Invited Session: Energy Recovery
Innovative Two-Phase Anaerobic Digestion (0.5 CEU)
Tuesday, September 26, 2017
15:30 – 16:00
Moderator: William Avila, Andean Waste Association, Colombia
Anaerobic digestion (AD) is gaining momentum as a cost-effective mean for organic solid waste treatment with potential energy recovery. Acid forming acidogenic bacteria and acid utilizing methanogenic archaea work in harmony in the AD process, and the physiological balance between these two groups is the key for the digester stability. In recent years, two-phase AD is proposed to treat high solids food waste by decoupling the acidogenesis from methanogenesis to optimize each reactor separately. Despite the theoretically sound approach, currently less than 10 percent of the commercial plants are using a two-phase approach. To understand the reasons behind it, a series of experiments have done to analyze the mass balance of the two-phase reactors treating food waste, and prevention of energy loss as H2 from the hydrolytic/acidogenic reactor was identified as one of the potential niches to enhance the methane recovery. This presentation will report the diversion of biogas from the leach bed reactor to the UASB and the influence of headspace pressure on improving hydrolysis and methane gas generation. This will lead to better commercialization potential for two-phase anaerobic digestion.
By attending this presentation, participants will better be able to understand the reasons behind two-phase anaerobic digestion, develop means to improve methane gas generation through diversion of biogas from the leach bed reactor to the UASB, examine the influence of headspace pressure on improving hydrolysis and methane gas generation and design more commercially viable two-phase anaerobic digestion system.