Solid Biomass Energy Pathways: Feedstock Resources, Conversion Routes, Sustainability Implications, and Deployment Prospects

Abstract

Solid biomass remains one of the few renewable resources capable of delivering dispatchable energy while also supporting waste valorization and rural economic activity. This review re-examines the role of solid biomass in low-carbon energy systems by synthesizing evidence on feedstock availability, thermochemical conversion routes, environmental performance, and techno-economic feasibility. The discussion covers agricultural residues, forestry by-products, dedicated energy crops, and the organic fraction of municipal waste, emphasizing how calorific value, moisture level, ash content, and logistics shape technology selection. Combustion, pyrolysis, and gasification are compared in terms of operating conditions, conversion efficiency, emissions, and product flexibility, with additional attention to co-benefits such as biochar generation and combined heat and power integration. The review also evaluates life-cycle emissions, policy support, feedstock supply chains, and scale-up barriers that determine whether biomass systems deliver genuine climate benefits or simply shift burdens to land, air quality, and food systems. Across the surveyed literature, the strongest performance is observed when biomass is locally sourced, properly pretreated, and deployed within robust sustainability frameworks. Although solid biomass cannot serve as a universal replacement for fossil fuels, it can make a meaningful contribution to distributed heat and power generation, circular waste management, and regional decarbonization. Continued progress will depend on cleaner conversion technologies, better resource governance, digital process monitoring, and stronger integration with bio-refinery and circular-economy models.