Optimization of small-scale anaerobic digesters for on-site organic waste processing

Anaerobic digestion (AD) is a microbial process where organic materials (sugars, starches, hemicellulose, etc) are broken down into renewable natural biogas and nutrient-rich biodigestate byproducts (roughly 5-10% solids in water). The performance of AD systems is heavily dependent on careful control of digester conditions, including pH, temperature, and health and proportions of the bacterial populations present, which are easily affected by varying characteristics of the waste input stream. CCI BioEnergy currently uses a large-scale AD-based system to convert municipal green bin organic compost into renewable biofuels; however, they aim to optimize low-maintenance, robust and efficient smaller-scale systems for processing at the waste source (eg. residential, commercial, and industrial organic waste producers), allowing for on-site natural gas production and use. One of the expected issues is that compared to municipal waste, on-site waste will be more variable on a day-to-day basis while also potentially lacking overall nutritional profile variety. This project aims both to characterize the performance of digester systems fed from different waste sources, with a particular focus on profiling biological diversity, and to use that information to develop bacterial inoculants to be used in site-specific AD systems to mitigate problems and differences in performance arising from varying waste compositions.

Faculty Supervisor:

Bryan Koivisto

Student:

Partner:

CCI BioEnergy;Toronto Metropolitan University

Discipline:

Physics

Sector:

Administrative and support, waste management and remediation services

University:

Toronto Metropolitan University

Program: