Assessment of Straw to Bioenergy Pathways Using the Analytic Hierarchy Process

Efficient utilization of agricultural residues plays an important role in advancing sustainable bioenergy development in China. This study established a multi-criteria evaluation framework integrating energy quality, economic performance, and environmental impact to assess three representative straw-to-energy pathways: direct combustion for power generation, anaerobic digestion for biogas production, and lignocellulosic ethanol production. The Analytic Hierarchy Process (AHP) was applied to determine indicator weights and calculate composite scores using operational and pilot-scale data obtained for each pathway. The results showed that anaerobic biogas achieved the highest overall performance (composite score 0.41), with balanced performance in economic viability, energy utilization efficiency, and environmental performance. Direct combustion demonstrated favorable economic performance (0.37) but exhibited higher process emissions, whereas lignocellulosic ethanol showed superior environmental performance but suffered from low energy conversion efficiency and negative economic returns (0.00). Sensitivity analysis confirmed the stability of the pathway ranking and highlighted the dominant influence of economic and energy-related indicators on the overall sustainability assessment. The study demonstrated that anaerobic biogas exhibited the most balanced performance among the evaluated pathways under the investigated technological and economic conditions, while integrated biorefining approaches, such as co-production of ethanol and biogas, showed potential for further enhancing resource efficiency and sustainability.