Sunil Kumar Singh, Director - Metals, Mining & Minerals, Schneider Electric India.
On thermal side, the cement plants have taken great care in using waste heat. But still with the amount of heat available, power generation can be done to make it further energy-efficient, says Sunil Kumar Singh, Director - Metals, Mining & Minerals, Schneider Electric India. Excerpts from the interview...
Sustained energy efficiency is possible only when plants run continuously with hundred per cent runtime and greater than hundred per cent production factor. What is your take on this?
Yes, that is one important parameter for reduced specific energy consumption. Generally, Indian cement plants are ahead of others in this. By operating in this manner, the overall key indicators - kWh/tonne of cement and kcal/kg of clinker will be less which is an indicator of the energy efficiency levels.
How do you assess the scope for energy optimisation in cement industry?
On thermal side, the cement industries have taken great care in using waste heat. But still with the amount of heat available, power generation can be done to make it further energy-efficient.
Also on electrical side, most of the cement plants have installed updated technology and process equipment. It is mainly grinding mills circuit, process fans and material conveying method which will determine the energy efficiency of a plant.
The plants are considered to be energy-efficient if they adopt the following:
What is the scope of AFR and what are the challenges in this regard?
There is a good scope for alternate fuels in the form of tyres, bio-fuels etc, which the industry has already initiated. The industry is producing cement apart from OPC like PPC, PSC etc for which there is a potential to add more additives like fly ash, slag etc.
Is cost a major deterrent in implementing WHR?
Yes, the investment is high for WHR applications, but that is the major energy efficiency project on thermal side. Power generation using WHR results in considerable savings and also Indian cement industry can take the advantage under PAT cycle.
What sort of modifications/process improvement do you suggest to help conserve energy in a new plant, and in retrofit of an existing one?
In a new plant, basically it starts with the design; lay out, selection of equipment, process etc. The general retrofits in existing plants are replacement with energy-efficient fans, and installing drives, mechanical conveying equipment, low pressure cyclones in pre-heaters, and installing power plant using WHR.
To what extent can IT be harnessed to save energy?
Energy monitoring systems are used in almost all plants to continuously monitor the energy consumption of major equipment. This helps to immediately address issues in case of any deviation / abnormality.
Could you give us with examples where you have helped cement companies reduce energy bills?
The results based on some of our energy audits are given below; this may not be the final figure as we were not involved in the implementation.