Biomasses

Biomass refers to organic matter from plants, animals, and microorganisms that can be used as an energy source or as a material. Common energy feedstocks include wood and wood residues, agricultural residues, dedicated energy crops, municipal solid waste, manure, and algae. Biomass is considered renewable when harvesting keeps pace with regrowth. Energy content and composition vary by feedstock, influencing suitability for heat, electricity, or liquid fuels.

Biomass can be converted by several pathways. Direct combustion produces heat or steam to generate electricity. Gasification converts biomass into a combustible gas (syngas) for power or chemical synthesis. Anaerobic digestion yields biogas rich in methane for heating or electricity, with the remaining digestate usable as fertilizer. Pyrolysis thermally decomposes biomass into bio-oil, gases, and char. Fermentation and related processes produce liquid fuels such as ethanol from sugars or starches and biodiesel from lipids.

Environmental and sustainability considerations vary with feedstock and management. Potential benefits include reduced fossil energy use, rural employment, and lower net emissions when land-use change is avoided. Risks include competition with food, water use, biodiversity loss, and emissions in some supply chains. Lifecycle analyses and sustainability standards help compare options and guide responsible deployment.

Applications range from residential heating to electricity generation and transport fuels. Deployment faces challenges such as logistics for bulky feedstocks, seasonal supply, capital costs, and ensuring high conversion efficiency and low emissions. Research and policy support aim to improve feedstock diversification, conversion performance, and integration with other renewable resources.