Effectiveness of polyacrylamide gel formulation for CO2 and H2S mitigation in biogas purification

Biogas, a renewable fuel source, requires purification to remove contaminants like carbon dioxide and hydrogen sulphide. This study explores the use of polyacrylamide gel, synthesized with chromium (III) acetate and Piperazine, as an effective biogas purification medium. The gel’s non-Newtonian behaviour, characterized by shear thinning, enhances its adsorption properties. Multiple characterization methods confirmed the gel’s structure and functional groups. Experiments under varying conditions revealed the gel’s ability to purify biogas, achieving a maximum methane concentration of 90.1 %. However, repeated use reduces the gel’s CO₂ adsorption capacity, necessitating regeneration. The purification efficiency reached 74.60 % and 77.39 %, accompanied by high equilibrium constants (K = 7.988 and 9.101) and the most negative ΔG values (–5206.11 and –5526.68 J/mol) among all gel matrices. This research highlights the potential of polyacrylamide gel as a sustainable solution for biogas purification, promoting cleaner and greener transportation.