Fischer–Tropsch synthesis is a set of catalytic processes that can be used to produce fuels and chemicals from synthesis gas (mixture of CO and H₂), which can be derived from natural gas, coal, or biomass. Biomass to Liquid via Fischer–Tropsch (BTL-FT) synthesis is gaining increasing interests from academia and industry because of its ability to produce carbon neutral and environmentally friendly clean fuels; such kinds of fuels can help to meet the globally increasing energy demand and to meet the stricter environmental regulations in the future. In the BTL-FT process, biomass, such as woodchips and straw stalk, is firstly converted into biomass-derived syngas (bio-syngas) by gasification. Then, a cleaning process is applied to remove impurities from the bio-syngas to produce clean bio-syngas which meets the Fischer–Tropsch synthesis requirements. Cleaned bio-syngas is then conducted into a Fischer–Tropsch catalytic reactor to produce green gasoline, diesel and other clean biofuels. This review will analyze the three main steps of BTL-FT process, and discuss the issues related to biomass gasification, bio-syngas cleaning methods and conversion of bio-syngas into liquid hydrocarbons via Fischer–Tropsch synthesis. Some features in regard to increasing carbon utilization, enhancing catalyst activity, maximizing selectivity and avoiding catalyst deactivation in bio-syngas conversion process are also discussed.

Biochar, a by-product from the fast pyrolysis of pine wood, was used as the support material for the synthesis of carbon-encapsulated iron nanoparticles. The nanoparticles were characterized for physicochemical properties by multiple morphological and structural methods (e.g., SEM, TEM, XRD, FTIR, and TPD). The Fischer–Tropsch synthesis (FTS) process was carried out to evaluate the catalytic activity of the nanoparticles on conversion of biomass-derived synthesis gas (bio-syngas) to liquid hydrocarbons. Characterization results revealed that the nanoparticles had core–shell structures with iron in situ encapsulated within a graphitic shell. Moreover, significant amounts of iron carbide (mainly Fe₃C) were formed as an interface between the carbonaceous shell and the iron core. FTS tests indicated that such carbon-encapsulated iron nanoparticles possessed a high activity on conversion of bio-syngas and good selectivity towards liquid hydrocarbons (of which olefins were the dominant product). Over a 1500 h testing period, the nanoparticles showed striking stability against deactivation, with CO conversion maintained at about 95% and liquid hydrocarbon selectivity at about 68%.