Ashok Kumar Dembla, President and Managing Director, Humboldt Wedag, discusses the integration of AFR and digital twins technology to upgrade cement plants to CCUS readiness.
Technology providers are now playing a decisive role in helping manufacturers reduce emissions while safeguarding efficiency and competitiveness. In this in-depth interview, Ashok Kumar Dembla, President and Managing Director, Humboldt Wedag, outlines how the company’s philosophy is being translated into practical solutions for Indian cement plants.
‘Cement Beyond Carbon’ is a strong strategic statement. How are you adapting this philosophy for Indian cement plants? ‘Cement Beyond Carbon’ is our campaign because we firmly believe that carbon dioxide is extremely harmful to human health. This belief led us to initiate this campaign around four to five years ago, backed by focused technological innovation. At the first level, it involves relatively straightforward solutions such as maximising the use of alternative fuels and raw materials (AFR), implementing waste heat recovery (WHR) systems, and increasing the use of blended cements. Beyond these, we are working on advanced technologies such as oxy-fuel combustion, kiln electrification, digitisation, and automation. We are also actively developing carbon capture and utilisation technologies, exploring how captured CO2 can be reused in downstream processes such as urea manufacturing or even innovative products like protein synthesis. The idea of ‘beyond carbon’ is not just about achieving net-zero emissions, but about thinking further. How innovation can reduce the cement industry’s contribution, which currently accounts for about 7–8 per cent of global CO2 emissions. This campaign reflects our long-term commitment to fundamentally changing how cement is produced.
You recently executed large 10,000 TPD cement plants. What key learnings from these projects would you like to share? In India today, due to strong demand growth, inquiries for 10,000 TPD plants have increased significantly, and we have been a major contributor in this segment. We have built plants for UltraTech, are executing projects for Dalmia Cement and My Home, and several of these large-scale units have already been commissioned. When designing such large plants, special precautions are essential. Cyclone sizes increase significantly, often exceeding 10 metres, so careful design is required to prevent material drop in ducts. NOx control becomes critical, and we address this through our Pyro-Redox technology, which allows NOx reduction without secondary steps such as urea injection. We have successfully implemented this technology in operating plants. Another important factor is AFR usage. To accommodate higher AFR volumes without disturbing process stability, the calciner size must be carefully planned. We also rely heavily on simulation tools during the design stage and during operation, we use CFD analysis to troubleshoot and optimise performance. Fortunately, these plants are performing extremely well. For example, at My Home Cement, the plant is operating at less than 40 kWh per tonne up to the pyro process, with thermal energy consumption of around 765 kcal/kg. We continue to optimise these parameters further.
How are cement plants benefiting from your PROMAX process control and digitalisation platform? PROMAX is our core digital platform that integrates multiple modules for process optimisation. It follows a modular approach, meaning systems such as kiln expert control and mill expert control are now implemented using digital twin technology supported by artificial intelligence (AI). We continuously enhance PROMAX by adding modules such as refractory control, inventory management, and advanced cooler control, which requires extensive sensor integration. The platform has already been implemented in China, and we are now actively promoting PROMAX in India. We are engaging with major cement groups such as UltraTech, Dalmia and Chettinad to deploy this system across their plants. PROMAX enables an additional 2–3 per cent optimisation in both thermal and electrical energy consumption, which directly contributes to CO2 reduction. It also improves operational stability, reliability, and long-term performance of cement plants.
How are you supporting the industry’s shift towards calcined clay and lower clinker factors? India is in a relatively strong position because most of its fly ash production is already utilised in blended cements, but in some cases, this is not techno-economically viable. Calcined clay provides an effective alternative SCM, and under current regulations, LC3 cement allows 25–35 per cent calcined clay content. A good example is Jaisalmer, where many new cement plants are being established despite the absence of nearby thermal power plants. In such cases, producing calcined clay locally makes strong economic and logistical sense. We are working with companies like Wonder Cement and JK Cement on calcined clay projects. However, calcined clay requires very specific quality parameters. The kaolinite content must meet certain thresholds, and other clay components must also fall within defined ranges. To support this, we have established a pilot testing facility at our Cologne office in Germany, where we evaluate clay samples. The colour of the calcined clay and its impact on cement strength are critical. One major advantage is that calcined clay requires only about 400 kcal per kg to produce, making it a highly energy-efficient substitute for fly ash and slag.
What role does KHD play in enabling higher AFR substitution at cement plants? Our AFR solutions cover the entire spectrum, from very low substitution rates to extremely high levels, approaching 90 per cent of calciner fuel. At a basic level, we modify the calciner design by increasing residence time, diameter, and related parameters, allowing up to 40 per cent fuel replacement, provided the RDF particle size is limited to around 25–50 mm. For higher substitution rates, we offer the PyroRotor system, which can handle larger fuel sizes of 200 mm or more with minimal processing. This material is fired in a separate vessel connected to the calciner. Using this approach, we can replace up to 85–90 per cent of calciner fuel, with around 60 per cent fired through the PyroRotor and fed into the Pyroclon. Whether a client targets 10, 40 or 90 per cent AFR substitution, we have tailored solutions to meet those goals.
With rising carbon regulations and increasing competition, how are you helping cement producers maintain competitiveness? Carbon reduction is now non-negotiable. While oxy-fuel technology will eventually play a role, its high capital cost means it will take time to be widely adopted in India. For now, we focus on all feasible measures to reduce CO2 emissions. In one plant, for example, we supplied roller presses for raw material grinding, finish grinding, and cement grinding. As a result, electrical energy consumption dropped to around 38.5 kWh per tonne up to the pyro process, while blended cement grinding consumes only about 16.5 kWh per tonne. This plant is also operating with 20 per cent AFR, including hazardous waste, with thermal energy consumption around 685 kcal/kg. We know that every 1 per cent AFR addition typically increases thermal energy consumption by 1–1.5 kcal/kg, so without AFR, consumption would be closer to 683 kcal/kg clinker. Given tightening carbon regulations, we are designing plants to operate with the lowest possible carbon footprint even without carbon capture technologies.
How do technologies such as CCUS and digital twins help transform cement plant operations? These technologies significantly reduce manual intervention while improving automation and reliability. In existing plants, the main challenge lies in data integration. Legacy systems often require upgrades to ensure data compatibility and seamless cloud connectivity. Platforms like PROMAX rely on cloud-based infrastructure to create accurate digital twins. Using simulations and AI-driven optimisation, plants can achieve the next level of efficiency. While initial investment for new plants may increase by 10–15 per cent, the long-term benefits are substantial. Plants typically gain around 3 per cent improvement in both thermal and electrical energy efficiency, along with better manpower utilisation, remote plant control through handheld devices, improved inventory management and higher overall reliability. Currently, many plants operate around 330–345 days per year. With digitalisation and automation, it is possible to improve availability by another 10 days annually—an enormous operational advantage.
Two cement concrete pavement roads covering a total stretch of 2.2 km in Akhoya village were inaugurated on 27th June 2026 by MLA Nuklutoshi Longkumer, who attended as the special guest. The project comprises the one km L Pangersowa Road and the one point two km Longchara Junction to RC Chiten Jamir Memorial Government High School road. A formal programme followed the inauguration at the school auditorium.
A technical report was presented by Er Waloniba of the Urban Engineering Wing-III, Kohima, which stated the project was sanctioned in March 2026 under the Special Assistance to States for Capital Investment scheme for 2025-26 at a sanctioned cost of Rs 29.1 million (mn). The work order was issued to M/s Ensign Construction on thirtieth April 2026 with a stipulated completion period of 12 months. Work commenced on fourth May 2026 and was completed on sixth June 2026, with the contractor and team finishing the tasks in around two months. The project included a single-lane cement concrete pavement with side drains, two slab culverts and breast walls at required locations.
Longkumer acknowledged the Chief Minister, the advisor for urban development, contractors and other stakeholders for the allocation and support, and he commended the contractor for early completion. He noted that cooperation from landowners and the community had been important in resolving land related issues that can otherwise delay developmental works. He emphasised that planned developmental activities carried out with collective effort would enable more projects to be implemented successfully.
The headmaster of RC Chiten Jamir Memorial Government High School, I Chubasenba Longkumer, outlined the school background, noting it was established in 1962, was earlier known as Government High School Changtongya and was renamed in 2014. Local representatives said the improved approach roads would ease access for students, staff, patients and the general public and fulfil a long standing aspiration of residents. A dedicatory prayer was offered by the pastor and the programme concluded with a ribbon cutting attended by village council and town council representatives.
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:
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
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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.
