Swiss cement works cover half of their high energy requirements using waste fuels. As a result, they reduce their fossil fuel consumption and CO2 emissions. They also recycle mineral waste. Together with the sector, the FOEN regulates the substances that may be used for cement production.
Cement production is very energy-intensive. To produce clinker, the main component of cement, lime and other mineral raw materials are heated to a temperature of 1450°C. The production of one tonne of clinker requires around 135 kg of coal or 86 kg of crude oil. If these fossil fuels are replaced by waste fuels, the overall CO2 emissions are reduced. Switzerland's six cement works cover between 40 and 50% of their energy requirements with replacement fuels from waste. In recent years, in addition to replacement fuels, the plants used over 300,000 tonnes of alternative raw materials from waste annually. This saves on natural raw materials (data source: Cemsuisse).
Cement works can use waste as fuel or as raw material as long as the pollutant levels in there is no increase in the flue gases from the kiln and in the clinker. The FOEN has developed guidelines for this in close cooperation with the sector and the cantons.
Low-pollution, high calorific bulk wastes like waste oil, sewage sludge, animal meal/fat, organic solvents, plastic waste, used tyres and waste wood are suitable for use as replacement fuels. Municipal waste and problematic hazardous waste, for example paint residues with a high heavy-metal content, are not authorised for use as replacement fuels.
Low-pollution mineral waste like excavated tunnel material, unpolluted excavated material, contaminated soil and certain fractions from contaminated site rehabilitation are suitable for use as raw materials.
Further information
Last modification 11.07.2019
