The effect of chemical activation of biochar on biogas purification

Abstract

Biogas become one of many alternative energies that are claimed to contribute to greenhouse gas mitigation. The improved technology to gain good quality biogas has been developed over many years such as carbon dioxide adsorption and methane enrichment. Implementing biochar-based renewable sources can replace activated carbon-based fossil fuels. This study is developing activated biochar-based rice husk by chemical activation to replace 25% volume of natural zeolite to adsorb carbon dioxide in biogas purification. Three treatments of adsorption time variation were used in this study: 10, 20, and 30 minutes. The results showed that activation of biochar repaired the capability of biochar to adsorb carbon dioxide and methane levels in biogas. The best result was shown by biogas purification for 30 minutes with a methane enrichment of 24% compared to biogas before purification. Our results highlight the activated biochar based-rice husk becomes a candidate for an adsorbent in biogas purification and the chemical activation process as a strategy to improve the capability of the adsorbent.