Gasification
Gasification is the thermal breakdown of a material into a gas via partial oxidation under the application of heat. It Involves the sub-stoichiometric oxidation or steam reformation of a substance to produce a gaseous mixture containing two or more of the following: (i) oxides of carbon, (ii) methane and (iii) hydrogen[1]. The gas is then generally burnt to raise steam and create electricity, but many plants are exploring the option of cleaning the gas for use in a gas engine or separating the gas into usable fractions such as hydrogen for use, as an example, of liquid fuels which in turn may be eligible under the RTFO.
Gasification can be considered a process between Pyrolysis and conventional EfW in that it involves the partial oxidation of a substance. This means that oxygen is added but the amounts are not enough to allow the fuel to be completely oxidised and full combustion to occur. The temperatures employed are typically above 650°C. Generally, the Syngas generated from Gasification will have a Net Calorific Value (NCV) of 4-10MJ/Nm3 [2].