FACT > Fuels from Agriculture in Communal Technology

Large biogas plant under construction

February 26th, 2010

The Groene Woudt Foundation (SHGW) supports a project of an integrated development project consisting of organic tea growing and processing, cattle raising and Jatropha in West Sumatra. Recently, a large biogas plant has been installed. The digester, a so called bag digester, converts cow manure, Jatropha cake and rice straw into biogas. SHGW aims to produce the organic tea with sustainable energy: the biogas is fed in generators (CHP units of 18, 66 and 125 kWe) that are to be running on Jatropha oil as well. The waste heat from the generators is again used to heat the installation. The biogas is also used for the tea drying.

The installation was carried out by Thecogas, a Dutch biogas company (www.thecogas.nl). Thecogas has installed numerous biogas plants in the EU and is now expanding internationally.

The technical data are given below:

Yearly input: 3,000 tonnes of cow manure, 1,750 tonnes of Jatropha press cake, rice straw
Mesophylic digestion (30-35 degC)
Residence time in digester >50 days
Digestion volume 3,000 m3: Digester bag PVC reinforced; 35 x 36 m, 3.5 m height
1,000 m3 gas storage volume in the digester bag.
Solid input through pre-mixing pit with pump with cutting knives.
Container with hot water distribution, dry coolers, gas cooling and emergency flare.

Although anaerobic digestion of animal manure is well known in Asia, hopefully this installation will result in more knowledge on co-digestion. The project should also prove that system costs can be reduced as compared to conventional installations made of concrete or steel.