This subproject is about gasification, in which a fuel is not completely burned but completely transformed into a burnable gas, also called syngas.
One of the main aims of this project is to couple the thermal process of gasification with the biological process of fermentation. In case of the biomass gasifier wood chips together with digestion residues shall be used as fuel. In order to accomplish this constructional adaptation of the biomass gasifier as well as fuel pretreatment is needed.
Biomass gasification is a thermal process which is influenced by many parameters. A key parameter is the fuel water content. Is it too high the gasification temperature is decreased causing more tars. Therefore the digestion residues have to be dewatered. A promising way could be the use of screw presses which also partially pelletize it.
Even with the pretreatment of digestion residues it is expected that the new fuel mixture has higher water contents as the currently used fuels and therefore more tars are created. With construction adaptations or with a catalytical syngas treatment this could be reduced (WP 7). A new developed tar sensor shall enable to change the process rapidly when being in bad operation conditions (WP 5).