The Effectiveness of Zeolite and Activated Charcoal Use in The Purification Process of Cow Manure Biogas

Abstract

This study examines the effectiveness of zeolite and activated carbon as adsorbent materials in the purification process of biogas produced from cattle manure, which generally still contains impurity gases such as carbon dioxide (CO₂) and hydrogen sulfide (H₂S) that can reduce calorific value and cause corrosion in equipment. The aim of this research is to increase methane (CH₄) concentration and optimize the utilization of biogas as a renewable energy source. An experimental study was conducted at CV. Berkah Sejati Farm, West Lombok, with three treatment variations: unpurified biogas, biogas purified using activated carbon, and biogas purified using a combination of activated carbon and zeolite. The results showed that the purification process had a significant effect on improving biogas quality. Activated carbon reduced the H₂S concentration from 407 ppm to 101 ppm, while the combination of activated carbon and zeolite reduced H₂S to 97 ppm and decreased CO₂ concentration from 9,527 ppm to 859 ppm. The CH₄ concentration remained relatively stable, indicating that the improvement in biogas quality was mainly due to the reduction of impurity gases. Furthermore, the fastest combustion rate was observed in biogas purified using activated carbon, with a heating time of 5.85–6.10 minutes. The ANOVA analysis showed that the calculated F-value was greater than the F-table value at a 5% significance level. In addition, the flame color changed from reddish to bright blue, indicating a more efficient combustion process. Overall, the combination of zeolite and activated carbon proved to be the most effective in enhancing biogas purity and has strong potential to be applied as an economical and environmentally friendly purification technology that supports the development of clean and sustainable energy in Indonesia.