ENERGY EFFICIENCY the crucial factor

Growing imports and macroeconomic concerns recently caused the Chemical Industries Association (CIA) to predict a slowdown in Europe's chemical industry in 1999. For UK firms, affected by the strong pound, conditions could be even worse.

One way companies can improve their competitiveness is by ensuring operations are run as efficiently as possible. Each year, British chemical firms spend £1.4 billion per year on energy. It is estimated that by applying best practice measures, the industry could save between 5-10 per cent of this per year, equivalent to £100million.

Improving energy efficiency is well within the process industries' means. Between 1967 and 1990, the industry's output of chemicals has more than doubled, while energy consumption per unit of output has reduced by an impressive 60 per cent. The contribution of natural gas to improvements already made cannot be underestimated, as this fuel now accounts for 43 per cent of all energy consumed by the chemical industry. But there is still room for improvement.

In this industry, the major proportion of energy is used in steam boilers, direct firing of process plant, electric motors, process equipment and refrigeration plant. Energy efficiency can be improved through such applications as combined heat and power (CHP), improved controls and distributed gas-fired heating systems which eliminate losses associated with steam distribution systems.

In addition to these more traditional operations, there are new gas technologies to consider in the areas of drying and refrigeration. Evaporation is a particularly energy intensive process. There are some 7000 dryers and evaporators in the UK, most of which will be suited to gas-firing.

Refrigeration can take up to 40 per cent of a site's electricity consumption with the sizes and types of plant and operation varying considerably. Already popular in the US and Japan, gas-fired cooling technology can reduce costs by up to 45 per cent and emit about half the amount of C02 than traditional electrical systems. These units can also operate in combination with energy-efficient CHP.

Looking to more conventional uses of energy, three areas should be considered where gas-fired equipment can benefit: boilers, CHP and process plant.

Natural gas-fired boilers have grown in popularity for raising industrial steam. Data from the DETR's best practice programme found that boilers operating on gas had the highest average thermal efficiency at 76 per cent.

One of the most efficient uses of fossil fuel for industrial sites is gas-fired CHP, a technology which has become increasingly popular in recent years. CHP plant can be driven by industrial gas turbines or reciprocating engines, providing overall efficiency of about 80 per cent.

Another method to improve efficiency is through process integration. This involves arranging the process so that the various streams exchange heat with each other to provide heating and cooling. Analysis involves complex techniques to optimise process configurations, temperature differentials, energy flows and the impact on capital costs. So far, 24 process integration studies have been published for the UK and of the 10 chemical firms analysed, average energy savings of 34 per cent could be made. PE

Paul Greengrass is business development manager at Transco