What is biogas and what is it made of? Definition and explanation:
biogas is produced by fermenting liquid manure, organic waste from feed and food production and renewable natural resources. This natural product can be converted into fuel, electricity or heat. In many countries biogas serves as an environmentally friendly alternative to fossil gas and is fed into the public gas grid. For this, it must have certain pressure and quality conditions that are ensured in the course of processing. The name Biogas deceives about the origin of the raw materials, because they do not have to come from organic farming.
Production of biogas
For the production of biogas different raw materials are used, which are of plant origin. The most important raw materials include biowaste from gardens and kitchens, silage, by-products of grain processing and renewable crops such as corn. Even livestock manure from excrement of cattle, pigs or poultry can serve as starting materials for biogas. These materials are slowly decomposed in huge steel vats under the exclusion of light and oxygen - ie under anaerobic conditions. The containers are also called fermenters, which refers to the conversion of raw materials by microorganisms. In the course of fermentation, a gas is gradually formed, which is collected in film hoods. Left behind are fermented remains, which are used in agriculture as fertilizer again. The recovered raw gas contains up to 75 percent methane and impurities such as sulfur or carbon monoxide. After these chemicals are removed by cleaning and drying, the methane content increases up to 96 percent. The resulting biogas can finally be fed into the gas network via a special system and made usable.
Use of biogas
Desulfurized and purified biogas has the same chemical properties as fossil natural gas and can therefore easily be used to operate heating systems. A major advantage of this renewable energy source is that, in contrast to solar or wind energy, it is available throughout the year and can be used continuously to generate heat and power. In Asia, millions of households today are powered exclusively by small biogas plants.