Evaluation of Electricity Production from Different Biomass Feedstocks Using a Pilot-Scale Downdraft Gasifier

Ten different types of biomass served as fuel to generate electricity using a pilot-scale downdraft biomass gasification power plant. The gasifier temperature profile, along with the syngas quality and performance were determined for varying flow rates. It was found that temperature profiles depended on syngas flow rate and type of biomass feedstock and can be divided into three groups. An increase in syngas flow rate from 105 to 211 m(3) h(-1) (across all biomass types) was found to have little effect on gas composition, causing calorific values peaking between 4.2 and 5.6 MJ (Nm)(-3). Maximum electrical power output of each tested biomass feedstocks was observed at the highest syngas flow rate, ranging from 47 to 63 kW with specific biomass consumption below 2.0 kg kW(-1) h(-1). Among them, gasification efficiency exceeding 70% was achieved from Eucalyptus and corncob, and Giant Leucaena. Engine-generator set efficiency and electrical efficiency ranged from 11.0 to 25.8% and from 6.3 to 18.6%, respectively. Overall, biomasses varying widely in their properties showed a strong potential for electricity generation using downdraft gasification technology.