A large-scale experimental study on CO2 capture utilizing slurry-based ab-adsorption approach

The increasing concentration of CO2 in atmosphere is deemed the main reason of global warming. Therefore, efficiently capturing CO2 from various sources with energy conservation is of great significance. Herein, a series of experiments were carried out to successfully test the slurry-based ab-adsorption method for continuously capturing CO2 in the large-scale cycled separation unit with cost-effect taking into account the scale-up criteria. A bubble column (with height 4900 mm and inner diameter 376 mm) and a desorption tank (with volume 310 L) are the essential components of the separation unit. The novel slurry used in this study was formed with zeolitic imidazolate framework-8 and 2-methylimidazole-water solution. The influence of operation conditions was investigated systematically. The results show that increasing sorption pressure and slurry height level, decreasing gas volume flow and sorption temperature are beneficial for separation processes. The volume fraction of CO2 in the feed gas was also studied. Although the scale-up effect had been observed and it was found that it exerted a negative effect on CO2 capture, depending on experimental conditions, CO2 removal efficiency could still reach 85%-95% and the maximum CO2 loading in the recycled slurry could be up to 0.007 mol.L-1.kPa(-1). Furthermore, the slurry-based method could be operated well even under very moderate regeneration conditions (333 K and 0.05 MPa), which means that the novel approach shows greater energy conservation than traditional amine absorption methods. (C) 2020 The Chemical Industry and Engineering Society of China, and Chemical Industry Press Co., Ltd. All rights reserved.

Automated summary

The study successfully tested a method of capturing CO2 using a slurry, showing that adjusting operational conditions can enhance separation efficiency and lead to greater energy conservation.