Medium-temperature conversion of biomass and wastes into liquid products, a review

The subject of this review is the production of new-generation biofuels and fuels from wastes by cost effective medium temperature conversion processes. Recent literature results concerning pyrolysis at medium-temperature (mainly 300–450 °C) of biomasses, plastics and wastes are reviewed. The focus is on processes usable to maximize the production of liquids. Conclusions concern the relation of raw material composition and reaction temperature on the quality and quantity of liquid products. The main limitation of this approach is the high heteroatom content that is frequently present in the resulting fuels, particularly oxygen from biomass-derived fuels, but also nitrogen, sulphur and chlorine from waste derived fuels. For this reason, further refining treatment could be necessary, depending on the use of the resulting fuel.