CN-121971958-A - Asymmetric-structure bis-secondary amino propane diamine carbon trapping agent and preparation method thereof

CN121971958ACN 121971958 ACN121971958 ACN 121971958ACN-121971958-A

Abstract

The invention discloses a bis-secondary amino propane diamine carbon trapping agent with an asymmetric structure and a preparation method thereof, and relates to the technical fields of organic synthesis technology and carbon dioxide trapping and separation. The method takes a propylene diamine compound with primary amino and secondary amino as raw materials, and an aldehyde compound as a primary amine modifier. Based on the principle that the aldehyde group and primary amine groups in the propylenediamine compound undergo nucleophilic addition reaction, primary amine groups of the propylenediamine compound are directionally converted into secondary amine groups containing hydroxyalkyl substituted structures, and the secondary amine groups become N-alkyl N-hydroxyalkyl propylenediamine compounds with asymmetric structures. The carbon trapping agent has two secondary amine group reaction sites, wherein alkyl substituent groups are used as electron donating groups, so that nucleophilicity of secondary amine nitrogen atoms can be induced to be increased, absorption performance is improved, hydroxyalkyl substituent groups can promote secondary amine and CO 2 to generate a carbamate with unstable structure, and desorption performance is improved.

Inventors

CUI PENG
CHEN WU
Yu Hanfang
CHEN JINCHEN
YIN JINBIN
Hu Genjian
YANG BOHAN

Assignees

合肥工业大学

Dates

Publication Date: 20260505
Application Date: 20260407

Claims (10)

1. The asymmetric structure bis-secondary amino propane diamine carbon trapping agent is characterized by comprising an asymmetric structure bis-secondary amino propane diamine compound, wherein the asymmetric structure bis-secondary amino propane diamine compound also has an asymmetric structure of N-alkyl substituent and N-hydroxyalkyl substituent, and the asymmetric structure bis-secondary amino propane diamine trapping agent is prepared from an asymmetric structure bis-secondary amino propane diamine compound, a corrosion inhibitor and an antioxidant through the processes of mixing and homogenizing.
2. The asymmetric-structure bis-secondary amino propane diamine carbon trapping agent according to claim 1, wherein the asymmetric-structure bis-secondary amino propane diamine compound, the corrosion inhibitor and the antioxidant account for 5-70 wt%, 0-30 wt% and 0-30 wt% respectively.
3. The preparation method of the asymmetric structure bis-secondary amino propane diamine carbon trapping agent is characterized by comprising the following steps of: The method comprises the steps of taking a propylenediamine compound with primary amine groups and secondary amine groups as raw materials, taking an aldehyde compound as a primary amine modifier, taking an alcohol compound as a solvent, carrying out nucleophilic addition reaction on the aldehyde group and the primary amine groups of the propylenediamine compound, directionally converting the primary amine groups into secondary amine groups containing hydroxyalkyl substituted structures to prepare a crude solution of the asymmetric structure di-secondary amine groups propylenediamine compound, separating and purifying to obtain the asymmetric structure di-secondary amine groups propylenediamine compound, and preparing the asymmetric structure di-secondary amine groups propylenediamine carbon trapping agent after being matched with corrosion inhibitors and antioxidants.
4. The method for preparing a bis-secondary amino propylenediamine carbon trapping agent with an asymmetric structure according to claim 3, wherein the propylenediamine compound having both hydroxyl groups and secondary amino groups is a compound A having the following structure: ; In the compound A, R 1 comprises a C1-C4 alkyl group, R 2 comprises a hydrogen proton and a C1-C4 alkyl group, R 3 comprises a hydrogen proton and a C1-C4 alkyl group, and R 4 comprises a hydrogen proton and a C1-C4 alkyl group.
5. The method for preparing the asymmetric-structure bis-secondary amino propane diamine carbon trapping agent as claimed in claim 3, wherein the raw materials further comprise propane diamine compound B with primary amino groups and secondary amino groups, aldehyde compound C and solvent D, and the raw materials respectively have the following structural characteristics: ; The structural formula of the compound B is that R 1 comprises C1-C4 alkyl, R 2 comprises hydrogen protons and C1-C4 alkyl, and R 3 comprises hydrogen protons and C1-C4 alkyl; r 4 in the structural formula of the compound C comprises hydrogen protons and C1-C4 alkyl; In the solvent D, R 5 is a straight-chain or branched-chain alkyl of C1-C6.
6. The method for preparing the asymmetric-structure bis-secondary amino propane diamine carbon trapping agent as claimed in claim 3, which is characterized by comprising the following steps: S1, dissolving a compound C in a solvent D to prepare a solution with the mass fraction of 20-60%, fully mixing, slowly dripping the solution into the compound B at normal temperature, controlling the molar ratio of the compound B to the compound C to be 1:1-1:3.5, and maintaining the temperature to be 10-40 ℃ for nucleophilic addition reaction for 1-5 hours to prepare a crude solution of the asymmetric-structure bis-secondary amino propane diamine compound; S2, obtaining a target compound A through a reduced pressure distillation, crystallization, filtration, separation and purification process of a crude solution of the asymmetric structure bis-secondary amino propane diamine compound; and S3, homogenizing and compounding the compound A, the corrosion inhibitor and the antioxidant at normal temperature to prepare the asymmetric structure bis-secondary amino propane diamine carbon trapping agent.
7. The method for preparing the asymmetric-structure bis-secondary amino propane diamine carbon trapping agent according to claim 6, wherein the reaction equation in S1 is: 。
8. the method for preparing the asymmetric-structure bis-secondary amino propane diamine carbon trapping agent according to claim 3, wherein the corrosion inhibitor is one or more of sodium metavanadate, sodium molybdate, potassium sodium tartrate, L-arginine and imidazoline.
9. The method for preparing a bis-secondary amino propane diamine carbon trapping agent with an asymmetric structure according to claim 3, wherein the antioxidant is one or more of diethylenetriamine pentaacetic acid, diethylenetriamine penta-methylene phosphonic acid, ethylenediamine tetraacetic acid, acetone oxime, potassium iodide and 2-mercaptobenzimidazole.
10. The application of the asymmetric-structure bis-secondary amino propane diamine carbon trapping agent according to claim 1, which is characterized in that the asymmetric-structure bis-secondary amino propane diamine carbon trapping agent can be applied to the trapping and recovery of CO 2 in industrial flue gas in the industrial fields of coal-fired power generation, iron and steel, metallurgy, cement building materials, petrochemical industry, glass and ultrafine powder.

Description

Asymmetric-structure bis-secondary amino propane diamine carbon trapping agent and preparation method thereof Technical Field The invention belongs to the field of mixed gas separation and purification, and particularly relates to an asymmetric structure bis-secondary amino propane diamine carbon trapping agent and a preparation method thereof. Background The post-combustion trapping technology of the flue gas in the chemical industry is mature and widely applied, wherein a renewable organic amine chemical absorption method is the first choice for large-scale carbon trapping, and has remarkable potential. Monoamine absorbents (such as primary amine ethanolamine and tertiary amine N-methyldiethanolamine) commonly used in industry have performance bottlenecks, namely, the primary amine has excellent absorption efficiency but high regeneration energy consumption, and the tertiary amine has low regeneration energy consumption but slow absorption rate. The carbamate generated by the reaction of the secondary amine and CO 2 is easier to desorb, can synchronously realize high absorption rate and low regeneration energy consumption, and just compensates for the performance short plate of the monoamine absorbent, so that the carbamate is one of the research directions of novel carbon trapping agents. Chinese patent CN201610921874.X discloses a synthesis method of N-methyl-N' -hydroxymethyl-1, 3-ethylenediamine, wherein trioxymethylene is used as a hydroxymethyl precursor, heating depolymerization is carried out to obtain formaldehyde monomer, carbon tetrachloride is used as a solvent to construct a homogeneous system, nucleophilic addition of amine group and formaldehyde is carried out under nitrogen protection to generate-NH-CH 2 OH, and after reaction, the product is obtained through decompression desolventizing, split-phase, washing drying and column chromatography separation. The preparation method has the advantages of harsh reaction conditions, low yield and raw material utilization rate, single product structure and difficulty in meeting the differentiation requirement of the carbon trapping agent on the amine molecular structure. Disclosure of Invention In view of the above, the present invention aims to provide a bis-secondary amino propane diamine carbon trapping agent with an asymmetric structure and a preparation method thereof. The invention provides a targeted design on molecular structure, which is characterized in that the differential construction of two amino reaction sites is realized, so that an N-alkyl N-hydroxyalkyl propylene diamine compound A with an asymmetric structure shown as follows is obtained: The invention takes the propylene diamine compound with primary amine and secondary amine as raw materials, realizes directional hydroxyalkylation modification by utilizing the high reactivity of the primary amine, and simultaneously retains the original secondary amine as the desorption performance basis. The three-carbon skeleton of the propylene diamine can balance the electronic synergy and the space effect among amino groups, so that the problems of overhigh solution viscosity, mass transfer degradation and the like possibly caused by long-chain amine are avoided. Primary and secondary amines of propylene diamine are modified to a bis-secondary amine structure by introducing hydroxyalkyl groups on the primary amine groups, and the two substituents of the secondary amine are asymmetric structures of the N-alkyl and N-hydroxyalkyl groups, respectively. The structure is characterized in that the alkyl-based induction effect can enhance the nucleophilicity of nitrogen atoms to increase the absorption rate, the hydroxyalkyl-based steric hindrance effect can weaken the stability of carbamate to reduce the desorption energy consumption, and the absorption capacity and the liquid fluidity are improved by means of the two-site synergy and the hydroxyl hydrophilism. The invention derives a series of compounds with novel structure and adjustable performance by adjusting the R 1、R2、R3 and R 4 groups, and has the comprehensive advantages of high absorption capacity, good stability and low regeneration energy consumption. The technical scheme of the invention is as follows: The invention provides a preparation method of an asymmetric structure bis-secondary amino propane diamine carbon trapping agent, which is characterized in that a propane diamine compound with both primary amino and secondary amino is taken as a raw material, an aldehyde compound is taken as a primary amine directional modifier, an alcohol compound is taken as a solvent, nucleophilic addition reaction is carried out on the aldehyde group and the primary amino of the propane diamine compound, the primary amino is directionally converted into secondary amino containing hydroxyalkyl substituted structure, a crude asymmetric structure bis-secondary amino propane diamine compound solution is prepared, the asymmetric structure bis-secondary