The fuel mix of cement manufacturers is going through a churn. The last decade saw cement companies partially substitute coal with pet coke.
However, the fuel mix now includes plastics and tyres, as companies look to rejig their sourcing.
“Our fuel mix currently comprises alternative fuels at 7 per cent. According to Geocycle (a waste management solution), the estimated amount in the long-term will be 13 per cent,” an official from Ambuja Cements had said last month.
The company has adopted Geocycle as a co-processing technique for industrial and other wastes at its kilns.
Co-processing refers to the use of waste materials in industrial processes as alternative fuel or raw material. Due to the high temperature in the cement kiln, different types of wastes can be effectively disposed of without harmful emissions, according to the Central Pollution Control Board.
Others like UltraTech, Nirma’s Nuvoco, JK Lakshmi and Madras Cement, are among companies which are burning waste ranging from tyre chips, rubber dust to rice husk and cashew nut shells in their kilns to generate heat.
At Dalmia Cement’s Responsible Industrialisation initiative, 18.9 tonnes of plastic waste was collected from residential areas, the plant and neighbouring villages and used in the kiln to save a good 56 million kilo calories of energy.
For the country’s largest cement maker UltraTech, alternative fuels contribute three per cent to the total fuel mix. In an investor presentation in February, the company said it is targeting 10 per cent contribution from alternative fuels by the end of the current financial year.
Cement manufacturers are also witnessing a cost benefit from alternative fuels. In its March quarter presentation, UltraTech said increased usage of industrial waste as a fuel has contributed to cost savings.
According to an India Brand Equity Foundation report, use of bio energy through the burning of coffee husk and cashew nut shells at Madras Cement’s Alathiyur plant has led to an annual cost savings of $1.7 million.
Most of the waste collection so far has been through arrangements with municipal authorities. However, companies like JK Lakshmi are also experimenting to further expand into waste collection. A rejig of fuel mix is under way for JK Lakhsmi where the company looks to increase its share of alternative fuels.
According to sources, it looks to formalise the supply of waste materials through community collection, including plastics, to be used as fuel in its kilns.
Companies like Shree Cements have also extended the fuel mix to sources like automobile sludge, waste water with high ammonia levels as well as medical waste. “Alternative fuel now contributes four to five per cent to our total fuel mix,” said HM Bangur, managing director of Shree Cements.
Anumita Roy Chowdhury, executive director at Centre for Science and Environment or CSE, said, “To ensure such processes do not cause environmental hazards, there is a need for stringent monitoring of stack and process emissions as well as profiling of emissions.”
She added, “Cement companies will have to invest in effective emission control systems to stay within the permissible limit and reduce toxic emissions. Adequacy of emission standards will have to be reviewed from time to time.”