Biomass Energy: Fuels, Energy Content, Densification, and Processes - Prof. Matt Ryan Alde, Study notes of Agricultural engineering

Download Biomass Energy: Fuels, Energy Content, Densification, and Processes - Prof. Matt Ryan Alde and more Study notes Agricultural engineering in PDF only on Docsity! AGR 225 Biomass • Fuels • Energy Content • Densification • Processes Biomass • Biological material from living or recently living organisms that can be used for energy • Contains primarily carbon, hydrogen, and oxygen • Source can be waste material from another industry Densification • Pellets and briquettes Source: TVA Source: SilvaTree Density approximations: Bales: ~8 lbs per cubic foot Pellets/Bricks/Pucks: ~ 30 lbs per cubic foot Densification • Pellets and briquettes Densification • Pellets vs. briquettes • Pellets: more expensive to manufacture, but more versatile (can be used on residential scale) • Briquettes: less expensive to manufacture, but not able to be burned in small systems Co-firing • Biomass is mixed with conventional coal at generation plant • Typically mixed in low ratios (<10% biomass by heat basis) Source: Climateprogress.org Co-firing • Hurdles: 1) Transportation cost 2) Needs to be in a useable form 3) Massive quantities required 4) Cost: needs to be ~$20/ton Pyrolysis • Thermal (high temp) process separating biological material into component parts in the absence of oxygen • Typical temp: ~400-500 C, but depends on material • First reaction that occurs in “burning” of a material • For biomass-based pyrolysis: • Variety of input products: nearly any biomass material • Variety of output products: Bio-char, bio-oil, gases • Bio-oil from pyrolysis is generally of low quality, requires further processing if intended for automobiles Gasification • Thermal (high temp) process separating biological material into component parts with a controlled amount of oxygen for combustion • Process is optimized for production of gas, with a minimum amount of liquid and solid production • Typical temp: ~700 C, but depends on material • First pyrolysis occurs, then combustion, then gasification (reaction with char, carbon dioxide, and steam) • For biomass-based pyrolysis: • Variety of input products: nearly any biomass material • Output product: syngas (composed of H2, CO, also small quantities of methane, CO2), ash Gasification Source: Alternative Energy Fuels Downdraft Reactor Process Map Energy and fuels from biomass + fy ota Source: SINTEF Corporation