Emerald Group Publishing Limited
Copyright © 2000, MCB UP Limited
I recently went to a conference organised by the Department of Environmental Sciences of the University of Hertfordshire. The theme of the conference was "Waste Reduction for the Third Millennium", and its main theme was waste minimisation in the food and drink industry. In these industries the true cost of waste is typically 4-5 per cent of turnover and energy costs are often 20 per cent of controllable costs. In many cases it is possible to reduce waste and energy costs by 20 per cent, and sometimes even 30 per cent. Food and drink manufacturers should look at their company accounts and see what is to be gained by taking more positive action towards waste minimisation.
Waste is not only discarded materials. It includes wasted time, energy, water and the excessive use of raw materials. A waste minimisation programme looks at reducing waste at source, at every processing stage, and it involves the majority of employees from top management to line operators. Walker's Crisps, for example, implemented a waste minimisation programme with an investment cost of £822,000 which gave an annual cost saving of £960,000 in a payback period of just ten months.
Food and drink companies use large volumes of water often as a raw material and for many other important aspects of production. In the past, water was cheap and abundant, and effluent disposal was not subject to strict regulation. Nowadays, water is a much more valuable resource with legislation tightening and costs for supply, treatment and disposal increasing. Anything that reduces water use will bring environmental and financial benefits. Ways of doing this are to:
monitor water use;
find and repair leaks;
use sprays or jets for washing;
fit triggers on hoses; and
recycle water for refuse.
The majority of food and drink processes have refrigeration systems and possibly cold stores, and the refrigeration plant is often the company's main energy cost. Plant replacement due to phase-out of chlorofluorocarbons is an ideal opportunity to install more energy-efficient equipment and so improve the relability and running costs of the plant. Many of the 50,000 boilers currently in use in the UK are ageing. It is estimated that a third of these are more than 20 years old and will need to be replaced within the next few years. Ways to reduce energy are to maintain the boiler well and to replace it if it is old and inefficient. Check combustion efficiency frequently and check steam distribution for leaks and poor insulation.
Wasting heat is throwing money down the drain. In cooking and pasteurisation of food, energy is required to heat up the food and more energy to cool it down immediately afterwards. "Pinch technology" may offer a chance for significant saving. Pinch is an analysis method which identifies the best use of heat transfer from hot streams (which require cooling) to cold streams (which require heating), thus minimising the heating and cooling required for a manufacturing process. Van den Bergh Oils makes edible oil products and used pinch technology to cut a massive 35 per cent off their energy bill.
An independent survey of 47 industrial sites in the UK found an average compressed air leakage of 39 per cent, and that represents a lot of wasted money. Energy is also lost through inefficient buildings. Making these more energy efficient by better design and insulation and insulating doors could make a substantial saving. It may also be possible to use waste heat from industrial processes to heat offices.
Waste minimisation clubs have proved to be a successful way of encouraging companies to reduce costs and improve environmental performance. These clubs involve local businesses and, possibly, organisations such as Business Links and the Chamber of Commerce, local authorities and Environment Agency area offices. For further information, the Energy Efficiency Enquiries Bureau can be contacted at: ETSU, Harwell, Didcot, Oxfordshire OX11 0RA. There is also an Energy Helpline on 9541 542 541 and an Environment Helpline on 0800 585 794.