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CN-121606995-B - Low-temperature desorption and high-cycle stability absorption liquid for capturing carbon dioxide and preparation method and application thereof

CN121606995BCN 121606995 BCN121606995 BCN 121606995BCN-121606995-B

Abstract

The invention discloses an absorption liquid for capturing carbon dioxide and having low-temperature desorption and high cycle stability, a preparation method and application thereof, relating to the technical field of gas separation and purification, and comprising a main absorption component, an auxiliary agent and a solvent; the main absorption component is at least one of N-ethylpiperazine, 1-methylpiperazine and N-hydroxyethyl piperazine, the solvent is at least one of 1-dimethylamino-2-propanol, diethylaminoethanol and N, N-dimethylethanolamine, and the auxiliary agent is selected from composite antioxidants and desorption accelerators. The multicomponent synergistic design of the invention ensures that the system has excellent low-temperature desorption performance and long-term circulation stability on the premise of maintaining high trapping efficiency, ensures long-term stable and efficient operation of amine liquid, reduces operation cost caused by degradation of amine liquid, equipment corrosion and high energy consumption, and has good application prospect.

Inventors

  • ZHAO YIMING
  • YANG XINPING
  • WANG CHAOQUN

Assignees

  • 迪普干冰制造(大连)有限公司
  • 大连碳合汇节能科技有限公司

Dates

Publication Date
20260508
Application Date
20260130

Claims (9)

  1. 1. An absorption liquid for capturing carbon dioxide and having low-temperature desorption and high cycle stability is characterized by comprising the following components in percentage by mass: 15% -45% of main absorption component, 0.5% -5% of auxiliary agent and the balance of solvent; the main absorption component is at least one of N-ethylpiperazine, 1-methylpiperazine and N-hydroxyethyl piperazine; the solvent is at least one of 1-dimethylamino-2-propanol and N, N-dimethylethanolamine; The auxiliary agent is selected from a composite antioxidant and a desorption accelerator with the mass ratio of (1.5-2.5): 1; the compound antioxidant is selected from 10-alkyl phenothiazine and 1-isopropyl-4-piperidinol with the mass ratio of (1-1.5); the desorption promoter is selected from 2- (tert-butyl) pyridin-3-ol; the mass ratio of the main absorption component to the auxiliary agent is (20-50): 1; after ten continuous absorption-desorption cycles of the absorption liquid, the cycle efficiency is 96.7-99.2%; the method comprises the steps of carrying out desorption regeneration at the conditions of the absorption temperature of 40 ℃ and the absorption pressure of normal pressure for 60min, then at the conditions of the desorption temperature of 80-110 ℃ and the desorption pressure of normal pressure for 60min, wherein the absorption rate is 0.074-0.087L/min, the absorption capacity is 4.44-5.2L (CO 2 )/100 g of absorption liquid, the desorption rate is 0.052-0.074L/min, and the desorption rate is 69.93-99.55%.
  2. 2. The absorbent for capturing carbon dioxide with low temperature desorption and high cycle stability according to claim 1, wherein the 10-alkylphenothiazine is selected from at least one of 10-methylphenothiazine, 10-ethylphenothiazine and 10-hexylphenothiazine.
  3. 3. The absorbent for low temperature desorption and high cycle stability for capturing carbon dioxide according to claim 1, wherein the mass ratio of the composite antioxidant and the desorption accelerator is 2:1.
  4. 4. The absorbent for low temperature desorption and high cycle stability for capturing carbon dioxide according to claim 1, wherein the mass ratio of 10-alkylphenothiazine to 1-isopropyl-4-piperidinol is 1:1.5.
  5. 5. A process for producing an absorption liquid for capturing carbon dioxide which comprises the steps of adding a main absorption component and an auxiliary agent to a solvent and mixing the components, wherein the absorption liquid is characterized by having a low temperature desorption and a high cycle stability as defined in any one of claims 1 to 4.
  6. 6. The method for producing an absorption liquid for capturing carbon dioxide according to claim 5, wherein the mixing temperature is 25 to 40 ℃ and the mixing time is 10 to 30 minutes.
  7. 7. Use of an absorption liquid for capturing carbon dioxide according to any one of claims 1-4 for capturing carbon dioxide in industrial tail gas with low temperature desorption and high cycle stability.
  8. 8. The use according to claim 7, characterized in that in the use, after ten successive absorption-desorption cycles, the cycle efficiency is 96.7-99.2%.
  9. 9. The use of claim 7, wherein the industrial tail gas comprises at least one of flue gas, steel mill tail gas, metallurgical plant tail gas, chemical plant tail gas, power generation boiler tail gas, and cement kiln tail gas; the volume fraction of CO 2 in the industrial tail gas is 5% -50%; The application conditions are that the absorption time is 60min under the conditions of the absorption temperature of 40 ℃ and the absorption pressure of normal pressure, then the desorption regeneration is carried out under the conditions of the desorption temperature of 80-110 ℃ and the desorption pressure of normal pressure, the desorption time is 60min, the absorption rate is 0.074-0.087L/min, the absorption capacity is 4.44-5.2L (CO 2 )/100 g of absorption liquid, the desorption rate is 0.052-0.074L/min, and the desorption rate is 69.93-99.55%.

Description

Low-temperature desorption and high-cycle stability absorption liquid for capturing carbon dioxide and preparation method and application thereof Technical Field The invention relates to the technical field of gas separation and purification, in particular to an absorption liquid for capturing carbon dioxide and having low-temperature desorption and high cycle stability, and a preparation method and application thereof. Background As global greenhouse gas emissions continue to rise, significant emissions of carbon dioxide (CO 2) have been recognized as one of the major causes of climate change and greenhouse effect. In this context, carbon capture, utilization and sequestration (CCUS) technology is one of the key technological paths for achieving emissions reduction goals in various countries. Among them, the chemical absorption method is a mainstream technology route for capturing CO 2 on an industrial scale because of its high maturity and excellent capturing efficiency. Traditional chemical absorption methods mainly use alcohol amine solutions, typically represented by Monoethanolamine (MEA) aqueous solutions. The absorbent can generate carbamate and bicarbonate through reversible reaction with CO 2, so that the CO 2 in the gas can be efficiently removed. Although the aqueous alcohol amine solution absorbent such as MEA has a certain industrial foundation, the conventional aqueous alcohol amine absorbent is usually about 30 wt% aqueous solution, the absorption of CO 2 is exothermic reaction, a large amount of heat energy is required to be provided in the desorption process, and especially the evaporation latent heat of water accounts for a large proportion of the whole regeneration energy consumption, so that the energy consumption of the capturing process of CO 2 per ton is generally 3.0-4.0 GJ/t CO 2, which is unfavorable for the energy efficiency optimization of the capturing system. Meanwhile, alcohol amine is easy to thermally degrade and oxidatively degrade under the high-temperature desorption condition, and byproducts such as organic acid, aldehydes, imine and the like are generated, so that long-term stable use of the absorbent is influenced, and corrosion of equipment and system performance degradation are possibly caused. In order to solve the problems, a plurality of novel CO 2 absorbent systems are proposed in recent years at home and abroad, including solid amine, ionic liquid, deep eutectic solvent, organic amine/nonaqueous solvent mixed systems and the like. Among them, the nonaqueous alcohol amine system has fluidity and operation convenience of the liquid absorbent, and at the same time, reduces the water content to reduce the regeneration energy consumption, increases the CO 2 load, improves the solvent stability, and becomes one of the hot spot directions of recent researches. Development of nonaqueous alcohol amine absorbent with low energy consumption, low corrosiveness, good stability and high carbon dioxide absorption capacity has been a difficulty and a hot spot in carbon dioxide capture process technology research. Piperazine (PZ) is used as a main component of the existing flue gas decarbonization absorbent, and has the advantages of high boiling point, low volatility and no ammonia odor compared with linear polyamine, but has high regeneration energy consumption and limited cyclic absorption stability, thereby affecting the stability of a decarbonization system. The Chinese patent publication No. CN110152452A discloses a ternary nonaqueous solid-liquid phase change absorption system and application thereof, wherein the ternary mixed system is composed of 2-amino-2-methyl-1-propanol, dipropylene glycol dimethyl ether and piperazine, the system is a uniform transparent liquid solution before absorbing CO 2, becomes solid-liquid two phases after absorbing CO 2, and the CO 2 is enriched in a solid phase, and the solid phase is separated and regenerated. However, the difficulty of continuous operability of solid-liquid phase separation is high, the existing device can not meet the production requirement, and the use of a large industrial absorption tower is limited. The Chinese patent application with the publication number of CN111097255A discloses a functional ionic liquid nonaqueous system special for CO 2 absorption and separation, which comprises the following components, by mass, 70-90% of ethylene glycol or propylene glycol, 5-15% of amino functional ionic liquid and 5-15% of piperazine, wherein the cation of the amino functional ionic liquid is N, N-methyl amine ethyl piperazine cation, and the anion is amino acid radical anion. Although the ionic liquid has the characteristics of ultralow vapor pressure, high thermal stability and the like, most ionic liquids have obviously increased viscosity under medium-high CO 2 load, so that the diffusion coefficient is reduced, and the mass transfer is limited. Meanwhile, the raw materials, synthesis and purification costs of the ion