Sustainability Trade-offs in Biochar Production

Abstract

Biochar production and application offer a promising strategy for carbon sequestration and soil improvement, yet the sustainability of different production technologies and feedstock remains underexplored. This study applied multi criteria analysis (MCDA) using TOPSIS method to evaluate 12 biochar production scenarios. Four indicator categories were used - environmental, economic, technological, agronomic. The results show that low temperature pyrolysis using herbaceous sources as feedstock consistently ranked highest, due to lowest production costs, high yield and strong agronomic performance. Biosolids (sludge - derived organic material) based scenarios performed best when agronomic indicators were prioritized. Overall, scenarios with higher temperature regime showed lowest ranking, due to lower biochar yield and crop productivity impact. The results highlight the importance of the synergy between feedstock and temperature regime in determining biochar sustainability. The sensitivity analysis demonstrates that scenario ranking is highly dependent on decision making priorities, underscoring the need for context specific assessment.