Gasification and Fischer-Tropsch with CCUS (biodiesel)

The biomass-based Fischer Tropsch pathway (bio-FT) is typically referred to as a biomass-to-liquid (BTL) route, though this umbrella term can apply to any route which produces liquid fuel from biomass. In the bio-FT route, biomass is first gasified into syngas and the syngas is then converted into hydrocarbon liquids via the Fischer-Tropsch process. Biomass with a high lignocellulosic content (e.g. wood, straw, residues from forestry and agriculture, municipal solid waste) is gasified via heating in an oxygen-restricted environment, producing a mixture of mostly hydrogen (H2), carbon monoxide (CO), carbon dioxide (CO2), and other hydrocarbons. This "syngas" is then sent to a water-gas shift (WGS) reactor to increase the H2/CO ratio required for Fischer-Tropsch (FT) synthesis. In the CCUS variant, the CO2 is separated from the syngas prior to FT synthesis, resulting in a pure stream of CO2 that can be captured and compressed for utilisation or storage rather than vented. If stored, negative emissions are created. The resulting liquids from the FT reactor are further cleaned and separated into their hydrocarbon products (diesel, jet, naphtha, wax, etc). Technical challenges revolve around tar buildup and removal during gasification. The biomass used to produce bio-FT are not food crops, avoiding direct competition with food and unwanted land-use change. Fuels resulting from bio-FT are "drop-in" and can therefore use existing fossil fuel infrastructure and technology without blending limits. Technical challenges revolve around tar buildup and removal during gasification. Bio-FT kerosene (biojet) is a American Society for Testing and Materials (ASTM)-certified sustainable aviation fuel (SAF), allowed to be blended up to 50%.