The plant, located in Suffolk, is jointly operated by AgriGen Ltd and Siemens, and supplies around 5000 households with power and heat. It has been fitted with Siemens automation technology including a controller, distributed I/O and visualisation software.
Height, pressure and temperature measurements are performed using radar level transmitters including the Sitrans LR200, which Siemens says is designed for flexible continuous monitoring of liquids within the plant.
The plant uses a biogas generation method developed by Austrian biopower firm Thöni, in which both liquid and solid material are continuously fed into a wet fermenter. Specially designed paddles keep the material moving and well homogenised, preventing sediment from settling on the fermenter floor and stopping suspended particles from forming floating layers. The paddle mixers are driven by a planetary gear and frequency converter, with the smaller propeller mixers also fitted with soft starters.
‘The optimum automation concept in combination with the patented paddle mixer has reduced the plant’s electricity consumption by 50% due to energy recovery’, Siemens said.