Nestlé's anaerobic digestion plant a sweet success

As part of Nestlé's efforts to develop environmentally sustainable manufacturing at its Fawdon confectionery factory, near Newcastle in northern England, the company commissioned British company Clearfleau to build an on-site anaerobic digestion (AD) plant.

Clearfleau’s design was chosen due to its high-rate, liquid-based digestion system, which uses an innovative and robust solids-processing system, together with its compact design to fit on the edge of the factory car park.

Previously, production residues from Fawdon - a producer of gums, pastilles and Rolos - were discharged to sewer or fed to pigs in the locality. Following the installation of the AD plant, all biodegradable production residues are now converted into renewable energy on the factory site.

One year after commissioning, the plant is converting 200,000 L/day of feedstock into renewable energy. This feedstock includes wash waters from the site and 1200 tonnes of residual by-products and ingredients per annum.

The biogas produced is fuelling a combined heat and power (CHP) engine, which produces 200 kW of electricity, used in the confectionery production process. This is about 8% of the factory’s power requirements, cutting the annual electricity bill by about £100,000 per annum. In addition, the site has registered for the UK’s feed-in tariff and will receive annual payments of about £250,000 per annum.

In addition to saving on fossil-fuel purchase plus the other savings and revenue benefits, the project has reduced the carbon footprint and environmental impact of the site. The payback period on Nestlé's investment in Clearfleau’s AD plant is predicted to be 4-5 years.

Clearfleau Chief Executive Craig Chapman, says: “Clearfleau was delighted to be selected by Nestlé to deliver this important plant and we very much appreciate their collaborative approach to the delivery of this project. For Nestlé, what was previously a processing overhead is now a valuable financial and environmental asset.”