Adsorption properties of biomass-based activated carbon prepared with spent coffee grounds and pomelo skin by phosphoric acid activation

► AC prepared from coffee grounds and pomelo skin were activated by phosphoric acid. ► Adsorption of ethylene and n-butane fitted well with Langmuir equation at 308 K. ► PS-AC could adsorb 129 cm3/g n-butane at room temperature up to 1 atm. ► Micropore filling effect was explained in a thermodynamic way.