Light tar is a significant contaminant in gas thermally produced from biomass using updraft gasifiers. This tar represents a server risk with respect to formation of deposits within the gas-driven
Utilisation of biomass and waste is generally expensive and not very efficient on small and medium scale plants. For gasification systems the main problem is the gas cleaning, where severe
Uneven char conversion and in extreme cases channels have been observed in the char bed of down draft gasifier. This might lead to a reduced efficiency of the gasifier.