Food researchers hoping to power ahead with cost-cutting process energy project

Researchers behind a proposed project to explore novel ways of using waste energy from food manufacturing plants will find out this month whether they have secured government cash to fund their work.

The project, proposed by Campden & Chorleywood Food Research Association (CCFRA) and Bristol University, will estimate how much waste process energy could be available for conversion into useable power and explore the technologies capable of recovering it. Stirling engines were the most likely means, said Gary Tucker, a CCFRA process development section manager.

"We're talking about recovering a proportion of waste energy - for example, heat loss from ovens and boilers - and converting it to rotary power in order to power pumps or compressors, or to generate electricity. But we will also look at combustible materials in general - for example, can we burn wooden pallets or waste packaging and convert that energy using Stirling engines?"

He added: "A lot of food companies in sectors from canning to milling and baking are extremely interested in this. As energy prices have gone up, finding ways of cutting the utility bill is moving further up the corporate agenda."

Stirling engines are external combustion engines that convert heat into mechanical movement.

"The technology is advancing all the time, but we need to do detailed research with participating food manufacturers to calculate the energy streams and find out what is commercially viable on a case by case basis," said Tucker.

The Stirling engine was invented by Scottish clergyman Robert Stirling in the early 19th century. It uses the energy difference between its hot end and cold ends to establish a cycle of a fixed amount of gas, which expands and contracts in the cylinder. That in turn drives pistons in the engine.