University of Northern British Columbia bioenergy plant: Performance review and opportunities for improvement.

The University of Northern British Columbia commissioned a biomass gasifier to generate heat to offset the use of natural gas in 2011. At an average boiler output of 6.9 GJ/hr the average thermal efficiency was determined to be 80% (LHV), the flue gas average temperature was 134°C with an energy content of 589 MJ/hr. Options investigated to improve the efficiency of the bioenergy system include: Installing a flue gas condensing heat exchanger, reducing the flue gas O₂ percentage, pre-drying the fuel, installing a chiller, and installing a thermal storage tank. The most viable opportunity that exists is to add a flue gas condensing heat exchanger and connect the residences to the hot water loop. Alternative technologies were compared to the bioenergy plant in terms of greenhouse gas displacement, and the system with the greatest potential is a slow pyrolysis system producing both heat and biochar for use in soils. --Leaf ii.