Abstract
Increasing CO2 emissions from using fossil fuels and the resulting greenhouse effect have received extensive concerns, and the reduction of CO2 has become the global trend. In this study, we select cheap mesoporous materials, AC (activated carbon) as adsorbents. Moreover, we also modify AC with impregnation method to improve its CO2 capture capacity. For solution, we select EG(ethylene glycol), DEG(diethylene glycol) and PEG-400(polyethylene glcol) for CO2 capture in flue gas. TGA was used to determine the adsorption capacity of the adsorbent and a break through experiment was used to determine the absorption capacity of the solvent and the hybrid in batch system. The result shows that 10wt% AC dispersed in EG, 5wt%AC dispersed in DEG and 5wt%AC dispersed in PEG-400 reach maximum value and are close to the sum of adsorption and absorption capacities of the adsorbent and absorbent. Further addition of adsorbent will lead to decrease in total capacity due to poor dispersion. In modified AC hybrid absorption-adsorption system, 20wt%AC-NaOH(2N) dispersed in EG and 20wt%AC-KOH(2N) dispersed in EG reach maximum value, 0.1984mmol/g(1bar,10%CO2)and 0.1551mmol/g(1bar,10%CO2)respectively, and are higher than the weighted average ad(b)sorption value of solid and liquid phase. Moreover, 20wt%AC-KOH(2N)+EG has lower degradation of absorption capacity after each cycle of regeneration test. The experimental results show that the selected absorbent, modified activated carbon, dispersed in EG has better absorption than that of ZIF-8/mIm in EG with absorption of 0.125mmol/L-1 (1bar, 10% CO2).