The cement industry operates under both national and state legislation for the management of the environment and also has specific licence conditions and reporting requirements for the operation of plant equipment.
Commonly monitored air emissions include the typical parameters of dust, and various products of combustion, such as oxides of nitrogen and sulphur. Also parameters that may be present in trace amounts include inorganic substances such as heavy metals and organic compounds like volatile organics, dioxins and furans.
In its effort to better understand emissions, industry investment is being directed toward new technologies that test and model emissions. Protocols have been established and computer models developed to relate stack emissions to ground level concentrations (GLC) for correlation with environmental and health standards. The industry works closely with government to ensure quality information is readily available.
Adelaide Brighton’s Munster plant used advanced computer technology in atmospheric modelling to determine the benefits of installing a state-of-the-art dust filter. Under a range of meteorological conditions the reduced GLC of dust were calculated from real emission data.
In supporting Australia’s commitment to international treaties the industry participates in discussions internally, with other industries, and with environment and government groups. These discussions lead to policy setting and prepare the cement industry for changes in emission measurements and standards. Sharing information about new technologies and process improvements is valuable and the industry regularly monitors developments in air quality standards in Europe to compare with local performance.
Various projects have been implemented to reduce other emissions such as water, noise, and waste to landfill. Harvesting storm water for dust suppression or diversion to specially prepared seasonal wetlands has been successful. Cleaner production initiatives to segregate site waste for recycling into cement making or facilitating other recycling opportunities continue to reduce waste to landfill. Cement kiln dust (a waste product in some plants) is, however, likely to increase as more alternative fuels and raw materials are used. In 2004, the manufacture of cementitious material utilised 60 times more waste than it produced for landfill.
Emissions from cement manufacturing facilities in Australia are monitored regularly to:
- control manufacturing processes for product
- quality and protection of equipment
- meet operating licence conditions
- meet national reporting requirements such as the National Pollutant Inventory, National Dioxin Program, Stockholm Convention, NEPM Air Quality (National Environmental Performance Measures)
- monitor specific effects of interest to local communities
- investigate the outcome of changes in process operations.
Blue Circle Southern Cement’s Berrima works installed best available technology in low- NOx precalciner and kiln burners. Following installation NOx emissions were shown to have reduced by 60 per cent, and are now amongst the lowest for Australian cement kilns.
A beautiful outcome for the environment.
Blue Circle Southern Cement Berrima
‘A beautiful outcome for the environment’ is how Blue Circle Southern Cement Berrima describes the environmental benefits resulting from the upgrade of Kiln 6. A study identified an annual 400 000 tonne shortfall in the supply of clinker on the Eastern seaboard. After looking at alternatives, BCSC decided that an upgrade of Kiln 6 offered the best solution, economically and environmentally. The upgrade installed world best technology into Berrima’s clinker production, meeting the objectives of the CSI to lower emissions while ensuring BCSC could meet demands for clinker with a modern, efficient plant. Overall the project successfully reduced process emissions by:
- 24 per cent reduction in greenhouse gasses (GHG)
- 75–95 per cent reduction in dust emissions
- 60 per cent reduction in oxides of nitrogen
- 95 per cent reduction in sulphur dioxide
- 85 per cent reduction in carbon monoxide
- 70 per cent reduction in heavy metals
The reduction in GHG is the equivalent of removing close to 38 000 cars from the road. Berrima is proposing to use alternative fuels to further improve its performance and commitment to sustainable cement production.