In order to produce liquid fuels from biomass, the biomass must first be reformed into synthesis gas (or syngas)—a mixture of hydrogen and carbon monoxide. Syngas can be produced directly via biomass gasification, or it can be produced in steps— first by pyrolyzing the biomass to produce pyrolysis oil, which can then be steam reformed to make syngas. Syngas is then used to make the desired fuel by varying the catalyst and the process conditions to yield ethanol, methanol, dimethyl ether or diesel via the Fisher-Tropsch process.
Liquid fuels are generally composed of hydrocarbons and/or oxygenated hydrocarbons. Biomass is an inherently heterogeneous material containing a mixture of lignin, cellulose, hemi-cellulose, proteins and other molecules. The challenge in producing syngas from biomass is to increase the energy density of the fuel by dehydrating and deoxygenating the material to produce pure syngas. In addition, all heteroatoms and tar must be removed as these can foul and/or deactivate the catalyst. This is a very challenging proposition to which there are multiple paths to success.
Please contact SERC for updates on syngas research being performed by our collaborative partners.
(Photo used with permission courtesy of Enerkem)