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Waste Heat Utilisation is now a proven technology

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Sanjay Kumar Khandelwal, Head – Power Plants, JK Cement, shares details about the working of waste heat recovery systems (WHRS) and its benefits, while elaborating on the efforts undertaken by his company to become energy-efficient.

What are the alternative or renewable sources of energy used by your organisation for the process of cement manufacturing?
At JK Cement, we are at the forefront of our sustainability journey. To achieve our clean energy targets, the alternative renewable energy sources used by our organisation are solar plants, wind energy, hydel energy, biomass and waste heat recovery systems (WHRS). The use of alternative fuels and raw material (AFR) to substitute fossil fuels has also been initiated.
We have installed WHRS with all the kilns except one kiln which we are planning to install in FY 22-23. In FY21 our Green Power Mix was 25 per cent and we are working to increase it to 75 per cent by FY 2030.
We started our AFR journey in FY 2013-14 with a very small quantity and now we have achieved a TSR of 6.5 per cent in FY 2020-21. We are proud to share that we have achieved a TSR of 20 per cent at one of our plants. To achieve the TSR target of 35 per cent we have made huge investments for installation of shredder, covered storage shed and feeding arrangement for both solid and liquid waste, refuse derived fuel (RDF), plastic waste etc. Further, to overcome the operational challenges we are installing chlorine bypass, an outside burning system and more shredders are also in the pipeline. For the supply side, we have recently signed a MoU with PRESPL for the supply of biofuel and biomass to achieve the proposed TSR target of 35 per cent

When did your organisation install the WHRS in cement plants and what were the key considerations taken into account while doing the same?
The first WHRS with a capacity of 13.2 MW was commissioned in 2008 at JK Cement Works, Nimbahera. Recently in our plant at Mangrol, we upgraded the capacity to 29.1 MW from 10 MW after the installation of Kiln-3. Our objective was to generate power without any additional fuels, maximise utilisation of waste heat generated from kiln operations, minimise heat losses into the environment and finally minimise water consumption.

What was the energy consumption of the plant prior to the system and how has that changed post installation?
Installation of WHRS plays a major role in not only reducing the overall energy consumption cost but also the requirement of other available non-renewable energy resources. This has resulted in minimising the Grid and CPP as a result of implementing WHRS to meet our energy requirements. Apart from that, regular monitoring of WHRS parameters and process optimisation is being done on a regular basis to recuperate maximum heat from the system so as to generate maximum power and to keep the WHRS system efficient.

How does the process of waste heat recovery work? What is the technology used by your organisation for its functionality and monitoring?
WHRS works on the thermal Rankine Cycle concept. Steam (hot gases) emitted from the preheater exit as well as clinker cooler from the Kiln operations, enters into the WHRS system. The steam then passes through the turbine to further the power generation process.
In order to ensure that our power generation is as efficient as possible, we have adopted the best operating and maintenance practices. This includes operating from a central control room using a state-of-the-art PLC-based operating system while keeping manual intervention to a minimum. We also compare the actual results with the design and the best data on a daily basis, making any adjustments necessary in real-time besides conducting regular system audits to ensure the efficiency of our WHRS.

On an average, energy cost is around 40 per cent of the production cost for cement manufacturing. What is the impact of the waste heat recovery system on the energy cost of the cement plant?
WHRS utilises hot gases emitted both from preheater as well as clinker cooler to generate power without the usage of any additional fuel. In other words, we are able to generate power without utilising any fossil fuels; which not only reduces overall carbon footprints but also restricts hot gases from entering into the atmosphere. This system results in reducing the overall cost of production by reducing overall power consumption cost followed by a reduction in cost through optimum power mix (maximum usage of WHRS and renewable power sources and least usage of grid and CPP power) through effective power management.

The WHRS is a major contributor towards reducing the carbon footprint. Tell us about its impact and support in achieving the decarbonising goals of the cement industry.
WHRS utilises hot gases emitted both from preheater as well as clinker cooler to generate power without the usage of any additional fuel. In other words, we are able to generate power without utilising any fossil fuels; which not only reduces the overall carbon footprint but also restricts hot gases from entering into the atmosphere.
This system results in reducing the overall cost of production by reducing our power consumption cost followed by a reduction in cost through optimum power mix and through effective power management.

What other technological or automation advancements can contribute towards making the process of cement manufacturing energy optimised?
To name a few: VFD installation, PID-based automation, low DP control valve installation, high energy efficient fans, high efficient motors, PF improvement system, cross country belt conveyors for material conveying, installation of horizontal roller press (HRP) mills with lower specific energy consumption, high efficiency cooler, lower pressure drop preheater, high efficiency latest motors, mechanical conveying in place of pneumatic conveying, replacement of reciprocating compressors with screw compressors, automation of compressed air pressure as per requirement with installation of controller, adopting drip irrigations to conserve water, regular audits etc, can all go a long way in improving and optimising cement manufacturing process.     

Are there any specific researches taken in the direction of finding more alternative sources of energy that have a lower impact on the environment?
At a global level, to extract heat at a low temperature range, Organic Rankine Cycle based power generation, Vapour Absorption Machine, water heating and the use of CPP are some of the latest developments, which contribute a lot in reducing the carbon footprint. However, this requires very high capital investments.
The use of green hydrogen as an alternative fuel, electrification of clinkering process, use of concentrated solar energy for producing clinker are the fields that can be explored that has the potential to lower environmental impact

How do you foresee the future of energy consumption in the cement manufacturing process and its impact on the end product cost?
World energy demand is expected to increase by 35 per cent by 2030 as developing nations have to modernise and expand their economic output. This creates a near impossible scenario for secure, low carbon energy supplies to keep pace with this demand. So, the need of the hour is to be 3 times more energy efficient!
In today’s scenario, the cement industry is becoming more and more energy efficient not only through its process optimisation but also by adopting newer technologies. Waste Heat Utilisation is now a proven technology and has become an integral part of the cement manufacturing process. AFR is another viable option that has the potential to reduce the consumption of fossil fuels. This can not only help in reducing carbon footprint but also improve cost economics besides reducing environmental impact. Other industry wastes like slag, red-mud, zinc waste etc. and hazardous wastes along with biomass are also being used.
Chemical gypsum and similar alternative raw materials are also being used in the cement process. This has not only made the manufacturing process energy efficient but has also optimised the end product cost. However, other factors like increasing fuel and raw materials cost, manpower, overheads, logistics and mining cost etc. are major concerns that can increase the end-product cost, therefore, nullifying the effect of optimisation and energy efficiency.
With a strong focus on AFR usage, the challenge that we face is in terms of its availability, utilisation, economic and technical feasibility. This also requires creating an ecosystem that supports its adoption. Therefore, regulatory authorities need to come forward and help take this to the level that has been achieved by developed countries.

-Kanika Mathur

Concrete

Green Construction Through Cement Innovation

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Indian Cement Review (ICR) and Fuller Technologies brought industry, policy and technology leaders together to discuss how cement innovation can drive green construction at scale, writes Rakesh Rao.

India is building at a pace few countries can match. Highways, airports, housing, logistics parks, industrial corridors and urban infrastructure are reshaping the country’s economic geography. But beneath this growth story lies a difficult question: can India continue to build at scale without locking itself into a high-carbon future?

That question formed the core of an online panel discussion titled “Driving Green Construction Through Cement Innovation”, organised by Indian Cement Review (ICR) in association with Fuller Technologies as the Presenting Partner on June 25, 2026. The webinar brought together experts from cement technology, R&D, global industry platforms, building performance policy and international development cooperation to examine how low-carbon cement and material innovation can accelerate India’s green construction transition.

The discussion came at a crucial time. India has committed to achieving net-zero emissions by 2070 and reducing the carbon intensity of its economy by 45 per cent by 2030. At the same time, the country’s construction sector is expanding rapidly, driven by urbanisation, infrastructure development, housing demand and industrial growth. Cement, as one of the most widely used construction materials, sits at the heart of this transition. It is indispensable to development, but also central to the challenge of reducing embodied carbon in buildings and infrastructure.

Moderated by Nitika Krishan, Senior Urban Infrastructure and Sustainable Policy Consultant, the panel featured:

  • Kiranmai Sanagavarapu, Director, Low Carbon Solutions, Fuller Technologies;
  • Dr Hemantkumar Aiyer, VP and Head R&D, Nuvoco Vistas Corp Ltd;
  • Devika Wattal, Innovation Lead, Global Cement and Concrete Association (GCCA);
  • Dr Sunita Purushottam, MD, GBPN India (Global Buildings Performance Network); and
  • Vaibhav Rathi, Senior Technical Advisor, GIZ (the German Agency for International Cooperation)

Setting the tone for the discussion, Nitika Krishan underlined the scale of the challenge before the sector. “The question before us is no longer whether we build, but how we build sustainably,” she said. She pointed out that construction accounts for nearly 40 per cent of global energy-related carbon emissions when both operational and embodied carbon are considered. Cement production, she added, remains one of the hardest industrial processes to decarbonise.

For India, this is not merely an environmental issue. It is a development issue, a competitiveness issue and increasingly, a market issue. As one of the world’s largest cement producers and among the fastest-growing construction markets, India’s material choices will influence the carbon trajectory of its built environment for decades. As Krishan observed, sustainability solutions in economies such as India must not remain limited to laboratory success. They must be scalable, commercially viable and practical at national level.

The innovation gap: From technology to market

Experts believe that there is a need to bridge the innovation gaps for making decarbonisation in cement and concrete scalable. Devika Wattal of GCCA, explained, “The starting point must be the core cement manufacturing process itself. The first and foremost is the heart of our process, the heart of cement manufacturing. How do we reduce clinker? That is always a topic where industry is working very intrinsically.”

Clinker reduction remains one of the most important pathways for lowering emissions in cement. Since clinker production is energy-intensive and chemically emits carbon dioxide, reducing the clinker factor through supplementary cementitious materials (SCMs), blended cements and new chemistries can have a significant impact. Wattal also noted that carbon capture, utilisation and storage (CCUS) will have a role, though it may not be the first lever for all markets.

However, she stressed that innovation cannot stop at technology development. A solution that works in the lab must also be adaptable to industry, scalable in production and acceptable in construction practice. “It is important for that innovation to be adaptable, to be scalable, and so that it can be executed in real time,” she said.

Wattal also called for stronger enabling systems around innovation. These include performance-based standards, product-level embodied carbon databases and clearer frameworks for evaluating green materials. Without these, low-carbon cement products may struggle to compete with conventional materials in procurement and design.

R&D must balance carbon, cost and performance

Bringing in the R&D perspective into the discussion, Dr Hemantkumar Aiyer of Nuvoco Vistas emphasised that low-carbon cement development cannot be treated as a single-variable exercise. Cement must perform in real construction conditions. It must deliver strength, durability, consistency and cost competitiveness, while also reducing carbon.

“The root of understanding and balancing all these aspects lies in materials, and knowing the materials,” he said.

According to Dr Aiyer, R&D teams must understand the variability of raw materials such as fly ash, slag and clinker. Different sources produce different material behaviours. This makes mix optimisation, material characterisation and processing-property relationships critical. When performance is affected, cement manufacturers must understand how strength enhancers, admixtures and other performance chemicals interact with the material system.

He also linked material science with process efficiency. Clinkerisation takes place at extremely high temperatures, around 1,400 to 1,450 degrees Celsius. Any improvement in raw mix design, process control or energy optimisation can, therefore, help reduce emissions and cost. Dr Aiyer pointed to artificial intelligence-based optimisation, Cement 4.0 tools and advanced software as important enablers for real-time process and material control.

“The more you understand the materials, the more you can control it,” he said.

LC3: The promise is proven, the sequencing is not

Limestone calcined clay cement, commonly referred to as LC3, has attracted global attention because it can reduce clinker content significantly by using calcined clay and limestone while maintaining performance in many applications. Kiranmai Sanagavarapu of Fuller Technologies said the technology itself has already moved beyond proof of concept. Fuller Technologies has worked with calcined clay technology for nearly two decades and has seen plants running in France and Ghana. These plants, she said, are meeting local and national specifications, while the economics are beginning to make sense.

“The calciner is performing, the economics is stacking up, it is making business sense to produce,” she said.

But if the technology is viable, why has adoption not scaled faster? For Sanagavarapu, the answer lies in project sequencing. Too often, clay characterisation happens after equipment is specified. This, she warned, is a backward approach because calciner design depends on clay mineralogy, kaolinite content, iron levels, reactivity, moisture and other variables.

“If you don’t know what your deposit looks like before you commit for the equipment, you are, in a way, going blind into designing,” she said.

She also identified permitting and plant integration as major bottlenecks. Environmental clearances, mining permissions and local regulatory approvals must begin early. Similarly, calcined clay must be integrated into existing grinding, blending and logistics systems from the design stage, not treated as an afterthought during commissioning.

India already has IS 18189:2023 standard for LC3, but Sanagavarapu pointed out that the standard is not yet visible enough in procurement documents. “The gap between what is technically being permitted and what the procurement is asking is the single biggest bottleneck,” she said.

In her view, successful scale-up depends on getting the sequence right: clay characterisation first, permitting in parallel, standards aligned with construction, and integration built into plant design.

India’s LC3 journey: Progress, but demand remains thin

Providing details of India’s LC3 commercialisation experience, Vaibhav Rathi of GIZ noted that JK Cement carried out the first commercial production of LC3 at its Rajasthan plant, followed by JK Lakshmi Cement three months later. These initiatives were supported by the International Climate Initiative of the Government of Germany, with IIT Delhi contributing deep institutional knowledge on LC3 research and BIS certification.

Rathi said India’s early experience has produced clear lessons. One of the biggest was the need to build capacity among regulators. While BIS certification existed, State Pollution Control Boards were unfamiliar with the technology and unsure about the approval pathway.

“The capacity building is not just needed amongst the producer and the users of the cement, but also the regulators who are working with this technology for the first time,” he said.

He also highlighted the need for better information on China clay deposits. Since China clay is currently classified as a minor mineral, centralised data on availability, quality and location is limited. If cement manufacturers are to adopt LC3 at scale, stronger mineral intelligence will be important.

The third issue is demand. LC3 has already been used in projects such as Palava City in Mumbai and Noida International Airport, but these remain limited examples. “It is in a chicken and egg situation,” Rathi said. “Cement companies are saying we need more demand, and users are saying there is not enough cement available.”

Public procurement, he suggested, could help break this cycle. If agencies such as CPWD and other public bodies begin testing, accepting and specifying LC3, it could create the market confidence needed for cement companies to invest in production and storage.

Building codes must catch up with innovation

Dr Sunita Purushottam of GBPN India argued that material choices will determine built environment emissions over the long term, but India’s current policy signals remain fragmented. Although LC3 has received BIS recognition, she pointed out that building codes, municipal bylaws, schedules of rates and sustainability codes do not yet provide uniform guidance on low-carbon cement.

“The current cement regulations are largely prescriptive and favouring traditional materials,” she said. This limits the ability of alternative materials to compete on performance, durability and emissions.

Dr Purushottam also raised the issue of taxation. Cement, including LC3, currently falls under the same GST bracket as conventional cement. A differentiated tax structure, she argued, could help accelerate market adoption. “In order for the market to demand LC3, that differentiation in the GST could go a long way,” she said.

She noted that green building certifications such as IGBC and GRIHA are already creating demand for low-carbon materials by assigning points for embodied carbon and sustainable material use. However, she said large-scale adoption will require regulatory mandates, particularly through building codes and state-level notifications.

She also cautioned that low-carbon cement alone does not solve the entire building performance problem. A material may reduce embodied carbon, but the operational carbon of a building depends on thermal performance, design, insulation and energy use. “The energy part has two elements,” she said. “One is the embodied carbon of the material itself, and the other is the operational carbon.”

Collaboration is the bridge between invention and impact

Wattal said GCCA sees innovation as a strategic priority and works through platforms that connect industry with academia and start-ups. “There is no way we will decarbonise our sector without innovation,” she said.

However, she stressed that research must be connected to actual industry challenges. Innovations developed in isolation may fail when they encounter real-world barriers such as raw material variability, plant integration, cost, standards and finance. Start-ups, too, need industry mentorship and scale-up pathways.

Wattal also flagged the importance of finance. Even strong technologies may struggle to attract investment if there is no common understanding of bankability. “We have always put projects into, is this a bankable project? But the definition of a bankable project has never been defined,” she said.

For India, she saw strong potential in its academic and start-up ecosystem, but said the challenge lies in alignment and prioritisation. The country has the research base, industrial capacity and market size. What it now needs is a coordinated route from innovation to deployment.

There is a practical concern for cement manufacturers: how can existing plants be adapted for lower emissions without compromising reliability or commercial viability?

Kiranmai Sanagavarapu addressed, “The reliability risk in calcined clay retrofit is definitely real, but it is almost always self-inflicted. The risk arises when a new process is added to an existing circuit without properly redesigning grinding and blending configurations.”

Existing cement plants, she explained, can take two broad routes. The first is external sourcing of calcined clay combined with mill optimisation. This requires lower capital investment and can potentially move in 12 to 18 months if other conditions are in place. It may reduce emissions by around 20 to 30 per cent. The second route is integrated calcination on site, which requires higher capital expenditure and longer lead times, but provides greater control over quality, supply and emissions reduction potential.

For Sanagavarapu, the principle is simple: low-carbon retrofits must be designed with intent. “Design it with an intent properly from the start. Start in the market conditions where the economics are already working,” she said.

Circularity: The overlooked advantage

According to Vaibhav Rathi, fly ash and slag are already well established in cement and construction (C&D), but construction and demolition waste remains underutilised. “C&D waste is a growing business opportunity which not many have taken up,” he said. India’s continuous construction and demolition activity creates huge volumes of waste, much of which contributes to air pollution, land degradation and material inefficiency. With the right processing and standards, this waste can be converted into useful construction products.

Rathi also pointed out that LC3 has a circular economy dimension that is often overlooked. It can use low-grade kaolin-rich clay left behind after high-grade clay is extracted for other applications. “LC3 is not only a low-carbon solution, but also a circular economy solution,” he said.

At the same time, he cautioned that LC3 in India is not yet cheap because it has not reached scale. Site-specific techno-commercial feasibility studies, supported jointly by development agencies and industry, could help companies assess whether LC3 production makes technical and financial sense at a given location.

Dr Purushottam added that India must address both low-carbon cement and construction waste together. “Both low-carbon cement and C&D waste go hand in hand. India does not have an option but to work on both,” she said.

Dr Aiyer called for policy shifts from both government and industry, including preferential purchasing of sustainable materials, minimum supplementary cementitious material requirements in public and public-private projects, and faster regulatory implementation. “If we can fast-track the regulatory standards and their implementation on the ground, that is the way to go,” he said.

From green ambition to green construction

Cement innovation is no longer only about chemistry. It is about systems. Low-carbon cement will scale only when technology, standards, procurement, finance, regulation, education and construction practice move together.

LC3 and other low-carbon technologies have shown promise. India has early commercial examples, strong research capability and growing market interest. But mainstream adoption will depend on whether demand can be created, regulators can be capacitated, standards can be embedded in procurement, and manufacturers can see a clear business case.

For a country building at India’s scale, the opportunity is enormous. Cement will continue to be central to infrastructure and urban development. The challenge now is to ensure that the cement used in India’s growth story carries a lower carbon burden.

  • Rakesh Rao

Participate in Cement Expo 2026 and discover how next-gen infrastructure can be built with innovations in cement.

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JK Cement Declared Preferred Bidder For Gilund Limestone Block

Shares Edge Higher As Company Wins Rajasthan Block

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JK Cement gained after being declared preferred bidder for the Gilund Limestone Block in Chittorgarh, Rajasthan, a lease area of 370.96 hectares. The firm saw its shares trade at Rs. 5550.05, up by 28.45 points or 0.52 per cent from the previous close of Rs. 5521.60 on the BSE. The scrip opened at Rs. 5569.15 and touched a high of Rs. 5625.00 and a low of Rs. 5531.00.

The stock recorded turnover of 1742 shares on the counter and the BSE group A stock with face value Rs. 10 has a 52 week high of Rs. 7565.00 on 20-Aug-2025 and a 52 week low of Rs. 4670.05 on 12-Jun-2026. Last one week high and low stood at Rs. 5625.00 and Rs. 5329.00 respectively. The promoters holding in the company stood at 45.66 per cent, while institutions and non-institutions held 40.61 per cent and 13.73 per cent respectively.

The e-auction conducted by the Government of Rajasthan resulted in the company being declared preferred bidder for the mining lease, and the allocation will enable the company to plan phased development of the deposit, subject to regulatory approvals. The Gilund block spans 370.96 hectares and its allocation is intended to support raw material security for the company’s cement operations in the region. The designation follows the government auction process and will allow the company to plan development and integration of the deposit into its supply chain.

The current market capitalisation stands at Rs. 430.38 billion (bn), reflecting market response to the mining news and prevailing valuation levels for the sector. Investors and analysts will watch for formal allotment and related disclosures that can clarify timelines, capital expenditure and expected production profiles. The report is intended for informational purposes and does not constitute investment advice, and market participants are advised to consult advisers before making decisions.

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Star Cement Named Preferred Bidder For Boro Lakhindong Block

Preferred bidder for limestone mining lease in Assam

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Star Cement has been declared the preferred bidder for the mining lease for Boro Lakhindong West Block following e-auctions conducted by the Government of Assam. The block is located in Boro Lakhindong Village, Umrangso Tehsil, Dima Hasao District, Assam, and extends over an area of 123 hectares. The estimated limestone resource is 207.822 million (mn) tonnes (t), a quantity that will supply raw material for cement production and support the company’s manufacturing operations in the region.

The company is engaged in the manufacturing and selling of cement clinker and cement and distributes products across the north-eastern and eastern states of India. Star Cement operates plants and logistics networks that procure and process limestone to produce clinker for cement, and the addition of Boro Lakhindong is presented as a strategic enhancement of feedstock availability. The preferred bidder status secures rights to the specified lease area under the terms of the auction process.

Financial results for the company in the fourth quarter of fiscal year 2026 showed a consolidated net profit rise of 20.24 per cent to Rs 1,481.0 mn on an 11.54 per cent increase in revenue to Rs 11,735.5 mn compared with the corresponding quarter of the previous year. Those results reflected higher sales volumes and revenue growth in the company’s primary markets and are cited in company disclosures accompanying the lease announcement. The reported performance provides context to the company’s ability to pursue and finance new mining lease opportunities.

Market reaction to the declaration was modest, with the scrip rising zero point thirty six per cent to trade at Rs 212 on the BSE. The award of the Boro Lakhindong lease concludes the e-auction process for the west block and assigns operational rights to Star Cement as the preferred bidder, subject to completion of statutory and contractual formalities.

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