JULY 2010

Anaerobic digestion plant opens in United Kingdom

A Waste & Resources Action Programme (WRAP) supported anaerobic digestion (AD) plant has opened on a Staffordshire farm. The plant will supply 1.3mw per year of renewable energy to the National Grid – enough to power more than 1,300 homes and businesses.

The venture, at Lower Reule, which has received a grant from WRAP, currently has capacity to process 15,000 tons of waste per year. It will be able to process 30,000 tons by the autumn when a second phase of development is completed.

Most of the waste will come from food waste collected separately at the curbside by Newcastle-under-Lyme Borough Council, plus food waste from supermarkets and food manufacturers. The AD plant will also process 1,000 tons of pig slurry and 1,250 tons of maize silage each year from the farm on which it is based.

The AD plant is run under the name Lower Reule Bioenergy and has provided a new venture for the farm, which keeps pigs and grows a variety of arable crops, including maize, barley, wheat and oats. The farm also supplies approximately 1,400 tons of strawberries per year to supermarkets.

The biogas will be burnt through a combined heat and power plant, which produces equal amounts of heat and power. Approximately 1.3mw per year of power will be supplied to the National Grid and the AD unit will produce enough electricity to run itself.

A number of options are being considered for the heat, which may be used to heat the strawberry tunnels on the farm to extend the growing season or to grow asparagus on heated beds.

The nutrient rich biofertilizer, which is an end result of the AD process, will be produced to the national specification –BSI PAS110 and used as a fertilizer on grassland and arable land at Lower Reule Farm and on neighbouring farms.

According to the Anaerobic Digestion and Biogas Association (ADAB), there could be 1,000 anaerobic digestion plants in the UK by the year 2020.