The basis of the biogas production in agriculture is the processing of waste agricultural products (particularly excrements of farm animals but also phytomass). Different but rather similar is the biogas production from biologically degradable municipal waste (BDMW) and biologically degradable industrial waste (BDIW) coming mainly from food industry. The processing of these wastes in agricultural biogas stations could significantly improve their economy. It is necessary to note that all these biogas stations differ from the wastewater cleaning plants where municipal sludge water from public sewers is processed. The municipal sludge water processing to biogas by anaerobic fermentation is a classical technology introduced all over the world. At present, about 100 wastewater cleaning plants operate in the Czech Republic using regular sludge processing into biogas. Electricity produced is utilised mainly for the needs of own operation of waste water treatment plant (WWTP), partly it is sold into public power net. The heat energy is used for heating in the process and its surplus is utilised for operational and administrative facilities. Usually, the heat and electricity quantities produced do not cover the wastewater cleaning plant operation. Agricultural biogas stations and biogas stations for BDMW processing provide considerably higher gas yields because they work with higher dry matter contents in substratum, i.e. 8–12% (compared with waste water treatment plants – 2–6%), and are able to produce high gas surpluses for following applications. Frequently discussed issue are the processing of slaughter waste and grass (or public green areas at biogas stations).
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