Development, optimization and validation of an innovative integrated anaerobic thermophilic digester for the treatment of organic waste and septage
Partner: SusGlobal Energy Corp. Date: Jan 2017 to Dec 2018 Funding: Southern Ontario Water Consortium’s Advancing Water Technologies program Lead Researchers: Leisa Kirkaldy, Barbara Siembida-Losch
What We Did
Ontario’s landfill network is notoriously deficient—too much garbage and no place to put it. This is a problem the world over, addressed through various measures. Source separation programs, for example, divert or transform the inconvenient dregs of our lives into valuable end products through recycling, waste-to-energy initiatives and composting. SusGlobal Energy, Canadian innovators in the circular economy, is committed to advancing long-term, creative solutions that divert solid organic wastes (which represent a whopping 30%-40% of the municipal waste stream) from landfill. Global in mindset but local in practice, they prioritize R&D that improves the performance and cost-effectiveness of waste treatment operations in rural and remote communities across Canada.
Together with SusGlobal, the CAWT developed, optimized and validated a new anaerobic digestion technology that converts biosolids and organic wastes into purposeful materials. The technology uses a process known as co-digestion, in which two unique temperatures are coupled within the same processing system to generate maximum yields of biogas and farm-grade fertilizer—magic for a practical cause.
The project unfolded in three phases, beginning with pilot-scale testing of the thermophilic (high temperature) digester at the CAWT. We tested the processing performance of the apparatus using manually dewatered and non-manually dewatered digestate, derived in turn from the mesophilic (medium temperature) digester. These results were used to develop a demonstration-scale prototype for study and validation under real world conditions, and provided the data necessary for evaluating the efficacy of the two-stage fermentation system.
A commercial-scale operating system utilizing the two-stage digestion technology was validated for biogas yield at current operating conditions. This validation and the data from the pilot-scale testing give SusGlobal a unique insight for design considerations.
Our research established the factors and methodologies that optimize the digestors’ yields of biogas and compost, ultimately helping to ensure that SusGlobal can continue to operate in rural and remote communities at break-even costs.