The current climatic and geopolitical situation leads to strong decarbonisation policies in several industries worldwide. Moreover, the European Union is pushing intensive industries to achieve a 55% reduction in CO₂ emissions towards 2030. Among them, the steel manufacturing sector is at the lead of alternative projects that can help achieve this ambitious target. Co-production of syngas and biochar is one potential solution for this sector. Herein, a techno-economic analysis is provided to evaluate the economic feasibility and the effect of the most influential parameters for a successful deployment. A bibliographic review has been carried out to establish a clear baseline for such an analysis in terms of investment costs at several scales for gasification projects. Additionally, the cost evolution for coke, natural gas, and CO₂ emission credits on the profitability of these projects are given. The case scenario processing 20,000 t_biomass/y is the most feasible solution, with a payback of around three years and a net present value (NPV) of around 15 million EUR, showing that biomass gasification can be an up-and-coming alternative in the mid-term.

This work proposes an innovative method for adjusting the natural gas from the grid to the consumer pipeline requirements in a full-scale pressure reduction station. The use of two counterflow vortex tubes instead of the traditional boiler to preheat the gas before throttling is demonstrated as a powerful alternative. Thus, a reduction of fossil fuel consumption is reached, which amounts to $7.1\%$ less CO${}_2$ emitted. To ensure the optimal configuration, the vortex tube was thoroughly characterized in laboratory facilities using nitrogen as the working fluid. Various operating conditions were tested to determine the most efficient setup. Computational Fluid Dynamics (CFD) simulations were conducted with nitrogen to validate the behavior of the vortex tube. Subsequently, the working fluid was switched to methane to assess the performance differences between the two gases. Finally, the vortex tubes were deployed at a full-scale installation and tested under real consumption demand. The results obtained from this study offer promising insights into the practical implementation of the proposed method for adjusting the natural gas flow, highlighting its potential for reducing fossil fuel consumption and minimizing CO${}_2$ emissions. Further improvements and refinements can be made based on these findings.