Indian cement industry – growth, ­development and future perspective

1 Overview

The cement industry in India continues to be the second largest producer in the world, which is about 7 % of the annual global cement production today. While the global economic scenario remained challenging with economic growth hovering around 3.4 %, ­Indian economic growth maintained 7.3 %. The govern­ment’s focus on concrete road projects, housing for all by 2022, make in India, creation of 100 smart ­cities, dedicated freight corridors, Swachh Bharat Abhiyan (Clean India mission), connectivity improvement including water transport will bring the required boost in infrastructure and housing sectors and further propel the Indian cement industry on the growth trajectory. Accordingly, the projected demand for cement in 2022 is in excess of 600 million t.

2 Manufacturing technology

The Indian cement industry has always been at the forefront in contemporary technology adoption. This is reflected in terms of the achievements in physical indicators such as energy consumption, kiln productivity, operating hours per year, stack emissions, renewable energy use etc. Technology developments that are being harnessed include ­installation of multi-stream preheaters and ­calciners with clinkering capacities exceeding 10 000–12 000 t/d, adoption of energy efficient coolers, modernization in finish grinding systems, higher use of automation, adoption of waste heat recovery systems, development of newer types of cement with reduced carbon footprints.

The technological advances in cement manufacture have been accomplished over the past two decades in the following major areas resulting in higher capacity production units, better process control, better quality control, improved energy efficiency and better pollution control:

Improved mining practices through remote sensing, computer-aided deposit evaluation, in-pit crushing through mobile/semi-mobile crushers, application

Improved mechanical material conveyors like pipe conveyors, high capacity bucket elevators in place of pneumatic conveyors

High efficiency size reduction techniques such as impact crushers, vertical roller mills, roller presses, high efficiency separators etc.

Improved blending/homogenizing silos such as controlled flow (CF) silos

Improved pyro-processing systems through latest generation precalciners, 5/6 stage low pressure preheaters, high efficiency multi-channel burners, high efficiency coolers etc.

High efficiency pollution control equipment such as electrostatic separators with pulse energisation, bag filters incorporating glass fabric etc.

Improved refractory practices such as mag-chrome bricks, magnesia-spinelide bricks, periclase spinel bricks, high strength insulating bricks, alumina-zircon refractory bricks, coating repellent aluminium-zirconium-silicate bricks etc.

Improved instrumentation and automation for quality control and process control through programmable-logic-controllers (PLC’s), distributed control systems, expert kiln and mill control systems, on-line bulk analysers, on-line quality control through industrial robots etc.

Product diversification/modification (production of blended cements)

3 Energy efficiency and carbon footprint

Cement manufacture is energy intensive with ­energy costs as high as 40-50 % of its production costs. The global and national focus on energy conservation has led to the adoption of technology that is continuously improving the production process. This has led to considerable savings in energy by a large number of plants with the incorporation of modern technologies in grinding, pyro-processing, cooling, material handling and pollution control systems. Sophisticated instrumentation and computerized control systems have led to better ­efficiency and economy. The Indian cement ­industry’s estimated weighted average specific energy consumption in the year 2014-15 was 721 kcal/kg clinker for thermal energy and 76 kWh/t cement for electrical energy. Currently the best specific thermal and electrical energy consumption reported by the Indian cement plants is 678 kcal/kg clinker and 71 kWh/t cement, which are comparable with the best values reported worldwide.

The present scenario of economic liberalization, environmental concerns and technological promotion have compelled the industry to constantly re-examine their manufacturing practices, business insights, management methods and production plans etc. Introduction of renewable energy resources such as wind mills and solar plants are among them. Presently around 6-8 plants have gone for installation of wind power with rated ­capacity of around 256 MW. Replication potential exists for other plants for around 30 % renewable energy substitutions. Some cement plants have also installed solar plants with an overall generation potential of around 16.5 MW. All these will contribute to achievement of the national targets of 175 GW of energy through the Renewable Energy route.

Apart from technology up-gradation, the ­Indian cement industry has also made substantial progress in insulating itself from the vagaries of grid power shortage. The supply from the state electricity grid being unreliable due to frequent power cuts and also costlier than captive generation, almost all cement plants had to set up thermal captive generation capacity, to overcome the power problem to a large extent. The captive power generation in the Indian cement industry increased substantially from just 118 MW in 1982 to the pres­ent level of around 5000 MW which resulted in production of ~ 60 % of total cement using captive power. However, the industry is striving hard to reduce the energy burden of the country as a whole through cogeneration of power through waste heat re­covery systems. The present installed capacity of the WHR system is about 200 MW and the estimated potential is to generate more than 600 MW power from the waste heat of pre-heater and cooler gases.

In the current Clean India drive in the country, cement kilns can contribute substantially in treating large amounts of hazardous and non-hazardous wastes in a safe and environmentally sound manner. Although some individual cement plants have achieved up to 11 % Thermal Substitution Rate (TSR) but the overall %TSR is abysmally poor being < 1 %. The major challenges remain the policy/regulatory norms like “polluter to pay concept”, availability of quality processed waste, which need further attention.

It is well known that blended cement has a lower clinker to cement ratio compared to OPC and consequently has less specific energy demand with reduced CO₂ footprint. As of now, about 200 million t of fly ash is generated by thermal power plants out of which 57 million t is being consumed by the cement industry. Thus there is a huge potential for utilizing fly ash by the cement plants which will not only help the environment but will help release significant areas of land from having to be used as dumps by the thermal power plants and turning them barren. Recently composite cement standards have been introduced in India and the production of composite cements will further help in reducing the clinker factor by maximizing the utilization of fly ash and slag together. Other ways of reducing the clinker factor are by increasing usage of different waste materials like lead zinc slag, copper slag, jarosite, marble slurry etc. in the making of cement blends. For old and energy inefficient plants, process optimization; installation of ­latest generation clinker coolers; energy efficient grinding systems; multi-channel burners etc. will remain the other energy efficient technological avenues.

The Indian cement industry’s efforts to reduce its carbon footprint by adopting the best available technologies and environmental practices are reflected in the achievement of reducing total CO₂ emissions to an industrial average of 0.719 t CO₂/t cement in 2010 from a substantially higher level of 1.12 t CO₂/t cement in 1996. NCB has been actively associated with the Cement Sustainability Initiative (CSI) of the World Business Council for Sustainable Development (WBCSD), a global voluntary initiative on sustainability. This has resulted in Development of the Low Carbon Technology Roadmap for the Indian Cement Industry. In order to further reduce the CO₂ emissions, five broad technological key levers have been identified in the technology roadmap jointly by NCB and CII. These five levers are increased use of alternative fuels and raw materials (AFR), improvement in thermal and electrical energy efficiency, reduction in clinker substitution, recovery of waste heat and application of newer technologies. Present production of blended cements in the country has been around 72 % as against only 36 % in 2000-2001 consuming about 28 % of the total fly ash generated and the entire quantity of granulated blast furnace slag, the waste generated by steel plants exceeding 10 million t annually. Accordingly, the current clinker factor, a major technology lever to reduce carbon footprints, is 0.77. The CO₂ emissions are targeted to be further reduced to 0.58 t CO₂/t of cement by 2020 and 0.35 t CO₂/t of cement by 2050 as estimated in the technology road map.

It is worth mentioning here that, the Indian cement sector is one of the most energy efficient worldwide, mainly due to modern technology being implemented in the plants as well as because of efficient monitoring of the plant’s performance on a daily basis, focusing on energy savings and CO₂ emissions reduction.

While focusing on the various aspects of cement manufacture and its utilization, the cement industry is also committed to the fact that its ­operations do not harm the biodiversity and do not to disturb the ecological or the environmental aspects of the surroundings. Major initiatives have been taken in cement plants as well as in captive mines to minimize emissions through ­latest generation bag filters or prevent land degradation through the development of green belts, conserve water through rain water harvesting or controlling fugitive dust, etc. More than 17 million trees have been planted in the last decade, which could act as a carbon sink. Abandoned mines have been turned into water reservoirs, with rain water harvesting and recreation sites. The modern economic distribution systems like bulk movement of cement, coastal transport and palletization or shrink wrapping of cement bags are options that the industry needs to adopt for effecting reduced loss in transit and at the same time conserving product quality.

Through water conservation efforts such as reduction of fresh water withdrawal, recycling of waste water, rain water harvesting and zero discharge the industry has begun a gradual shift towards becoming a water positive industry. The cement plants have been giving due attention to occupational safety and health of the workers. Through its CSR activities, the cement plants are creating value for the local communities in the ­areas of healthcare, education, community development, environment etc.

4 Quality management competence

and business excellence

The NCB is at the forefront in assisting the cement and construction industry in its excellence efforts. The organization is maintaining accreditation to ISO 17025 – which lays down requirements for competence of testing and calibration labora­tories – for its testing and calibration activities, for the past 17 years. Quite a few cement plants have also received accreditation with assistance from the NCB. Now, the NCB has become the first accredited PT (Proficiency Testing) provider in the country as per ISO 17043. Nearly 25–30 cement plants, along with many R&D and independent testing laboratories from the construction sector, regularly participate in the PT schemes conducted by the NCB. The NCB has completed 44 PT schemes on cement and other construction materials and also carried out more than 45 laboratory assessment studies in cement plants. Then, NCB’s certified reference materials (CRMs) are also sought after by the industry in India and abroad. The NCB has so far developed 75 types of CRMs.

5 Research and development

Research and development is a continuous need for any industry to remain competitive and keep pace with the demand and growth of the society and the country at large and the cement industry is no exception. The National Council for Cement and Building Materials (NCB) is a premier R&D institution in India, conducting frontline research activities catering to the needs of the cement and construction industries. Over the years, it has contributed immensely towards the development and the growth of the cement industry, appropriately addressing the country’s concerns in the area of sustainable development and growth, raw materials and energy conservation, environmental protection and so on. Based on detailed investigations carried out at the NCB, waste materials such as lead-zinc slag, copper slag and oil refinery E-cat (Equilibrium-catalyst) waste have been recommended by the working group of the Bureau of Indian Standards (BIS) for use as a performance improver in OPC. The R&D efforts in the recent past have been directed towards producing more sustainable cements through reduction of the clinker factor in cement, enhancing utilization of low grade and waste materials in cement manufacture and developing composite cements. BIS has formulated a new standard for composite cement permitting thereby simultaneous use of fly ash and granulated blast furnace slag as add­i­­tives for cement manufacture, specific to Indian conditions. Moreover the NCB has been compiling the National Inventory for cement grade limestone. The National Awards for Energy Efficiency, Environmental Excellence & Quality Excellence in the Indian cement industry instituted by the NCB in 1986 and being given away every year since then, have also played a catalytic role in motivating the cement industry for competitive improvement.

6 Perform achieve and trade scheme

The National Action Plan on Climate Change outlines eight missions including the National Mission for Enhanced Energy Efficiency (NMEEE). The NMEEE is an integrated approach for climate change mitigation through energy efficiency measures and its basic objective is to ensure a sustainable growth by an approximate mix of four E’s, namely – Energy, Efficiency, Equity and Environment. The mission is based on market-based approaches to unlock energy efficiency opportunities. Perform Achieve and Trade (PAT) is one of the four components of NMEEE. PAT is a market-based mechanism to enhance cost effectiveness of improvements in energy efficiency in energy-intensive large industries and facilities, through certification of energy savings that could be traded. Baseline Energy Audits have been carried out in the Indian cement industry and targets for energy reduction have been specified. The Perform Achieve & Trade (PAT) scheme launched by the Bureau of Energy Efficiency (BEE), Ministry of Power, played a pivotal role in promoting energy efficiency in major industrial sectors including the cement sector in India. During PAT cycle 1, the energy monitoring/energy audit, process optimization studies have revealed that the efforts made for energy efficiency were mainly directed towards optimization and retrofitting of systems and adoption of energy efficient equipment. The energy target for the cement sector during PAT cycle 1 was 0.815 MTOE (million t oil equivalent). However, the achieved figure was 1.480 MTOE, 82 % higher than the target and shows a commendable performance of the Indian cement industry.

7 Conclusion

The Indian cement industry has adopted state-of-the-art productivity improvement and energy ­efficiency measures very well and also implemented in-house optimization measures to achieve plant operational excellence. The Indian cement industry will be quick to develop and adopt any forthcoming major/minor technology innovation and invention in its effort to achieve higher productivity and quality. The development of India’s infrastructure is vital to the growth of its overall economy. The government of India has launched various new infrastructure development missions including setting up of 100 smart cities in the country by 2022, affordable housing under “Housing for all till 2022”, dedicated freight corridors and development of roads, airports, ports etc. Considering these various initiatives and announcements of the government for infrastructure and housing development, the cement demand would be in excess of 600 million t cement in the next five years. Therefore, the role and responsibility of the cement industry will increase manifold.

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