Dr. Volker Hoenig
Tel.: (0211) 45 78-254
Fax: (0211) 45 78-400
The German cement industry has always made efforts to reduce CO2 emissions, increase energy efficiency and conserve natural resources. Progress in reducing CO2 emissions essentially comes from the following areas:
Increases in efficiency in thermal energy consumption are based on various innovations in process technology. For example, development of kiln technology has led to a changeover to kilns that work using the dry process and are equipped with cyclone preheaters. More than 90 per cent of cement clinker is now produced in such plants in Germany. Furthermore, rotary kiln plants can now be designed with smaller dimensions than before, for example thanks to modern precalcining technology. This reduces the kiln's radiation losses.
Substitution of primary fuels is another very important measure for reducing CO2 emissions in cement manufacture. Fossil fuels, especially coal and lignite, are increasingly being replaced by alternative fuels (including used tyres, waste oil, animal meal, plastic waste). In 2018, over 67 per cent of the fuel energy required industry-wide was covered by alternative fuels, saving around 1.9 million tonnes of coal, or 2.12 million tonnes of CO2.
Using other, sometimes alternative, input materials in cement grinding not only saves natural raw materials, but reduces the clinker content in the cement, thus reducing fuel consumption and CO2 emissions. In Germany, it is primarily granulated blast furnace slag and limestone (unburnt), as well as (to a lesser extent) fly ash, natural pozzolan and burnt oil shale that are used alongside clinker as main constituents in cement. These measures alone have led to a total saving of approx. 5.5 million tonnes of CO2 in 2018.