A Pilot Study of Syngas Production from Bio-oil Thermal Cracking in a Bubbling Fluidized Bed Reactor

Abstract

A fluidized bed reactor that is operating in the bubbling regime has been developed for the conversion of bio-oils to syngas.The reactor consists of a 7.6 cm I.D. (or internal diameter) bed, with an expanded freeboard. The volume of the reactor can be adjusted to vary the gas residence time. This reactor has been used to carry out either thermal or catalytic cracking for reforming bio-oils.A gas-atomized injector has been specially developed to feed a bio-oil, which may be viscous and contaminated with small ash and char particles. Besides, the gas-atomized nozzle allows it to remain cool until coming in contact with the fluidized particles inside the bed.This article presents the product yields and compositions obtained by thermally cracking the bio-oil at various temperatures and gas residence times. The bed temperature was varied from 500 to 700 °C. Moreover, the vapor residence time ranged from 7.8 to 27.6 seconds.Also, the effect of particle size and mass of bed was investigated. Finally, based on this study, the conversion of bio-oil to gas increased with an increase in temperature and residence time.

Keywords

• bio-oil
• syngas
• hydrogen
• fluidized bed reactor
• thermal cracking