Biomass (predominately cellulosic material) may be converted into hydrocarbon liquids through a two stage process. Through high temperature gasification, producing syngas, followed by the Fischer-Tropsche process, converting the syngas into liquid fuel. A similar process has also been used to convert coal to liquids.

When restricting the amount of oxygen during combustion of organic material such as biomass, the consequence is partial oxidation, producing carbon monoxide and hydrogen (syngas) differently to complete oxidation, when the combustion is provided sufficient amount of oxygen, producing carbon dioxide and water.

The carbon monoxide and hydrogen mixture is the feedstock for the Fischer-Tropsche process producing liquid hydrocarbon fuel.

Biomass may also be converted into liquids through thermal depolymerisation. Learn more about thermal depolymerisation, go to Bio-oil.