Not just food waste or plastics: even agricultural by-products can be transformed into resources for sustainable mobility. This is the key message from the scientific poster presented by Professor Piero Mastrorilli of the Polytechnic University of Bari, in collaboration with the ENEA research centre in Trisaia, during the III National Conference of the SCI Division of Chemistry for Technologies and the XIV AICIng Conference.
The study, titled “Utilization of Lignin-Rich Biorefinery Residues to Produce Biofuels and Value-Added Chemicals”, shows how lignin-rich residues resulting from the biorefinery processing of wheat straw can be converted into biofuels and high-value-added chemical compounds.
The project is part of the activities funded by the PNRR – NextGenerationEU, specifically within Spokes 11 and 14 of the national MOST centre, focused respectively on green chemistry for the automotive sector and new fuels for the energy transition.
Lignin: an underestimated resource
Lignin is one of the main by-products of the process used to extract fermentable sugars from lignocellulosic biomass, such as wheat straw. Following treatments like steam explosion and enzymatic hydrolysis, the resulting solid residue—known as lignin-rich solid (LRS)—is often regarded as low in value.
In this study, however, LRS was directly subjected to catalytic hydrogenation, without any additional pretreatment, to obtain valuable molecules such as 4-ethyl-2-methoxyphenol (an aromatic compound for chemical use) and eicosane, a saturated hydrocarbon with potential application as a renewable fuel.
An optimised and scalable process
The process was carried out in a high-pressure autoclave using a commercial Raney nickel catalyst. By varying parameters such as the amount of catalyst, hydrogen pressure, temperature and solvent, the researchers were able to optimise the yield and selectivity of the products.
Using gas chromatography–mass spectrometry (GC-MS) and multifactorial statistical analysis, the team identified the most favourable operating conditions, laying the groundwork for industrial-scale application of the process.
A building block for sustainable mobility
The poster highlighted how lignin valorisation can help integrate bioenergy supply chains with those of alternative fuels, contributing to reduced fossil fuel dependency and more sustainable management of agricultural residues.
In line with the mission of the CO-SMART project, this research shows that even what is currently considered waste—like lignin—can become a strategic resource for the energy transition and the development of new renewable fuels for the transport sector.
From a wheat field to a fuel tank, via a hydrogen reactor: the mobility of the future also takes shape through the residues of the past—if science knows how to transform them.
