The sweet taste of sustainability
The chair of Leatherhead's Ingredients Research Committee, Dr Julian Cooper (British Sugar's head of food science), gave me a personal tour. It's difficult not to be impressed by the operation's scale. Each year, it handles 3Mt of sugar beet from 1,500 growers sited only 50km from the factory. The beet contains about 17% sucrose, so the core objective is to extract as much of the sweet stuff as possible.
But, in the process, 65,000t of adhering soil is separated, cleaned and sold as topsoil. 15,000t of stones are washed and sold as aggregate. Once the sugar has been squeezed from the beet, the remaining fibre is compressed to produce over 100,000t of animal feed. The purification process uses heat, milk of lime and carbon dioxide. Over 800t of chalk by-product are sold as fertiliser.
But the really clever part is that excess heat and carbon dioxide are piped to massive greenhouses where 7080M tomatoes are produced annually. This makes British Sugar the UK's biggest producer of round and salad tomatoes!
The secret to success is efficient power generation. Wissington's combined heat and power plant produces steam and electricity using gas turbines. The process is so efficient it provides virtually all the factory's energy requirements and still has enough to sell back to the national grid to supply 120,000 people.
Just when I thought things couldn't get any better, Julian showed me the bioethanol plant, which ferments lower grade sugar syrups to produce 55,000t of renewable biofuel a year.
With growing concern about food security and waste minimisation, it's gratifying to see a major UK ingredient manufacturer using innovative science and engineering so effectively.
Wissington also produces 400,000t of sugar each year. That's sweet!
Paul Berryman is chief executive of Leatherhead Food Research.
