Gasification is conversion of solid fuels, such as biomass, into primarily gaseous fuels called syngas or producer gas (Fig. 1). The conversion occurs through partial oxidation of biomass at high temperatures breaking down biomass polymers into small gaseous compounds such as CO, H2, CO2 and CH4. For gasification to occur, two things are required: the presence of oxidizing agent (gasifying agent) and high temperature (>600-700°C). Oxygen, air and steam have been used as gasifying agents. When oxygen or air is used, partial oxidation of biomass provides heat for the endothermic reaction eliminating the need for an external heat source. Steam requires an external heat source to raise the temperature to about 900°C.

Heating

Chemical

reactions

Catalysis

Y

Gasification

Figure 1. Operations in biomass conversion through gasification.