Cement Manufacturers Association (CMA)

24 Indian Scenario on Utilisation of Alternative Fuels and Raw Materials Cement manufacture requires a lot of energy and resources, thus coprocessing waste-derived materials as fuels is a frequent way to cut costs and lessen environmental effect. The cement industry is currently considering the use of materials like waste oils, plastics, auto shredding wastes, waste tires, sewage sludge (SS), and most recently, slaughterhouse residues, as alternative fuels. Along with moisture and volatiles, energy and ash concentrations are also significant. The use of alternative fuels and raw materials in Indian cement kilns is still developing. The earliest and most popular alternative raw material used in the production of cement in India is fly ash. India’s coal and lignite thermal power plants produce about 226 million tons annually, and the country’s industry is currently using this waste to make resource material. The Bureau of Indian Standards restricts the use of fly ash in cement manufacturing in India, requiring a minimum of 15% and a maximum of 35% to produce Portland Pozzolana Cement. Fly ash is currently used by plants in both wet and dry forms. PPC based on fly ash is produced by nearly all Indian cement manufacturers. In India, PPC manufacture makes up between 60% and 70% of all cement produced. Appropriate adaptation of the plant equipment to handle the challenges introduced by alternative fuels It is difficult to add alternative fuel (AFR) to a cement plant without further research and understanding because of the limitations and the effects that the firing of AFR has on the energy balance, operation stability, clinker quality, and emissions. Process-related issues can lead to significant issues. High substitution rates of alternative fuels can only be achieved if the process and the machine technology is tuned and adapted to the requirements occurring additionally using alternative fuels. Undoubtedly, the cement industry had to spend much more efforts than the optimistic plans provided originally at the time of inception. This is attributable to both the complexity of the overall technical task and to the diversity of waste derived fuels used. Nevertheless, the use of alternative fuels for these plants can be economically viable - and it usually is - when the process is optimally adapted. In the case of new installations, these arrangements can be considered in the system design, so that no production risk occurs. In modern cement kiln systems, there are two firing zones; one in the Calcinedr, where most of the carbonate in the raw meal is decomposed into calcium oxide and carbon dioxide, and another one in the rotary kiln outlet. After availability, it becomes important to use technology to use Alternate Fuels and Raw Materials which is cost and energy efficient. As a technology provider KHD developed the systems as summarized below: PYRO-JET® Burner with AFR Swirl Nozzle for Alternate Fuels and NOx Reduction: The Key features are • Retractable swirl element. • No additional primary air is necessary for AFR nozzle. • Adjustable during operation. • Fracturing, and mixing of the AF flow shortly before entering the kiln (increasing the spraying angle). • Improving the mixture within the flame core and with oxygen. Figure 1: AFR Swirl Nozzle KHD has modified various numbers of Burners with newly developed AFR Nozzle in various plants across the globe. The demand for switching to alternate fuels has increased in India as well. Almost all the upcoming pyro lines in India are opting for AFR provision.