follows:

[0053] In the formula, The reaction rate constant is... ; Let be the acid dissociation constant. ; The activation energy of the reaction. ; The reaction temperature, ; and These are the concentrations of MF and water, respectively. ; and These represent the concentrations of FA (formic acid) and MA (methanol), respectively. ; This is the reaction equilibrium constant.

[0054] The mass balance equation for the reaction process inside the tubular reactor is as follows:

[0055] In the formula, Let i be the mass flux of component i at position z. ; The stoichiometric ratio of component i in reaction j; Let j be the reaction rate. ; As the head of the department, .

[0056] The distillation column within the subsystem is a plate distillation column, and calculations are performed based on material balance, phase balance, component balance, and energy balance equations.

[0057] The material balance equation is as follows:

[0058] In the formula, For the j-th tray; and These are the mass flow rates of the gas phase and liquid phase leaving tray j, respectively. ; and These represent the mass flow rates of the gas phase and liquid phase entering tray j, respectively. ; and These represent the mass fractions of component i in the gas phase and liquid phase leaving tray j, respectively. and These represent the mass fractions of component i in the gas phase and liquid phase entering tray j, respectively.

[0059] The phase equilibrium equations are as follows:

[0060] In the formula, and , respectively, are the fugacity coefficients of component i in the gas phase and liquid phase of tray j; and , respectively, represent the mole fractions of component i in the gas and liquid phases of tray j.

[0061] The component equilibrium equations are as follows:

[0062] The energy balance equation is as follows:

[0063] In the formula, and These are the enthalpy ratios of the gas and liquid phases leaving the tray, respectively. ; and These are the enthalpy ratios of the gas and liquid phases entering tray j, respectively. .

[0064] The directional terms used in this specification are defined relative to the structures shown in the accompanying drawings. They are relative concepts and may therefore vary depending on their location and usage. Therefore, these or other directional terms should not be interpreted as restrictive.

[0065] The above description is only a preferred embodiment of the present invention and is not intended to limit the design of this case. All equivalent changes made based on the key design features of this case shall fall within the protection scope of this case.

Claims

1. A biomass pyrolysis co-production system coupling carbon capture and formic acid synthesis, characterized in that: This includes a biomass pyrolysis electron-generating system, a carbon capture subsystem, and a formic acid synthesis subsystem; The biomass pyrolysis power generation system includes a pyrolyzer, a first combustion chamber, and a gas turbine. The pyrolyzer is used to pyrolyze the dried first biomass feedstock to produce pyrolysis gas, gaseous biomass oil, and solid biomass carbon. The first combustion chamber is used to burn the pyrolysis gas to produce flue gas, which includes CO2 and water vapor. The gas turbine is connected to a generator. The gas turbine receives the flue gas and drives the generator to generate electricity. The pyrolysis gas includes H2, CO, CO2, CH4, C2H2, C2H4, and C2H6. The carbon capture subsystem includes an absorption tower, a stripping tower, a first cooler, and a first gas-liquid separator. The absorption tower contains a lean-loaded ethanolamine solution as the absorbent, which absorbs CO2 from the flue gas to form a rich ethanolamine solution. The stripping tower receives the rich ethanolamine solution from the absorption tower and releases the CO2 from the solution, forming a CO2 mixture. The CO2 mixture includes CO2, water vapor, and gaseous ethanolamine. The first cooler cools the water vapor and gaseous ethanolamine in the CO2 mixture into a liquid state. The first gas-liquid separator separates the liquid water, liquid ethanolamine, and CO2. The formic acid synthesis subsystem includes a reduction reactor, a carbonylation reactor, a first distillation column, and a hydrolysis reactor. The reduction reactor is connected to a first gas-liquid separator and is used to reduce CO2 separated from the first gas-liquid separator and biomass carbon produced by the pyrolysis unit to produce CO. The carbonylation reactor is used to carbonylate CO and methanol to produce methyl formate solution. The first distillation column is used to distill the methyl formate solution to obtain methyl formate distillate. The hydrolysis reactor is used to hydrolyze the methyl formate distillate and water to produce formic acid and methanol.

2. The biomass pyrolysis co-production system coupled with carbon capture and formic acid synthesis as described in claim 1, characterized in that: The biomass pyrolysis power generation system also includes a first heat exchanger, a second gas-liquid separator, a first compressor, and a second compressor. The first heat exchanger is used to cool the gaseous biomass oil and pyrolysis gas to produce liquid biomass oil. The second gas-liquid separator is used to separate the liquid biomass oil and pyrolysis gas. The first compressor is used to compress the separated pyrolysis gas and send it into the first combustion chamber. The second compressor is used to compress air and send it into the first combustion chamber. The first heat exchanger is connected to the domestic water network. The first heat exchanger absorbs heat from the gaseous biomass oil and pyrolysis gas, thereby cooling the gaseous biomass oil and pyrolysis gas and heating the water flow in the domestic water network.

3. The biomass pyrolysis polygeneration system coupled with carbon capture and formic acid synthesis as described in claim 1, characterized in that: The biomass pyrolysis power generation system also includes a second heat exchanger, a steam turbine, and a first condenser. The second heat exchanger contains water and receives flue gas from the gas turbine. The flue gas exchanges heat with the water in the second heat exchanger, vaporizing the water into steam and simultaneously cooling the flue gas. The steam turbine is connected to a generator. The steam turbine receives the steam and drives the generator to generate electricity. The first condenser is used to condense the steam from the steam turbine into liquid water, which can then flow back into the second heat exchanger. The first condenser is connected to the domestic water network and heats the water flow in the domestic water network by condensing the steam.

4. The biomass pyrolysis polygeneration system coupled with carbon capture and formic acid synthesis as described in claim 1, characterized in that: The biomass pyrolysis power generation system also includes a first distributor, a third compressor, a third heat exchanger, and a fourth heat exchanger. The flue gas also contains unburned pyrolysis gas. The first distributor separates the unburned pyrolysis gas from the flue gas after heat exchange in the second heat exchanger. The third compressor compresses the separated unburned pyrolysis gas. The third heat exchanger cools the compressed unburned pyrolysis gas, allowing it to return to the first combustion chamber. The third heat exchanger is connected to the domestic water network and cools the compressed unburned pyrolysis gas by absorbing its heat, while also heating the water flow in the domestic water network. The fourth heat exchanger cools the CO2 and water vapor separated by the first distributor. It is also connected to the domestic water network and cools the CO2 and water vapor by absorbing their heat, while heating the water flow in the domestic water network. The cooled CO2 can be absorbed by the absorbent in the absorption tower.

5. The biomass pyrolysis polygeneration system coupled with carbon capture and formic acid synthesis as described in claim 1, characterized in that: The carbon capture subsystem also includes a fifth heat exchanger and a second cooler. The fifth heat exchanger is used to heat the rich amine liquid from the absorption tower. The stripping tower can receive the preheated rich amine liquid. A reboiler is provided at the bottom of the stripping tower. The reboiler is used to heat the rich amine liquid to release CO2 from the rich amine liquid, resulting in a CO2 mixture and a lean amine liquid. The reboiler can transfer the CO2 mixture back into the stripping tower. The lean amine liquid can flow back into the fifth heat exchanger to provide heat for heating the rich amine liquid that subsequently enters the fifth heat exchanger. The second cooler is used to receive the lean amine liquid from the fifth heat exchanger and cool it. The cooled lean amine liquid flows back into the absorption tower.

6. The biomass pyrolysis polygeneration system coupled with carbon capture and formic acid synthesis as described in claim 1, characterized in that: The first gas-liquid separator is connected to the stripping tower. The first gas-liquid separator is used to send the separated liquid ethanolamine and water back into the stripping tower for reuse.

7. The biomass pyrolysis co-production system coupled with carbon capture and formic acid synthesis as described in claim 1, characterized in that: The formic acid synthesis subsystem also includes a sixth heat exchanger, which is used to heat the CO2 separated by the first gas-liquid separator. The heated CO2 can enter the reduction reactor and undergo a reduction reaction with biomass carbon to produce CO. The produced CO can enter the sixth heat exchanger and provide heat for the CO2 that subsequently enters the sixth heat exchanger. The hydroxylation reactor can receive the CO from the sixth heat exchanger.

8. The biomass pyrolysis polygeneration system coupled with carbon capture and formic acid synthesis as described in claim 1, characterized in that: The formic acid synthesis subsystem also includes a first pressure reducing valve, a third cooler, and a third gas-liquid separator. The first pressure reducing valve reduces the pressure on the methyl formate solution and unreacted methanol produced by the carbonylation reactor. The third cooler cools the methyl formate solution and unreacted methanol. The third gas-liquid separator allows the methyl formate solution and unreacted methanol to flash evaporate within it, vaporizing the methanol and separating the methyl formate solution and unreacted methanol. The gaseous methanol can be returned to the carbonylation reactor. The first distillation column receives the methyl formate solution from the third gas-liquid separator and distills it.

9. A biomass pyrolysis co-production system coupled with carbon capture and formic acid synthesis as described in claim 1, characterized in that: The formic acid synthesis subsystem also includes a second condenser, a first heater, and a second heater. The hydrolysis reactor includes a pre-hydrolysis reactor and a main hydrolysis reactor. The second condenser is used to condense the distilled methyl formate vapor to obtain the methyl formate distillate. The first heater is used to heat the mixture of the methyl formate distillate and water to promote the hydrolysis of methyl formate. The pre-hydrolysis reactor is used for the initial hydrolysis of methyl formate. The second heater is used to receive and heat the solution in the pre-hydrolysis reactor to promote the hydrolysis of methyl formate. The main hydrolysis reactor is used to receive the solution heated by the second heater and is used for the hydrolysis of methyl formate to produce methanol and formic acid. The produced methanol is refluxed into the carbonylation reactor to continue reacting with CO.

10. A biomass pyrolysis co-production system coupled with carbon capture and formic acid synthesis as described in claim 9, characterized in that: The formic acid synthesis subsystem also includes a second pressure reducing valve, a fourth gas-liquid separator, a second distillation column, a third distillation column, a fourth distillation column, and a fifth distillation column. The second pressure reducing valve is used to reduce the pressure of formic acid and methanol. The fourth gas-liquid separator is used to separate methanol and formic acid, and methanol can be refluxed back into the carbonylation reactor. The second distillation column is used to receive formic acid and heat it through a reboiler at the bottom of the column to distill off the residual methyl formate and methanol in the formic acid. After condensation, a mixed distillate of methyl formate and methanol is obtained. The third distillation column is used to receive the mixed distillate of methyl formate and methanol, and then heats the mixed distillate of methyl formate and methanol through a reboiler at the bottom of the column to obtain methyl formate vapor. After condensation, it is transferred to the second heater. The remaining methanol can be returned to the carbonylation reactor. The fourth distillation column is used to receive the remaining formic acid in the second distillation column and is connected to the fifth distillation column for the distillation purification of formic acid.

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