Dibyendu De, Director, Reliability Management Consultant
Improving energy efficiency is directly connected to improving the reliability of the plant. Here, reliability means extending the continuous run hours of the plant and its various units by reducing failures to the minimum possible level, which is nearly zero, says Dibyendu De Director, Reliability Management Consultant. Excerpts from the interview.
What are the major challenges in retrofitting / or setting up of new cement plants?
The first major challenge of setting up a new cement plant is to estimate demand as accurately as possible and not to build a cement plant of higher capacity than needed. A higher capacity cement plant operating at a lower capacity simply wastes energy and money.
The second challenge is to conduct a design review before setting up a plant. It consists of three stages, which are review of conceptual design, design review followed by detailed design review. This is important since around 60 per cent of operating costs are determined before the plant is set up and commissioned. Costs and energy efficiency have to be taken into account at this design stage. In such reviews, questions of layout, sizing, selection, reliability, maintenance and maintainability issues of the equipment are to be addressed along with other issues. If not done, higher operating costs would keep reflecting throughout the plant life cycle. And it is really difficult to bring down costs during the operation phase of the plant.
The third challenge is to conduct through pre-commissioning tests of equipment and systems to discover inherent imperfections and faults in the system that would push up costs during operation through breakdowns and inefficient performance.
What is the scope for greenfield projects?
The scope for greenfield projects is huge. With 750 new cities coming up, demand for cement will soar. The demand of cement would further accelerate with growth of other infrastructural facilities that are bound to come in the coming years. However, as of now, the demand is sluggish and is expected to be so for at least the next two years. I don’t think anyone can say how soon the economy will show recovery. In brief, the demand for cement is invariably linked to economic progress and the rise of the middle class.
Which section or processes in a cement industry has the highest scope for improvement in terms of energy efficiency?
In fact, energy savings is connected to preventing waste of energy. And that can happen anywhere in the plant. However, the highest scope lies in the utilities, grinding units and clinker processing.
How much can an existing plant improve its energy efficiency through a repair or retrofit job?
Improving energy efficiency is directly connected to improving the reliability of the plant. Here, reliability means extending the continuous run hours of the plant and its various units by reducing failures to the minimum possible level, which is nearly zero. Such improvement in reliability is connected more to the maintainability of the plant and not directly to maintenance of the plant. Maintainability is the process of improving plant performance on a continuous basis.
What kinds of energy saving measures/technologies do you recommend to your clients?
The normal measures and technologies are now quite well known in industry circles. However, incorporation of all such technologies must be linked to improving maintainability of the plant.
What is your outlook on the PAT scheme introduced by the Bureau of Energy Efficiency?
Many cement plants in India with modern technology have already achieved the minimum possible energy levels compared to the best in the world. So, the scope of gaining from the PAT scheme for these plants is very limited indeed, in my opinion. For other plants which are not as per norms, it is a matter of capital investments, which management might not be willing to undertake, especially during a sluggish economic phase as we are currently experiencing. For such plants, much would depend on marketing and maintenance departments to adhere to the norms of the PAT scheme.
Could you give us with examples where you have helped cement companies reduce energy bills?
For most cement plants where I was involved in improvement of plant reliability and improvement of kiln running hours, the measurable energy reduction was to the tune of 7 per cent to 15 per cent. In some cases, the savings were even higher. The added benefits are that costs go down and productivity goes up. This gives the plant ongoing benefits for years.
The principle is – energy tries to freely flow across systems. However, when impeded or hindered energy goes up and is either wasted or triggers breakdowns. Hence by identifying energy blockages within the system and eliminating such blockages both energy consumption and costs comes down. In addition reliability also goes up.
Following graph illustrates such savings from the real world of cement business. This case was done in one of the largest cement plants in India. Interesting to note that growth of reliability and the lowering of costs are almost mirror images.
How much can a plant expect to save in energy costs by applying IT solutions?
So far, I have not come across any study that links application of IT solutions to energy savings.