Читать книгу Encyclopedia of Renewable Energy - James Speight G., James G. Speight - Страница 206

Biomass has to be produced either by the cultivation of dedicated crops (such as wood by means of short rotation forestry, perennial grasses), by harvesting forest and other residues (thinnings, straw, etc.), or by collecting biomass waste (such as sludge, organic industrial waste, and organic domestic waste). Next, the biomass has to be harvested or collected, then transported, and if necessary, it may have to stored and transferred.

Biomass can be converted by means of numerous processes. The actual choice of a process will depend on the type and quantity of available biomass feedstock, the desired energy carrier(s) (end-use), environmental standards, economic conditions, and other factors.

Most biomass energy conversion processes can be divided into (i) thermochemical conversion and (ii) biochemical conversion routes, and (iii) mechanical processes. With respect to thermochemical conversion options, a distinction can be made between combustion, gasification and pyrolysis. Biochemical conversion options can be divided into digestion (production of biogas, a mixture of mainly methane and carbon dioxide) and fermentation (such as the production of ethanol). Extraction is another, mainly mechanical, process for producing an energy carrier from biomass (e.g., rapeseed oil from rapeseed). With regard to the energy carriers produced from biomass, a distinction can be made between the production of heat, electricity, and fuels.

See also: Bioconversion Platform, Thermoconversion Platform.