ZIF-8 and ZIF-67 as catalysts for promoting carbon dioxide capture based on monoethanolamine solution

Abstract

Carbon dioxide capture, utilization and storage (CCUS) technology is considered an effective solution to achieve carbon neutrality. In CCUS, chemical absorption stands out as an efficient CO₂ capture method suitable for environments with low CO₂ partial pressures. This study aims to enhance the CO₂ capture performance of monoethanolamine (MEA) solution by employing zeolitic imidazolate frameworks ZIF-8 and ZIF-67 as catalysts. The impacts of catalyst concentration and experimental temperature on the quantity, rate of absorption, rate of desorption, and reusability of MEA for CO₂ absorption were investigated. Changes in the volume concentration of CO₂ in the mixed gas were monitored to assess these parameters. The results demonstrated that at a catalyst concentration of 150 mg/mL for ZIF-8 and 125 mg/mL for ZIF-67, MEA achieved CO₂ absorption quantity of 22.22 % and 18.89 %, respectively. This corresponded to substantial increases of 63.39 % and 125.9 % in the CO₂ maximum absorption rate of MEA solution. While the maximum desorption rate of MEA was enhanced by 130.1 % and 148.2 %. In conclusion, the introduction of ZIF-8 and ZIF-67 catalysts effectively catalyzed the CO₂ capture process, significantly enhancing the CO₂ capture quantity of MEA and ensuring energy-efficient regeneration of MEA. This study provides a novel approach for improving the performance of MEA in terms of capturing CO₂.