Rehmann, Lars (The University of Western Ontario)

Purpose

Anaerobic digestion is a sustainable technology to convert organic waste into bio gas. Anaerobic digesters are commonly found on farms and co-located with the food-processing industry. Typically anaerobic digesters use a consortium of bacteria converting a seasonally varying feedstock into methane and carbon dioxide. Depending on the composition of the feedstock and operating conditions the gas output might vary. Partial of full poisoning of a digester can occur if unwanted materials enter the reactor. This project aims to develop a 'biogas booster' with the ability to increase or revive gas production in continuous digesters particularly after operating disruptions. The commercial partner in the project operates sugar refining plants and some of the side-streams of their plants have low economic value. Though potentially not meeting guidelines for human consumption, these sugar streams will provide an excellent and easily accessible feedstock for the microbial population in an anaerobic digester. Various formations will be tested for their ability to enhance gas production while the microbial population will be monitored to avoid the loss of microbial diversity due to the selection for sugar degraders. The project will result in a prototype biogas booster that will be tested at Ingredion's digester, as well as guidelines for its usage without negatively impacting the long-term digester performance.