CN-116935988-B - Design method of organic amine phase change absorption system for capturing carbon dioxide

CN116935988BCN 116935988 BCN116935988 BCN 116935988BCN-116935988-B

Abstract

The invention discloses a design method of an organic amine phase change absorption system for capturing carbon dioxide, which comprises the following steps of constructing and optimizing a three-dimensional molecular configuration of a phase-splitting agent to be predicted, analyzing molecular information based on a molecular structure, calculating analysis factors related to the phase-splitting performance of the phase-splitting agent, substituting the analysis factors into a trained theoretical prediction model to obtain a phase-splitting performance prediction result of the phase-splitting agent, and selecting a proper phase-splitting agent to construct the organic amine phase change absorption system according to the prediction result and process conditions. The invention can accurately predict the phase separation behavior of the organic amine and the absorption system formed by different solvents based on the designed analysis factors and theoretical prediction models, and screens out a proper phase-splitting agent based on the phase separation behavior, thereby rationally designing the organic amine phase-separation system, improving the problem that the screening and construction of the current phase-change absorbent are completed through a large number of repeated experiments, and providing powerful support for the efficient design and construction of the phase-change absorbent.

Inventors

ZHANG LIQI
GAO XIAOYI
LI XIAOPAN
JIANG WUFENG
XU BIN
GAO GE

Assignees

华中科技大学

Dates

Publication Date: 20260512
Application Date: 20230802

Claims (7)

1. The design method of the organic amine phase change absorption system for capturing carbon dioxide is characterized by comprising the following steps of: s1, constructing and optimizing a three-dimensional molecular configuration of a phase splitting agent to be predicted; S2, carrying out molecular information analysis based on the optimized molecular structure to obtain molecular analysis data, wherein the molecular analysis data comprises at least one of molecular structure, energy, bond vibration and wave function information; S3, calculating analysis factors related to the phase separation performance of the phase separation agent based on the obtained molecular analysis data, wherein the analysis factors comprise at least one of molecular descriptors and physicochemical parameters related to description of polarity and molecular descriptors and physicochemical parameters related to description of weak interaction among molecules, the molecular descriptors and the physicochemical parameters related to the polarity comprise polar surface area, polar surface area ratio, nonpolar surface area ratio, molecular surface polarity index, dipole moment and polarization rate, and the molecular descriptors and the physicochemical parameters related to weak interaction among molecules comprise hydrogen bond acidity, hydrogen bond alkalinity, hydrogen bond interaction energy, van der Waals energy and surface tension; S4, substituting the calculated analysis factors into a trained theoretical prediction model to obtain a phase separation performance prediction result of the phase splitting agent, wherein the theoretical prediction model comprises a linear equation or a multiple linear regression equation which is composed of the analysis factors as main parameters, and the phase separation performance prediction result is a phase separation characteristic value and comprises at least one of lean/rich liquid volume ratio, rich phase CO 2 percentage, phase separation load and absorbent saturation load; s5, selecting a phase splitting agent meeting the requirements to construct an organic amine phase change absorption system according to the prediction result and the process conditions.
2. The method for designing an organic amine phase change absorption system according to claim 1, wherein the step S1 is a construction and optimization of a molecular structure by quantum chemical calculation software, and the quantum chemical calculation software includes any one or more of Gaussian and MATERIALS STUDIO.
3. The method for designing an organic amine phase change absorption system according to claim 1, wherein the step S2 performs molecular information analysis by molecular information analysis software, and the molecular information analysis software includes any one or more of Gaussian, multiwfn, vmd.
4. The method for designing an organic amine phase change absorption system according to claim 1, wherein the calculation of the analysis factor related to the phase separation performance of the phase separation agent in the step S3 is implemented based on a quantum chemical wave function analysis program.
5. The method for designing an organic amine phase change absorption system according to claim 1, wherein the theoretical prediction model is obtained through training of limited experimental data, and aims to improve the accuracy of phase separation behavior prediction.
6. The method for designing an organic amine phase change absorption system according to claim 1, wherein the phase separation characteristic value is used for judging the phase separation performance of the phase separation agent by threshold analysis, wherein a smaller phase separation characteristic value indicates a greater possibility of phase separation.
7. The method for designing an organic amine phase-change absorbing system according to claim 1, wherein the organic amine phase-change absorbing system contains 2-amino-2-methyl-1-propanol (AMP) as an organic amine component, and the phase-splitting agent includes any one or more of water, ethanol, ethylene glycol, dimethyl carbonate, or n-propanol.

Description

Design method of organic amine phase change absorption system for capturing carbon dioxide Technical Field The invention belongs to the technical field of carbon dioxide trapping, and particularly relates to a design method of an organic amine phase change absorption system for trapping carbon dioxide. Background The organic amine-based chemical absorption method is a main method for capturing CO 2 after combustion in the power industry. The organic amine absorbent has the advantages of high reaction rate, large absorption capacity and the like, has strong applicability to the characteristics of low concentration of CO 2 and large smoke amount of the smoke gas of a power plant, but has high regeneration energy consumption, so that the power generation cost is increased. With the development of organic amine absorbent, the regeneration energy consumption of common secondary absorbent-mixed amine absorbent can reach 2.4-3.5 GJ t1CO2 Compared with the first-generation absorbent, the method saves the regeneration energy consumption by 50 percent at most. At present, most of the demonstration projects use mixed amine solutions as absorbents, such as W.a. Parish power plants near Houston, tex, use mixed amine solutions named KS-1, and national energy group national electric power brocade power plants combine multiple organic amines such as multistage amines, sterically hindered amines and the like into a composite solution for carbon capture, but the regenerated energy consumption of the secondary absorbent is still at a higher level. The third generation novel absorbent-phase change absorbent can be divided into lean/rich two phases after absorbing saturation, and only the rich phase enriched with CO 2 is heated during regeneration, so that the regeneration latent heat and sensible heat are greatly reduced, and the novel absorbent-phase change absorbent has higher theoretical energy-saving potential. The phase change absorbent is formed by mixing two or more components and mainly comprises organic amine (one or more absorption components) and a solvent (one or more solvents with phase separation function, namely the phase separation agent, and one or more solvents without phase separation function, such as water, can be also present). Among them, the absorption performance of the absorbent is mainly dependent on the absorption component, and the phase-splitting agent is the key to whether the absorbent can undergo phase change. The phase-splitting agent is not directly loaded with CO 2 in the absorption process, the whole reaction process is relatively simple, and after phase splitting, the phase-splitting agent is enriched in a lean phase and can be directly sent to an absorption tower for recycling. When the volume of the absorption solvent is fixed, the addition of the phase splitting agent reduces the water content in the system, and part of water is replaced, so that the vaporization heat is greatly reduced. At present, the research on phase-change absorbents is still insufficient, and the energy-reducing effects of different phase-change systems are uneven. Meanwhile, the CO 2 absorption principle and the phase separation mechanism of the phase change absorbent are still unclear, so that the construction of the phase change absorbent needs to be screened through a large number of repeated experiments, and the phase change absorbent has strong blindness. The development of phase change absorbers has the problems that limit the theoretical development of the phase change absorbers and limit the further industrial application of the phase change absorbers. Therefore, there is a need in the art to construct a rational design method for organic amine phase-change absorbers to accomplish efficient design and construction of phase-change absorbers, supporting further development thereof. Disclosure of Invention The invention aims to solve the problem of strong blindness in screening and constructing the existing phase-change absorbent, and provides a design method of an organic amine phase-change absorbent system for capturing carbon dioxide, which is used for predicting the phase separation behavior of an absorbent system formed by organic amine and different solvents, and screening out a proper phase-splitting agent according to the phase separation behavior, so as to rationally design the organic amine phase-separation system. The invention provides a design method of an organic amine phase change absorption system for capturing carbon dioxide, which comprises the following steps: s1, constructing and optimizing a three-dimensional molecular configuration of a phase splitting agent to be predicted; S2, carrying out molecular information analysis based on the optimized molecular structure to obtain molecular analysis data; S3, calculating analysis factors related to the phase separation performance of the phase separation agent based on the obtained molecular analysis data; S4, substituting the calculated analy