Fluidized Bed Gasification of Solid Recovered Fuels in a 500 Kwth Pilot Plant

Abstract

On the way to climate-neutrality with low resource consumption, the economics worldwide needs ways to obtain high-quality products from existing material flows. If waste is used as a feedstock for gasification, high-quality synthesis gas is obtained from which new products for the chemical industry (e.g. methanol) or the transport sector (Fischer-Tropsch products) can be obtained. The fluidized bed-based High-Temperature-Winkler process is particularly suitable for the gasification of solid recovered fuel (SRF) and biomass that are difficult to grind since the feedstock can be processed in lump form. The gasification characteristics of SRF pellets were investigated in a 500 kWth pilot gasifier at the Technical University of Darmstadt. After a co-gasification with pre-dried lignite, a mono SRF gasification could be realized. This paper presents the effects of operating temperature and the SRF content in the feedstock on the syngas quality, which is characterized by the target components CO and H2, the undesired fraction of CH4, and some representative higher hydrocarbons. It could be shown, that the syngas gas components CO and H2 depend mainly on the gasification temperature and not on the used feedstock. On the other hand, the higher amount of volatiles in the SRF fraction rises the methane concentration and the amount of higher hydrocarbons in the syngas. It was observed that these components are decomposed at higher gasification temperatures and an almost tar-free synthesis gas is produced.

Keywords: Gasification, bubbling fluidized bed, waste recycling, closed carbon cycle, experimental data