Manufacturers aim to slash water use in £3.5M project

Academics at three British universities have teamed up with food manufacturers on a £3.5M project aiming to slash factory water consumption by 50%, through the application of advanced modelling techniques to optimise cleaning regimes.

Project leader professor Peter Fryer, who heads food process engineering at Birmingham University, said that food processes were “over-designed and over-cleaned. Everyone uses too much water. The problem is that it’s difficult to evaluate the effectiveness of cleaning regimes. How do you know when the cleaning is done?”

New approaches covering the measurement, modelling, monitoring and control of cleaning in fast- moving consumer goods plants could result in a significant reduction in their environmental impact, he claimed.

Fryer, who was speaking at a conference hosted by the Food Processing Knowledge Transfer Network and the Department for Environment, Food and Rural Affairs (DEFRA), is working with Unilever, GlaxoSmithKline, Cadbury, Scottish & Newcastle (S&N), plus suppliers of equipment and cleaning materials.

The three-year ‘Zeal’ project (Zero Emissions by Advanced cLeaning) also involves engineers and scientists from Newcastle University and Imperial College, London. “There is a big opportunity here,” said Fryer. “Take Nestlé. It used 40bn litres of water in 2006 - only half of that was actually sold to us. The rest was used for operational processes or cleaning. There are many reasons for this, from poor plant design, to too many changeovers and wash-downs, but also because people don’t know how much water and how much cleaning material to use.”

By inputting precise data about the structure of the waste material (how easy is it to break up) and the strength of the interface (how easy it is to unstick it from a surface), it was possible to predict how much energy (chemicals/water) was required to clean it up and therefore optimise your cleaning regime, said Fryer. “In the first instance, we’re looking at the cohesive force between deposits (waste chocolate crumb, milk solids, toothpaste etc) and the adhesive force between the deposit and the surface (the floor or equipment).

More efficient cleaning also offered productivity improvements through longer run-time and higher plant usage, plus knowledge transfer through combining the understanding of products, equipment and processes to develop designs that minimised cleaning load and effluent production, said Fryer.