Cement Manufacturers Association (CMA)

21 Alternative Fuels & Raw Material Substitution A Comprehensive solution by KHD A K Dembla, President & Managing Director Deepti Varshney, General Manager Humboldt Wedag India Private Limited, New Delhi Introduction The cement industry’s thermal process faces various obstacles in meeting environmental and economic demands, such as high costs, environmental limits, and thermal energy efficiency. The best method to address these difficulties is to increase operational excellence and sustainable cement manufacturing by reusing waste materials as alternative fuels and raw materials. In today’s world, the finite nature of global fossil fuel resources, high prices, and most critically their negative impact on the environment highlight the need to create alternative fuels for many industrial systems that rely on them. Increased use of renewable and alternative fuels has the potential to extend fossil fuel supply and help resolve difficulties related with traditional fuel consumption. Clinker production is an energy intensive process that consumes 2,886-3347 kJ/kg of clinker produced. The electrical energy use is approximately 90-120 kWh per tonne of cement. This all has an influence on the environment as well as expensive costs. Without question, today’s cement industry has hurdles in reducing manufacturing costs while adhering to environmental protection measures. Alternative fuels, alternative raw material, by product utilisation, and the use of products and procedures to control the environment, among other things, have emerged as important tasks. The cement business is dedicated to achieving this in a sustainable manner: ecologically friendly, socially responsible, and economically viable. The following section covers environmentally beneficial, efficient, and cost effective solutions and references for sustainable development by usage of alternate fuels. Alternative RawMaterials used in Cement Manufacturing In the cement industry, alternative raw materials are widely used in two ways, Use of natural alternative raw materials and disposal of industrial waste as alternative raw materials. Replacing limestone with alternative calcium containing raw materials that already emit carbon dioxide is an attractive option to reduce CO 2 emissions. Such substitution offers a double advantage, because in addition to the emissions associated with the decarbonization of the raw material, the emissions associated with the fuel used for such decarbonization can be eliminated. Blast furnace slag, lignite ash, coal ash, concrete crusher sand, aerated concrete flour, similar fractions of demolition waste or lime residues from the sugar industry are examples of such carbon dioxide-free alternative raw materials. However, the extent to which such opportunities can be used is largely determined by: