Even as the world's energy utilisation is growing at 2.6 per cent, India is at 6.8 per cent, which make it imperative to have a positive approach towards framing policies for energy security, especially for making renewable energy economically viable. There has to be a standard for energy supplies, a benchmark on the price and a proper quality redressal mechanism to ensure the right energy services to the industry.
The Indian cement industry is probably one of the most energy- efficient in the world today. Being a highly energy- intensive sector, most of the major players have been adopting the best manufacturing practices right from mining to production to sales and distribution, across all units and disciplines by optimising energy, natural resources and technology. Further to that, the industry produced 137 MT of CO2 in 2010, approximately 7 per cent of India's total man-made CO2 emissions. It has successfully reduced CO2 emissions from 1.12 T CO2 per tonne of cement in 1996 to 0.719 CO2 per tonne of cement in 2010. What's more, some of the plants have thermal and electrical specific energy consumption (SECs) comparable to the best cement plants in the world, resulting in low emission intensities. The industry, which is on top in the Certified Emission Reductions Projects list registered with the Clean Development Mechanism (CDM) of the Kyoto Protocol, has contributed significantly to the eco-friendly use of industrial wastes and thereby succeeded in reducing its carbon footprint.
According to Sujit Sen, Vice-president, Process, Penta India, there are certain macro factors that determine the focus on energy efficiency within the cement plants. These are the forces from outside which govern the decisions within the plant. Sunit says "The first one would be the price and availability of fuel. India has always seen higher fuel costs as well as electrical energy costs compared to many other parts of the world, so most of our cement plants have been installed with highly energy efficient processes and technology."
Kcal/kg of Clinker
kWh/ t of Cement
installed pre 1990
50 - 60
20 - 25
installed post 1990
20 - 30
3 – 5
Gains feasible by revamping old plants. - Holtec
He adds, "Market forces are another factor that one has to contend with. Running the plants at 70 - 80 per cent of installed capacity will drive out the benefits perceived in installing good equipment or carrying out energy management drives. In that case, any discussion on energy efficient operation of the plant is purely academic.
Productivity is the denominator in this equation and as long as plants cannot work at design or higher capacity, the specific energy consumption will not be reduced. Operating at capacity for half the month and then shutting down or operating continuously with lower than design throughput is also not a viable solution as it will reduce the life of equipment and increase the cost of expensive consumables like refractories, lubricants, etc. Sustained energy efficiency is possible only when plants run continuously with a hundred per cent run-time and greater than a hundred per cent production factor."
Dibyendu De, Director, Reliability Management Consultants, supports the view. According to Dibyendu, the first major challenge of setting up a new cement plant is to estimate demand as accurately as possible and not to build a plant of higher capacity than needed. A higher capacity cement plant operating at a lower capacity simply wastes energy and money.
Dibyendu says, "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 lifecycle. And it is really difficult to bring down costs during the operation phase of the plant. "
The third challenge according to him, 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 with breakdowns and inefficient performance.
Sustainability awareness has picked up momentum in recent years in the cement industry, and several efforts are on by both cement manufacturers and major plant and machinery and auxiliary equipment manufacturers to integrate sustainability issues, essentially in energy conservation, resource optimisation and environmental planning, with business plans and reviews. For the cement industry, the major focus areas for sustainability are improving thermal energy efficiency and process technology, optimising fuel composition, including the use of waste as fuel, waste heat recovery, reduction in clinker factor, especially through increased rates of blending, and renewable energy. It is heartening to note that most of the cement companies have developed specific initiatives and road maps to reduce their organisational carbon footprint.
kWh/ t of Cement
Kcal/ kg clinker
Comparison of electrical and thermal specific energy consumption for a few selected countries around the world. - Courtesy: Holtec Consulting
Says Biswajit Dhar, Senior Vice President (Technology and Research Centre), UltraTech Cement, "Energy conservation is a key focus area for us. Operational measures towards energy conservation include constant monitoring to reduce downtime, reducing operational inefficiencies ensuring reliability of equipment, optimising productivity, minimising leakages, monitoring day-to-day energy consumption, and sharing of best practices." Biswajit adds, "We are constantly examining and evaluating measures to optimise clinker component per tonne of cement. Fly ash has a direct impact in reduction of specific energy consumption, since it reduces clinker component in cement to a certain extent.
However, use of fly ash has its own constraints like the availability of good quality fly ash. In certain cases, transportation costs of fly ash is also a constraint, when it has to be sourced from a distance."
"Energy consumption is a high-cost component of cement production. Conserving energy is essential to minimising the cost of production. International standard of energy consumption per tonne of cement varies but in the Indian industry, it is as low as 76 units per tonne of cement. To achieve this target, KJS has constituted an energy audit team which monitors energy consumption on a day to day basis and we are pretty sure we shall achieve the target very shortly though this new unit," says Pawan Ahluwalia, Managing Director, KJS Cements.
VM Moorthy, Senior General Manager (Tech), Rain Cements, says "We have taken immense efforts to raise our energy efficiency, Today our efforts have made Rain cements one of the most energy-efficient cement plants in Andhra Pradesh." He adds, "Firstly, we have been doing regular energy audits of the company. Such audits bring out the faults in our system and highlight energy leaks. They help us identify areas of improvements. We have been able to save ourselves from considerable energy wastage by taking corrective action to fix issues highlighted during the audit process.
We are aware of the immense potential for energy saving with the Waste Heat Recovery systems. Going in for WHR is one of the best investments that one can make for saving energy in a cement industry. We are planning for it."
"The data available from various sources indicates that the thermal energy consumption and the specific electricity consumption of Indian cement industry is definitely better than the rest of the world average. Please see adjoining table.
The Indian cement industry's average specific electrical energy consumption is 82 kWh/ tonne of cement compared to the world average in the range of 100-110 kWh/ tonne of cement. Average specific thermal energy consumption is 725 Kcal/ kg clinker compared to the world average of about 850-860 Kcal/ kg clinker," says Kamal Kumar, Chief General Manager, Holtec Consulting. Kumar continues, "Total energy consumption in a typical dry process cement plant is 75-80 per cent fuel (thermal energy) and 20-25 per cent electricity (electrical energy). 99 per cent of the fuel consumption is used for clinker burning or pyro-processing. Hence, pyro-processing has highest scope about 5 - 40 per cent for improvements in terms of energy efficiency. Some of the major energy efficiency improvement activities include alternative fuel utilisation and waste heat recovery addition of stage in the pre-heater."
Bidyut Bhattacharya, Technical Director, Sinoma International Engg Co India says, "The amount of energy saving varies on a case- to- case basis, depending on the actual selection of process and equipment, quality and consistency of fuel, raw material characteristics, etc.
However, it is important to understand here that long- term plant energy efficiency cannot be guaranteed on the mere selection of the most efficient individual equipment alone. Rather, over the long term, energy (fuel and power) efficiency is largely driven by the uniformity of the kiln feed chemistry, mastery of the burning zone which is primarily a kiln operation, and plant reliability factor i.e, avoiding stoppages due to incidents; all this in turn, is connected to plant preventive maintenance."
Potential sources of energy and the amount in actual use.
Says Mahathi Parashuram, Head - Public Affairs, Grundfos Pumps India, "The Indian market and consumers are slowly but steadily moving towards adopting energy-efficient products. India is also realising that sustainability is not just the right path forward but will also help in saving costs and resources (energy and water).
The government now needs to push the sustainability agenda further by promoting the development and use of energy- efficient products through subsidies.
It is vital that the government encourages energy efficiency labelling and ratings of products. These moves will definitely open up the market for eco-friendly products, making India more competitive on this front."
Highlighting the importance of integration of IT solution, Sujit says, "The implementation of MIS (management information systems) helps to keep track of key performance indicators. Management is able to monitor both plant operations and the productivity in a continuous manner." He adds, "Many MNCs have successfully used IT systems for years. However, in India, it is often observed that the plant personnel do not fully utilise these tools which are then limited to generating reports rather than help in decision- making.
It is also necessary to ensure that all sensors are calibrated and are working properly. Proper implementation of IT systems will enable us to reduce not only energy costs but all operating costs as well. However, the exact value of the savings depends on the maturity of the owners and plant personnel in exploiting these tools to their best capabilities."
It is worth mentioning that the government has launched a laudable initiative through the Perform - Achieve-Trade (PAT) scheme, an energy conservation drive launched by BEE (Bureau of Energy Efficiency) under the National Mission for Enhanced Energy Efficiency. The PAT scheme is a unique and innovative programme with no precedence elsewhere in the world.
The main goal of the scheme is to mandate specific energy efficiency for the most energy- intensive industries, and further incentivise them to achieve better energy efficiency, above their specific energy consumption improvement targets.
The cement plant is an energy- intensive unit, where the energy costs account for about 30 per cent of the total manufacturing cost. Energy savings of 0.816 million tonnes of oil equivalent (Mtoe) (34PJ) per year are expected to be achieved, which is around 12 per cent of the total national energy savings targets assessed under PAT.
Another major initiative in this direction is the GreenCo Rating System launched by CII - Godrej GBC. Energy efficiency, water and material conservation, waste management, product stewardship and greening the supply chain are all agents of change that will play a significant role in facilitating a sustainable rate of growth.In this regard, the GreenCo Rating System is the first of its kind in the world to provide a much needed holistic framework to evaluate industries on their environmental performance.
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