4. Conclusion
Two kinds of biologic matters were chosen as the raw materials
for preparing activated carbon. Pomelo skins were directly
treated with hydrothermal treatment. The activated agent for
both materials was phosphoric acid. Commercial activated carbon
was used for reference. N2 adsorption–desorption, SEM, XRD and
FTIR revealed that the activated carbon was successfully prepared.
CG-AC owned super-micropore structure and PS-AC possessed
mesoporous pores. During the adsorption properties tests of asprepared
activated carbon, ethylene and n-butane were chosen as
the representatives of VOCs. All the adsorption isotherms fitted
well with Langmuir equation. For ethylene adsorption, the commercial
activated carbon which owned mainly micropores could
adsorb more gas than the as-prepared samples. PS-AC could adsorb
nearly twice larger n-butane than commercial activated carbon.
Clausius–Clapeyron equation was used to calculate the isosteric
heats of adsorptions at different coverage. It explained the differences
during the adsorption processes. Micropore filling effect was
also observed in a thermodynamic way.