A plug flow digester vessel is a long, narrow, insulated and heated tank made of reinforced concrete, steel or fibreglass with a gas-tight cover to capture the biogas. Biogas produced by the digester is used to heat the digester to the desired temperature. Plug flow reactors are used in the treatment of wastes with high solid content 10-12% TS.
An unmixed system that works on a semi-continuous mode by regularly receiving untreated wastes in one side of the reactor, and ejecting digested waste out at the end of the digester. Low maintenance and operational costs due to its simplicity and the heating system is the only mechanical components of the digester.
• Suitable for difficult feedstock that can’t be treated in any other digester (CSTR, UASB, anaerobic filter, etc.)
• Secure sanitation. The risk of discharge un-decomposed substrate (shortcuts between inlet and outlet) is lower than in other digesters.
• Due to its simplicity, plug flow reactors are widely used in developing countries, particularly India, Nepal, China and Vietnam, providing a cheap source of fuel, and reducing diseases caused by the use of untreated manure as fertilizer.