In general, the PAC showed excellent
cyclability of adsorption/desorption of CO2 and a minimal capacity loss after subsequent cycles. In addition,
the PAC showed a rapid adsorption of CO2. Both characteristics are essential for the eventual use of
such PACs in the adsorption driven separation of CO2 from flue gas. A chemically activated carbon (CAC)
was prepared by treating hydrothermally carbonized beer waste with H3PO4 and a heat treatment in a
flow of N2. This CAC showed a significant amount of mesopores in the range of 5 nm, in addition to
micropores. The apparent selectivity for the activated carbons for CO2-over-N2 adsorption was determined
at 0 C and 10 kPa.