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Fuelling a new way of thinking

Cement

Earlier this year 10 of the world's largest cement companies launched their agenda on sustainable development. Dave Parker reports on how UK cement producers are responding, and how they compare to their European counterparts.

Back in July, the three companies who together produce over 97% of the cement manufactured in the UK (Castle, Rugby and Lafarge) signed up to the Cement Sustainability Initiative and its agenda for action. Produced in association with the World Business Council for Sustainable Development (WBCSD), the agenda focused on six priority areas (see box). Commenting on the initiative, BCA chief executive Mike Gilbert said it complemented work already in hand in the UK.

'In fact the UK industry is already one of the most advanced in areas such as environmental reporting and health and safety performance tracking. We are also using increasing amounts of industrial byproducts and society's wastes in place of fossil fuels and virgin raw materials.'

The industry's long struggle to get alternative fuels accepted by regulators and public alike has been well documented in NCE over the years. With two of the three main producers now owned by European cement producers (Castle Cement by Heidelberg of Germany and Lafarge, formerly Blue Circle, by Lafarge of France), this process will inevitably continue.

France and Germany substitute up to 40% of all its cement making fuels with alternative materials. Some countries are nearer the 50% mark. In the UK the figure barely tops 7%. Given the country's well-publicised problems with waste disposal, this low level of substitution is approaching a national disgrace.

Public reaction to the use of alternative fuels is now much less negative, according to BCA technical manager Les Parrott.

'The cement producers have put a lot of effort into reassuring local residents, ' he says. 'And by now they can see that what's coming out of the chimney isn't smelly or dirty, and we have the figures to show that in fact emissions are improved by using these alternatives.'

At first sight, Castle's use of alternative fuels at its Ketton works - processed waste solvents, processed paper and plastic waste, and tyres - and Lafarge's imminent trials of processed sewage pellets at Cauldon, is reassuring. The reality is that formidable obstacles to increased use of alternative fuels still remain.

'The Environment Agency really puts a brake on expansion plans, ' Parrot maintains. 'Under existing arrangements producers aren't allowed to use experience at one plant as a basis for the use of exactly the same alternative fuels at another.

'They have to carry out yet another set of trials, costing up to £500,000 a time. This even applies if they want to convert another kiln at the same works.'

However, alternative fuels are not the only possible use of otherwise unusable industrial byproducts. The natural raw materials used for cement production often need supplementing to achieve the right proportions of calcium, silica, aluminates and iron oxide.

In some cases waste shale from coal extraction forms a major constituent. Mill scale from the steel industry, used refractory bricks and reject concrete roof tiles can also be used.

Even gypsum, which has to be interground with the cement clinker to prevent flash setting, can come from waste products such as broken moulds from the ceramic industry. And one of the less obvious benefits of burning old tyres is that they add iron via their steel reinforcement.

Old tyres, of course, are one of the top waste disposal problems in the UK at the moment. 'In five years the UK cement industry could be using more than half the scrap tyres in the country, ' Gilbert points out.

'Lafarge has the capacity to dispose of more than 14M used tyres a year through its kilns, ' adds Lafarge Cement UK operations director Rob Davies.

'That's a saving of 100,000t of fossil fuel.'

Comparisons between Lafarge works in France and the UK are illuminating, to say the least (see box). In the UK, Lafarge has set a target of a 20% reduction in CO 2emissions by 2010 and other producers have similar aspirations.

Animal passions

The infamous mounds of blackened, smoking animal carcasses that polluted the British countryside last year at the height of the foot and mouth epidemic could have been avoided if the cement industry had been allowed to do what its Belgian equivalent did in 1999. Then, when it was discovered that a large proportion of Belgium's livestock population was contaminated with cancerlinked polychlorinated biphenyls (PCBs), the government ordered destruction by high temperature incineration (pyrolisation) of all contaminated meat and associated products.

Belgium did not have enough modern incinerator capacity to achieve this, so the government ruled that three cement works could use rendered down carcasses as fuel for cement production.

Some 17,500t of fats and powders were burnt in the last four months of 1999. Eighteen months later, when the slaughter of British livestock was in full swing, the UK cement industry offered to help in the same way. It was told it could indeed burn carcasses in its kilns - provided that no cement was manufactured at the same time.

Cement production would only be allowed under the requirements of the Substitute Fuels Protocol. This would have meant months of trials, by which time the epidemic would have been over. Instead, as the whole world looked on in astonishment, carcasses were burnt in the open at low temperature, spewing dioxides and other environmentally unfriendly emissions over the countryside.

Agenda for action

Cement producers from Brazil, France, Germany, Italy, Japan, Mexico, Portugal, Switzerland, Thailand and the UK agreed a three-year programme concentrating on six priority issues. These are:

co2emissions

Development of common

Climate protection via control of CO guidelines on the use of alternative materials and fuels

Improvements in health and safety

Emissions reduction

Development of common guidelines for environmental and social impact assessment

Establishment of key performance indicators

Cement facts

World production in 2000 was around 1.6bn tons in more than 150 countries.

The biggest producer is China, with 33% of the world market.

The industry directly employs approximately 850,000, with annual revenues approaching £60bn

Cement manufacture is the source of 5% of global man-made CO 2

The energy equivalent to 60130kg of fuel oil and 110kWH of electricity is needed to produce one ton of cement

It is cheaper per ton to transport 35,000t of cement across the Atlantic than to truck 30t for 300km.

A modern cement works costs three years' revenue to build. It will produce more than 1M tons of cement a year with a staff of less than 200.

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