Dr. Suchismita Bhattacharya, Head – Process, Penta India Cement & Minerals.
An energy audit is the first step in knowing the existing energy consumption levels in an operating plant. Penta India has had the opportunity to work with cement plants and help in ensuring the sustainability of the cement industry by reducing their energy consumptions, says Dr. Suchismita Bhattacharya, Head – Process, Penta India Cement & Minerals. Excerpts from the interview..
Which section/process in a cement plant has the highest scope for improvement in terms of energy efficiency?
The scope for energy optimisation will depend on the existing conditions in the plant. Most of the new plants in India are based on the best technologies; hence any improvement in energy consumption may be possible only by tweaking certain operational parameters in the grinding and pyro-processing departments.
In some plants, there will be certain low hanging fruits such as material conveying equipment, which can be converted from pneumatic to mechanical systems which are more energy efficient. Elsewhere, the use of effective automation may be able to stabilise operations and reduce losses.
Mines operation, logistics or movement of both raw materials and products to and from the cement plant also offer opportunities for reduction of the energy footprint per tonne of cement.
What sort of modifications/process improvement do you suggest to help conserve energy?
An energy audit is the first step in knowing the existing energy consumption levels in an operating plant. Once the baseline is fixed, the performance of the various departments can be compared against the standard energy consumption patterns in the best performing plants. We can then determine which areas require immediate attention.
These modifications could be some nominal measures as reducing false air entry into the pyro system, changing operating parameters or major changes such as addition of low pressure drop pre-heater cyclones or addition of pre-grinders to grinding circuits.
In case of new plants, use of AFR or installation of WHRs could be some of the additional power consumption measures. Another area is harnessing of solar power by exploiting certain areas available in some of the cement plants as well as the roof tops material storage sheds for installation of solar panels.
What are the areas/methods where IT can be applied to bring down energy consumption?
Information technology and plant automation are going hand-in-hand these days to improve equipment availability and indirectly reduce energy consumption costs, which occur due to unplanned breakdowns. Equipment health data can be logged and remotely monitored by experts who can send technicians to site in the advent of impending breakdown. Similarly, any variation in raw material and fuel quality can be dealt with instantaneously and the stable operation of the kiln will ensure that fuel is conserved.
Also, with the help of IT, plant operation can be planned such that some of the energy intensive operations can be carried out during times when grid power is less costly.