Bioenergy means energy generated by the use of solid, liquid and gaseous biomass products. Biomass is a biodegradable part of products, residues/by-products and agricultural waste (including plant and animal matter), forestry and wood industry, as well as biodegradable parts of municipal and industrial waste. Therefore, biomass products are divided into:
Biogas is created due to the biological decomposition of various types of a waste of biological origin, in the first place biomass and organic matter of solid urban waste. Biogas typically consists of methane (approximately 52.5 to 72.5% by volume) and carbon dioxide, in the presence of other compounds. The basic component of biogas is methane and its content directly affects the thermal value of gas.
Biomass can be converted into biogas through biological processes, such as anaerobic digestion or through gasification that belongs to a group of thermochemical processes. In anaerobic digestion, biogas is produced by fermenting organic matter. This material can be a wet organic material such as manure, sludge of wastewater, industrial wastewater and agricultural and forest residues. Biogas from anaerobic digester consists mainly of methane, which can be used as a fuel or chemical raw material.
Various oils or alcohols, as substitutes for conventional liquid fuels, especially suitable for use in existing internal combustion engines – biodiesel, ethanol.The world is focusing on the development of new biomass production processes from biomass. Planing by-products of biofuel production are also very important for the ultimate economy of biofuels. For example, glycerine produced during biodiesel production can be purified to pharmaceutical quality, and by-products of bioethanol production can be used as protein-rich foods.Currently, biodiesel and bioethanol are dominated by the biofuels market.
Solid biomass includes the remnants of crop production, residues of fruit and vineyard residues, forestry residues, a vegetable mass of fast growing plants, and above all fast-growing forests, part of the selected municipal waste, from the wood processing industry, residues of primary and secondary processing of agricultural products, and others. Liquid biofuels include liquid biofuels – vegetable oils, transesterified vegetable oils – biodiesel and bioethanol. Gaseous biomass is biogas, which can be produced from animal excrements or energy plants (grass and corn silage), but other raw materials can also be used as raw materials. Gaseous, even liquid, biomass, are also products of gasification, that is, pyrolysis of solid biomass.