Biochar as a Sustainable Adsorbent for Syngas Purification in Biomass Gasification

The present work proposes the integration of biochar, derived from pyrolysis or gasification, into the syngas cleaning system as a sustainable, low-cost, and circular adsorbent. Biochar’s high specific surface area, developed microporosity, and tunable surface functional groups confer strong adsorption capabilities for contaminants such as CO2, tars, H2S, and NH3. The use of biochar valorizes a byproduct of thermochemical conversion within the same process chain, thereby reducing dependence on fossil-derived adsorbents, lowering operational costs, and enhancing environmental sustainability. The expected outcomes include improved purification efficiency, reduced greenhouse gas emissions, and the generation of cleaner syngas with higher calorific value. Utilizing biochar produced from the same or similar biomass feedstocks fosters a closed-loop system, minimizing waste generation and promoting circular resource utilization. The implementation of biochar-based syngas cleaning systems represents a scientifically robust and environmentally aligned approach that enhances the efficiency, sustainability, and economic feasibility of thermochemical conversion technologies. This innovation contributes directly to the realization of European climate and energy goals, supporting the development of low-carbon, circular bioenergy systems and strengthening regional bioeconomic resilience in line with EU sustainability directives.