Pilot demonstration of micro-aeration for anaerobic digestion

本方案的重点是中试规模的厌氧消化原位沼气脱硫微曝气技术的开发和完善。来自厌氧消化器的沼气在利用之前需要广泛的净化过程，例如热能和发电，或升级为可再生天然气(RNG)或管道质量的沼气。值得注意的是，沼气中的挥发性硫化物，如硫化氢和其他有机硫化合物，对金属管道和沼气利用设备都是有害的。由于末端管道沼气脱硫技术成本高，大多数厌氧消化设施燃烧沼气，导致大量温室气体(GHG)排放。微曝气是一种新兴的、潜在的低成本的替代脱硫方法，它是通过控制向消化器中注入少量空气或纯氧气来进行操作的。这项建议建立在我们初步的实验室测试结果的基础上，旨在推动微曝气技术在工艺设计、控制/监测、维护和详细的技术经济评估方面的全面应用。在拟议的项目中，发展微曝气作为一种低成本的脱硫工艺，将通过减少沼气燃烧来促进沼气利用和减少温室气体排放。除了提高伙伴组织全面厌氧消化设施的沼气质量外，从该项目中学到的经验教训也将有助于加拿大各地废物和废水部门的其他厌氧消化设施。

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.