Many biofuel production pathways have achieved commercial status, including ethanol production from corn and sugarcane, FAME biodiesel, HVO renewable diesel and HEFA biojet kerosene from vegetable oils and waste oils. Yet an innovation gap remains in converting woody and grassy biomass to liquid biofuels, for example via thermochemical routes such as biomass gasification followed by bio-FT synthesis, hydrothermal liquefaction and fast pyrolysis with upgrading. These routes can tap into different and more abundant biomass waste and residue resources than HVO and HEFA, allowing renewable diesel and biojet kerosene to sustainably scale up to the quantities required in the Net Zero Scenario.
While bio-FT is currently at the demonstration phase, several commercial-scale projects are now in the pipeline, mostly in the United States, but also in Europe and Japan. The projects encompass a wide selection of feedstock choices (forestry residues and municipal solid waste) and end products (renewable diesel and biojet kerosene). One project, the Bayou Fuels biorefinery in the United States, will even include carbon capture and storage to produce negative emissions, also known as carbon dioxide removal.
Both hydrothermal liquefaction and fast pyrolysis with upgrading are at a lower level of technology readiness than bio-FT, hindered by challenges in pre-treating the bio-oils for further hydroprocessing into renewable diesel. But once pre-treated, the bio-oil can be co-processed with petroleum products (up to around 10%) at existing oil refineries in the near term and thus avoid costly capital expenditure related to scaling up. Currently, only a handful of pilot projects exist, such as the EU HyFlexFuel project and Sweden’s Pyrocell, a joint partnership between a sawmill and an oil refinery.