Quantitative analysis on chemical influence of modified activated carbon in TSA/PSA for methanol via alterable phosphorus functional groups and stable structure

Volatile organic compounds (VOCs) emissions cause serious health problems and environmental pollution, and modified activated carbon is widely used in the treatment of VOCs pollution. Methanol was selected as adsorbate and activated carbon with alterable phosphorus functional groups was synthesized as adsorbent. In the absence of the influence of the physical properties, the chemical functional groups influence coefficient (AC) was proposed, which can be used to analysis and predict the influence of chemical functional groups specially. The results show that the performances including adsorption capacity and enrichment ratio are positively related to the AC whether in temperature swing adsorption (TSA) or pressure swing adsorption (PSA). By comparison, the adsorption capacity of PSA is greater than that of TSA because of the higher efficiency caused by faster cycle. Further research on process showed that the curve character of TSA, including breakthrough time and equilibrium time, is highly related with AC, but the curve character of PSA is mainly depended on the state of activated carbon. Therefore, the attenuation of TSA is mainly caused by the change of chemical functional groups, while the attenuation of PSA is mainly caused by the failure of activated carbon.