Читать книгу Liquid Biofuels - Группа авторов - Страница 37

Wood (energy forests, wood waste), oilseed plants (sunflower, rapeseed, soy, cotton, etc.), carbohydrate plants (potatoes, wheat, corn, etc.), fiber plants (flax, hemp, etc.), vegetable residues (branch, stalk, straw, root, shell etc.), animal fats, animal wastes and urban and industrial wastes are evaluated in biofuel technology [123]. Biomass is renewable and can be grown anywhere, providing socioeconomic development and an environmentally friendly, strategic energy source. Many liquid, solid or gas biofuels are obtained by burning the biomass directly or by physical processes (size reduction-crushing and grinding, drying, extraction and accumulation) and conversion processes (biochemical and thermochemical processes). Biofuels are utilized in two basic areas, namely bioelectric generation and engine biofuel, other than traditional methods for heating purposes (wood, waste-waste, incineration, etc.) [123, 124].

Vegetable oils, biogas, landfill gas and solid biofuels are used in heating systems and bioelectric production. Vegetable oils are used in heating systems by blending directly, fuel biodiesel and fossil fuels [125].

Biogas is a mixture of organic substances in an anaerobic (oxygen-free) environment, in the presence of different groups of microorganisms, by biomethanization processes [126]. Biogas can be used as an alternative gas to natural gas, in direct combustion-heating and heating, as engine fuel and in electricity generation. Biogas technology is an integrated facility application that produces energy (electricity, heat-cold) and organic (liquid and solid) fertilizers [127].

The most widely used fuel in biofuels in the world is bioethanol and more than 95% of bioethanol production is obtained by processing agricultural products. In many countries of the world, the use of bioethanol in vehicles has been made compulsory and its rate has been varied according to its own production size in each country. Ethanol is used by mixing with gasoline at different rates in order to reduce air pollution or reduce the consumption of petroleum products [128].