Wood Bio-Oil Noncatalytic Gasification: Influence of Temperature, Dilution by an Alcohol and Ash Content

Biomass gasification is gaining attention as a route for biomass energy production. When large scale units are considered, bio-oil shows lots of advantages compared to solid biomass such as high energy volume density and easy handling and storing. Syngas (H-2 and CO) can be produced from bio-oil by two gasification processes, also called reforming processes: catalytic reforming at medium temperature and noncatalytic reforming at high temperature. In the literature, most of the works focus on the catalytic reforming and mainly concern the aqueous fraction of bio-oil or model compounds. Only very few works can be found on the noncatalytic reforming of crude bio-oil. The objectives of this work were to perform experimentally the injection and gasification of nondiluted bio-oil in a lab-scale High Temperature Entrained Flow Reactor (HT-EFR) and to determine the syngas composition and yield. The influence of temperature on the gasification process has been investigated over a wide range from 1000 to 1400 degrees C. Hydrogen yield increases with temperature via steam reforming of CH4 and C2H2 and with water gas shift reaction. A thermodynamic equilibrium calculation was conducted. It shows that equilibrium is reached within several seconds at the temperature of 1400 degrees C. After that, experiments of gasification were realized at 1400 degrees C with pure ethanol and with ethanol added bio-oil and in order to study the impact of dilution on the syngas yield. The influence of ash on the gasification process has also been evaluated. The ash seems to cause a decrease in the total amount of gas produced.