Decarbonising of the Indian Cement Industry Through Alternative Fuels – Challenge of Transfer Chute Jamming

Abstract

The Indian cement industry in COP27 highlighted its commitment to achieving net zero CO2 emission by 2070 made during COP26. The industry is moving towards decarbonisation and has identified various levers to achieve the goal. Fossil fuel replacement by Alternative Fuels (AFs) has been identified as one of the levers. Refused Derived Fuel (RDF), surplus biomass, industrial waste, and other societal wastes, etc., have emerged as potential AFs; however, their use comes with technical challenges like transfer chute jamming due to the wide range of variations in their properties. Jammed transfer chute leads to the breakdown of the entire transportation system and further fluctuation in AFs feeding to the kiln/calciner. Fluctuation in the feed rate of the AFs disturbs the fuel mix ratio (mix ratio of fossil fuel and AFs) and ultimately negatively impacts the process, operation, and quality of the produced cement. Transfer chute design is often overlooked, leading to build-up, blockage, and wear in chutes. Designing of transfer chute is more challenging when handling solid alternative fuels in cement plants, as the properties of these fuels have a wide range of variation where moisture may be as high up to 40%, bulk density may vary from 0.1 to 0.75 tonnes/m3, and particle size ranges from 1 to 100 mm, etc. This study covers a survey to establish which types of AFs, and their characteristics contribute to the chute jamming problem. The outcome of this study shall help the Indian cement industry to consider the appropriate inputs for transfer chute design and selection of the correct alternative fuels and their mix to avoid chute jamming.