Cement manufacture is an extremely carbon-intensive process, from extraction of the raw materials from which it is made through emissions from heating limestone to create cement and the energy consumed in heating the kilns where this process takes place.

Because of these enormous environmental impacts – as well as those related to the quarrying of raw materials and its impact on the landscape – sustainability is a key focus for companies such as Cemex UK, a manufacturer of cement as well as a supplier of building products.

The company says: “Sustainability has become a key part of our licence to operate and trade – both global and local policy surrounding sustainability issues have led to regulatory and market pressures – so we have to rise to the challenge to continue operations and remain competitive.

“In particular, climate policy and greater uptake of green building codes such as the Code for Sustainable Homes and BREEAM have led to a paradigm shift in the way we approach many tender opportunities – sustainability is often at the heart of contracts. Many customers now expect good sustainability performance across a number of metrics as a baseline to trade.

“We recognise our industry has an impact on the environment and the communities in which we operate, and we have an obligation to balance the needs and demands of society for roads, homes, hospitals and other infrastructure with the impact on the natural environment. As well as safeguarding our licence to operate and trade, sustainability initiatives help ensure ongoing legal compliance, improve efficiency, reduce costs, preserve more natural resources and have a positive effect on biodiversity.”

Sustainability director, Andy Spencer, says: “With around 40% of global carbon dioxide emissions relating to buildings, it’s no surprise there is a real focus on our products and services and that by reducing those emissions we can have a really positive effect going forward.”

Cemex has invested “tens of millions in the past few years” on improving its environmental performance, and considerable achievements have already been made, with CO2 emissions down 21% per tonne of cement than the baseline year of 1990.

Spencer says: “There are further improvements we can make, which largely centre on the use of alternative fuels, particularly those containing biomass, to reduce carbon emissions relating to the combustion of fuels in our kilns to produce cement.”

Cemex says burning Climafuel (“a waste-derived fuel made using household residual and commercial waste that looks like shredded paper and consists of paper, cardboard, wood, carpet, textiles and plastics”) instead of fossil fuels at its cement plants saves hundreds of thousands of tonnes of waste from landfill and a similar tonnage of CO2 due to its biomass content.

Spencer says: “We have invested many millions of pounds at Rugby, which is our flagship cement plant in the UK, to increase the ability for the plant to effectively handle and burn very high percentages of alternative fuels. Those investments have had a return financially, but also very nicely fit into our overall strategy of reducing emissions, both of carbon but also other pollutants to air generated by the cement manufacturing process.

“Burning alternative fuels also contributes to our targets to reduce waste to landfill – and we now consume far more waste than we generate.”

Cemex’s Sustainable Development Update, published in January and covering performance for 2010, says that use of waste derived fuels is up by 7%, resulting in a saving of nearly 194,000 tonnes of CO2. The report adds: “This saving equated to replacement of 52% traditional fossil fuels by alternative fuels such as Climafuel. This compares well with the average for the cement sector of 38%.”

The company has also invested in energy efficiency measures, such as heat recovery systems, that can be retrofitted onto existing cement plants. Cemex has developed a global embodied CO2 tool to calculate the embodied CO2 from any of its sites, which can also simulate different concrete mixes, enabling the company to work with customers to “green the supply chain and come up with more sustainable solutions”.

It also takes action to measure the return on its investments in increased sustainability. Cemex says: “In many cases there is a quantitative return on investment that can be calculated – for example investing in increased alternative fuel capacity with returns based on fuel costs and saved CO2.

“In many circumstances, the business case has centred on a more qualitative theme. An example would be investing in a certification such as the Carbon Trust Standard – we know it will benefit the organisation, and it is being requested in the marketplace, but it can be difficult to make exact return calculations.”


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