Gasification is a cost efficient process that converts solid or liquid feedstock for production of transportation fuels, chemicals, heat and/or electricity. The gasification process takes place at high temperatures, exceeding 700 °C, and with a controlled amount of oxygen and/or steam.
The produced gas consists of varying levels of carbon dioxide (CO2), carbon monoxide (CO), methane (CH4), hydrogen (H2), water and lower levels of light hydrocarbons (≥C2) and tar. The gas composition depends on several different parameters such as gasification temperature, oxidant (air, oxygen, steam), reactor type and feedstock. When gasifying at higher temperatures, using oxygen, normally exceeding 1200 ° C, a product gas mainly consisting of CO and H2 is generated that can be upgraded to synthesis gas, i.e. a gas suitable for synthesis of chemical products. At gasification temperatures below 1000 ° C, a product gas with higher levels of different hydrocarbons (e.g. methane) is generated and which by means of post-gasifier catalytic or thermal cracking or by scrubbing can be further upgraded to synthesis gas. If air is used instead of oxygen in the gasifier, the product gas is diluted by nitrogen from the air and is suitable as a fuel gas for co-generation of power and heat in engines and gas turbines or used in boilers and furnaces.