Indoor evaluation method and evaluation device for amine-method carbon capture

Abstract

The invention discloses an indoor evaluation method and evaluation device for amine-method carbon capture, and the method comprises the following steps: measuring the content data of mixed gas of a to-be-measured mixed gas source before absorption treatment, and the content data contains carbon dioxide gas; absorbing the carbon dioxide gas by the barren solution to obtain a rich solution; a part of the rich solution is conveyed to a regeneration tower for desorption, a part of the rich solution is subjected to vacuum flash evaporation and phase separation, a phase-separated rich solution is conveyed to the regeneration tower, and a phase-separated barren solution and a desorbed barren solution are conveyed to a barren solution storage tank; the barren liquor in the barren liquor storage tank is conveyed to an absorber to absorb carbon dioxide in the mixed gas, and content data of the mixed gas after absorption treatment is measured to obtain the absorption rate; the average solubility of the loaded barren liquor is measured in a gas phase circulation mode after measurement, the barren liquor obtained after measurement is refluxed and reused, and mixed gas is purified and separated after measurement. The method can be used for research, development and evaluation of the chemical absorption solvent with low energy consumption and low trapping cost. Evaluation is comprehensive, structure is simple, and detection is accurate and reliable.

Description

Technical Field

[0001] The invention relates to the technical field of carbon capture, and in particular to an indoor evaluation method and an evaluation device for amine-based carbon capture. Background Art

[0002] In recent years, carbon dioxide in the atmosphere has attracted more and more attention as a cause of global warming. Therefore, as a large-scale source of carbon dioxide emissions, efficient separation and recovery of carbon dioxide in waste gas from thermal power plants, steel mills, cement plants, etc. is an important means of reducing carbon dioxide emissions. Under the pressure of my country's environmental protection requirements, the economic feasibility of carbon capture technology has received more and more attention. At present, the flue gas of domestic natural gas purification plants is directly discharged after tail gas desulfurization without carbon capture. Carbon emission reduction work in natural gas purification plants is imperative, and the construction of tail gas carbon capture equipment is a top priority.

[0003] Carbon capture is an important industrial process, which is widely used in the purification of synthetic ammonia, natural gas and flue gas. Traditional carbon capture methods are mainly physical absorption, chemical absorption, adsorption, freezing, etc. At present, the carbon capture method in the existing technology is mainly based on chemical absorption, using the alcohol amine method. Whether it is the construction of the device or the use of new high-efficiency carbon capture solvents, the main goal should be to reduce production costs and improve the return on investment.

[0004] The patent publication number is "CN211284280U" and the name is "An amine decarbonization system", which includes an absorption part, a regeneration tower and a heat exchanger. The absorption part is provided with a gas phase inlet, a gas phase outlet, a rich liquid outlet and a lean liquid inlet. The regeneration tower includes a regeneration tower body and a boiler. The regeneration tower body is provided with a gas phase outlet, a rich liquid inlet and a lean liquid outlet. The gas phase outlet of the regeneration tower body is provided with a demister, and the boiler is provided with a condensate outlet. The rich liquid outlet of the absorption part is connected to the rich liquid inlet of the regeneration tower body through a heat exchanger, and the lean liquid outlet of the regeneration tower body is connected to the lean liquid inlet of the absorption part through a heat exchanger.

[0005] Another example is Li Xiaofei's "Process Improvement and Optimization Simulation of Amine Decarbonization System". The use of monoethanolamine (MEA) for flue gas decarbonization in coal-fired power plants is a relatively mature and feasible technology, but it has a serious defect of high regeneration energy consumption. Process improvement and optimization of amine decarbonization system can effectively reduce regeneration energy consumption. Aspen Plus software was used to simulate the traditional amine decarbonization process and its improved process based on the rate model. These improved processes include the absorption section intermediate cooling process, rich liquid diversion process, lean liquid vapor recompression process, diversion process and rich liquid diversion and lean liquid vapor recompression integration process.

[0006] However, in all the above technologies, the high regeneration energy consumption in the above technologies leads to high costs and new carbon emissions. The regeneration energy consumption is related to the chemical solvents and processes used. How to evaluate the performance of chemical solvents and processes is the premise for building low-energy carbon capture technology. However, there is currently no device or method for reliable performance evaluation of amine carbon capture, and it is impossible to evaluate and confirm the process quality during the carbon capture process. Summary of the invention

[0007] In order to solve the above problems, the purpose of the present invention is to provide an amine carbon capture indoor evaluation method and evaluation device, which can perform absorption rate, gas-liquid equilibrium measurement and decarbonization agent process evaluation, with comprehensive evaluation and accurate and reliable detection.

[0008] The first object of the present invention is to provide an indoor evaluation method for amine-based carbon capture, comprising the following steps:

[0009] (1) measuring the content data of the mixed gas of a gas source to be tested before absorption treatment, wherein the mixed gas source to be tested contains carbon dioxide gas;

[0010] (2) The lean liquid absorbs the carbon dioxide gas in the mixed gas source to be tested to obtain the rich liquid;

[0011] (3) transporting part of the rich liquid in step (2) to a regeneration tower to desorb and remove carbon dioxide, vacuum flashing part of the rich liquid to separate the rich and poor liquids, transporting the rich liquid obtained by phase separation to a regeneration tower to desorb and remove carbon dioxide, and transporting the lean liquid obtained by phase separation and the lean liquid obtained after desorption and separation to a lean liquid storage tank;

[0012] (4) transporting the lean liquid in the lean liquid storage tank to the absorber to absorb the carbon dioxide in the mixed gas source to be tested, and measuring the content data of the mixed gas after the absorption treatment to obtain the absorption rate of carbon dioxide in the lean liquid;

[0013] (5) preheating the loaded lean solution obtained after the measurement in step (4) to a certain temperature, and measuring the average solubility of carbon dioxide in the lean solution at different temperatures by gas phase circulation;

[0014] (6) The liquid in the absorber is refluxed for reuse, and the mixed gas after measurement is purified and separated.

[0015] In an optional embodiment, the process further includes preheating the rich liquid obtained by phase separation in step (3) and part of the rich liquid in step (2) and then transporting them to a regeneration tower for desorption and separation of carbon dioxide.

[0016] In an optional embodiment, the reflux lean liquid obtained in step (6) absorbs carbon dioxide to obtain rich liquid, and the rich liquid is inter-stage cooled and refluxed to repeat steps (3) to (6).

[0017] In an optional embodiment, the lean liquid flowing out of the regeneration tower is cooled and then enters the lean liquid storage tank;

[0018] The gas and liquid flowing out of the regeneration tower are subjected to acid gas separation.

[0019] In an optional embodiment, the source of the mixed gas to be tested is a mixed gas that has been preheated and saturated with water.

[0020] The second object of the present invention is to provide an indoor evaluation device for amine carbon capture, comprising:

[0021] The gas distribution system is equipped with different gas storage tanks and distributes the mixed gas source to be tested in proportion;

[0022] A first flue gas analyzer, connected to the gas distribution system, for measuring the content data of the mixed gas before absorption treatment;

[0023] The second absorption part is connected to the gas distribution system and is equipped with fillers, and is used for the lean liquid to absorb the carbon dioxide gas in the mixed gas source to obtain the rich liquid;

[0024] Flash tank phase separation tank, used for vacuum flashing the rich liquid and performing phase separation of the lean and rich liquid to obtain lean liquid and rich liquid;

[0025] A regeneration tower is used for desorption and separation of carbon dioxide from the rich liquid, and the outlet of the second absorption section and the flash tank phase separation tank are both connected to the inlet of the regeneration tower;

[0026] A lean liquid storage tank is used to cool the incoming lean liquid to a certain temperature, and the outlets of the flash tank, the phase separation tank and the regeneration tower are all connected to the lean liquid storage tank;

[0027] An absorber, used to receive the lean liquid in the lean liquid storage tank to absorb the carbon dioxide in the mixed gas, and the absorber is equipped with a heating system to serve as a lean liquid preheating tank;

[0028] The first absorption part is provided with fillers for absorbing the measured lean liquid flowing out of the absorber for reflux utilization;

[0029] A purified gas separator is used to purify and separate the mixed gas after measurement;

[0030] A second flue gas analyzer, connected to the absorber and the purified gas separator, for measuring the content data in the gas after absorption and purification;

[0031] The sampling pump is connected between the absorber and the second flue gas analyzer and is used to circulate the gas phase between the absorber and the second flue gas analyzer until gas-liquid equilibrium is reached, so as to determine the average solubility.

[0032] In an optional embodiment, a rich liquid preheating tank is further provided between the second absorption section, the flash tank phase separation tank and the regeneration tower for heating the rich liquid flowing in from the second absorption section and the flash tank phase separation tank to form hot rich liquid.

[0033] In an optional embodiment, the outlet of the first absorption section is connected to the inlet of the second absorption section, and an interstage cooling device is provided between the connecting pipes of the first absorption section and the second absorption section, for interstage cooling of the rich liquid formed after the reflux lean liquid absorbs carbon dioxide and refluxes it to the second absorption section.

[0034] In an optional embodiment, a lean liquid cooling tank is provided between the regeneration tower and the lean liquid storage tank, and a lean liquid pump is further provided between the lean liquid storage tank and the absorber;

[0035] The outlet of the regeneration tower is connected to an acid gas separator for separating the acid gas flowing out of the regeneration tower.

[0036] In an optional embodiment, the gas distribution system is also connected to the absorber to deliver the mixed gas source to be tested to the absorber, so as to perform gas metering and analysis data collection before and after the mixed gas source enters the absorber to obtain the absorption rate.

[0037] In an optional embodiment, the gas distribution system is equipped with a gas mixing preheating tank and a water saturation tank. The water saturation tank is located at the rear end of the gas mixing preheating tank and is used to mix and preheat the gas flowing out of the gas storage tank and form a saturated state with water vapor to form a mixed gas source to be tested.

[0038] In an optional embodiment, the flash tank phase separation tank adopts a rotary separation design and is connected to a vacuum pump;

[0039] The rich liquid preheating tank is equipped with an impeller stirring paddle, on which a test piece hook is arranged for evaluating the corrosion rate of different materials at different temperatures and flow rates.

[0040] Compared with the prior art, the present invention has the following advantages and beneficial effects:

[0041] The present invention provides an amine carbon capture indoor evaluation device and method, which can be used for the development and evaluation of chemical absorption solvents with low energy consumption and low capture cost. The absorption rate, average solubility and decarbonizing agent process evaluation can be performed, and the evaluation is comprehensive, the structure is simple, and the detection is accurate and reliable. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] In order to more clearly illustrate the technical solutions of the exemplary embodiments of the present invention, the following briefly introduces the drawings required for use in the embodiments. It should be understood that the following drawings only illustrate certain embodiments of the present invention and should not be regarded as limiting the scope. For those of ordinary skill in the art, other relevant drawings can be obtained based on these drawings without creative work. In the drawings:

[0043] Figure 1 A schematic structural diagram of an indoor evaluation device for amine-based carbon capture provided by an embodiment of the present invention.

[0044] Figure 2 Schematic diagram of the absorption rate and average solubility when the absorber is used alone. DETAILED DESCRIPTION

[0045] In order to make the objectives, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with embodiments and drawings. The exemplary embodiments of the present invention and their description are only used to explain the present invention and are not intended to limit the present invention.

[0046] In order to make the purpose, technical solution and advantages of the embodiments of the present application clearer, the technical solution in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, rather than all the embodiments. The components of the embodiments of the present application described and shown in the drawings here can be arranged and designed in various different configurations.

[0047] It should be noted that similar reference numerals and letters represent similar items in the following drawings, so once an item is defined in one drawing, it does not need to be further defined and explained in subsequent drawings. In the absence of conflict, the embodiments and features in the embodiments of this application can be combined with each other.

[0048] In the description of the embodiments of the present application, the terms "center", "up", "down", "left", "right", "vertical", "longitudinal", "lateral", "horizontal", "inside", "outside", "front", "back", "top", "bottom", etc. indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, or are the orientations or positional relationships in which the products of the application are conventionally placed when in use, or are the orientations or positional relationships conventionally understood by those skilled in the art. They are merely for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present application.

[0049] In the description of the present invention, unless otherwise clearly specified and limited, the terms "disposed", "opened", "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0050] like Figure 1 As shown in , an indoor evaluation device for amine-based carbon capture comprises:

[0051] The gas distribution system is equipped with different gas storage tanks, such as carbon dioxide, H2S, O2, N2, SO2 and water, and also equipped with delivery pipelines. Each pipeline has a valve. Different gases are delivered and mixed in a certain amount according to needs to form mixed gases with different volume ratios, which can simulate various flue gas or exhaust gas compositions. The gas distribution system is also equipped with a gas mixing preheating tank and a water saturation tank. The mixed gas is mixed and heated to a suitable temperature in the gas mixing preheating tank, and then the gas flows out into the water saturation tank, and the water vapor forms a saturated state, forming a gas source for the mixed gas to be tested.

[0052] The first flue gas analyzer is connected to the gas distribution system and is located at the rear end of the water storage tank of the gas distribution system, and can measure the content data of each gas in the mixed gas before absorption treatment.

[0053] The second absorbing part (i.e. Figure 1 The absorption part II) is equipped with the required filler and connected to the rear end of the water storage tank. When the mixed gas enters the second absorption part, the lean liquid absorbs the carbon dioxide gas in the mixed gas source to be tested to obtain the rich liquid.

[0054] The flash tank phase separation tank is located at the rear end of the second absorption section, and is used to perform vacuum flash evaporation on the rich liquid to facilitate the flash release of the carbon dioxide gas dissolved in the rich liquid. At the same time, the flash tank phase separation tank also performs phase separation between the lean and rich liquid to obtain lean liquid and rich liquid after phase separation; the flash tank phase separation tank is also connected with a vacuum pump. The flash tank phase separation tank adopts a rotary separation design, and is equipped with a rotating packed bed. The centrifugal force generated by high-speed rotation is used to accelerate the phase separation of the rich liquid and create a certain vacuum degree (with a vacuum pump) to facilitate the rapid flash release of the CO2 gas dissolved in the rich liquid, so as to improve the flash phase separation efficiency. The flash tank phase separation tank can also serve to examine the phase change solvent.

[0055] The regeneration tower is located at the rear end of the second absorption section and the flash tank phase separation tank. The outlet of the second absorption section and the flash tank phase separation tank are connected to the inlet of the regeneration tower. The regeneration tower is used to desorb and separate carbon dioxide from the rich liquid. The rich liquid in the second absorption section can directly enter the regeneration tower for regeneration. It can also be that part of the rich liquid in the second absorption section enters the regeneration tower for regeneration, and the other part of the rich liquid enters the flash tank phase separation tank for flash evaporation and phase separation before entering the regeneration tower. Or the rich liquid in the second absorption section enters the flash tank phase separation tank before entering the regeneration tower. The cold rich liquid directly reaches the top of the regeneration tower, and the latent heat of the rising water vapor in the regeneration tower is used to regenerate the cold rich liquid, optimizing energy utilization.

[0056] The lean liquid storage tank is used to cool the incoming lean liquid to a certain temperature. The outlets of the flash tank, the phase separation tank and the bottom of the regeneration tower are all connected to the lean liquid storage tank. A circulating pump is also provided between the flash tank, the phase separation tank and the lean liquid storage tank.

[0057] The absorber is equipped with a lean liquid pump to dispense a certain volume (2 / 3 of the absorber volume) of lean liquid to be tested (i.e., amine liquid, used as a decarbonization absorbent) from a lean liquid storage tank, and the absorber is connected to the gas distribution system.

[0058] The absorber can be used alone to measure the absorption rate and average solubility while being disconnected from the first absorption section, or it can be connected to the first absorption section to reflux the lean solution after the measurement.

[0059] When the absorber is used alone, the flue gas of any composition is obtained by the gas distribution device, and after passing through the gas mixing preheating tank and the water saturation tank, it enters Figure 2 In the gas distribution pipe, the lean liquid to be tested in the absorber absorbs carbon dioxide from the mixed gas in the gas distribution system. The gas flowing out of the absorber outlet is connected to the gas online analyzer (i.e. the second flue gas analyzer) to collect data. When the gas composition no longer changes, the absorption is considered to have reached equilibrium, so as to determine the absorption rate.

[0060] A heating system (such as an electric heating insulation layer) is arranged on the outside of the absorber. When the absorber is not used alone, it is connected to the first absorption part and used as a lean liquid preheating tank. Under the action of the lean liquid pump, the amine liquid from the lean liquid storage tank fills the lean liquid preheating tank body and then enters the feed end of the first absorption part.

[0061] The first absorbing part (i.e. Figure 1 The absorption section I) in the first absorption section is equipped with the required fillers. The lean liquid flowing in from the feed end of the absorber absorbs the CO2 gas from the bottom through the filler section to form a rich liquid at the bottom, which is then cooled. The rich liquid outlet of the first absorption section is connected to the lean liquid inlet of the second absorption section, and flows into the second absorption section to reabsorb the CO2 in the gas using the rich liquid.

[0062] Also includes:

[0063] The purified gas separator is used to purify and separate the mixed gas in the first absorption section.

[0064] The second flue gas analyzer is connected to the absorber and the purified gas separator, and is used to measure the content data of the gas after absorption and purification, and to measure the average solubility and / or absorption rate in combination with the content data of the mixed gas source to be tested before absorption treatment measured by the first flue gas analyzer, so as to obtain the average solubility of carbon dioxide in the decarbonization absorbent and / or the absorption rate of carbon dioxide in the decarbonization absorbent.

[0065] The sampling pump is connected between the outlet of the absorber and the online analyzer (i.e., the second flue gas analyzer), such as Figure 2 As shown in . An amine solution with a certain load is obtained in the absorber from the absorption rate experiment. The absorber is used alone. At this time, the absorber is disconnected from the first absorption part, and the heating system of the absorber heats the loaded amine solution to maintain a certain temperature. Close valve 1, open valve 2, start the sampling pump, and draw the gas in the gas phase space in the absorber into the online analyzer to collect data. The gas outlet of the online analyzer returns to the absorber, and the gas phase circulates in this way. When the measured value of the online analyzer no longer changes, it is regarded as reaching a gas-liquid equilibrium state at a certain temperature. Open valve 7 to release the liquid, and obtain the liquid phase load value of the sample through chemical analysis. The gas phase partial pressure of CO2 at different temperatures is calculated based on the data obtained by the analyzer, that is, the average solubility. Through this embodiment, a reliable performance evaluation of amine-based carbon capture can be achieved to obtain the process quality during the carbon capture process.

[0066] Furthermore, a rich liquid preheating tank is provided between the second absorption section, the flash tank phase separation tank and the regeneration tower, which is used to heat the rich liquid flowing in from the second absorption section and the flash tank phase separation tank to form hot rich liquid. A No. 1 pump is also provided on the connecting pipeline between the rich liquid preheating tank and the second absorption section and the flash tank phase separation tank. A part of the rich liquid flowing out of the second absorption section and the flash tank phase separation tank enters the regeneration tower as cold rich liquid, and another part of the rich liquid is preheated to form hot rich liquid and enters the regeneration tower, thus forming a rich liquid diversion. A part of the cold rich liquid directly enters the upper part of the regeneration tower from the bottom of the absorption tower or the flash tank phase separation tank, and the latent heat of the rising water vapor in the regeneration tower is used to regenerate the cold rich liquid, thereby optimizing energy utilization. The amount of hot rich liquid after diversion is reduced, so the required regeneration energy is also reduced accordingly, and energy consumption is reduced.

[0067] Furthermore, the outlet of the first absorption part is connected to the inlet of the second absorption part, and an interstage cooling device is provided between the connecting pipes of the first absorption part and the second absorption part for interstage cooling of the rich liquid formed by the reflux lean liquid and reflux to the second absorption part.

[0068] By setting up the first absorption tower and the second absorption tower, the process of rich liquid interstage cooling and rich liquid reflux can be realized. The conventional process is to set up one absorption tower, and the rich liquid at the bottom of the absorption tower enters the upper part of the regeneration tower after flash evaporation and heat exchange. However, the present invention sets up interstage cooling, and the rich liquid still has a certain absorption capacity after cooling. The advantage of this is that the flow rate of rich liquid to the regeneration tower is significantly reduced, which is bound to reduce the regeneration energy consumption of the amine liquid.

[0069] In addition, the first absorption tower and the second absorption tower can be connected in series and the packing sections of the two towers can be used. The packing height of the absorption tower can be adjusted arbitrarily, so as to investigate the effects of different packing heights and the mass transfer effects of different packings and meet the purification needs of different flue gas decarbonization.

[0070] Furthermore, a lean liquid cooling tank is provided between the regeneration tower and the lean liquid storage tank, and the lean liquid flowing out of the regeneration tower enters the lean liquid storage tank after being cooled.

[0071] The outlet of the regeneration tower is connected to an acid gas separator, and the separated carbon dioxide enters the acid gas separator. In the acid gas separator, gravity gas-liquid separation is used to avoid corrosion of the pipeline and maintain the water balance of the solution.

[0072] By setting up an acid gas separator, a purification separator and an absorber, it is also possible to monitor gas carryover loss and regeneration evaporation loss. The acid gas separator, the purification separator and the absorber are respectively built with easily disassembled thin film adsorbents (known technology), and the amine liquid loss is calculated by weight change, providing a basis for industrial application agent consumption.

[0073] The present invention integrates absorption rate, gas-liquid equilibrium determination and decarburizing agent process evaluation. The device can be used to perform comprehensive analysis, which is not available in current devices.

[0074] Furthermore, an impeller stirring paddle is placed inside the rich liquid preheating tank, and a test piece hook is provided on the impeller stirring paddle. Test pieces of different materials can be hung on the test piece hook. The corrosion rates of different materials at different temperatures and flow rates can be evaluated by stirring with the impeller stirring paddle and heating with the rich liquid preheating tank. At the same time, the deterioration rates of different amine solutions can be investigated.

[0075] The evaluation method is described below in conjunction with the above-mentioned device.

[0076] It is configured according to the flue gas composition after the combustion of fossil fuels, generally CO2 4-15%, the rest is nitrogen, a small amount of H2S or SO2 less than 100mg / m3 of the mixed gas source, and heated by a gas mixed preheating tank. The mixed gas source to be tested enters the water saturation tank to ensure that the mixed gas source to be tested fully simulates the content in the actual gas, and the first flue gas analyzer is used to measure the inlet and outlet of the mixed gas source to obtain the content of carbon dioxide, hydrogen sulfide, oxygen, sulfur dioxide, nitrogen, and water before absorption treatment; this data is used as a comparison of the post-processing data for the comparison of the measurement data of the equilibrium solubility and absorption rate.

[0077] When the gas source of the mixed gas to be tested can enter the first absorption part or / and the lower part of the second absorption part (the first absorption part and the second absorption part can be used separately or in series), the lean liquid absorbs carbon dioxide to become a rich liquid. Then, the rich liquid and the lean liquid are separated into rich and lean liquid phases using a flash tank and a phase separation tank; the lean liquid obtained by phase separation enters the lean liquid storage tank. The rich liquid enters the regeneration tower through the No. 1 pump and the rich liquid preheating tank, where cold rich liquid and hot rich liquid are obtained in the regeneration tower. The carbon capture solvent (amine liquid) is used in the regeneration tower, and the rich liquid desorbs carbon dioxide at high temperature to become a lean liquid. The reaction process is a low-temperature gas-liquid absorption reaction and a high-temperature gas-liquid desorption reaction, that is, the reaction of amine and carbon dioxide. The separated carbon dioxide enters the acid gas separator. In the acid gas separator, gravity gas-liquid separation is used.

[0078] In addition, the lean liquid in the regeneration tower flows into the lean liquid storage tank after cooling, and the lean liquid is transported to the absorber through the lean liquid pump to obtain the absorption rate and equilibrium solubility data. When measuring the absorption rate and average solubility, the absorber is used alone and is not connected to the first absorption part.

[0079] Specific measurement process combined Figure 2 To explain:

[0080] Absorption rate determination:

[0081] 1. Open valve 6 and use the lean liquid pump to send the amine solution to be tested in the lean liquid storage tank into the absorber, occupying 1 / 3 to 2 / 3 of the tank volume, and set the preheating temperature.

[0082] 2. After preheating is completed and reaches the set temperature, open valves 4 and 5, and N2 and CO2 are measured by the flow meter at 500-1000 ml / min and mixed into the gas distribution pipe of the absorber to evenly diffuse the gas in the liquid for absorption. At the same time, open valve 1 and close valve 2. After absorption, the mixed gas leaves the top of the absorber and enters the online analyzer to collect data.

[0083] 3. When the measured value of the analyzer no longer changes, it is considered that the absorption has reached the saturation state. The absorption rate of the test sample is calculated by the calculation formula based on the acquired data.

[0084] Absorption rate calculation formula:

[0085]

[0086] Where: V, absorption liquid volume, unit L

[0087] Inlet CO2 flow rate, unit mol / s

[0088] n N2 , nitrogen flow rate, unit mol / s

[0089] The volume fraction or mole fraction of CO2 in the outlet gas, unit: %.

[0090] Equilibrium solubility determination:

[0091] 1. Obtain the absorption liquid with a certain load from the above absorption rate experiment, close valve 1, valve 2, and valve 5. Set the preheating temperature for heating.

[0092] 2. After preheating is completed and reaches the set temperature, open valve 2, close valve 1, start the sampling pump, and draw the gas in the gas phase space in the absorber into the online analyzer to collect data. The gas outlet of the online analyzer returns to the gas phase in the absorber, and the cycle continues.

[0093] 3. When the measured value of the analyzer no longer changes, it is considered that the gas-liquid equilibrium state is reached at a certain temperature. The liquid is released and analyzed to obtain the liquid phase load value of the sample. The gas phase partial pressure of CO2 at different temperatures is calculated based on the data obtained by the analyzer.

[0094] After the measurement, the absorber is connected to the first absorption part, and the first absorption part is used to reflux the measured lean liquid for reuse. The flue gas or tail gas or liquid (chemical absorption liquid) is also delivered to the first absorption part or the second absorption part. The first absorption part can be used alone or in series with the second absorption part. When used in series, an interstage cooling process can be implemented (the liquid at the bottom of the first absorption part is cooled and then enters the liquid inlet at the top of the second absorption part) to reflux the rich liquid.

[0095] In addition, in one embodiment of the present invention, an automatic amine solvent replenishing device can be added to automatically meter and replenish solvent or water into the system according to the changes in gas composition and purification requirements to ensure long-term stable operation of the device.

[0096] The evaluation device and evaluation method provided by the present invention have the following advantages:

[0097] (1) The present invention can evaluate the absorption rate, average solubility and decarbonizing agent process, and has the advantages of simple structure, accurate and reliable detection, and emission compliance with standards.

[0098] (2) The present invention can realize the process of rich liquid inter-stage cooling and rich liquid reflux by setting the first absorption section and the second absorption section. The rich liquid still has a certain absorption capacity after cooling. The advantage of rich liquid reflux is that the rich liquid flow rate to the regeneration tower is significantly reduced, which is bound to reduce the regeneration energy consumption of the amine liquid.

[0099] (3) The present invention can examine the phase change solvent by setting up a flash tank and a phase separation tank, which is an essential equipment for phase separation. The rotating packed bed design uses the centrifugal force generated by high-speed rotation to accelerate the phase separation of the rich liquid and create a certain vacuum degree, so as to facilitate the rapid flash release of the CO2 gas dissolved in the rich liquid.

[0100] (4) The present invention is provided with an acid gas separator and a purification separator, which are used to separate gas and liquid, avoid corrosion of pipelines and maintain the water balance of the solution. At the same time, an absorber is provided, which is a gas-liquid mass transfer device for separating CO2 in the gas into the absorption liquid. By the combined use of the acid gas separator, the purification separator and the absorber, the gas carryover loss and the regeneration evaporation loss can be monitored to provide a basis for the industrial application agent consumption.

[0101] (5) The present invention is provided with a rich liquid preheater to realize the rich liquid diversion, from the cold rich liquid directly to the top of the regeneration tower without preheating, and the cold rich liquid is regenerated by using the latent heat of the water vapor rising in the regeneration tower, thereby optimizing energy utilization. The amount of hot rich liquid after diversion is reduced, and the required regeneration energy is also reduced accordingly. The steam potential is fully utilized and energy consumption is reduced.

[0102] (6) The rich liquid in the second absorption part of the present invention enters the rich liquid preheating tank and then enters the regeneration tower. The rich liquid preheating tank has a corrosion monitoring function, which can evaluate the corrosion rate of different materials at different temperatures and flow rates, and can also investigate the deterioration rate of different amine solutions.

[0103] (7) The present invention can add an automatic amine solvent replenishing device to automatically meter and replenish solvent or water into the system according to the changes in gas composition and purification requirements to ensure the long-term stable operation of the device.

[0104] (8) The present invention provides a flue gas analyzer, which is connected to the gas source of the mixed gas to be tested and the absorber, and detects the gas before and after absorption, so as to obtain reliable average solubility / reaction rate data.

[0105] (9) The present invention has a gas distribution function, which can simulate various flue gas or exhaust gas compositions; it has multiple process flows such as interstage cooling, rich liquid diversion, phase change separation, etc., which can examine and evaluate many solvent systems; it can conduct a single gas-liquid absorption test or a degradation corrosion test, which consumes a small amount of solvent and improves the test efficiency; it also has an energy consumption evaluation function, which can analyze and calculate the regeneration energy consumption of the solvent.

[0106] In terms of energy saving, the energy consumption of the energy-saving process using the method and device of the patented invention is compared as shown in Table 1:

[0107] Table 1: Energy consumption of energy-saving processes

[0108]

[0109] When conducting energy-saving process energy consumption tests:

[0110] Gas flow rate: 300L / h, lean liquid flow rate is 1L / h;

[0111] Gas composition: CO2 15% + N2 85% (volume or molar fraction);

[0112] The test solution is: 20%wt methyldiethanolamine + 15%wt hydroxyethylethylenediamine + 5%wt piperazine (conventional decarbonizing agent);

[0113] 20%wt sulfolane+20%wt hydroxyethylethylenediamine+5%wt piperazine (phase change absorbent);

[0114] When using phase absorption + regeneration, the data are all related to phase change absorbent;

[0115] The above table only considers the energy consumption during solvent regeneration, and the present invention does not take into account the pump power consumption and water consumption.

[0116] The present invention can select energy-saving processes by combining different process means, such as the various combination methods listed in Table 1.

[0117] In Table 1:

[0118] Interstage cooling + rich liquid absorption: The first absorption section and the second absorption section are used in series, and the interstage cooling and rich liquid reflux absorption are performed and then directly enter the regeneration tower.

[0119] Phase separation absorption + regeneration: The rich liquid is separated by phase in the flash tank and the phase separation tank, and then enters the rich liquid preheating tank and then enters the regeneration tower.

[0120] Rich liquid diversion: The rich liquid in the second absorption section enters the regeneration tower after rich liquid diversion.

[0121] Interstage cooling + rich liquid absorption + rich liquid diversion: The first absorption section and the second absorption section are used in series to perform interstage cooling and rich liquid reflux absorption, and then the rich liquid is diverted and enters the regeneration tower.

[0122] Phase separation absorption + rich liquid diversion + regeneration: After the rich liquid is separated by the flash tank and the phase separation tank, a small part of it directly enters the top of the regeneration tower, and the rest enters the rich liquid preheating tank for heating before entering the regeneration tower.

[0123] From the data in the table, it can be seen that the present invention can adopt conventional decarbonization processes and energy-saving processes, and the energy-saving processes can also be used in combination with each other to achieve different energy-saving effects. In the test examples, the energy-saving processes can ensure that the CO2 removal rate is above 85%. For the conventional decarbonization agent samples tested, the energy-saving effect is: rich liquid diversion > interstage cooling + rich liquid absorption; for the phase change absorbent samples tested, the energy-saving effect is: phase absorption + regeneration + rich liquid diversion > interstage cooling + rich liquid absorption + rich liquid diversion > phase absorption + regeneration.

[0124] The decarbonization device of the present invention can select a suitable energy-saving process for verification according to the decarbonization solvent system, which is helpful for subsequent industrial design.

[0125] In summary, the present invention is a multifunctional device integrating basic experimental determination and experimental process evaluation.

[0126] First, it can determine basic thermodynamic (equilibrium solubility) and kinetic (absorption rate) parameters;

[0127] Second, it can evaluate the energy-saving effects of different energy-saving processes, using a single or combined method to provide necessary process parameters for the industrial application of solvents;

[0128] Third, it has the functions of corrosion detection and deterioration rate investigation, which can comprehensively evaluate the service life of the decarbonizer and provide a basis for material selection for industrial equipment.

[0129] The invention has the advantages of simple structure, accurate and reliable detection, and emission in compliance with standards.

[0130] The above specific implementation methods further illustrate the objectives, technical solutions and beneficial effects of the present invention in detail. It should be understood that the above are only specific implementation methods of the present invention and are not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. An indoor evaluation method for amine-based carbon capture, characterized in that: The following steps are involved: (1) measuring the content data of the mixed gas of a gas source to be tested before absorption treatment, wherein the mixed gas source to be tested contains carbon dioxide gas; (2) The lean liquid absorbs the carbon dioxide gas in the mixed gas source to be tested to obtain the rich liquid; (3) transporting part of the rich liquid in step (2) to a regeneration tower to desorb and remove carbon dioxide, vacuum flashing part of the rich liquid to separate the rich and poor liquids, transporting the rich liquid obtained by phase separation to a regeneration tower to desorb and remove carbon dioxide, and transporting the lean liquid obtained by phase separation and the lean liquid obtained after desorption and separation to a lean liquid storage tank; (4) transporting the lean liquid in the lean liquid storage tank to the absorber to absorb the carbon dioxide in the mixed gas source to be tested, and measuring the content data of the mixed gas after the absorption treatment to obtain the absorption rate of carbon dioxide in the lean liquid; (5) preheating the loaded lean solution obtained after the measurement in step (4) to a certain temperature, and measuring the average solubility of carbon dioxide in the lean solution at different temperatures by gas phase circulation; (6) The liquid in the absorber is refluxed for reuse, and the mixed gas after measurement is purified and separated.

2. The indoor evaluation method for amine carbon capture according to claim 1, characterized in that: The method also includes preheating the rich liquid obtained by phase separation in step (3) and part of the rich liquid in step (2) and then transporting them to a regeneration tower for desorption and separation of carbon dioxide.

3. The indoor evaluation method for amine carbon capture according to claim 1, characterized in that: The method also includes the step (6) of absorbing carbon dioxide with the refluxed lean liquid to obtain a rich liquid, and inter-stage cooling and reflux of the rich liquid to repeat the steps (3) to (6).

4. The indoor evaluation method for amine carbon capture according to claim 1, characterized in that: The lean liquid flowing out of the regeneration tower is cooled and then enters the lean liquid storage tank; The gas and liquid flowing out of the regeneration tower are subjected to acid gas separation.

5. The indoor evaluation method for amine-based carbon capture according to any one of claims 1 to 4, characterized in that: The mixed gas source to be tested is a mixed gas that has been preheated and saturated with water.

6. An evaluation device for performing the indoor evaluation method for amine-based carbon capture according to any one of claims 1 to 5, characterized in that: include: The gas distribution system is equipped with different gas storage tanks and distributes the mixed gas source to be tested in proportion; A first flue gas analyzer, connected to the gas distribution system, for measuring the content data of the mixed gas before absorption treatment; The second absorption part is connected to the gas distribution system and is equipped with fillers, and is used for the lean liquid to absorb the carbon dioxide gas in the mixed gas source to obtain the rich liquid; Flash tank phase separation tank, used for vacuum flashing the rich liquid and performing phase separation of the lean and rich liquid to obtain lean liquid and rich liquid; A regeneration tower is used for desorption and separation of carbon dioxide from the rich liquid, and the outlet of the second absorption section and the flash tank phase separation tank are both connected to the inlet of the regeneration tower; A lean liquid storage tank is used to cool the incoming lean liquid to a certain temperature, and the outlets of the flash tank, the phase separation tank and the regeneration tower are all connected to the lean liquid storage tank; An absorber, used to receive the lean liquid in the lean liquid storage tank to absorb the carbon dioxide in the mixed gas, wherein the absorber is equipped with a heating system; The first absorption part is provided with fillers for absorbing the measured lean liquid flowing out of the absorber for reflux utilization; A purified gas separator is used to purify and separate the mixed gas after measurement; A second flue gas analyzer, connected to the absorber and the purified gas separator, for measuring the content data in the gas after absorption and purification; The sampling pump is connected between the absorber and the second flue gas analyzer and is used to circulate the gas phase between the absorber and the second flue gas analyzer until gas-liquid equilibrium is reached, so as to determine the average solubility.

7. The evaluation device according to claim 6, characterized in that A rich liquid preheating tank is also provided between the second absorption section, the flash tank phase separation tank and the regeneration tower, for heating the rich liquid flowing from the second absorption section and the flash tank phase separation tank to form hot rich liquid.

8. The evaluation device according to claim 6, characterized in that The outlet of the first absorption part is connected to the inlet of the second absorption part, and an interstage cooling device is provided between the connecting pipes of the first absorption part and the second absorption part for interstage cooling of the rich liquid formed after the reflux lean liquid absorbs carbon dioxide so as to reflux it to the second absorption part.

9. The evaluation device according to claim 6, characterized in that A lean liquid cooling tank is provided between the regeneration tower and the lean liquid storage tank, and a lean liquid pump is provided between the lean liquid storage tank and the absorber; The outlet of the regeneration tower is connected to an acid gas separator for separating the acid gas flowing out of the regeneration tower.

10. The evaluation device according to claim 6, characterized in that The gas distribution system is also connected to the absorber and is used to deliver the mixed gas source to be tested to the absorber, so as to perform gas metering and analysis data collection before and after the mixed gas source enters the absorber to obtain the absorption rate.

11. The evaluation device according to claim 6, characterized in that The gas distribution system is equipped with a gas mixing preheating tank and a water saturation tank. The water saturation tank is located at the rear end of the gas mixing preheating tank and is used to mix and preheat the gas flowing out of the gas storage tank and form a saturated state with water vapor to form a mixed gas source to be tested.

12. The evaluation device according to claim 6, characterized in that The flash tank phase separation tank adopts a rotary separation design and is connected with a vacuum pump; The rich liquid preheating tank is equipped with an impeller stirring paddle, on which a test piece hook is arranged for evaluating the corrosion rate of different materials at different temperatures and flow rates.

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