Thermochemical conversion, and process integration solutions for biomass-derived feedstocks and their upgrading into usable fuel blends.

The transition toward sustainable energy systems is especially important for the Nordic region, where ambitious climate targets coexist with the availability of large amounts of biomass and industrial residues. The EU-Interreg Aurora project FORBLEND addresses this challenge by exploring sustainable fuel blending concepts based on locally available renewable resources. This study presents an overview of ongoing work within the project, combining laboratory results and preliminary process simulations to evaluate low-carbon fuel pathways suitable for Nordic conditions. The work focuses on the thermochemical conversion of biomass-derived feedstocks and their upgrading into usable fuel blends. Experimental observations are supported by steady-state process modelling using Aspen Plus, which is applied to represent key unit operations such as conversion reactors, gas cleaning, and separation units. Attention is given to the selection of thermodynamic property models, as accurate description of phase behaviour and reaction equilibria is essential for biomass-based systems. The Redlich–Kwong equation of state is selected due to its reliable performance at elevated temperatures and moderate pressures, especially for gas mixtures containing hydrogen, carbon monoxide, carbon dioxide, and light hydrocarbons. Reaction behaviour is evaluated using equilibrium-based approaches, allowing
comparison with experimental trends while keeping the model computationally efficient. Initial simulation results suggest that process integration and appropriate fuel blending strategies can improve energy efficiency and carbon utilization compared to conventional fossil-based fuels. Sensitivity analyses indicate that operating conditions and feedstock composition strongly influence system performance, highlighting the importance of region specific design for Nordic applications. Future work within FORBLEND will extend this modelling framework by incorporating techno-economic assessment and life-cycle considerations, as well as closer integration with experimental data. Overall, this study contributes to the early-stage evaluation of sustainable fuel blends and supports the development of low-carbon energy solutions for the Nordic region.