Gasification is classed as an Advanced Conversion Technology (ACT). The process has been in use for many years, and is similar to that used for making town gas from coal, which has been done for decades.
Gasification describes the process by which material, refuse derived fuel (RDF) in this instance, is converted into a synthetic gas (and ash) by using an external heat source in a low oxygen environment. The syngas is combusted in a high efficiency boiler and the heat generated is used to raise steam for a turbine, where electricity is generated.
In addition, a proportion of the heat generated can be supplied for use in external applications, either as steam or very hot water. Heat is recirculated from the gas combustion process to heat up the incoming RDF to create more syngas so only a small amount of fossil fuel (usually natural gas) is required to kick-start the process.