ACC has taken an important step in energy conservation with the installation of a new Waste Heat Recovery System (WHRS) at its Gagal Cement Plant in Himachal Pradesh. This is the company’s first WHRS plant and also the first project in the state of Himachal Pradesh to deploy waste heat recovery technology.
The WHRS system harnesses waste heat discharged in the cement manufacturing process as exhaust gases and converts it into useful electrical energy. Heat from hot flue gases discharged as waste into the atmosphere from the cement manufacturing process is converted into electricity by channelizing them into a waste heat boiler that runs a steam turbine using Steam Rankine Cycle technology. The newly commissioned WHRS project, which can generate about 7.5 MW of electricity, comprises a suspension pre-heater boiler, an air quenching chamber boiler, a steam turbine generator, distributed control system, water-circulation system and a dust-removal system.
The electrical energy thus generated requires no additional fuel as it utilizes waste heat. The cost of generating such energy is significantly lower than that of a captive power plant and only a fraction of the cost of grid power.
Apart from the economy involved, WHRS units simultaneously offer several advantages. These systems play a vital role in energy conservation, they are entirely environment-friendly as they do not need any additional fuels to generate electricity and hence directly help conserve fuels and reduce overall carbon emissions.
The WHRS at Gagal is expected to lead directly to a reduction of over 44,000 tonnes of carbon dioxide (CO2) emissions per annum. Since this energy is based on waste heat and requires no additional fossil fuel, the energy thus produced is green energy that is equivalent to renewable energy.
Waste heat recovery can comprise a valuable and reliable alternate source of captive power generation to an industry like cement that is so energy-intensive. In view of the many advantages, units like these mark an important step in sustainable development.
Following the commissioning of the WHRS at Gagal, ACC is exploring the possibility of installing Waste Heat Recovery systems at some of its other cement plants.