Cel To design, construct, operate and manage a biogas plant to treat the manure of dairy cattle, located in several farms in the village of Deersum, Neth. The expected energy production is yearly of 63,000 m3 biogas (210 GJ heat and 78 MWh). The simple payback time is equal to 12 years.During the first year of operation, the digester received 1,900 m3 manure corresponding to 5.2 m3 per day. In all, it has produced 30,500 m3 gas. Thus the specific rate of gas production has been 16 m3 gas per m3 manure. The average volumetric gas production was 0.40 m3 of digester capacity per day. Over 29,000 m3 gas was delivered to the co-generation power plant, which generated 33,000 kWh of electricity and heat utilized to heat the digester plant. Thus, the specific electricity production amounted to 1.14 kWh per m3 gas. Various teething troubles were experienced with the digestion plant : repeated blockage of the manure pumps, which were remedied by installing a strirrer in the pump pit; malfunctioning of the mixing system (gas injection); high hydrogen sulphide (H2S) levels in the gas, necessitating a larger desulphurisation capacity; low specific electricity production of the power plant.Also, scum formation was experienced in the digester from time to time. The first problems either seem surmontable or have meanwhile been resolved, whilst scum formation is combated by adding spent motor oil.As a result of these problems, only 1,900 m3 manure could be delivered to the installation per year, against 3,950 m3 as initially foreseen. The cooperation between the farmers concerning the delivery and offtake of the manure gave no troubles.During the measuring period (from early 1988 until early 1989), the electricity demand of Deersum amounted to 331,000 kWh per year and the aggregate windmill/digester electricity output amounted to 255,000 kWh per year. Of this, 69 % (176,000) was utilized in Deersum. Thus, the wind turbine and the digestion plant could meet half of the electricity demand of Deersum. The balance was covered by the provincial energy utility PEB Friesland. Additionnally, there were also savings on the weekly maximum power demand of Deersum.The surplus electricity, 31 % or 79,000 kWh per year, was delivered to PEB Friesland.The power plant of the digestion plant was put into operation during the peak loads of Deersum (between 7.30 and 9.30 h a.m and 6.00 and 8.30 h p.m) by means of a timer.During the first year the Deersum Energy Project was not profitable. The average cost price of the electricity amounted to Dfl. 0.33 per kWh. This can be reduced to Dfl. 0.18 (Dfl. 0.15 per kWh for the wind turbine and Dfl. 0.29 for the manure digestion plant) by increasing the manure feed rate to the digester; higher rates for the sale of electricity; choosing a cheaper site; and assigning a higher money value to digested manure than to undigested manure because of the former's higher fertilizing value. Through series production of the main equipment, the cost price could be reduced still further to Dfl. 0.12 per kWh (Dfl. 0.10 per kWh for the windturbine and Dfl. 0.16 for the manure digestion plant). These figures do not take into account the beneficial effects in the way of employment opportunities and the environment.The manure collected from dairy cattle in several farms in the village of Deersum (Neth), which represent 3,950 m3 manure yearly with a content in organic matter of 7%, will be stored in a storage tank of 275 m3.The methane digester will have a capacity of 210 m3. It is constructed in polyester. The mixing will occur by gas recirculation. The digester will be equipped with an internal heat exchanger.The digestion process will be conducted in the continuous mode without recycle at the temperature of 35 deg.C. The mean hydraulic residence time will be 20 days. The expected gas production rate is equal to 0.83 m3 biogas per m3 digester and per day.The digester effluent will be stored in a silo of 2,000 m3 capacity. The produced gas will be stored in a balloon gasholder of 100 m3 capacity.The yearly gas production will amount to 63,000 m3 biogas. H2S will be removed from the biogas by passing through iron oxides. Part of the purified gas (10,000 m3 per year) will be used in a boiler yielding 210 GJ for farm housing heating. The remaining of the biogas will be used in a TOTEM cogenerator of 15 kW and is expected to yield yearly 78 MWh, that is 30% of the municipality demand. Part of the heat produced by cogeneration will be recycled to heat the methane digester.Monitoring will include mass and flow balances around the biogas plant concerning the inputs and the outputs of the methane digester including gas, electricity and heat, and temperatures.The innovative character of the project lies in the managing of a collective biogas plant, linked with a wind-turbine (subject of another contract : WE/607/84). Program(-y) ENG-ENALT 2C - Programme (EEC) of demonstration projects relating to the exploitation of alternative energy sources and to energy saving and the substitution of hydrocarbons, 1983-1985 Temat(-y) 1.3 - PRODUCTION AND USE OF BIOGAS Zaproszenie do składania wniosków Data not available System finansowania DEM - Demonstration contracts Koordynator MUNICIPALITY OF BOARNSTERHIM Wkład UE Brak danych Adres POSTBUS 40 9000 Grouw Niderlandy Zobacz na mapie Koszt całkowity Brak danych
