Viridor, one of the UK’s leading recycling, renewable energy and waste management companies, has installed a Babcock Wanson HEB 1050 hot water boiler into its anaerobic digestion plant at Walpole near Bridgwater, Somerset
Each year, Viridor transforms over two million tonnes of materials into high quality recyclate, and yet more into more than 760 gigawatt hours of renewable energy. It operates several Anaerobic Digestion (AD) facilities across the UK, which use renewable energy technology to capture methane expelled by digesting unwanted food within enclosed tanks.
The gas is then used as a source of energy for heat and electricity, which is fed into the National Grid. To aid the production of methane, the digestors are warmed by circulating hot water around them.
There in one boiler at the new Walpole site — a Babcock Wanson HEB 1050 hot water boiler — which has been used to start the initial AD process and will acts as a standby should the Combined Heat and Power (CHP) system require maintenance or supplementary heat. Gas Oil fired, the boiler has been supplied by Babcock Wanson as a fully containerised solution for ease of installation and operation.
The Walpole AD plant will be able to process up to 30,000 tonnes of food waste per year and is expected to save Somerset council tax payers £200,000 a year. Gas from the plant will be used initially to generate electricity — about 9,500MWh a year — with nearly four-fifths exported to the Grid, which is enough to power more than 1700 homes.
In addition to converting the waste into biogas, it also produces a nutrient rich digestate that is used on local farms as a fertilizer and soil improver.
Babcock Wanson’s HEB Boiler is a forced-circulation, fully automatic packaged unit, specifically designed for high efficiency and long working life. The reverse flame design provides optimum furnace loading and the radial firetube assembly minimises material stresses. An easily reversible front door allows simple and quick access for inspection of the combustion chamber and reversal tubes without the need to remove the burner.