**3.1 Fast pyrolysis**

This process involves decomposition of biomass at high heating rate (10–250°C/s), high temperature (500–1200°C) and short vapor retention time (<2 s) in the absence of oxygen. Due to high heating rate, biomass is rapidly heated to pyrolysis temperature before it is decomposed. Although, this process yield gaseous, liquid and solid fractions, but exclusively for bio-oil (liquid fuels) production, if pyrolysis temperature is less than 650°C. Quick vapor condensation enhanced formation of bio-oil, usually >50% products fraction is liquid, while gaseous formation is favored if pyrolysis temperature is up to 1000°C (about 30% yield is obtainable) and solid fraction is less 30% of pyrolysis products [26].
