Effects of Different Physical Activation Agents on Adsorbent Pore Development and Methane Uptake

Abstract

Introduction: The effects of different physical activation agents on carbon material pore development and the subsequent methane adsorption were studied. Methods: Palm kernel shell (PKS) as a carbon precursor was pre-treated with ZnCl2 and activated for two hours with (i) CO2, (ii) steam, and (iii) the combination of CO2 and steam (in series). Results: The findings indicate that the combination of two activation agents in series resulted in a considerably high value of methane uptake of 118.73 V/V at 10 bar. Compared to the activation with a single activating agent (steam or CO2), double activation agents produced activated carbon (AC) with a higher BET surface area of 869.8 m2/g and a total pore volume of 0.47 cm3/g. The obtained carbon materials were predominantly microporous, with 92.08% micropores and 7.92% mesopores, respectively. Conclusion: The results show that combining two activation agents with different diffusivity and reactivity significantly affects carbon pore development for methane adsorption.