Bio-Oil Production from Biomass by Flash Pyrolysis in a Three-Stage Fluidized Bed Reactors System

Abstract

A novel system of fast pyrolysis and vapour quenching was developed at pilot scale to obtain bio-oil from bio mass. The system uses three-stage of interconnected fluidized bed reactors that continuously circulate silica sand from an internal pyrolysis reactor to a second external annular reactor for char burning, which generates most of the heat required by the pyrolysis reactor, and a third sand-preheating reactor that burns non-condensable pyrolysis gas. The hot vapours, after high temperature cleaning, are quenched in a flash cooling system. The process generates up to 62% of bio-oil, 25% of char and 13% of non-condensable gas. The heat requirements for the total system are provided by burning part of the char and non-condensable gases generated in the pyrolysis step and by preheating the fluidizing gas for the pyrolysis reactor.