Sustainable fuel production from biomass

Currently, biomass resources can only be processed using large energy amounts. In the EU-funded project SUSFUELCAT, scientists are using an alternative to the intensive drying process: aqueous-phase reforming (APR). Given that this process does not consume much energy, APR is one of the most promising, competitive routes to producing liquid and gaseous fuels from biomass.

The key to an efficient process is the catalyst enabling the conversion of low-value biomass to hydrogen. SUSFUELCAT focuses on optimising APR catalysts, while ensuring hydrothermal stability. It is developing catalysts based on metal nanoparticles and using carbon-based materials as a catalyst support.

To deduce the fundamental structure-property relationships that influence the catalytic activity, project members are performing an initial screening of commercial catalysts. The properties of the model catalysts vary with respect to their active metal, cluster and pore sizes, and carbon graphitisation. Additionally, the model catalysts are implemented in in silico studies for theoretical investigations. Catalyst activity and selectivity will be studied experimentally with real and model feedstocks.

Project members have synthesised colloids of noble nanoparticles with various surface areas, with palladium and platinum demonstrating excellent stability. Base metals showed a tendency to reoxidise. Computer simulations help to optimise the catalyst properties.

Another task was to prepare sugar alcohols such as xylitol, sorbitol and galactitol for use in feedstock. Project members have deduced the first structure-property relationships for platinum and carbon xylitol. Carbon supports proved to be well-suited for tuning hydrogen and alkane selectivity. Pure carbon materials were tested for their hydrothermal stability, with stability being increased for higher degrees of graphitisation.

A main project conclusion is that except for the noble metal price, recycling cost and efficiency are also important for catalysts' economic assessment.

SUSFUELCAT should boost Europe's competitiveness in catalysts for hydrogen production. APR technology will enable efficient sustainable fuel production from biomass, reducing Europe's reliance on fossil fuels.