High-rate micro-aeration digestion for advanced process stability and sulphide-free biogas
Kraakman, B.1 and Lee, P-H.2, 1Jacobs, 2Imperial College London
(free)
Many anaerobic digestors have not been fully driven to its stable performance potential (0.35 L/g COD sludge). Traditional anaerobic digestion (AD) processes will benefits from a facelift that maximizes biogas production, enhancing process stability and broadening substrate treatability without major infrastructure modification. Moreover, elevated concentrations of hydrogen sulfide (H2S) in the biogas is often a limitation for downstream processing of biogas that typically requires expensive gas conditioning before it is used to generate energy.
This facelift could be given by implementing micro-aeration, a process-integrated technology that is defined as a system with zero concentration of oxygen present in the sludge and limited (trace) consumption of oxygen. Bench-scale and full-scale tests using micro-aeration technology was undertaken and showed that this process-integrated technology has potential using minimum plant upgrading while contributing to the sustainability and economic efficiency of the energy recovery process of organic waste digestion as operated for example at WRRFs.
Keywords: anaerobic digestion, biogas, energy recovery, hydrogen sulfide, micro-aeration. Conference Theme: Engineering and biological advances in AD.
