Fast pyrolysis of greenhouse waste into bio-oil and optimization of process conditions using response surface methodology

Different parameters are effective on bio-oil yield and quality during the production of bio-oil from biomass through fast pyrolysis. Knowing the optimum values of these parameters is important to obtain bio-oil in the desired yield and quality and therefore economic production of energy. This study investigated the optimum process conditions of fast pyrolysis in a drop-tube-reactor system for high yield and quality bio-oil production from the mixture of greenhouse vegetable wastes (GVW) such as tomato, pepper, and eggplant. The experimental design was performed for optimization by using response surface methodology (RSM) with central composite design (CCD). The effects of biomass particle size (0.5–1.5 mm), pyrolysis temperature (450–600 °C), and nitrogen gas flow rate (1000–1700 mL min −1 ), and their reciprocal interaction were determined. The optimum conditions were determined as a particle size of 1.5 mm, a reaction temperature of 400 °C, and a nitrogen gas flow rate of 300 mL min −1 . The maximum bio-oil yield was obtained as 49 wt% at the optimum fast pyrolysis conditions. GC–MS analysis of bio-oil sample obtained under optimum process parameters indicated an abundance of hydrocarbon and acid contents.