Opportunities for biomass valorisation through sorption-enhanced gasification: assessing environmental and economic aspects on biochar production

Biochar has garnered significant attention for its potential to enhance soil quality and mitigate climate change. Despite its promise, comprehensive studies evaluating the feasibility of biochar systems remain limited. This research addresses this gap by analysing biochar production via sorption-enhanced gasification (SEG) using sewage sludge and grape seeds as feedstocks. A life cycle assessment evaluates the environmental impacts of producing 1 kg of biochar, while a life cycle costing examines the economic viability of SEG technology. Results show that grape seeds-based biochar yields lower environmental impacts compared to sewage sludge, with GHG emissions of 11.0 and 17.8 kg CO2, respectively. The economic analysis also supports agricultural waste as a more favourable feedstock, obtaining a higher profit of 0.94 €/kg compared to 0.82 €/kg. This study underscores biochar's potential as a sustainable solution for waste management and soil amendment, while highlighting the need for further optimisation to improve its economic viability.