External ceramic membrane contactor for in-situ H₂ assisted biogas upgrading

Biological H₂-assisted biogas upgrading has gained significant attention as an environmentally friendly substitute to common physico-chemical upgrading techniques, but is largely limited by the low solubility of H₂. This study evaluated the design of a ceramic membrane contactor module for H₂ injection. H₂ dissolution was maintained at high efficiency by controlling gas supply and sludge recirculation rate, achieving a biogas quality of average 98.8% CH₄ during the stable operation phase with a 108% increase in the CH₄ production rate. This also outperforms conventional H₂ injection using diffuser sparging which could only achieve a biogas quality of 84% CH₄ content. Microbial community analysis found high Methanobacterium spp. abundance within the archaea at 95.2% at the end of the operation, allowing the dominance of the hydrogenotrophic methanogenesis pathway for high upgrading efficiencies. The system is a high-performance external membrane connector module coupled to common anaerobic digestion systems for biogas upgrading.