The biogas plant in Fraddon (UK), engineered and constructed by HoSt, consists mainly of disposal of category 3 animal by-products and input based on plant material, such as fodder beet, grass silage and silage corn.

Digesting 40,000 tons of these materials annually, in the two 2,100 m3 digesters and one 1,500 m3 after-digester, results in the production of 450 Nm3/hr raw biogas and 250 Nm3/hr biomethane. This is equivalent to the consumption of natural gas by 2,000 households. The produced biomethane is fed into the UK national grid. The plant is equipped with a 250 kWe CHP, running on biogas, to produce enough heat and electricity in order to keep the plant going.

The plant is as well equipped with one solid feeding mixing / dosing bin, three gas tight after-storage polyester silo’s for liquid waste and a reception building for solid waste, a batch pasteuriser for the pasteuristation between the digesters and the after-digester and a screw press separator for the treatment of the digestate.

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PROJECT SPECIFICATIONS
Location Fraddon, England
Start construction March, 2013
Start-up January, 2014
Capacity 40,000 tons/year
Input Expired food products, fish waste, rumen content, blood, fodder beet, grass silage, silage corn
Digester(s) 2 x 2,280 m³ (Ø 22 m)
After-digester(s) 1 x 1,527 m³ (Ø 18 m)
CHP 250 kWe + flue gas cooler
Solid feeding input • 1 x 60 m³ mixing/dosing bin with input screws
• 1 x 18 m³ mixing/dosing bin with Quickmix
After-storage 60 m³ buffer silo for liquid waste
Digestate treatment • Pasteurisation at 70 °C with 25 m³ batch pasteuriser
• Screw press separator

CHARACTERISTICS
  • Possibility to feed category 3 material and also plant based material in liquid and solid form
  • 25 m³ batch pasteuriser between digesters and after-digester
  • Combination CHP and biogas upgrading