There has been considerable interest in the development of new technologies and materials that allow CO2 removal from natural gas which is typically contaminated with over 40% CO2 and N2. The removal of CO2 would increase the energy density of natural gas making its storage and transpiration more efficient, and enhances its conversion to hydrogen fuel. Given the relatively small and similar kinetic diameter of CH4 and CO2 molecules, their efficient separation remains a nontrivial task.
 

The preparation of a library of benzimidazole-linked polymers (BILPs) featuring high surface area and amine functionalized pore walls will be presented and their performance in CO2 removal from natural gas will be discussed. Our studies show that the efficiency of BILPs in CO2 removal from CH4 depends upon the pore metrics and surface chemical functionalization.High CO2/CH4 selectivity in the range of 8.0~17 makes BILPs attractive for future use in natural gas purification applications.