ABSTRACT
A great number of biomass conversion processes exist for converting solid biomass directly into liquid fuels. While biological conversion processes are always noted for the production of liquid fuels, thermal conversion processes are always associated with the production of gaseous fuels such as synthesis gas. Thus, for most thermal conversion processes, there are additional steps required to convert this gaseous fuel into liquid fuels. Hence, biomass liquefaction is normally associated with the production of liquid fuels directly or indirectly from thermal conversion of solid biomass. Sometimes, this process is also referred to as the “gas-to-liquid” or GTL process. There are basically two routes for biomass liquefaction processes-direct liquefaction, where biomass slurry is directly converted into hydrocarbon fuels, and indirect liquefaction, where biomass is rst gasied before the gaseous fuels are converted further into liquid fuels. Synthesis gas becomes the primary feed input to the indirect conversion process and the efciency of the nal product will depend on the heating value of the synthesis gas. In previous chapters, it was shown that the synthesis gas from pyrolysis has a higher heating value than those from gasication.
