CN114405246B - Is suitable for low partial pressure CO2Energy-saving process for trapping and purifying - Google Patents
Is suitable for low partial pressure CO2Energy-saving process for trapping and purifying Download PDFInfo
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- CN114405246B CN114405246B CN202111628987.8A CN202111628987A CN114405246B CN 114405246 B CN114405246 B CN 114405246B CN 202111628987 A CN202111628987 A CN 202111628987A CN 114405246 B CN114405246 B CN 114405246B
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- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
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- B01D53/00—Separation of gases or vapours; Recovering vapours of volatile solvents from gases; Chemical or biological purification of waste gases, e.g. engine exhaust gases, smoke, fumes, flue gases, aerosols
- B01D53/34—Chemical or biological purification of waste gases
- B01D53/74—General processes for purification of waste gases; Apparatus or devices specially adapted therefor
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- B01D53/34—Chemical or biological purification of waste gases
- B01D53/343—Heat recovery
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
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- B01D53/34—Chemical or biological purification of waste gases
- B01D53/46—Removing components of defined structure
- B01D53/48—Sulfur compounds
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- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
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- B01D53/34—Chemical or biological purification of waste gases
- B01D53/46—Removing components of defined structure
- B01D53/54—Nitrogen compounds
- B01D53/56—Nitrogen oxides
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D53/00—Separation of gases or vapours; Recovering vapours of volatile solvents from gases; Chemical or biological purification of waste gases, e.g. engine exhaust gases, smoke, fumes, flue gases, aerosols
- B01D53/34—Chemical or biological purification of waste gases
- B01D53/46—Removing components of defined structure
- B01D53/62—Carbon oxides
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D53/00—Separation of gases or vapours; Recovering vapours of volatile solvents from gases; Chemical or biological purification of waste gases, e.g. engine exhaust gases, smoke, fumes, flue gases, aerosols
- B01D53/34—Chemical or biological purification of waste gases
- B01D53/74—General processes for purification of waste gases; Apparatus or devices specially adapted therefor
- B01D53/77—Liquid phase processes
- B01D53/79—Injecting reactants
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D53/00—Separation of gases or vapours; Recovering vapours of volatile solvents from gases; Chemical or biological purification of waste gases, e.g. engine exhaust gases, smoke, fumes, flue gases, aerosols
- B01D53/34—Chemical or biological purification of waste gases
- B01D53/96—Regeneration, reactivation or recycling of reactants
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
- F25B—REFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS
- F25B30/00—Heat pumps
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
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- B01D2251/00—Reactants
- B01D2251/30—Alkali metal compounds
- B01D2251/304—Alkali metal compounds of sodium
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
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- B01D2251/604—Hydroxides
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D2251/00—Reactants
- B01D2251/80—Organic bases or salts
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D2258/00—Sources of waste gases
- B01D2258/02—Other waste gases
- B01D2258/0283—Flue gases
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- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02B—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO BUILDINGS, e.g. HOUSING, HOUSE APPLIANCES OR RELATED END-USER APPLICATIONS
- Y02B30/00—Energy efficient heating, ventilation or air conditioning [HVAC]
- Y02B30/52—Heat recovery pumps, i.e. heat pump based systems or units able to transfer the thermal energy from one area of the premises or part of the facilities to a different one, improving the overall efficiency
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- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02C—CAPTURE, STORAGE, SEQUESTRATION OR DISPOSAL OF GREENHOUSE GASES [GHG]
- Y02C20/00—Capture or disposal of greenhouse gases
- Y02C20/40—Capture or disposal of greenhouse gases of CO2
Abstract
The invention discloses a method suitable for low partial pressure CO2The energy-saving process for trapping and purifying adopts a coupling process of a graded flow system, an interstage cooling system, a combined heat pump system, an MVR flash evaporation heat pump system and a compression heat pump system, can effectively reduce the volume of a boiler, greatly reduce the regeneration energy consumption, reduce the medicament loss and the degradation and deterioration of the medicament, improve the recycling frequency of a chemical absorbent, save the investment cost, and realize the purposes of recycling and reducing the environmental pollution; the composite absorption heat pump and MVR flash evaporation heat pump system can realize effective recovery of barren solution waste heat and is used for heating rich solution; the 'regeneration tower top compression heat pump system' can effectively recover the regeneration tower top gas; the tail gas washing process of the dry bed and the two-stage tail gas washing tower is adopted, so that the aerosol growth is facilitated, large particles can be effectively removed, the solvent loss is reduced, and the emission of tail gas pollutants is reduced.
Description
Technical Field
The invention relates to CO2A trapping and purifying process, in particular to a process suitable for low partial pressure CO2An energy-saving process for trapping and purifying, which belongs to the technical field of flue gas purification.
Background
The CCUS (Carbon Capture, utilization and Storage) technology is a new development trend of the CCS (Carbon Capture and Storage) technology, namely, the CO discharged in the production process of emission sources such as large-scale power plants, steel plants, chemical plants and the like2Collected and purified and then put into a new production process for recycling, rather than simply sequestration, CCUS can sequester CO, as compared to CCS2The resource utilization generates economic benefits and has more practical operability.
Coal is the most important energy type in China at present, and a coal-fired power plant is CO in China2The main emission source of the method can reach the CO in China2Over 50 percent of the total emission, and low partial pressure flue gas CO discharged by a coal-fired power plant2The key of carbon emission reduction in China is to carry out capture, recovery, utilization and sealing storage. CO 22Capture technique is the determination of CO in CCUS2The most critical links of the purity and the cost of resource utilization are that the energy consumption of the process accounts for more than 60 percent of the total energy consumption of the CCUS project, so that the energy consumption is reduced for the CO in the flue gas2The trapping is very important, and the technical bottleneck problem of key link in large-scale CCUS popularization is solved.
As shown in the following table, the current low partial pressure flue gas captures CO2The method comprises the methods of chemical absorption, physical absorption, membrane separation and the like, wherein the chemical absorption method is the most commonly selected flue gas CO in the CCUS project at present due to the technical maturity and the application prospect2A trapping method.
The chemical absorption method is to selectively mix CO in the flue gas with the absorbent2Chemical reaction to realize CO2Separated from other gases and regenerated by means of the reverse reaction of this reaction, releasing high-purity CO2And (4) carrying out enrichment. The reaction principle is that weak base and weak acid react to form water soluble salt which absorbs or releases CO2Is controlled by the chemical reaction equilibrium. The most important bottleneck limiting the large-scale application of the chemical absorption method at present is that the energy consumption is large and the cost is high.
In order to reduce energy consumption, researchers in the industry have conducted research in two major ways: the development of a high-efficiency absorbent absorption system and the capture process optimization of the capture system. Aiming at the absorbent, at present, there are several main types of absorbent, such as amine solution, ammonia water, caustic potash solution, ionic liquid and amino acid salt solution, etc., caustic potash solution and ionic liquid have high cost and are not easy to be used in large scale, while ammonia water is easy to volatilize and forms crystals to block pipelines, so that the mixed absorbent of different amines (ammonia) and novel phase change absorbent are the research focus of researchers in the industry at present. Aiming at the process optimization of the trapping system, the research focuses on an absorption system (a first type of phase-change absorption system) which is layered after absorption and an absorption system (a second type of phase-change absorption system) which is layered after desorption, and the regeneration energy consumption is reduced by reducing the regeneration liquid amount.
Disclosure of Invention
Aiming at the problems in the prior art, the invention provides a low partial pressure CO separating agent suitable for low partial pressure CO2An energy-saving process for capturing and purifying, which can effectively reduce CO2Energy consumption capture and CO reduction2And (4) trapping cost.
To achieve the above purpose, the method is suitable for low partial pressure CO2The trapping and purifying system assembly used in the trapping and purifying energy-saving process comprises a water washing tower, an absorption tower, a regeneration tower, a flash tank and a combined heat pump, wherein an evaporator, an absorber, a generator and a condenser are arranged in the combined heat pump;
suitable for low partial pressure CO2The energy-saving process for trapping and purifying specifically comprises the following parts:
a. washing with water: flue gas enters a washing tower through a pipeline, is subjected to desulfurization, denitrification, dedusting and heat exchange by washing liquid, is discharged from the top of the washing tower and enters an induced draft fan;
b. decarbonization: the method comprises the following steps that (1) flue gas enters an absorption tower from bottom to top after being pressurized by a draught fan, a barren liquor absorbent discharged by a barren liquor cooler is sprayed from top to bottom to enter the absorption tower, and the barren liquor absorbent and the absorption tower are in countercurrent contact to perform decarburization reaction;
c. washing tail gas: the decarbonized gas passes through a dry bed section at the top of the absorption tower and is discharged through a tail gas discharge port at the top of the absorption tower to enter a tail gas washing system, the tail gas washing system comprises a tail gas washing tower, aerosol recovered in the tail gas washing process flows back to a liquid preparation tank, a lean solution in the liquid preparation tank is replenished with a solution again and then enters the absorption tower, and the washed tail gas discharged by the tail gas washing tower is discharged into a chimney;
d.CO2desorbing: absorb CO2The rich liquid of the gas is discharged from the bottom of the absorption tower, and is pressurized by a rich liquid pump and then is conveyed in a grading way, wherein the primary rich liquid directly enters a primary spray pipeline at the top of the regeneration tower, the secondary rich liquid enters a secondary rich liquid heat exchanger for heat exchange and temperature rise, and enters a secondary spray pipeline of the regeneration tower below the primary spray pipeline after heat exchange; the tertiary rich liquid enters a tertiary rich liquid heat exchanger for heat exchange and temperature rise through external circulating water, and enters a secondary spraying pipeline of the regeneration tower after heat exchange;
e. flash evaporation heat supply: a liquid supplementing pipeline of the flash tank is communicated with a pipeline leading to the regeneration tower from the secondary rich liquid heat exchanger; the rich liquid in the flash tank enters an absorber of the combined heat pump for heat exchange and temperature rise after being pressurized by a flash circulating pump, and returns to the flash tank for a flash process after being heated; the flash steam discharged from the top of the flash tank enters a third-stage spraying pipeline of the regeneration tower below the second-stage spraying pipeline after being pressurized by a flash compressor;
f. and (3) cyclic regeneration of the absorption solvent: the desorbed barren solution is pressurized by a barren solution pump from a barren solution outlet at the bottom of the regeneration tower and then is divided into two stages, wherein, the first stage enters a condenser of the compound heat pump for heat exchange and temperature rise, and the temperature rises and then enters a second stage spray pipeline of the regeneration tower again; the other stage as a heat exchange working medium of the secondary rich liquid heat exchanger enters the secondary rich liquid heat exchanger for heat exchange and temperature reduction, then enters an evaporator of the composite heat pump for continuous heat exchange and temperature reduction, then enters a barren liquor cooler for continuous temperature reduction, and finally enters a spray pipeline of an absorption tower to start a new absorption process;
g. treating regenerated gas: the regenerated gas sucked out by the rich liquor decomposition enters a regenerated gas compressor from an outlet at the top of the regeneration tower for pressurization, then enters a regenerator condenser for condensation and cooling, and the condensation heat is transferred to a heat pump working medium; the cooled regeneration gas enters a regeneration gas heat exchanger for heat exchange and cooling through external circulating water, then enters an air cooler for continuous cooling, finally enters a gas-liquid separator for gas-liquid separation, and separated CO2The gas is used as product gas to enter a subsequent flow, and the separated dilute solution enters a tower kettle of a regeneration tower after being pressurized by a reflux pump;
h. a compression heat pump cycle: the compression type heat pump system comprises a solution boiler, a heat pump working medium heating coil is arranged in the solution boiler, a solution input end at the lower part of the solution boiler is connected with the tower kettle of the regeneration tower, and a gasification output end at the upper part of the solution boiler is connected with a gasification input end at the lower part of the tower kettle of the regeneration tower; the heat pump working medium in the regenerator condenser absorbs the condensation heat of the regenerated gas, then is completely vaporized and overheated, then enters a heat pump working medium compressor for temperature and pressure increasing, the high-temperature and high-pressure heat pump working medium enters a heat pump working medium heating coil in the solution boiler, the solution is vaporized and then returns to the regeneration tower through the vaporization output end, and the heat pump working medium condensed into liquid is cooled and depressurized through a throttle valve, then returns to the regenerator condenser for heating and next cycle.
As a further improvement scheme of the invention, in the part a, the gas temperature of the flue gas discharged from the top of the water scrubber is controlled to be 35-45 ℃;
in the part b, the temperature of the barren liquor absorbent discharged from a barren liquor cooler and entering an absorption tower is controlled to be 35-45 ℃;
in the part d, the temperature of the secondary pregnant solution is controlled to be 95-105 ℃ after the heat exchange and temperature rise of the secondary pregnant solution are carried out by a secondary pregnant solution heat exchanger; the temperature of the third-stage rich liquid is controlled to be 95-105 ℃ after the heat exchange and the temperature rise of the third-stage rich liquid are carried out by a third-stage rich liquid heat exchanger;
in the part e, the rich liquid in the flash tank is subjected to heat exchange and temperature rise through an absorber of the composite heat pump, and then the temperature is controlled to be 90-100 ℃; the temperature of flash steam discharged from the top of the flash tank is controlled to be 105-115 ℃ after being pressurized by a flash compressor;
in the part f, the temperature of the first-stage barren solution entering a condenser of the composite heat pump for heat exchange and temperature rise is controlled to be 105-115 ℃; the other grade of barren solution enters a second grade rich solution heat exchanger for heat exchange and temperature reduction, the temperature is controlled to be 55-65 ℃, the barren solution continues to enter an evaporator of the composite heat pump for heat exchange and temperature reduction, the temperature is controlled to be 40-50 ℃, and the barren solution continues to enter a barren solution cooler for temperature reduction;
and in the part g, the regenerated gas discharged from the outlet at the top of the regeneration tower is pressurized by a regenerated gas compressor, then the temperature of the regenerated gas is controlled to be 120-160 ℃, and then the regenerated gas enters a regenerator condenser for condensation and cooling, the temperature of the regenerated gas is controlled to be 80-90 ℃ after condensation and cooling, the regenerated gas continues to enter a regenerated gas heat exchanger for heat exchange and cooling, and the regenerated gas continues to enter an air cooler for cooling to below 40 ℃ after the temperature is reduced to 60-70 ℃.
As a further improvement scheme of the invention, in the h part, a steam heating coil connected with an external steam source is arranged in the solution boiler, the output end of the steam heating coil is connected with the input end of circulating water outside the third-stage rich liquid heat exchanger, hot steam in the steam heating coil is condensed into water after heat exchange and is used as a heat exchange heating working medium of the third-stage rich liquid heat exchanger, and the condensed water is further cooled by the third-stage rich liquid heat exchanger and is deoxidized by a condensed water deoxidizer for recycling.
In the part g, the input end of the external circulating water of the regenerated gas heat exchanger is connected with the condensed water output end of the generating set shaft seal heater, and the output end of the external circulating water of the regenerated gas heat exchanger is connected with the condensed water input end of the generating set shaft seal heater.
As a further development of the invention, part b is the reaction of the amine with CO during the decarbonation2And the amino carbonate generated by the reaction enters an interstage cooler for heat exchange through external circulating water to be cooled, and then enters the absorption tower again after being pressurized by an interstage cooling pump.
As a further improvement scheme of the invention, the temperature of the amino carbonate is controlled to be 35-45 ℃ after the amino carbonate enters an interstage cooler for cooling.
As a further improvement of the present invention, in the part c, the tail gas washing system includes a two-stage tail gas washing tower, the two-stage tail gas washing tower includes a tail gas washing tower a and a tail gas washing tower B connected in series in sequence, and mist eliminators are disposed on exhaust ports of the tail gas washing tower a and the tail gas washing tower B, the tail gas washing tower a and the tail gas washing tower B are respectively provided with a tail gas washing liquid circulating device for circularly conveying tail gas washing liquid from bottom to top, the tail gas washing liquid circulating device of the tail gas washing tower a includes a tail gas washing liquid storage tank a, a tail gas washing liquid pump a and a tail gas washing liquid cooler a, the tail gas washing liquid circulating device of the tail gas washing tower B includes a tail gas washing liquid storage tank B, a tail gas washing liquid pump B and a tail gas washing liquid cooler B, and the recovered aerosol flows back to the liquid preparation tank through the tail gas washing liquid storage tank a and the tail gas washing liquid storage tank B.
As a further improvement scheme of the invention, in the part a, the washing tower is provided with a washing liquid circulating device for circularly conveying washing liquid from the bottom to the top, the washing liquid circulating device comprises a washing pump and a washing liquid heat exchanger, the washing liquid enters the washing liquid heat exchanger for heat exchange through external circulating water after being pressurized by the washing pump, and enters the washing tower for spraying after heat exchange; the alkali supplementing quantity of the water washing liquid is controlled by a PH meter arranged on the circulating pipeline, the PH meter is interlocked with an alkali supplementing pump, the output end of the alkali supplementing pump is communicated with the circulating pipeline, and the NaOH supplementing quantity is adjusted by adjusting the rotating speed of the alkali supplementing pump according to the feedback of the PH meter.
As a further improvement scheme of the invention, the input end of the composite heat pump generator is connected with an external steam source, and the output end of the composite heat pump generator is connected with the input end of the condensed water deoxygenator.
As a further improvement scheme of the invention, the evaporator, the absorber, the generator and the condenser of the compound heat pump are respectively arranged as an evaporator A and an evaporator B which are connected in series, an absorber A and an absorber B which are connected in series, a generator A and a generator B which are connected in series and a condenser A and a condenser B which are connected in series.
Compared with the prior art, the method is suitable for low partial pressure CO2The energy-saving process for trapping and purifying adopts a coupling process of a graded flow system, an interstage cooling system, a combined heat pump system, an MVR flash evaporation heat pump system and a compression heat pump system to partially replace the traditional processThe regeneration process of the desorption tower and the boiler can effectively reduce the volume of the boiler, greatly reduce the regeneration energy consumption, reduce the medicament loss and the degradation and deterioration of the medicament, improve the recycling times of the chemical absorbent, save the investment cost, realize the purposes of resource recovery and reduction of environmental pollution, and ensure that CO can be recycled2The regeneration energy consumption of the trapping system is lower than 2.3GJ/tCO2. The composite absorption heat pump and MVR flash evaporation heat pump system can effectively recover the waste heat of the barren solution and is used for heating the rich solution, and compared with the regeneration energy consumption of the traditional process, the regeneration energy consumption can be reduced by 0.2-0.3 GJ/tCO2(ii) a The 'regeneration tower top compression heat pump system' can effectively recycle the regeneration tower top gas, and can reduce the regeneration energy consumption by 0.25-0.35 GJ/tCO compared with the conventional process2(ii) a By adopting the tail gas washing process of 'a dry bed and a two-stage tail gas washing tower', the dry bed can directly lead the organic amine to return to an absorption circulation system, the organic amine in the tail gas washing tower is slowly accumulated, the frequent water regulation and control can be effectively avoided, the three control links are favorable for the growth of aerosol, large particles can be effectively removed, the solvent loss is reduced, the emission of tail gas pollutants is reduced, and the absorption entrainment loss amount is less than 0.6kg/tCO2Compared with the traditional first-stage water washing process (about 1.0 kg/tCO)2) The reduction can be more than 40%.
Drawings
FIG. 1 is a process flow diagram of the present invention.
In the figure: 1. a water washing pump, 2, a water washing tower, 3, an alkali pump, 4, a water washing liquid heat exchanger, 5, an induced draft fan, 6, an absorption tower, 7, an interstage cooler, 8, an interstage cooling pump, 9, a dry bed section, 10, a tail gas washing tower A,11, a tail gas washing liquid cooler A, 12, a tail gas washing liquid pump A,13, a tail gas washing liquid storage tank A,14, a tail gas washing tower B,15, a tail gas washing liquid cooler B, 16, a tail gas washing pump B,17, a tail gas washing liquid storage tank B,18, a liquid distribution tank, 19, a rich liquid pump, 20, a regeneration tower, 21, a secondary rich liquid heat exchanger, 22, a lean liquid cooler, 23, a tertiary rich liquid heat exchanger, 24, a flash tank, 25, a flash evaporation pump, 26, a flash compressor, 27, a lean liquid pump, 28, a composite heat pump, 29, an evaporator A,30, an evaporator B,31, an absorber A,32, an absorber B,33, a generator A,34, a generator B,35, a condenser A,36, a condenser B, a 37, a regeneration gas compressor, a throttle valve, a boiling water solution, a boiling water solution,
Detailed Description
Is suitable for low partial pressure CO2The trapping and purifying absorption system is a phase-change nano-fluid absorption system, and the regenerative layered phase-change nano-absorbent of the phase-change nano-fluid absorption system consists of base liquid, a layering agent, an activating agent, nano-particles, a corrosion inhibitor and an antioxidant; the base liquid is a basic absorption liquid for ensuring the large load and high absorption rate of the absorbent and consists of hydroxyethyl ethylenediamine (AEEA) and tetraethylenepentamine (TETA); layering agent for realizing CO regeneration of absorption system2The subsequent layering realizes the autonomous self-extraction of the organic phase, ensures a large layering proportion, thereby reducing the energy consumption, and consists of N-ethyl ethylenediamine (N-ELDE) and 1,4-Butanediamine (BDA); the activator is used for improving the absorption of CO by the absorption system2Reaction rate and desorption of CO2The reaction rate of (a) is composed of Piperazine (PZ) or Diethanolamine (DEA); the nano particles are used for strengthening mass transfer, improving the absorption rate and increasing the mass transfer absorption load and consist of copper oxide (CuO) or magnesium oxide (MgO); the corrosion inhibitor is used for reducing the corrosivity of an absorption system to steel (a reactor, heat exchange equipment, various storage tanks, pipelines and the like), and consists of benzoic acid imidazoline-dimethyl sulfate quaternary ammonium salt (IBDSQAS) or benzoic acid imidazoline-chloromethane quaternary ammonium salt (ICQAB); the antioxidant is used for reducing thermal degradation and oxidative degradation of the effective components of the absorbent and ensuring the stability of an absorption system and is composed of Carbohydrazide (CD) or pyrogallol (OTP). The total mass fraction of the regenerative layered phase-change nano absorbent of the phase-change nano fluid absorption system is 30wt%, and the proportions of the base liquid, the layering agent, the activating agent, the nano particles, the corrosion inhibitor and the antioxidant are as follows: 15% -20%: 5% -9%: 1% -5%: 0.01% -0.05%: 0.025% -0.05%: 0.025 to 0.05 percent.
Phase-change nano-fluid absorption system-based low partial pressure CO absorption system2An energy-saving process for capturing and purifying adopts a coupling process of a graded flow system, an interstage cooling system, a combined heat pump system, an MVR flash evaporation heat pump system and a compression heat pump system, as shown in figure 1Is suitable for low partial pressure CO2The capturing and purifying system assembly comprises a water washing tower 2, an absorption tower 6, a regeneration tower 20, a flash tank 24 and a composite heat pump 28, wherein an evaporator, an absorber, a generator and a condenser are arranged in the composite heat pump 28, the input end of the generator is connected with an external steam source, and the output end of the generator is connected with the input end of a condensed water deoxygenator. To ensure the efficiency of the compound heat pump 28, the evaporator, the absorber, the generator, and the condenser may be provided as an evaporator a29 and an evaporator B30 connected in series, an absorber a31 and an absorber B32 connected in series, a generator a33 and a generator B34 connected in series, and a condenser a35 and a condenser B36 connected in series, respectively.
Suitable for low partial pressure CO2The energy-saving process for trapping and purifying specifically comprises the following parts:
a. washing with water: the washing tower 2 is provided with a washing liquid circulating device for circularly conveying washing liquid from bottom to top, the washing liquid circulating device comprises a washing pump 1 and a washing liquid heat exchanger 4, the washing liquid enters the washing liquid heat exchanger 4 for heat exchange through external circulating water after being pressurized by the washing pump 1, and enters the washing tower 2 for spraying after heat exchange (the temperature is reduced to 35-45 ℃); the alkali supplementing amount of the water washing liquid is controlled by a pH meter arranged on a circulating pipeline, the pH meter is interlocked with an alkali supplementing pump 3, the output end of the alkali supplementing pump 3 is communicated with the circulating pipeline, and the NaOH supplementing amount is adjusted by adjusting the rotating speed of the alkali supplementing pump 3 according to the feedback of the pH meter; flue gas discharged from a coal-fired power plant enters a washing tower 2 through a pipeline, is subjected to desulfurization, denitrification, dedusting and heat exchange by using washing liquid (the gas temperature is controlled to be 35-45 ℃), and is discharged from the top of the washing tower 2 and enters an induced draft fan 5.
b. Decarbonization: the flue gas enters an absorption tower 6 from bottom to top after being pressurized by a draught fan 5, a barren liquor absorbent (with the temperature of 35-45 ℃) discharged by a barren liquor cooler 22 is sprayed into the absorption tower 6 from top to bottom and is in countercurrent contact with the barren liquor absorbent, and amine and CO2The amino carbonate (with the temperature of 45-55 ℃) generated by the reaction enters an interstage cooler 7 for exchanging heat through external circulating water to be cooled to 35-45 ℃, and enters an absorption tower 6 again after being pressurized by an interstage cooling pump 8 so as to improve the amine and CO2The decarburization reaction rate of (3).
c. Tail gas washing: a dry bed section 9 is arranged above the filler at the top of the absorption tower 6, the height of the filler of the dry bed section 9 is larger than 2m, the main function is to provide a cooling and condensing space for the tail gas discharged by the absorption tower 6, generally, moisture and organic amine in the tail gas discharged from a tail gas discharge port of the absorption tower 6 are in a supersaturated state, the moisture and the organic amine are cooled and condensed in the dry bed section 9 to form a liquid film with low amine concentration, the liquid film further generates gas-liquid equilibrium mass transfer with the flue gas, and most of the organic amine in the gas phase is recovered; the decarbonized gas passes through a dry bed section 9 at the top of an absorption tower 6 and is discharged through a tail gas discharge port at the top of the absorption tower 6 to enter a tail gas washing system, the tail gas washing system comprises a two-stage tail gas washing tower, the two-stage tail gas washing tower comprises a tail gas washing tower A10 and a tail gas washing tower B14 which are sequentially connected in series, enough growth space is mainly provided for aerosol to grow to 3 mu m or above, the conventional demister arranged on exhaust ports of the tail gas washing tower A10 and the tail gas washing tower B14 is matched to effectively remove organic amine in the form of aerosol, the tail gas washing tower A10 and the tail gas washing tower B14 are respectively provided with a tail gas washing liquid circulating device for circularly conveying tail gas washing liquid from the bottom to the top, the tail gas washing liquid circulating device of the tail gas washing tower A10 comprises a tail gas washing liquid storage tank A13, a tail gas washing liquid pump A12 and a tail gas washing liquid cooler A11, the tail gas washing liquid circulating device of the tail gas washing tower B14 comprises a tail gas washing liquid storage tank B17, a tail gas washing liquid pump B16 and a tail gas washing liquid cooler B15, the tail gas washing liquid tank and a tail liquid solution distribution tank 18 in the tail gas washing liquid distribution tank, and a tail gas washing liquid distribution tank balance liquid distribution tank in the tail gas washing liquid distribution system, and a poor absorption system is maintained, the tail gas washing liquid distribution tank 6 is maintained; the tail gas after being washed discharged from the tail gas washing tower B14 is discharged into a chimney.
d.CO2Desorbing: absorb CO2The rich liquid of the gas is discharged from the bottom of the absorption tower 6, and is pressurized by a rich liquid pump 19 and then is conveyed in a grading way, wherein the first-stage rich liquid (the temperature of the rich liquid is 50-55 ℃) directly enters a first-stage spraying pipeline at the top of the regeneration tower 20, the second-stage rich liquid (the temperature of the rich liquid is 40-45 ℃) enters a second-stage rich liquid heat exchanger 21 for heat exchange and temperature rise, and the second-stage rich liquid (the temperature of the rich liquid is 95-105 ℃) enters a second-stage spraying pipeline of the regeneration tower 20 below the first-stage spraying pipeline after heat exchange; third-level rich liquid (rich liquid temperature is 50 ℃ C. To E)Entering a third-stage rich liquid heat exchanger 23 for heat exchange and temperature rise through external steam condensed water at 55 ℃, entering a second-stage spraying pipeline of the regeneration tower 20 after heat exchange (the temperature of rich liquid is 95-105 ℃), and realizing CO2Desorption from the absorbent.
e. Flash evaporation heat supply: a liquid supplementing pipeline of the flash tank 24 is communicated with a pipeline from the secondary rich liquid heat exchanger 21 to the regeneration tower 20, so that a liquid supplementing process of the flash tank 24 is realized; the rich liquid (the temperature is 80-90 ℃) in the flash tank 24 is pressurized by a flash circulating pump 25 and then sequentially enters an absorber A31 and an absorber B32 of the compound heat pump 28 for heat exchange and temperature rise, and returns to the flash tank 24 for a flash process after the temperature rises to 90-100 ℃; the flash steam discharged from the top of the flash tank 24 enters a third-stage spray pipeline of the regeneration tower 20 below the second-stage spray pipeline after being pressurized by a flash compressor 26 (the temperature is 105-115 ℃) to provide heat for the solution regeneration process in the regeneration tower 20.
f. And (3) cyclic regeneration of the absorption solvent: the desorbed barren solution (with the temperature of 100-105 ℃) is pressurized by a barren solution outlet at the bottom of the regeneration tower 20 through a barren solution pump 27 and then divided into two-stage processes, wherein one stage of the barren solution enters a condenser A35 and a condenser B36 of the compound heat pump 28 in sequence for heat exchange and temperature rise, and enters a secondary spraying pipeline of the regeneration tower 20 again after the temperature rises to 105-115 ℃; the other stage as a heat exchange working medium of the secondary rich liquid heat exchanger 21 enters the secondary rich liquid heat exchanger 21 for heat exchange and temperature reduction, the temperature is reduced to 55-65 ℃, then the working medium sequentially enters an evaporator A29 and an evaporator B30 of the compound heat pump 28 for heat exchange and temperature reduction, the working medium enters the lean liquid cooler 22 for temperature reduction to be below 40 ℃ after the temperature is reduced to 40-50 ℃, and finally the working medium enters a spray pipeline of the absorption tower 6 to start a new absorption process, so that the cyclic regeneration of the absorption solvent is realized.
g. Treating regenerated gas: the regenerated gas (the temperature is more than 100 ℃) sucked out by rich liquor decomposition enters a regenerated gas compressor 37 from the top outlet of the regeneration tower 20 for pressurization (the temperature is raised to about 120-160 ℃), then enters a regenerator condenser 38 for condensation and temperature reduction, and the condensation heat is transferred to the working medium of the heat pump; the cooled regeneration gas (the temperature is reduced to 80-90 ℃) enters a regeneration gas heat exchanger 42 for heat exchange and cooling through external circulating water, and the temperature is reduced to 60-70 ℃ and then enters an air cooler 43 for continuous coolingCooling to below 40 deg.C, gas-liquid separating in gas-liquid separator 44 to obtain CO2The gas is used as product gas to enter a subsequent flow, and the separated dilute solution enters the tower kettle of the regeneration tower 20 after being pressurized by the reflux pump 45, so that the water balance of the system is maintained. In order to further realize energy conservation and consumption reduction, the input end of the external circulating water of the regenerated gas heat exchanger 42 is connected with the condensed water output end of the shaft seal heater of the generator set, and the output end of the external circulating water of the regenerated gas heat exchanger 42 is connected with the condensed water input end of the shaft seal heater of the generator set.
h. A compression heat pump cycle: the compression type heat pump system comprises a solution boiler 40, a heat pump working medium heating coil is arranged in the solution boiler 40, a lean solution input end at the lower part of the solution boiler 40 is connected with the tower kettle of the regeneration tower 20, and a gasification output end at the upper part of the solution boiler 40 is connected with a gasification input end at the lower part of the tower kettle of the regeneration tower 20; the heat pump working medium can be 141b or 123a or 507a, etc., the heat pump working medium in the regenerator condenser 38 absorbs the condensation heat of the regeneration gas, then is completely vaporized and superheated, and then enters the heat pump working medium compressor 41 for heating and pressurizing, the heat pump working medium with high temperature and high pressure enters the heat pump working medium heating coil in the solution boiler 40 as a heat source to release the heat to the barren solution in the solution boiler 40, and the barren solution is gasified and then returns to the regeneration tower 20 through the gasification output end, the heat pump working medium is completely condensed into liquid, and then is cooled and depressurized through the throttle valve 39 to be returned to the regenerator condenser 38 for heating and next cycle. In order to realize better gasification effect and ensure that the heat pump working medium is completely condensed into liquid after flowing through the solution boiler 40 and further realize energy conservation and consumption reduction, a steam heating coil connected with an external steam source can be arranged inside the solution boiler 40, the output end of the steam heating coil is connected with the input end of external circulating water of the tertiary rich liquid heat exchanger 23, the external steam source can supply hot steam to realize better gasification effect, meanwhile, the hot steam in the steam heating coil is condensed into water after heat exchange, the condensed water can be used as a heat exchange warming working medium of the tertiary rich liquid heat exchanger 23, and the condensed water can be recycled after being further cooled by the tertiary rich liquid heat exchanger 23 and deoxidized by a condensate water deoxidizer.
To be discharged from a coal-fired power plantFlue gas of (2) to CO2The present invention will be described with reference to the capture purification as an example.
The parameters of the absorption tower and the regeneration tower are shown in Table 1, the flue gas composition is shown in Table 2, and CO is2Trap purification experiment operating parameters are shown in table 3. The absorption tower and the regeneration tower are both made of stainless steel materials and are filled with stainless steel corrugated structured packing, the absorption tower, the regeneration tower and the pipeline are all wrapped with heat insulation materials, the regeneration heat comes from an electric heater at the bottom of the regeneration tower 20, and the regeneration temperature of a voltage control system is adjusted by adopting silicon controlled rectifiers.
TABLE 1 absorption column and regeneration column parameters
TABLE 2 Smoke composition
TABLE 3CO2Trapping and purifying experiment operation parameters
Example 1:
the regenerative layered phase change nano absorbent of the phase change nano fluid absorption system comprises the following components in percentage by mass:
AEEA：TETA：N-ELDE：BDA：PZ：CuO：IBDSQAS：CD＝15％：9％：5％：3％：3％： 0.01％：0.05％：0.05％。
the specific performance parameters of the conventional process and the energy-saving process are shown in tables 4 (a) and 4 (b).
Table 4 (a) table of performance parameters for example 1 using conventional process
Table 4 (b) table of performance parameters for example 1 using energy saving process
Example 2:
the regenerative layered phase change nano absorbent of the phase change nano fluid absorption system comprises the following components in percentage by mass:
AEEA：TETA：N-ELDE：BDA：DEA：CuO：ICQAB：OTP＝20％：5％：1％：5％：5％： 0.05％：0.05％：0.05％。
the specific performance parameters of the conventional process and the energy-saving process are shown in tables 5 (a) and 5 (b).
TABLE 5 (a) TABLE of Performance parameters for example 2 using conventional process
TABLE 5 (b) TABLE of Performance parameters for example 2 with energy saving Process
Example 3:
the regenerative layered phase change nano absorbent of the phase change nano fluid absorption system comprises the following components in percentage by mass:
AEEA：TETA：N-ELDE：BDA：PZ：MgO：IBDSQAS：CD＝17％：7％：5％：1％：1％： 0.03％：0.035％：0.035％。
the specific performance parameters of the conventional process and the energy-saving process are shown in tables 6 (a) and 6 (b).
Table 6 (a) table of performance parameters for example 3 using conventional process
TABLE 6 (b) TABLE of Performance parameters for example 3 with energy saving Process
Example 4:
the regenerative layered phase change nano absorbent of the phase change nano fluid absorption system comprises the following components in percentage by mass:
AEEA：TETA：N-ELDE：BDA：DEA：MgO：ICQAB：OTP＝15％：9％：3％：2％：3％： 0.035％：0.035％：0.035％。
the specific performance parameters of the conventional process and the energy-saving process are shown in tables 7 (a) and 7 (b).
Table 7 (a) table of performance parameters for example 4 using conventional process
TABLE 7 (b) TABLE 4 TABLE of Performance parameters Using energy saving Process
Example 5:
the regenerative layered phase change nano absorbent of the phase change nano fluid absorption system comprises the following components in percentage by mass:
AEEA：TETA：N-ELDE：BDA：PZ：MgO：ICQAB：OTP＝17％：7％：4％：2％：3％： 0.03％：0.025％：0.025％。
the performance parameters of the energy-saving process are shown in table 8.
Table 8 table of performance parameters for example 5 using energy saving process
Example 6:
the regenerative layered phase change nano absorbent of the phase change nano fluid absorption system comprises the following components in percentage by mass:
AEEA：TETA：N-ELDE：BDA：PZ：MgO：IBDSQAS：OTP＝16％：6％：3％：2％： 3％：0.03％：0.035％：0.035％。
the performance parameters of the energy-saving process are shown in table 9.
Table 9 table of performance parameters of example 6 using energy saving process
Example 7:
the regenerative layered phase change nano absorbent of the phase change nano fluid absorption system comprises the following components in percentage by mass:
AEEA：TETA：N-ELDE：BDA：PZ：MgO：ICQAB：CD＝18％：5％：4％：2％：3％： 0.05％：0.04％：0.04％。
the performance parameters of the energy-saving process are shown in table 10.
Table 10 table of performance parameters for example 7 using energy saving process
Example 8:
the regenerative layered phase change nano absorbent of the phase change nano fluid absorption system comprises the following components in percentage by mass:
AEEA：TETA：N-ELDE：BDA：DEA：MgO：ICQAB：CD＝17％：7％：3％：2％：3％： 0.05％：0.04％：0.04％。
the performance parameters of the energy-saving process are shown in table 11.
Table 11 table of performance parameters for example 8 using energy saving process
Example 9:
the regenerative layered phase change nano absorbent of the phase change nano fluid absorption system comprises the following components in percentage by mass:
AEEA：TETA：N-ELDE：BDA：PZ：CuO：ICQAB：CD＝17％：6％：4％：1％：2％： 0.05％：0.04％：0.04％。
the performance parameters of the energy-saving process are shown in table 12.
Table 12 table of performance parameters for example 9 using energy saving process
Example 10:
the regenerative layered phase change nano absorbent of the phase change nano fluid absorption system comprises the following components in percentage by mass:
AEEA：TETA：N-ELDE：BDA：DEA：CuO：ICQAB：CD＝18％：5％：3％：2％：2％： 0.05％：0.04％：0.04％。
the performance parameters of the energy-saving process are shown in table 13.
TABLE 13 TABLE 10 TABLE of Performance parameters for example 10 with energy saving Process
The method is suitable for low partial pressure CO2The regenerative layered phase-change nano absorbent of the trapping and purifying absorption system can reduce the regeneration energy consumption and the regeneration temperature through phase change in the regeneration process, improve the regeneration rate, has the characteristics of large absorption load, high absorption and desorption rate and low regeneration energy consumption, and the self regeneration energy consumption of the absorbent is less than 2.7GJ/tCO2。
The flash evaporation heat of a graded flow system, an interstage cooling system, a composite heat pump system and an MVR (mechanical vapor recompression) is adoptedPump system + compression heat pump system coupling process applicable to low partial pressure CO2The energy-saving process of trapping and purifying partially replaces the traditional regeneration process of 'a desorption tower and a boiler', can effectively reduce the volume of the boiler, greatly reduce the regeneration energy consumption, reduce the medicament loss and the degradation and deterioration of the medicament, improve the recycling frequency of the chemical absorbent, save the investment cost, realize the purposes of resource recovery and environmental pollution reduction, and ensure that CO can be recycled2The regeneration energy consumption of the trapping system is lower than 2.3GJ/tCO2. The composite absorption heat pump and MVR flash evaporation heat pump system can effectively recover the waste heat of the barren solution and is used for heating the rich solution, and compared with the regeneration energy consumption of the traditional process, the regeneration energy consumption can be reduced by 0.2-0.3 GJ/tCO2(ii) a The 'regeneration tower top compression heat pump system' can effectively recycle the regeneration tower top gas, and can reduce the regeneration energy consumption by 0.25-0.35 GJ/tCO compared with the conventional process2(ii) a By adopting the tail gas washing process of 'a dry bed and a two-stage tail gas washing tower', the dry bed can directly lead the organic amine to return to an absorption circulation system, the organic amine in the tail gas washing tower is slowly accumulated, the frequent water regulation and control can be effectively avoided, the three control links are favorable for the growth of aerosol, large particles can be effectively removed, the solvent loss is reduced, the emission of tail gas pollutants is reduced, and the absorption entrainment loss amount is less than 0.6kg/tCO2Compared with the traditional first-stage water washing process (about 1.0 kg/tCO)2) The reduction can be more than 40%.
Claims (7)
1. Is suitable for low partial pressure CO2The energy-saving process for trapping and purifying is characterized in that a used trapping and purifying system assembly comprises a water washing tower (2), an absorption tower (6), a regeneration tower (20), a flash tank (24) and a combined heat pump (28), wherein an evaporator, an absorber, a generator and a condenser are arranged in the combined heat pump (28), the evaporator, the absorber, the generator and the condenser are respectively provided with an evaporator A (29) and an evaporator B (30) which are connected in series, an absorber A (31) and an absorber B (32) which are connected in series, a generator A (33) and a generator B (34) which are connected in series, and a condenser A (35) and a condenser B (36) which are connected in series;
suitable for low partial pressure CO2The energy-saving process for trapping and purifying specifically comprises the following stepsThe method comprises the following steps:
a. washing with water: flue gas enters a washing tower (2) through a pipeline, is discharged from the top of the washing tower (2) and enters a draught fan (5) after being subjected to desulfurization, denitrification, dedusting and heat exchange by washing liquid, and the gas temperature of the flue gas discharged from the top of the washing tower (2) is controlled to be 35-45 ℃;
b. decarbonization: the flue gas enters an absorption tower (6) from bottom to top after being pressurized by a draught fan (5), a barren liquor absorbent discharged by a barren liquor cooler (22) is sprayed from top to bottom to enter the absorption tower (6), the barren liquor absorbent and the absorption tower are in countercurrent contact for decarburization reaction, and the temperature of the barren liquor absorbent discharged by the barren liquor cooler (22) and entering the absorption tower (6) is controlled to be 35-45 ℃;
c. washing tail gas: the decarbonized gas passes through a dry bed section (9) at the top of an absorption tower (6) and is discharged through a tail gas discharge port at the top of the absorption tower (6) to enter a tail gas washing system, the tail gas washing system comprises two stages of tail gas washing towers, the two stages of tail gas washing towers comprise a tail gas washing tower A (10) and a tail gas washing tower B (14) which are sequentially connected in series, demisters are arranged on exhaust ports of the tail gas washing tower A (10) and the tail gas washing tower B (14), the tail gas washing tower A (10) and the tail gas washing tower B (14) are respectively provided with a tail gas washing liquid circulating device for circularly conveying tail gas washing liquid from bottom to top, the tail gas washing liquid circulating device of the tail gas washing tower A (10) comprises a tail gas washing liquid storage tank A (13), a tail gas washing liquid pump A (12) and a tail gas washing liquid cooler A (11), the tail gas washing liquid circulating device of the tail gas washing tower B (14) comprises a tail gas storage tank B (17), a tail gas washing liquid pump B (16) and a tail gas washing liquid cooler B (15), tail gas washing liquid recycling device of the tail gas washing liquid enters a tail liquid storage tank (18) after passing through a tail gas washing liquid tank (18), and an aerosol recovery tank, the tail gas washing liquid washing tank B washing tank (18) of the tail gas washing tower returns to the absorption tower;
d.CO2desorbing: absorb CO2The rich liquid of the gas is discharged from the bottom of the absorption tower (6), and is pressurized by a rich liquid pump (19) and then is conveyed in stages, wherein the first-stage rich liquid directly enters a first-stage spray pipeline at the top of the regeneration tower (20), the second-stage rich liquid enters a second-stage rich liquid heat exchanger (21) for heat exchange and temperature rise, the heat exchange and temperature rise temperature is controlled to be 95-105 ℃, and the second-stage rich liquid enters the regeneration tower (20) and is positioned below the first-stage spray pipeline after heat exchangeA stage spray pipeline; the third-stage rich liquid enters a third-stage rich liquid heat exchanger (23) for heat exchange and temperature rise through external circulating water, the temperature of the heat exchange and temperature rise is controlled to be 95-105 ℃, and the third-stage rich liquid enters a second-stage spraying pipeline of the regeneration tower (20) after heat exchange;
e. flash evaporation heat supply: a liquid supplementing pipeline of the flash tank (24) is communicated with a pipeline leading to the regeneration tower (20) from the secondary rich liquid heat exchanger (21); the rich liquid in the flash tank (24) enters an absorber of a composite heat pump (28) for heat exchange and temperature rise after being pressurized by a flash circulating pump (25), the temperature of the heat exchange and temperature rise is controlled to be 90-100 ℃, and the rich liquid returns to the flash tank (24) for flash evaporation after being heated; the flash steam discharged from the top of the flash tank (24) is pressurized by a flash compressor (26), the temperature is controlled to be 105-115 ℃ after pressurization, and the flash steam enters a third-stage spraying pipeline of the regeneration tower (20) below a second-stage spraying pipeline;
f. and (3) cyclic regeneration of the absorption solvent: the desorbed barren solution is pressurized by a barren solution pump (27) from a barren solution outlet at the bottom of the regeneration tower (20) and then divided into two-stage processes, wherein the first stage enters a condenser of a compound heat pump (28) for heat exchange and temperature rise, the temperature is controlled to be 105-115 ℃ after temperature rise, and the barren solution enters a secondary spray pipeline of the regeneration tower (20) again; the other stage of the heat exchange working medium as the heat exchange working medium of the secondary rich liquid heat exchanger (21) enters the secondary rich liquid heat exchanger (21) for heat exchange and cooling, the temperature is controlled to be 55-65 ℃ after heat exchange and cooling, then the heat exchange and cooling are continuously carried out in an evaporator of the composite heat pump (28), the temperature is controlled to be 40-50 ℃ after heat exchange and cooling, then the heat exchange and cooling are continuously carried out in a lean liquid cooler (22), and finally the heat exchange and cooling enters a spray pipeline of an absorption tower (6) to start a new absorption process;
g. treating regenerated gas: the regenerated gas sucked out by the rich liquor decomposition enters a regenerated gas compressor (37) from an outlet at the top of a regeneration tower (20) for pressurization, the temperature is controlled to be 120-160 ℃ after pressurization, and then the regenerated gas enters a regenerator condenser (38) for condensation and cooling to 80-90 ℃, and the condensation heat is transferred to a heat pump working medium; the cooled regeneration gas enters a regeneration gas heat exchanger (42) for heat exchange and cooling through external circulating water, the temperature is reduced to 60-70 ℃, the regeneration gas enters an air cooler (43) for continuous cooling to below 40 ℃, finally, the regeneration gas enters a gas-liquid separator (44) for gas-liquid separation, and the separated CO2The gas is used as product gas to enter the subsequent flow and is separatedThe discharged dilute solution enters a tower kettle of a regeneration tower (20) after being pressurized by a reflux pump (45);
h. a compression heat pump cycle: the compression type heat pump system comprises a solution boiler (40), a heat pump working medium heating coil is arranged in the solution boiler (40), a solution input end at the lower part of the solution boiler (40) is connected with a tower kettle of the regeneration tower (20), and a gasification output end at the upper part of the solution boiler (40) is connected with a gasification input end at the lower part of the tower kettle of the regeneration tower (20); the heat pump working medium in the regenerator condenser (38) absorbs the condensation heat of the regenerated gas, then is completely vaporized and superheated, then enters a heat pump working medium compressor (41) for heating and pressurizing, the high-temperature and high-pressure heat pump working medium enters a heat pump working medium heating coil in the solution boiler (40), the solution is vaporized and then returns to the regeneration tower (20) through the vaporization output end, and the heat pump working medium condensed into liquid is cooled and depressurized through a throttle valve (39) and then returns to the regenerator condenser (38) for heating and next cycle.
2. The method of claim 1 adapted for low partial pressure of CO2The energy-saving process for trapping and purifying is characterized in that in the h part, a steam heating coil connected with an external steam source is arranged inside a solution boiler (40), the output end of the steam heating coil is connected with the input end of circulating water outside a third-stage rich liquid heat exchanger (23), hot steam in the steam heating coil is condensed into water after heat exchange and is used as a heat exchange and temperature rise working medium of the third-stage rich liquid heat exchanger (23), and the condensed water is further cooled by the third-stage rich liquid heat exchanger (23) and then is deoxidized by a condensed water deoxidizer for recycling.
3. The method of claim 1 for low partial pressure CO2The energy-saving process for trapping and purifying is characterized in that in the part g, the input end of the external circulating water of the regenerated gas heat exchanger (42) is connected with the condensed water output end of the shaft seal heater of the generator set, and the output end of the external circulating water of the regenerated gas heat exchanger (42) is connected with the condensed water input end of the shaft seal heater of the generator set.
4. The method of claim 1 for low partial pressure CO2An energy-saving process for the capture purification, characterized in that bIn part, the amine reacts with CO during the decarburization reaction2The amino carbonate generated by the reaction enters an interstage cooler (7) for heat exchange through external circulating water to be cooled, and then enters the absorption tower (6) again after being pressurized by an interstage cooling pump (8).
5. The method of claim 4 adapted for low partial pressure of CO2The energy-saving process for trapping and purifying is characterized in that the temperature of the amino carbonate is controlled to be 35-45 ℃ after the amino carbonate enters an interstage cooler (7) for cooling.
6. The method of claim 1 for low partial pressure CO2The energy-saving process for trapping and purifying is characterized in that in the part a, a washing tower (2) is provided with a washing liquid circulating device for circularly conveying washing liquid from bottom to top, the washing liquid circulating device comprises a washing pump (1) and a washing liquid heat exchanger (4), the washing liquid enters the washing liquid heat exchanger (4) for heat exchange through external circulating water after being pressurized by the washing pump (1), and enters the washing tower (2) for spraying after heat exchange; the alkali supplementing quantity of the water washing liquid is controlled by a PH meter arranged on a circulating pipeline, the PH meter is interlocked with an alkali supplementing pump (3), the output end of the alkali supplementing pump (3) is communicated with the circulating pipeline, and the NaOH supplementing quantity is adjusted by adjusting the rotating speed of the alkali supplementing pump (3) according to the feedback of the PH meter.
7. The method of claim 1 for low partial pressure CO2The energy-saving process for trapping and purifying is characterized in that the input end of a composite heat pump (28) generator is connected with an external steam source, and the output end of the composite heat pump generator is connected with the input end of a condensed water deoxygenator.
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Citations (12)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101524621A (en) * | 2009-03-31 | 2009-09-09 | 西安热工研究院有限公司 | Flue gas decarbonization system of stepped absorption and regeneration |
| CN102671510A (en) * | 2011-11-29 | 2012-09-19 | 中国石油化工股份有限公司 | Recovery process of flue gas CO2 |
| CN103418210A (en) * | 2013-08-08 | 2013-12-04 | 中石化宁波工程有限公司 | CO2 full capture and H2S enrichment process |
| CN203671628U (en) * | 2014-01-10 | 2014-06-25 | 清华大学 | Spraying absorption type gas and smoke total heat recovery, desulfurization and denitrification device |
| CN204601956U (en) * | 2015-04-29 | 2015-09-02 | 古浪鑫辉化工有限公司 | Produce the system of food-grade carbon-dioxide |
| CN105194995A (en) * | 2014-06-19 | 2015-12-30 | 中石化洛阳工程有限公司 | Method for trapping carbon dioxide in FCC smoke |
| US20160263518A1 (en) * | 2013-11-27 | 2016-09-15 | Korea Institute Of Energy Research | Energy-saving system and method of capturing acidic gas by using separated water |
| CN106310881A (en) * | 2016-10-26 | 2017-01-11 | 成都华西堂环保科技有限公司 | Regenerable cyclic absorption flue gas desulfurization technology |
| CN109958485A (en) * | 2017-12-22 | 2019-07-02 | 华北电力大学 | A kind of NGCC decarburization integrated system based on second-kind absorption-type heat pump |
| CN209173703U (en) * | 2018-12-07 | 2019-07-30 | 山东祥桓环保工程有限公司 | A kind of flue gas cool-down condensation receipts water reheat system |
| CN111500331A (en) * | 2020-04-27 | 2020-08-07 | 中海石油气电集团有限责任公司 | Natural gas decarburization experimental device with semi-barren solution logistics |
| CN113528206A (en) * | 2020-04-13 | 2021-10-22 | 中国石油天然气股份有限公司 | Desulfurization system and method |
-
2021
- 2021-12-28 CN CN202111628987.8A patent/CN114405246B/en active Active
Patent Citations (12)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101524621A (en) * | 2009-03-31 | 2009-09-09 | 西安热工研究院有限公司 | Flue gas decarbonization system of stepped absorption and regeneration |
| CN102671510A (en) * | 2011-11-29 | 2012-09-19 | 中国石油化工股份有限公司 | Recovery process of flue gas CO2 |
| CN103418210A (en) * | 2013-08-08 | 2013-12-04 | 中石化宁波工程有限公司 | CO2 full capture and H2S enrichment process |
| US20160263518A1 (en) * | 2013-11-27 | 2016-09-15 | Korea Institute Of Energy Research | Energy-saving system and method of capturing acidic gas by using separated water |
| CN203671628U (en) * | 2014-01-10 | 2014-06-25 | 清华大学 | Spraying absorption type gas and smoke total heat recovery, desulfurization and denitrification device |
| CN105194995A (en) * | 2014-06-19 | 2015-12-30 | 中石化洛阳工程有限公司 | Method for trapping carbon dioxide in FCC smoke |
| CN204601956U (en) * | 2015-04-29 | 2015-09-02 | 古浪鑫辉化工有限公司 | Produce the system of food-grade carbon-dioxide |
| CN106310881A (en) * | 2016-10-26 | 2017-01-11 | 成都华西堂环保科技有限公司 | Regenerable cyclic absorption flue gas desulfurization technology |
| CN109958485A (en) * | 2017-12-22 | 2019-07-02 | 华北电力大学 | A kind of NGCC decarburization integrated system based on second-kind absorption-type heat pump |
| CN209173703U (en) * | 2018-12-07 | 2019-07-30 | 山东祥桓环保工程有限公司 | A kind of flue gas cool-down condensation receipts water reheat system |
| CN113528206A (en) * | 2020-04-13 | 2021-10-22 | 中国石油天然气股份有限公司 | Desulfurization system and method |
| CN111500331A (en) * | 2020-04-27 | 2020-08-07 | 中海石油气电集团有限责任公司 | Natural gas decarburization experimental device with semi-barren solution logistics |
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