KN Rao, Director, Environment and Energy Conservation, ACC Ltd.
At ACC, we benchmark our plants with the best performing plants of similar technology and process across the world. This benchmarking exercise helps the company in setting long-term target for each plant, says KN Rao, Director, Environment and Energy Conservation, ACC Ltd. Excerpts from the interview...
How do you rate your company when it comes to energy efficiency?
ACC had many challenges to transform the old technology plants to energy-efficient ones. ACC Lakheri, the oldest cement plant of India, has been now transformed into one of the most efficient cement plants in the country. It is the first plant in the world to install a seventh stage pre-heater on the oldest cement kiln of India. ACC experience has shown transforming the old technology plants into energy efficiency plants is more challenging than incremental improvement in the energy-efficient new plants. ACC demonstrated this capability over the years and is rated as one of the top three cement companies in India on energy efficiency improvement.
What is your unit per tonne of cement target in terms of energy efficiency?
We have taken a target of specific total energy intensity (MTOE per tonne of cement) reduction of 3 per cent by 2017 vs 2013 at company level. The total energy includes electrical energy consumed (produced within the plant and imported from the grid) and all fuels (kiln fuels, fuels for drying, fuels for internal transport and oil consumed in the mining operation). The specific total energy is derived from the total energy consumed within the boundary of the plants and the total amount of products manufactured. This is a holistic approach of energy intensity reduction which is in line with the BEE definition of specific total energy intensity.
What are the achievement made so far?
Thermal: Many initiatives for process optimisation were taken to reduce specific thermal energy in clinker manufacturing. Different plants have achieved different levels of reduction and some of our plants achieved reduction as high as 6.4 per cent in the last five years. Some of the ACC plants are currently in the top three plants of the country in terms of specific thermal energy. The lowest specific thermal energy achieved is 686 kcal/kg of clinker in one of our plants.
Electrical: Due to energy conservation initiatives, the clinkering plants have achieved specific electrical energy reduction as high as 25 per cent in the last five years. Our lowest specific electrical energy achieved is 67.2 kW/T of cement in one of our plants. Similarly, our grinding units have achieved substantial reduction of specific electrical energy as high as 33 per cent. Our lowest specific electrical energy for grinding achieved is 26.61 kW/T of cement.
What are the modifications/process improvement done?
Almost all plants have undergone modification/process improvements which resulted substantial reduction in specific, thermal and electrical energy. We have also developed many products which have a low carbon footprint and energy footprint aligning with our sustainable development road map. Our blended cement CDM project is the biggest one in the Indian cement sector with annual CO2 emission reduction potential of approximately 200,000 tonne of CO2 per year.