New characterisation method of biomass and solid recovered fuels for gasification processes

The characterisation method, developed for biomass and solid recovered fuel (waste) gasification processes, consists of simultaneous determination of gasification reactivity and ash sintering behaviour in a thermobalance. After the gasification is finished, the ash residue is inspected under microscope to detect the possible molten phases and sintering. The thermobalance tests are followed by 2–3 test runs in a laboratory fluidisedbed reactor, which are carried out to complement the results, to study e.g. the tar formation and the type of the ash deposits in the gasifier. According to the test results, potential biomass fuels have usually high gasification reactivity, but the ashes can sinter dramatically already at 700–800 °C. The sintering can be more enhanced in high pressures. Usually over 800 °C gasification temperature is required for achieving satisfactory carbon conversion and for avoiding tarrelated problems in gas cooling and filtration. Typical for solid recovered fuels is that they have higher contents of impurities and they are more inhomogeneous compared to biomass.