From laboratory to pilot: Design concept and techno-economic analyses of the fluidized bed fast pyrolysis of biomass

For scaling up a lab-designed process of fluidized bed fast pyrolysis, a design concept and techno-economic analysis were both conducted in this study, including system development, experimental investigations and process evaluation. Rice husk was chosen as the feedstock based on its availability in Taiwan. The product distributions were studied with varying temperature, carrier gas flow rate and biomass feeding. The results showed that the optimal experimental conditions for obtaining the maximum bio-oil yield were at the temperature between 400 °C and 450 °C, the flow rate of 45 L/min and biomass feeding of 21.3 g per inject time. The analysis through GC-MS indicated that the major components of bio-oil contain n-hexadecanoic acid, octadecaoic acid, 9-octadecenoic acid and decanoic acid. The element and property analyses of bio-oil demonstrated that the bio-oil has high oxygen content and low heating value. The analyses of GC-MS/FID and GC-TCD showed that the major components of noncondensable gas are CO, CO2, H2, CH4 and N2. The design concepts and experimental conditions were plugged into a process model and the techno-economic analyses were conducted according to the local data. The minimum bio-oil selling price was calculated as $0.55/liter for the plant size of 1000 tonnes/day.