Selective fractionation and depolimerization of lignocellulosic biomass using sub and supercritical water to produce liquid fuels for conversion into middle distillates
The project FRACBIOFUEL is based on the research need of the fractionation of lignocelullosic biomass to produce different fractions enriched in celullose, hemi-celullose and lignins, as starting fractions for subsequent depolymerization into biofuel with clean technologies, targetting the aromatic fraction. Specifically, the project will focus in the depolimerization of lignin to produce a biofuel suitable for further conversion into middle distillates (gasoline and diesel). This fraction will be in mid term a source of selective aromatics compounds.
A well established subcritical and supercritical water technology will be used, using alcohols as modifiers, aromatics as chain terminators that prevent and biomass polymerization and high lignin content vine biomass as a suitable natural source.
The depolymerization process is a complex process and it is necessary to study the phenomena that occurs at chemical level (compounds and reactions), polymeric level (depolymerization to oligomers, molecular weight population balance), microscopic level (mass and heat transfer, particle population balance) and macroscopic level (reactor design and influence of non-ideal flow pattern).
Vine biomass has been selected as it contains high percentages of lignin (up to 43% seeds and 28% pomace) compared to other natural sources, and also eucaliptus globulus.
The study will be conducted using a high pressure reactors (up to 30 MPa and 500 º C) operating in semicontinuos and continuos flow.
The project will be developed through the following objectives:
- Selective fractionation of biomass (vine and eucaliptus) in sub and supercritical water.
- Depolymerization and hydrolisis of the lignin fraction for the production of biofuel for conversion into middle distillates.
- Modeling the fractionation and depolymerization process of biomass and lignin.
The applicant research group has proven experience in subcritical and supercritical water technology, in the design and implementation of innovative high-pressure processes, in depolymerization of other polymers such as polycarbonate and epoxy resins, in the analysis of polymers and aromatic compounds, and in modeling of physic-chemical processes.
FRACBIOFUEL will provide the necessary engineering knowledge in the area of selective depolymerization of lignin and it will underpin the future use of lignin and lignocellulosic biomass as a source of biofuel and also aromatic compounds (in mid/long term).