No pun intended. What are the fuels that fuel the cement production processes, is the question. However, even before we delve into that matter, why not spend a few words on why is it important to talk about cement fuels. Cement is an energy intensive process, no doubt, and bulk of the energy is consumed as carbonaceous fuels which are fired in the kiln during clinkerisation, and the rest is electrical power spent throughout the manufacturing processes, and predominantly in the clinker grinding process. So, directly or indirectly, on-site or off-site, CO2 is emitted into the environment as conventional forms of energy are consumed. Globally, cement industry has been identified as a major emitter of greenhouse gases. Cement generates about 8% of the world's carbon dioxide (CO2) emissions, according to a reputed global think tank, and to illustrate through an analogy, were the cement industry like a country, it would be the third largest global polluter - after China and the US. All that makes a rather strong case for a scrutiny of cement fuels. Another interesting aspect of fuels used in cement is that these work as fuel as well as raw materials in the clinkering process, and in that sense choice of fuels is not just driven by their energy value, but also by the composition of their combustion residue. This becomes very interesting to consider, when we see the diverse range of fuels being used in cement kilns ranging from coal to lignite to petroleum coke to natural gas to even oil and paint residues and such other "alternative fuels". In each and every one of such fuel choices, the process engineers have to take into account the mineral content of the fuel residue and its impact on the chemical process of clinkering, in addition to the conventional fuel considerations such as calorific value and price.
Availability of different types of fuels depend on geographies. For example, India favours coal and petroleum coke, but some plants near Tamil Nadu or Rajasthan tend to prefer lignite. Plants near the coastal regions can look for imported coal or pet coke, whereas the landlocked plants in and around Jharkhand, Madhya Pradesh, Chhattisgarh, Vidarbha, etc may prefer domestic coal from Coal India. The volatility of international prices of coal, currency swings, variations in shipping costs and dynamic pricing of petroleum coke - all contribute to making it a big challenge to optimise the fuel basket for a cement plant.
And, it is no less intriguing to analyse and report on such a vibrant topic of the cement industry.
Sumit Banerjee Chairman, Editorial Advisory Board