Carbon dioxide absorbent, absorption method and preparation method of carbon dioxide absorbent

Abstract

The invention provides a carbon dioxide absorbent, an absorption method and a preparation method of the carbon dioxide absorbent, and belongs to the field of carbon capture. The carbon dioxide absorbent comprises 20% of a decarburization solvent and 80% of deionized water, and the decarburization solvent is composed of a main absorbent, an activating agent, an antioxidant and a defoaming agent; the main absorbent is 100 parts by mass, and 100 parts by mass of the main absorbent is composed of 65-85 parts by mass of ethanolamine and 15-35 parts by mass of N-methyldiethanolamine; 7 to 9 parts by mass of an activating agent and 0.4 to 0.8 part by mass of an antioxidant. The invention aims to solve the problem of poor carbon dioxide absorption effect of a carbon dioxide absorbent in the prior art. The technical effects of high carbon dioxide absorptivity, low corrosivity, weak oxidative degradability and the like are achieved.

Description

Technical Field

[0001] The present invention relates to the technical field of carbon capture, and in particular to a carbon dioxide absorbent, an absorption method and a method for preparing the carbon dioxide absorbent. Background Art

[0002] With the continuous advancement of modern urbanization and industrialization, the demand for energy and electricity is growing rapidly, and the consumption of fossil fuels is increasing. Decarbonization and emission reduction must be carried out.

[0003] According to the CO2 separation process at different combustion stages, CO2 capture technology is mainly divided into three categories: pre-combustion capture, post-combustion capture and oxygen-enriched combustion. In comparison, post-combustion capture technology is currently the carbon capture technology with the most promising industrial application prospects, mainly including: chemical / physical absorption, adsorption, low-temperature separation and membrane separation. Chemical absorption has been widely and deeply applied and studied due to its advantages such as high absorption efficiency, large processing capacity and good absorption selectivity. Existing absorbents used in chemical absorption methods include amine absorbents, hot potassium alkali solution, ammonia water, ionic liquids, etc., among which amine absorbents are the most widely used absorbents.

[0004] In comparison, the chemical absorption post-combustion carbon capture technology based on ethanolamine MEA is the most mature, and related commercial operation projects have been established. Although MEA has been widely studied and applied, it still has many shortcomings, including high desorption and regeneration energy consumption, low CO2 absorption rate, strong corrosion to equipment, and large oxidative degradation and thermal degradation losses. Summary of the invention

[0005] The present invention provides a carbon dioxide absorbent, which is used to solve the problem that the carbon dioxide absorbent in the prior art has a poor carbon dioxide absorption effect, and achieves the effects of high carbon dioxide absorption rate, low corrosivity, weak oxidative degradation and the like.

[0006] A first aspect of the present invention provides a carbon dioxide absorbent, comprising 20% ​​of a decarbonization solvent and 80% of deionized water, wherein the decarbonization solvent is composed of a main absorbent, an activator, an antioxidant and a defoamer; The main absorbent is 100 parts by mass, and 100 parts by mass of the main absorbent is composed of 65 to 85 parts by mass of ethanolamine and 15 to 35 parts by mass of N-methyldiethanolamine; The activator is 7 to 9 parts by mass, and the antioxidant is 0.4 to 0.8 parts by mass.

[0007] In addition, the carbon dioxide absorbent according to the present invention may also have the following additional technical features: In some embodiments of the first aspect of the present invention, a corrosion inhibitor is further included, and 400 to 600 mg of the corrosion inhibitor is added per liter of the primary absorbent.

[0008] In some embodiments of the first aspect of the present invention, a defoaming agent is further included, and 0.4 to 0.8 parts by mass of the defoaming agent is added for every 100 parts by mass of the main absorbent.

[0009] In some embodiments of the first aspect of the present invention, the antioxidant is 0.64 parts by mass, the ethanolamine is 75 parts by mass, the N-methyldiethanolamine is 25 parts by mass, and the activator is 9 parts by mass.

[0010] In some embodiments of the first aspect of the present invention, the activator includes 8 parts by mass of piperazine, 0.4 parts by mass of N-methylethanolamine and 0.6 parts by mass of diglycolamine.

[0011] The carbon dioxide absorbent of the first embodiment of the present application includes at least one of the following beneficial technical effects: due to the strong alkalinity of ethanolamine, the CO2 removal rate is fast, but the regeneration energy consumption is high and the corrosiveness is strong; N-methyldiethanolamine is a tertiary amine, and there is no active hydrogen atom in the molecule. It cannot react directly with CO2, but combines with the hydrogen ions produced by the hydrolysis reaction to form bicarbonate. The reaction rate of the process is low, but the absorption capacity is large, the regeneration energy consumption is low, and it is not easy to degrade. Using ethanolamine as the main amine absorbent, compounding N-methyldiethanolamine can effectively reduce energy consumption and improve CO2 absorption capacity.

[0012] The setting of the corrosion inhibitor not only reduces the oxygen content in the absorbent, but also prevents metal ions from entering the solution to accelerate corrosion, thereby achieving an anti-degradation effect. The setting of the activator and mixing with the main absorbent will reduce the surface tension, leading to foam generation, and at the same time make the membrane surface charged, increasing the stability of the foam. The setting of the defoamer can reduce the foaming performance of the absorbent, and the setting of the antioxidant can effectively alleviate the oxidative degradation of the absorbent.

[0013] By using this absorbent, the absorption rate of CO2 can reach more than 80%, and the highest can reach 91.6%. In addition, this absorbent has the effects of high absorption rate, low corrosiveness, weak oxidative degradation, etc.

[0014] The second aspect of the present invention provides a carbon dioxide absorption method, using the carbon dioxide absorbent of the first aspect of the present invention, using a high gravity reactor in combination with the absorbent to absorb carbon dioxide, the high gravity reactor comprising a raw material storage tank, a liquid pump, a rotating packed bed and a raw gas preheating tank connected in sequence, in addition to the above, the following steps are also included: Step S100: The prepared carbon dioxide absorbent is heated to a specified temperature in a raw material storage tank; Step S200: pumping the carbon dioxide absorbent into the rotating packed bed by a liquid pump; Step S300: the flue gas to be captured and absorbed enters the raw gas preheating tank for mixing and heating, and then enters the rotating packed bed through the gas inlet; Step S400: In the rotating packed bed, the flue gas and the carbon dioxide absorbent are contacted and reacted in countercurrent; after the contact reaction is completed, the flue gas is discharged through the top outlet of the rotating packed bed, and the carbon dioxide absorption is completed.

[0015] In some embodiments of the second aspect of the present invention, the ultragravity reactor further comprises a first flow meter disposed between the liquid pump and the rotating packed bed.

[0016] In some embodiments of the second aspect of the present invention, the high gravity reactor further comprises a thermometer disposed between the first flow meter and the rotating packed bed.

[0017] In some embodiments of the second aspect of the present invention, in step S100, the temperature range of the designated temperature is between 35 degrees and 55 degrees.

[0018] The carbon dioxide absorption method of the second embodiment of the present application includes at least one of the following beneficial technical effects: by using a supergravity reactor, energy consumption is greatly reduced compared to a traditional packed tower. The supergravity machine mainly uses a rotating drum, and fillers are loaded into the rotating drum, and then the motor drives the rotating drum to rotate at high speed to achieve good gas-liquid contact and micro-mixing.

[0019] A third aspect of the present invention provides a method for preparing a carbon dioxide absorbent, comprising the following steps: Step S100: Ethanolamine and N-methyldiethanolamine are mixed uniformly according to a proportion; Step S200: adding an activator after maintaining the temperature at 50° C. for 1 hour, stirring evenly and continuing to maintain the temperature for 3 hours, then cooling to room temperature to obtain a mixed solution of ethanolamine, N-methyldiethanolamine and the activator; Step S300: adding a corrosion inhibitor, a defoaming agent and an antioxidant to the prepared mixed solution of ethanolamine, N-methyldiethanolamine and an activator in sequence to prepare a decarbonization solvent; Step S400: adding a decarbonizing solvent to deionized water to prepare a carbon dioxide absorbent mixed solution. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Various other advantages and benefits will become apparent to those of ordinary skill in the art by reading the detailed description of the preferred embodiments below. The accompanying drawings are only for the purpose of illustrating the preferred embodiments and are not to be considered as limiting the present invention. Moreover, the same reference numerals are used throughout the accompanying drawings to represent the same components. In the accompanying drawings: Figure 1 The structural diagram of the supergravity reactor according to some embodiments of the present invention is schematically shown.

[0021] Figure 2 The structural diagram of the rotating packed bed according to some embodiments of the present invention is schematically shown.

[0022] Figure numerals: 1. Raw material storage tank, 2. Liquid pump 2, 3. First flow meter 3, 5. Rotating packed bed, 51. Rotor, 52. Rotating shaft, 53. Gas outlet, 54. Liquid inlet, 55. Packing, 56. Gas inlet, 57. Liquid outlet, 6. Storage tank, 7. Raw gas preheating tank, 8. Second flow meter, 9. Thermometer. DETAILED DESCRIPTION

[0023] The exemplary embodiments of the present disclosure will be described in more detail below with reference to the accompanying drawings. Although the exemplary embodiments of the present disclosure are shown in the accompanying drawings, it should be understood that the present disclosure can be implemented in various forms and should not be limited by the embodiments described herein. On the contrary, these embodiments are provided in order to enable a more thorough understanding of the present disclosure and to fully convey the scope of the present disclosure to those skilled in the art.

[0024] It should be understood that the terms used herein are only for the purpose of describing specific example embodiments and are not intended to be limiting. Unless the context clearly indicates otherwise, the singular forms "one", "an" and "" as used herein may also be meant to include plural forms. The terms "include", "comprise", "contain", and "have" are inclusive and therefore specify the presence of stated features, steps, operations, elements and / or parts, but do not exclude the presence or addition of one or more other features, steps, operations, elements, parts, and / or combinations thereof. The method steps, processes, and operations described herein are not interpreted as necessarily requiring them to be performed in the specific order described or illustrated, unless the execution order is clearly indicated. It should also be understood that additional or alternative steps may be used.

[0025] Although the terms first, second, third, etc. can be used in the text to describe multiple elements, components, regions, layers and / or sections, these elements, components, regions, layers and / or sections should not be limited by these terms. These terms can only be used to distinguish an element, component, region, layer or section from another region, layer or section. Unless the context clearly indicates, terms such as "first", "second" and other numerical terms do not imply order or sequence when used in the text. Therefore, the first element, component, region, layer or section discussed below can be referred to as the second element, component, region, layer or section without departing from the teaching of the example embodiments.

[0026] For ease of description, spatial relative terms may be used in the text to describe the relationship of one element or feature relative to another element or feature as shown in the figure, such as "inside", "outside", "inner side", "outer side", "below", "below", "above", "above", etc. Such spatial relative terms are intended to include different orientations of the device in use or operation in addition to the orientation depicted in the figure. For example, if the device in the figure is flipped, the element described as "below other elements or features" or "below other elements or features" will then be oriented as "above other elements or features" or "above other elements or features". Therefore, the example term "below..." can include both upper and lower orientations. The device can be additionally oriented and rotated 90 degrees or in other directions and the spatial relative descriptors used in the text are interpreted accordingly.

[0027] Example 1

[0028] The carbon dioxide absorbent comprises 20% of a decarbonization solvent and 80% of deionized water, wherein the decarbonization solvent comprises a main absorbent, an activator, an antioxidant and a defoaming agent; The main absorbent is 100 parts by mass, and 100 parts by mass of the main absorbent is composed of 65 to 85 parts by mass of ethanolamine and 15 to 35 parts by mass of N-methyldiethanolamine; The activator is 7 to 9 parts by mass, and the antioxidant is 0.4 to 0.8 parts by mass.

[0029] In the above embodiment, it should be noted that a corrosion inhibitor is also included, with 400 to 600 mg of corrosion inhibitor added per liter of main absorbent, and a defoamer is also included, with 0.4 to 0.8 parts by mass of defoamer added per 100 parts by mass of main absorbent. Specifically, the defoamer uses 7533# defoamer, 0.6 parts by mass of defoamer, 0.64 parts by mass of antioxidant; 75 parts by mass of ethanolamine, 25 parts by mass of N-methyldiethanolamine; 9 parts by mass of activator, the activator includes 8 parts by mass of piperazine, 0.4 parts by mass of N-methylethanolamine and 0.6 parts by mass of diglycolamine; the corrosion inhibitor is a composite imidazoline corrosion inhibitor, namely ODD# corrosion inhibitor, and 547 mg of ODD# corrosion inhibitor is added per liter of main absorbent; the absorption temperature is the absorption temperature of the absorbent, specifically 45°C, and the absorbent flow rate is 3 liters per hour.

[0030] The beneficial effects of Example 1 are as follows: due to the strong alkalinity of ethanolamine, the CO2 removal rate is fast, but the regeneration energy consumption is high and the corrosiveness is strong; N-methyldiethanolamine is a tertiary amine, and there is no active hydrogen atom in the molecule. It cannot react directly with CO2, but combines with the hydrogen ions produced by the hydrolysis reaction to form bicarbonate. The reaction rate of the process is low, but the absorption capacity is large, the regeneration energy consumption is low, and it is not easy to degrade. Using ethanolamine as the main amine absorbent, compounding N-methyldiethanolamine can effectively reduce energy consumption and improve CO2 absorption capacity.

[0031] In addition, the corrosion inhibitor is through the adsorption of nitrogen atoms. When the metal contacts the solution, the imidazoline corrosion inhibitor will be adsorbed on the surface of the metal to produce a dense adsorption film. At the same time, the hydrophobic group will also form a hydrophobic layer to protect the metal and prevent the corrosive medium from entering the metal surface, thereby achieving the purpose of corrosion inhibition. The setting of the corrosion inhibitor not only reduces the oxygen content in the absorbent, but also prevents metal ions from entering the solution to accelerate corrosion, thereby achieving the effect of anti-degradation. After the setting of the activator and the main absorbent are mixed, the surface tension will decrease, resulting in foam generation. At the same time, the membrane surface will be charged, increasing the stability of the foam. The setting of the defoamer can reduce the foaming performance of the absorbent, and the setting of the antioxidant can effectively alleviate the oxidative degradation of the absorbent.

[0032] The antioxidant adopts EDTA antioxidant, and the defoaming agent adopts composite polyether defoaming agent.

[0033] In summary, by using the above absorbent, the absorption rate of CO2 can reach more than 80%, and the highest can reach 91.6%. In addition, the absorbent has the characteristics of high absorption rate, low corrosiveness, and weak oxidative degradation.

[0034] Example 2

[0035] Carbon dioxide absorption methods, such as Figure 1 and Figure 2 As shown, the carbon dioxide absorbent according to the first aspect of the present invention is used, and a high gravity reactor is used to absorb carbon dioxide in combination with the absorbent. The high gravity reactor includes a raw material storage tank 1, a liquid pump 2, a rotating packed bed 5, and a raw gas preheating tank 7 connected in sequence. In addition, the following steps are also included: Step S100: The prepared carbon dioxide absorbent is heated to a specified temperature in the raw material storage tank 1; Step S200: The liquid pump 2 pumps the carbon dioxide absorbent into the rotating packed bed 5; Step S300: the flue gas to be captured and absorbed enters the raw gas preheating tank 7 for mixing and heating, and then enters the rotating packed bed 5 through the gas inlet; Step S400: In the rotating packed bed 5, the flue gas and the carbon dioxide absorbent are contacted and reacted in countercurrent; after the contact reaction is completed, the flue gas is discharged through the top outlet of the rotating packed bed 5, and the carbon dioxide absorption is completed.

[0036] In the above embodiment, it should be noted that the heating temperature of the flue gas to be captured and absorbed entering the raw gas preheating tank 7 for mixed heating is between 100°C and 120°C, preferably 115°C, and the heating temperature of the mixed heating in the raw gas preheating tank 7 is the regeneration temperature; the absorption rate of the flue gas to be captured and absorbed is 3L / h.

[0037] The ultra-gravity reactor further comprises a first flow meter 3 , which is arranged between the liquid pump 2 and the rotating packed bed 5 .

[0038] The ultragravity reactor further includes a thermometer 9 , which is disposed between the first flowmeter 3 and the rotating packed bed 5 .

[0039] Optionally, in step S100, the temperature range of the specified temperature is between 35 degrees and 55 degrees.

[0040] In the above optional embodiment, it should be noted that it also includes a second flow meter 8, which is arranged on the pipeline of the raw gas preheating tank 7. The rotating packed bed 5 is composed of a rotor 51, a rotating shaft 52, a gas outlet 53, a liquid inlet 54, a filler 55, a gas inlet 56 and a liquid outlet 57.

[0041] Infrared gas analysis devices are provided at the positions of the gas inlet 56 and the gas outlet 53 .

[0042] The beneficial effect of the above optional embodiment is that the energy consumption is greatly reduced by using a supergravity reactor compared with a traditional packed tower. The supergravity machine mainly uses a rotating drum, and fillers are loaded into the rotating drum, and then the motor drives the rotating drum to rotate at high speed to achieve good gas-liquid contact and micro-mixing.

[0043] Example 3

[0044] A method for preparing a carbon dioxide absorbent comprises the following steps: Step S100: Ethanolamine and N-methyldiethanolamine are mixed uniformly according to a proportion; Step S200: adding an activator after maintaining the temperature at 50° C. for 1 hour, stirring evenly and continuing to maintain the temperature for 3 hours, then cooling to room temperature to obtain a mixed solution of ethanolamine, N-methyldiethanolamine and the activator; Step S300: adding a corrosion inhibitor, a defoaming agent and an antioxidant to the prepared mixed solution of ethanolamine, N-methyldiethanolamine and an activator in sequence to prepare a decarbonization solvent; Step S400: adding a decarbonizing solvent to deionized water to prepare a carbon dioxide absorbent mixed solution.

[0045] Comparative Example 1: absorption temperature 40°C, absorbent flow rate 5L / h, supergravity reactor speed 750 rpm, 85 parts by mass of ethanolamine, 15 parts by mass of N-methyldiethanolamine, 7 parts by mass of piperazine, 0.5 parts by mass of N-methylmonoethanolamine, 0.5 parts by mass of diglycolamine, 400 mg of ODD# corrosion inhibitor, 0.72 parts by mass of sodium metavanadate antioxidant, and 0.8 parts by mass of 5530# defoaming agent were added per liter of main absorbent.

[0046] Comparative Example 2: absorption temperature 40°C, absorbent flow rate 5L / h, supergravity reactor speed 750 rpm, 80 parts by mass of ethanolamine, 20 parts by mass of N-methyldiethanolamine, 7 parts by mass of piperazine, 0.5 parts by mass of N-methylmonoethanolamine, 0.5 parts by mass of diglycolamine, 400 mg of ODD# corrosion inhibitor, 0.72 parts by mass of sodium metavanadate antioxidant, and 0.8 parts by mass of 5530# defoaming agent were added per liter of main absorbent.

[0047] Comparative Example 3: Absorption temperature 40°C, absorbent flow rate 5 L / h, supergravity reactor speed 750 rpm, 75 parts by mass of ethanolamine, 25 parts by mass of N-methyldiethanolamine, 7 parts by mass of piperazine, 0.5 parts by mass of N-methylmonoethanolamine, 0.5 parts by mass of diglycolamine, 400 mg of ODD# corrosion inhibitor, 0.72 parts by mass of sodium metavanadate antioxidant, and 0.8 parts by mass of 5530# defoaming agent were added per liter of main absorbent.

[0048] Comparative Example 4: absorption temperature 40°C, absorbent flow rate 5 L / h, supergravity reactor speed 750 rpm, 70 parts by mass of ethanolamine, 30 parts by mass of N-methyldiethanolamine, 7 parts by mass of piperazine, 0.5 parts by mass of N-methylmonoethanolamine, 0.5 parts by mass of diglycolamine, 400 mg of ODD# corrosion inhibitor, 0.72 parts by mass of sodium metavanadate antioxidant, and 0.8 parts by mass of 5530# defoaming agent were added per liter of main absorbent.

[0049] Comparative Example 5: absorption temperature 40°C, absorbent flow rate 5 L / h, supergravity reactor speed 750 rpm, 65 parts by mass of ethanolamine, 35 parts by mass of N-methyldiethanolamine, 7 parts by mass of piperazine, 0.5 parts by mass of N-methylmonoethanolamine, 0.5 parts by mass of diglycolamine, 400 mg of ODD# corrosion inhibitor, 0.72 parts by mass of sodium metavanadate antioxidant, and 0.8 parts by mass of 5530# defoaming agent were added per liter of main absorbent.

[0050] Comparative Example 6: absorption temperature 40°C, absorbent flow rate 5 L / h, supergravity reactor speed 750 rpm, 75 parts by mass of ethanolamine, 25 parts by mass of N-methyldiethanolamine, 6 parts by mass of piperazine, 0.5 parts by mass of N-methylmonoethanolamine, 0.5 parts by mass of diglycolamine, 400 mg of ODD# corrosion inhibitor, 0.72 parts by mass of sodium metavanadate antioxidant, and 0.8 parts by mass of 5530# defoaming agent were added per liter of main absorbent.

[0051] Comparative Example 7: absorption temperature 40°C, absorbent flow rate 5 L / h, supergravity reactor speed 750 rpm, 75 parts by mass of ethanolamine, 25 parts by mass of N-methyldiethanolamine, 8 parts by mass of piperazine, 0.5 parts by mass of N-methylmonoethanolamine, 0.5 parts by mass of diglycolamine, 400 mg of ODD# corrosion inhibitor, 0.72 parts by mass of sodium metavanadate antioxidant, and 0.8 parts by mass of 5530# defoaming agent were added per liter of main absorbent.

[0052] Comparative Example 8: absorption temperature 40°C, absorbent flow rate 5L / h, high gravity reactor speed 750 rpm, absorption temperature 40°C, absorbent flow rate 5L / h, high gravity reactor speed 750 rpm, 75 parts by mass of ethanolamine, 25 parts by mass of N-methyldiethanolamine, 9 parts by mass of piperazine, 0.5 parts by mass of N-methylmonoethanolamine, 0.5 parts by mass of diglycolamine, 400 mg of ODD# corrosion inhibitor, 0.72 parts by mass of sodium metavanadate antioxidant and 0.8 parts by mass of 5530# defoaming agent were added per liter of main absorbent.

[0053] Comparative Example 9: absorption temperature 40°C, absorbent flow rate 5L / h, high gravity reactor speed 750 rpm, absorption temperature 40°C, absorbent flow rate 5L / h, high gravity reactor speed 750 rpm, 75 parts by mass of ethanolamine, 25 parts by mass of N-methyldiethanolamine, 10 parts by mass of piperazine, 0.5 parts by mass of N-methylmonoethanolamine, 0.5 parts by mass of diglycolamine, 400 mg of ODD# corrosion inhibitor, 0.72 parts by mass of sodium metavanadate antioxidant and 0.8 parts by mass of 5530# defoaming agent were added per liter of main absorbent.

[0054] Comparative Example 10: absorption temperature 40°C, absorbent flow rate 5L / h, high gravity reactor speed 750 rpm, absorption temperature 40°C, absorbent flow rate 5L / h, high gravity reactor speed 750 rpm, 75 parts by mass of ethanolamine, 25 parts by mass of N-methyldiethanolamine, 8 parts by mass of piperazine, 0.4 parts by mass of N-methylmonoethanolamine, 0.6 parts by mass of diglycolamine, 400 mg of ODD# corrosion inhibitor, 0.72 parts by mass of sodium metavanadate antioxidant and 0.8 parts by mass of 5530# defoaming agent were added per liter of main absorbent.

[0055] Comparative Example 11: absorption temperature 40°C, absorbent flow rate 5 L / h, high gravity reactor speed 750 rpm, absorption temperature 40°C, absorbent flow rate 5 L / h, high gravity reactor speed 750 rpm, 75 parts by mass of ethanolamine, 25 parts by mass of N-methyldiethanolamine, 8 parts by mass of piperazine, 0.3 parts by mass of N-methylmonoethanolamine, 0.7 parts by mass of diglycolamine, 400 mg of ODD# corrosion inhibitor, 0.72 parts by mass of sodium metavanadate antioxidant and 0.8 parts by mass of 5530# defoaming agent were added per liter of main absorbent.

[0056] Comparative Example 12: absorption temperature 40°C, absorbent flow rate 5 L / h, supergravity reactor speed 750 rpm, 75 parts by mass of ethanolamine, 25 parts by mass of N-methyldiethanolamine, 8 parts by mass of piperazine, 0.2 parts by mass of N-methylmonoethanolamine, 0.9 parts by mass of diglycolamine, 400 mg of ODD# corrosion inhibitor, 0.72 parts by mass of sodium metavanadate antioxidant, and 0.8 parts by mass of 5530# defoaming agent were added per liter of main absorbent.

[0057] Comparative Example 13: absorption temperature 40°C, absorbent flow rate 2L / h, supergravity reactor speed 750 rpm, 75 parts by mass of ethanolamine, 25 parts by mass of N-methyldiethanolamine, 8 parts by mass of piperazine, 0.4 parts by mass of N-methylmonoethanolamine, 0.6 parts by mass of diglycolamine, 547 mg of ODM# corrosion inhibitor, 0.64 parts by mass of ethylenediaminetetraacetic acid antioxidant, and 0.6 parts by mass of 7533# defoaming agent were added per liter of main absorbent.

[0058] Comparative Example 14: absorption temperature 40°C, absorbent flow rate 2L / h, supergravity reactor speed 750 rpm, 75 parts by mass of ethanolamine, 25 parts by mass of N-methyldiethanolamine, 8 parts by mass of piperazine, 0.4 parts by mass of N-methylmonoethanolamine, 0.6 parts by mass of diglycolamine, 547 mg of ODM# corrosion inhibitor, 0.64 parts by mass of ethylenediaminetetraacetic acid antioxidant, and 0.6 parts by mass of 7533# defoaming agent were added per liter of main absorbent.

[0059] Comparative Example 15: absorption temperature 40°C, absorbent flow rate 3L / h, supergravity reactor speed 750 rpm, 75 parts by mass of ethanolamine, 25 parts by mass of N-methyldiethanolamine, 8 parts by mass of piperazine, 0.4 parts by mass of N-methylmonoethanolamine, 0.6 parts by mass of diglycolamine, 547 mg of ODM# corrosion inhibitor, 0.64 parts by mass of ethylenediaminetetraacetic acid antioxidant, and 0.6 parts by mass of 7533# defoaming agent were added per liter of main absorbent.

[0060] Comparative Example 16: absorption temperature 40°C, absorbent flow rate 4L / h, supergravity reactor speed 750 rpm, 75 parts by mass of ethanolamine, 25 parts by mass of N-methyldiethanolamine, 8 parts by mass of piperazine, 0.4 parts by mass of N-methylmonoethanolamine, 0.6 parts by mass of diglycolamine, 547 mg of ODM# corrosion inhibitor, 0.64 parts by mass of ethylenediaminetetraacetic acid antioxidant, and 0.6 parts by mass of 7533# defoaming agent were added per liter of main absorbent.

[0061] Comparative Example 17: absorption temperature 40°C, absorbent flow rate 5 L / h, supergravity reactor speed 750 rpm, 75 parts by mass of ethanolamine, 25 parts by mass of N-methyldiethanolamine, 8 parts by mass of piperazine, 0.4 parts by mass of N-methylmonoethanolamine, 0.6 parts by mass of diglycolamine, 547 mg of ODM# corrosion inhibitor, 0.64 parts by mass of ethylenediaminetetraacetic acid antioxidant, and 0.6 parts by mass of 7533# defoaming agent were added per liter of main absorbent.

[0062] Comparative Example 18: absorption temperature 40°C, absorbent flow rate 6L / h, supergravity reactor speed 750 rpm, 75 parts by mass of ethanolamine, 25 parts by mass of N-methyldiethanolamine, 8 parts by mass of piperazine, 0.4 parts by mass of N-methylmonoethanolamine, 0.6 parts by mass of diglycolamine, 547 mg of ODM# corrosion inhibitor, 0.64 parts by mass of ethylenediaminetetraacetic acid antioxidant, and 0.6 parts by mass of 7533# defoaming agent were added per liter of main absorbent.

[0063] Comparative Example 19: absorption temperature 35°C, absorbent flow rate 3L / h, supergravity reactor speed 750 rpm, 75 parts by mass of ethanolamine, 25 parts by mass of N-methyldiethanolamine, 8 parts by mass of piperazine, 0.4 parts by mass of N-methylmonoethanolamine, 0.6 parts by mass of diglycolamine, 547 mg of ODM# corrosion inhibitor, 0.64 parts by mass of ethylenediaminetetraacetic acid antioxidant, and 0.6 parts by mass of 7533# defoaming agent were added per liter of main absorbent.

[0064] Comparative Example 20: absorption temperature 35°C, absorbent flow rate 3L / h, supergravity reactor speed 750 rpm, 75 parts by mass of ethanolamine, 25 parts by mass of N-methyldiethanolamine, 8 parts by mass of piperazine, 0.4 parts by mass of N-methylmonoethanolamine, 0.6 parts by mass of diglycolamine, 547 mg of ODM# corrosion inhibitor, 0.64 parts by mass of ethylenediaminetetraacetic acid antioxidant, and 0.6 parts by mass of 7533# defoaming agent were added per liter of main absorbent.

[0065] Comparative Example 21: absorption temperature 40°C, absorbent flow rate 3L / h, supergravity reactor speed 750 rpm, 75 parts by mass of ethanolamine, 25 parts by mass of N-methyldiethanolamine, 8 parts by mass of piperazine, 0.4 parts by mass of N-methylmonoethanolamine, 0.6 parts by mass of diglycolamine, 547 mg of ODM# corrosion inhibitor, 0.64 parts by mass of ethylenediaminetetraacetic acid antioxidant, and 0.6 parts by mass of 7533# defoaming agent were added per liter of main absorbent.

[0066] Comparative Example 22: absorption temperature 50°C, absorbent flow rate 3L / h, supergravity reactor speed 750 rpm, 75 parts by mass of ethanolamine, 25 parts by mass of N-methyldiethanolamine, 8 parts by mass of piperazine, 0.4 parts by mass of N-methylmonoethanolamine, 0.6 parts by mass of diglycolamine, 547 mg of ODM# corrosion inhibitor, 0.64 parts by mass of ethylenediaminetetraacetic acid antioxidant, and 0.6 parts by mass of 7533# defoaming agent were added per liter of main absorbent.

[0067] Comparative Example 23: absorption temperature 55°C, absorbent flow rate 3L / h, supergravity reactor speed 750 rpm, 75 parts by mass of ethanolamine, 25 parts by mass of N-methyldiethanolamine, 8 parts by mass of piperazine, 0.4 parts by mass of N-methylmonoethanolamine, 0.6 parts by mass of diglycolamine, 547 mg of ODM# corrosion inhibitor, 0.64 parts by mass of ethylenediaminetetraacetic acid antioxidant, and 0.6 parts by mass of 7533# defoaming agent were added per liter of main absorbent.

[0068] Experimental example: A small batch experiment was conducted on the carbon dioxide absorbents configured in Example 1 and Comparative Examples 1 to 24. The components of the simulated flue gas used in the experiment were a mixed gas of 2.85% CO2 and 97.15% N2. The flow rate of the simulated flue gas (CO2 accounted for 2.85%) was fixed at 2 m 3 / h.

[0069] The experimental process of absorbent includes the following steps: In the first step, the prepared absorption liquid is heated to a specified absorption temperature by low-pressure steam 4 in the raw material storage tank 1.

[0070] In the second step, the liquid is pumped into the rotating packed bed 5 through the first flow meter by the liquid pump 2.

[0071] In the third step, the N2 and CO2 gases released from the carbon dioxide cylinder pass through the second flow meter 8 respectively, then enter the preheating tank 7 for mixing, and then enter the rotating packed bed 5.

[0072] Step 4: In the rotating packed bed 5, the gas and liquid are contacted and reacted in countercurrent. The liquid after the reaction is discharged from the liquid outlet of the rotating packed bed 5 and enters the storage tank 6; the gas is discharged from the gas outlet 53 of the rotating packed bed 5.

[0073] The optimization evaluation method of the absorbent ratio: This experiment tested the inlet and outlet carbon dioxide concentrations, prepared different ratios of absorption liquids for multiple times, measured the CO2 concentration when the gas entered and exited the rotating packed bed (5) under different absorption temperatures and other experimental conditions, calculated the CO2 absorption rate, and then optimized the absorbent ratio and process conditions. The absorption rate calculation formula is as follows: η= ×100%; Among them, y in represents the inlet CO2 concentration; y out Represents the CO2 outlet concentration.

[0074] A mixture of 2.85% CO2 and 97.15% N2 was used as simulated flue gas.

[0075] The absorption rates of the carbon dioxide absorbents configured in Example 1 and Comparative Examples 1 to 24 are shown in Table 1:

[0076] Table 1

[0077] From Table 1, it can be seen that the optimal dosage ratio of the absorbent is 75 parts by mass of ethanolamine, 25 parts by mass of N-methyldiethanolamine, 8 parts by mass of piperazine, 0.4 parts by mass of N-methylethanolamine, and 0.6 parts by mass of diglycolamine. 547 mg of ODD# corrosion inhibitor, 547 mg / LODD# corrosion inhibitor, 0.64 parts by mass of antioxidant, and 0.6 parts by mass of 7533# defoamer are added per liter of the main absorbent.

[0078] The optimal process conditions were determined to be: 3 L / h absorbent flow rate and 45 °C absorption temperature.

[0079] Under the optimal composite decarbonization solvent ratio and process conditions, the CO2 absorption rate is higher than 90%.

[0080] In summary, the present invention obtains a carbon dioxide absorbent with a ratio of 75 parts by mass of ethanolamine, 25 parts by mass of N-methyldiethanolamine, 8 parts by mass of piperazine, 0.4 parts by mass of N-methylethanolamine, and 0.6 parts by mass of diglycolamine by proportioning the carbon dioxide absorbent. The best effect of carbon dioxide absorption is achieved by adding 547 mg of ODD# corrosion inhibitor, 547 mg / LODD# corrosion inhibitor, 0.64 parts by mass of antioxidant, and 0.6 parts by mass of 7533# defoamer per liter of main absorbent with an absorption temperature of 45°C and a flow rate of 3L / h.

[0081] The above is only a preferred specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or substitutions that can be easily thought of by a person skilled in the art within the technical scope disclosed by the present invention should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention shall be subject to the protection scope of the claims.

Claims

1. A carbon dioxide absorbent, characterized in that The method comprises 20% of a decarbonization solvent and 80% of deionized water, wherein the decarbonization solvent is composed of a main absorbent, an activator, an antioxidant and a defoaming agent; The main absorbent is 100 parts by mass, and 100 parts by mass of the main absorbent is composed of 65 to 85 parts by mass of ethanolamine and 15 to 35 parts by mass of N-methyldiethanolamine; The activator is 7 to 9 parts by mass, and the antioxidant is 0.4 to 0.8 parts by mass.

2. The carbon dioxide absorbent according to claim 1, characterized in that The main absorbent further comprises a corrosion inhibitor, wherein 400 to 600 mg of the corrosion inhibitor is added per liter of the main absorbent.

3. The carbon dioxide absorbent according to claim 2, characterized in that The defoaming agent is also included, and 0.4 to 0.8 parts by mass of the defoaming agent is added per 100 parts by mass of the main absorbent.

4. The carbon dioxide absorbent according to claim 2, characterized in that The antioxidant is 0.64 parts by mass, the ethanolamine is 75 parts by mass, the N-methyldiethanolamine is 25 parts by mass, and the activator is 9 parts by mass.

5. The carbon dioxide absorbent according to claim 5, characterized in that The activator includes 8 parts by mass of piperazine, 0.4 parts by mass of N-methylethanolamine and 0.6 parts by mass of diglycolamine.

6. A method for absorbing carbon dioxide, using the carbon dioxide absorbent according to any one of claims 1 to 5, using a high gravity reactor in combination with the absorbent to absorb carbon dioxide, the high gravity reactor comprising a raw material storage tank (1), a liquid pump (2), a rotating packed bed (5) and a raw gas preheating tank (7) connected in sequence, and in addition, further comprising the following steps: Step S100: the prepared carbon dioxide absorbent is heated to a specified temperature in the raw material storage tank (1); Step S200: The liquid pump (2) pumps the carbon dioxide absorbent into the rotating packed bed (5); Step S300: the flue gas to be captured and absorbed enters the raw gas preheating tank (7) for mixing and heating, and then enters the rotating packed bed (5) through the gas inlet; Step S400: In the rotating packed bed (5), the flue gas and the carbon dioxide absorbent are contacted and reacted in a countercurrent manner; After the contact reaction is completed, the flue gas is discharged through the top outlet of the rotating packed bed (5), and the carbon dioxide absorption is completed.

7. The carbon dioxide absorption method according to claim 6, characterized in that: The ultra-gravity reactor further comprises a first flow meter (3), which is arranged between the liquid pump (2) and the rotating packed bed (5).

8. The carbon dioxide absorption method according to claim 7, characterized in that: The ultra-gravity reactor further comprises a thermometer (9), wherein the thermometer (9) is arranged between the first flow meter (3) and the rotating packed bed (5).

9. The carbon dioxide absorption method according to claim 8, characterized in that: In step S100 , the temperature range of the designated temperature is between 35 degrees and 55 degrees.

10. A method for preparing a carbon dioxide absorbent, characterized in that: The following steps are involved: Step S100: Ethanolamine and N-methyldiethanolamine are mixed uniformly according to a proportion; Step S200: adding an activator after maintaining the temperature at 50° C. for 1 hour, stirring evenly and continuing to maintain the temperature for 3 hours, then cooling to room temperature to obtain a mixed solution of ethanolamine, N-methyldiethanolamine and the activator; Step S300: adding a corrosion inhibitor, a defoaming agent and an antioxidant to the prepared mixed solution of ethanolamine, N-methyldiethanolamine and an activator in sequence to prepare a decarbonization solvent; Step S400: adding a decarbonizing solvent to deionized water to prepare a carbon dioxide absorbent mixed solution.

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