Carbon capture from humid gases using alkaline-promoted polypyrrole by a vacuum swing adsorption process

• Published in: Separation and purification technology Vol. 323; p. 124399
• Main Authors: Wang, Zhe, Liu, Liying, Ren, Tingsheng, Gao, Peng, Sang, Haoyuan, Yang, Xue, Li, Zhuo, Wang, Zijian, Li, Shupeng, Li, Gang Kevin
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 15.10.2023
• Subjects: Alkaline promoted; CO2 capture; Polypyrrole; Vacuum swing adsorption; Vacuum swing adsorption; CO2 capture; Polypyrrole; Alkaline promoted
• ISSN: 1383-5866; 1873-3794
• DOI: 10.1016/j.seppur.2023.124399

[Display omitted] •An alkaline-promoted polypyrrole shows an 80% increase in CO2 adsorption capacity.•The CO2 adsorption amount of AP-PPy is totally preserved in presence of water.•Excellent recovery is demonstrated in vacuum swing adsorption cyclic experiments.•This work allows for post combustion carbon capture and separation from flue gases. Post-combustion carbon capture from humid flue gas is one of the urgent research projects for achieving the target of carbon neutrality in near future. Nitrogen-containing polymers are considered as a promising adsorbent for carbon capture in flue gases due to their potential water resistance. Here, two-step synthesis of alkaline-promoted polypyrrole (AP-PPy) with water resistance was investigated as an adsorption material for carbon capture and separation. It was found from chemical and physical analysis that the alkaline-promoted sample kept the similar morphological structure as the pristine polypyrrole but possessed more amino groups. The adsorption of single component gases revealed that the adsorption amounts of CO2, CH4, and N2 were 1.31, 0.28 and 0.065 mmol/g at 303 K respectively, among which the CO2 uptake was 80% higher compared with the original polypyrrole. The breakthrough point of AP-PPy in moisture is comparable to that of dry mixture, but the dynamic CO2 adsorption capacity is calculated to be larger than that of dry condition. A single-bed three-step vacuum swing adsorption cycling device was constructed in the laboratory and the effect of adsorption time, vacuum pressure and feed flowrate on product purity and recovery were explored with over 50 cycles in each condition to ensure cyclic steady adsorption, thereby also verifying the recyclability of AP-PPy. The excellent CO2 adsorption and separation properties demonstrated that AP-PPy can be a promising material for post combustion carbon capture.