Optimization of a free-fall reactor for the production of fast pyrolysis bio-oil

► A novel, 1 kg/h free-fall reactor is designed for bio-oil production. ► We investigated and modeled yields from the biomass fast pyrolysis reactor. ► Response surface methodology was used to identify optimal conditions for bio-oil. ► We examined heater temperature, gas flow rate, biomass particle size and feed rate. ► Liquid yields greater than 70 wt.% were achieved with minimal sweep gas flow.