The EHLCATHOL project, Horizon 2020 H2020-LC-SC3-2018-2019-2020 (BUILDING A LOWCARBON, CLIMATE RESILIENT FUTURE: SECURE, CLEAN AND EFFICIENT ENERGY), with a topic ”Chemical transformation of enzymatic hydrolysis lignin (EHL) with catalytic solvolysis to fuel commodities under mild conditions”, was designed based on the state-of-the-art of catalytic solvolysis of lignin and the important results of the consortium members before the proposal. Specifically, they were the first to achieve complete conversion of technical lignin to fuel range precursor molecules. However, they as well as others in follow-up works encountered typical challenges in scaling up this process, such as, recondensation of the monomers during product distillation, a relatively low lignin-to-solvent ratio in the feed, low reaction rates and yields of desired products. The key to overcome these challenges enroute to commercialization of this promising approach is to build up the needed fundamental knowledge about the underlying chemistry and process steps towards specific fuel cuts. The EHLCATHOL project is aimed to boost 2G Advanced Bioethanol Technologies, which utilizes lignocellulose, the material making up the cell wall of land-based plants, to produce fuel-grade ethanol. Bioethanol production via fermentation of non-edible lignocellulose has been demonstrated at the commercial scale at all continents in the past decade. As such, it is also expected to contribute to the EU’s 2050 carbon neutral renewable fuel goals. Nevertheless, fermentation primarily converts saccharide polymers, i.e. cellulose and hemicellulose, to fuel ethanol, leaving EHL as a waste. Therefore, the profitability of 2G bioethanol plants is hampered by the lack of efficient methods to valorise EHL, i.e. transforming the current waste by-product into more valuable products, such as fuel blends. The mid-to-long term target of the 2G bioethanol technology is to utilize forestry and agricultural residues, which contain lignin in larger amounts, roughly 35-45% in terms of energy content. It can therefore be foreseen that, as the efficiency and scale of the 2G bioethanol technology is improved, the switch of the feed to lignin-rich biomass would make EHL utilization even more demanding.
In the 4 years EHLCATHOL project, intensive and efficient collaborative research has been done within the consortium. We achieved all the goals specified in the Grant Agreement; obtained bio gasoline, bio jet-fuel samples and a promising bio-marine fuel blend with high efficiency; established knowledge on the principles of the interaction of EHL and fuel compatible solvents; and were enabled to illustrate the superiority of catalytic solvolysis in lignin valorization. We also contributed greatly to the scientific community with 28 high-quality articles, 2 special issues of an international journal and organization and presentations of/on conferences, as well as 3 webinars.
