Grant: Alliance Grants

This proposal focuses on the pilot-scale development and refinement of micro-aeration technology for in-situ biogas desulfurization in anaerobic digestion. The biogas from anaerobic digesters requires extensive purification processes prior to its utilization, such as heat and power generation or upgrading to renewable natural gas (RNG) or pipeline-quality biogas. Notably, volatile sulfur compounds, such as hydrogen sulfide and other organosulfur compounds in biogas, are detrimental to metal pipes and biogas utilization equipment. Due to the high cost of end-pipe biogas desulfurization technologies, most anaerobic digestion facilities flare biogas, leading to significant greenhouse gas (GHG) emissions. Micro-aeration is an emerging and potentially low-cost alternative desulfurization method, which is operated via controlled injection of a little amount of air or pure oxygen into digesters. This proposal builds upon our preliminary bench-scale testing results and aims to advance micro-aeration regarding process design, control/monitoring, maintenance, and detailed techno-economic assessment toward its full-scale application. Developing micro-aeration as a low-cost desulfurization process in the proposed project will promote biogas utilization and reduce GHG emissions by reducing biogas flaring. Besides enhancing biogas quality in the partner organization's full-scale anaerobic digestion facility, the lessons learned from the project will also be helpful to other anaerobic digestion facilities in waste and wastewater sectors across Canada.