Optimizing pyrolysis parameters and product analysis of a fluidized bed pilot plant for Leucaena leucocephala biomass

Abstract

This study aimed to optimize the production of bio-oil from Leucaena leucocephala wood using a fluidized bed reactor. Response surface methodology was used to optimize the fast pyrolysis through three operational parameters: pyrolysis temperature, nitrogen flow rate, and temperature of the first condensation stage. The optimum conditions obtained for bio-oil production were 500 °C, 26.4 L min–1, that is, about 3.3 times the minimum fluidization flow, and 80 °C, respectively. The bio-oil obtained under optimum conditions was of good quality and did not require further treatment. Physical properties of the bio-oil were analysed according to ASTM D7544-12. In addition, the chemical composition of the non-condensed gases and bio-oil were identified using GC–MS. The non-condensed gases were found to contain mainly ketones and lignin derivatives, while the bio-oil contained cyclic ketones, alcohol ethers, aromatic alcohols, and lignin derivatives. The study found that increasing the pyrolysis temperature did not significantly increase the yield of H2 and CO for syngas production. Regarding the solid obtained, a large amount of unreacted material (66.7 wt.%) is generated at 400 °C, and as the temperature is increased, a high-quality biochar is obtained.