At least 750 MW power generation is possible through waste heat recovery in Indian cement industry, writes Rajendra Maurya.
Cement industry is energy intensive. Even a modern high efficiency plant would consume thermal energy about 700 kcal/kg clinker and electrical energy of about 70 kWh/tonne of OPC. For a 1 MTPA plant, the approximate power requirement would be to the tune of about 13-14 MW. Waste heat recovery (WHR) has been one area where the Indian cement industry has a lot of opportunities still untapped. Two major sources of waste heat recovery available in the cement industry are:
Organic Rankine Cycle
The Organic Rankine Cycle (ORC) converts thermal energy to mechanical shaft power. The benefit of ORC systems is that they recover useful energy, often as electrical output, from low-energy sources such as the low-pressure steam associated with steam-driven turbines generation. ORC is an attractive option for heat recovery in the range of 200-¦C to 250-¦C. Other organic fluids can also be used.
The author, Technical Director, AEGIS Projects Technology, has developed on HFC R 245 Fa (working fluid application) based heat recovery power plant.