Substitution of fossil gaseous fuels with biomass-based gases is of interest to the iron and steel industry due to its role in the mitigation of anthropogenic CO2emissions. In switching from fossil fuels to biomass-based gases, a systems analysis of the full value chain from biomass supply to the production and supply of final gas products becomes crucial. This study uses process and heat integration methods in combination with a supply chain evaluation to analyse full value chains of biomass-based gases for fossil gas replacement within the iron and steel industry. The study is carried out as a specific case study in order to understand the implications of utilizing bio-syngas/bio-SNG as heating fuels in iron- and steel-making, and to provide insights into the most sensitive parameters involved in fuel switching. The results show a significant cost difference in the fuel production of the two gas products owing to higher capital and biomass use in the bio-SNG value chain option. When tested for sensitivity, biomass price, transportation distance, and capital costs show the most impact on fuel production costs across all options studied. Trade-offs associated with process integration, plant localisation, feedstock availability and supply were found to varying extents.

This paper considers the utilisation of forest biomass in iron and steel making by putting focus on the supply of available raw biomass assortment, biomass conversion technologies, and distribution of biomass-based products towards reduced fossil CO₂ emissions in the iron and steel industry. Biomass-based products are produced by converting biomass assortments from forestry operations and forest industries via slow pyrolysis and gasification technologies. Using a spatially explicit cost optimisation model, biomass supply is optimised to suit the corresponding demand for energy and material substitution, and the extent to which biomass can be a tool in CO₂ abatement is explored. The study findings show that maximum use of biomass-based products result in a 43% reduction in CO₂ emissions across the existing steel producing technologies. Results also show that increasing the rate of biomass utilisation via substitution targets is more effective than the use of a carbon pricing policy, since the maximum CO₂ reduction is unmet even with very high CO₂ prices. In the scenario analysis, it is found that low fossil fuel prices constitute a barrier to adopting biomass as an alternative to fossil energy use. Compared to the business-as-usual case, a maximum of 27% increase in energy-related costs was calculated for the industry.