Concrete

Taking a Carbon-Negative Approach

Published

3 years ago

April 7, 2023

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Pankaj Kejriwal, Whole Time Director and COO, Star Cement talks about the future of eco-friendly green cement, its advantages, efforts taken by cement producers, new technological innovation and operational efficiency improvements.

The hon’ble Finance Minister in her budget speech for FY 2023-24 has highlighted seven priorities to act as Saptarishi, guiding us through the Amrit Kaal. One of them is Green Growth. This Green Growth will be achieved by using green fuel, green energy, green buildings etc. and eventually providing green jobs.
Green cement is a step in this direction. Green cement is an eco-friendly cement that uses a carbon-negative process of manufacturing. The major raw materials used to produce green cement include mostly the discarded waste from the industry. The slag from the blast furnace and fly ash are the chief materials used in the manufacturing of green cement.
Concrete with green cement is a form of eco-friendly concrete that is manufactured using waste or residual materials from different industries, and requires less energy for production. Compared to traditional concrete, it produces less carbon dioxide, and is considered environmentally friendly and more durable. Green concrete has a lower shrinkage rate and also becomes stronger far more quickly than concrete made with traditional cement.

Types of Newly Invented Green Cement

Ekkomaxx Cement
It is a type of green cement produced in the United States that is composed of 95 per cent fly ash and 5 per cent renewable liquid additives. Based on standards such as the International Code Council and United States Green Building Council, this cement, which is manufactured by Ceratech Company, has nearly zero carbon footprint.
Not only did the process of cement production decline the use of virgin material by 95 per cent but it also decreased the water requirement by half.
The main characteristics of Ekkomax cement are high early strength, resilience, crack resistance, low chloride permeability, sulphate attack resistance, durability and corrosion resistance, which is more than three times of conventional cement, and the resistance to freezing and thawing is greater than that of normal cement.
Magnesium Oxychloride Cement
Magnesium Oxychloride Cement (MOC) is an environmentally friendly and carbon-neutral cement, which is produced from two main materials namely: magnesium oxide (MgO) powder and a concentrated solution of magnesium chloride (MgCl2). These are by products from magnesium mining.
The MOC has great compressive strength and sets quickly and MgO absorbs CO2 from the atmosphere, but water can reduce its strength considerably. However, this weakness of MOC can be tackled to a certain extent by introducing 15 per cent of fly ash and the same amount of silica fume.
These additives fill the pore structure in MOC, which makes the concrete denser. Consequently, both strength and durability of concrete is improved considerably. Furthermore, it is required to add phosphoric acid and soluble phosphates to improve the resistance of this type of green cement against warm water.
Finally, Magnesium Oxychloride Cement leads to the corrosion of steel, hence this type of cement cannot be used for construction reinforced concrete structure unless this problem is tackled.
Geopolymer cement
Geopolymer, which is also known as alkali-activated cement, is produced from alumino-silicates instead of the more environmentally damaging calcium oxide.
The aluminosilicates are obtained from industrial by-products like fly ash. The geopolymer cement is competitive with ordinary Portland cement in performance and cost, and it emits 95 per cent less CO2 than the ordinary Portland cement.
Ferrocrete
Ferrocrete cement is manufactured by mixing silica and iron, which are waste by products from the steel and glass industry. This material mixture is then cured with CO2, and consequently, it potentially becomes carbon-negative material. The scientists at the University of Arizona invented Ferrocrete.
Calcium Sulfoaluminate Cement
The calcium sulfoaluminate cement is produced in a kiln that requires a temperature of 1232oC (2250F) rather than 1426.6oC (2500oF) of conventional cement. As a result, less CO2 would be released into the atmosphere. The calcium sulfoaluminate cement sets rapidly and gains 28-day strength of conventional concrete in 24 hours.
That is why it is used in projects where rapid setting of concrete is crucial such as bridge decks and airport runways. The calcium sulfoaluminate cement can be used as shrinkage compensating cement when a higher quantity of gypsum is added.
This type of cement can achieve energy savings as high as 25 per cent and provide environmental benefits by reducing CO2 emissions by around 20 per cent when compared with Portland cement.
Sequestrated Carbon Cement
The Calera Corp. cement in California produced cement from seawater or brine mixed with CO2 that may be used as a Portland cement substitute. In this cement production process, CO2 rich gases are filtered through seawater.
The calcium and magnesium are stripped from the seawater and react with CO2 to produce high-quality cement, which is white, air-permeable and stronger than regular OPC.
Cement Produced Using Superheated Steam
The process of superheated steam can be used to change the cement particles in order to make them more reactive. In this process, the emitted CO2 can be captured after it has been separated.
Low Carbon Cement (Ecocem Technology)
This type of cement contains clinker content up to 20 per cent with 80 per cent SCM’s and limestone filler. The drastic reduction in clinker factor will provide significant savings in energy consumption.
Cement Produced with Reactive Hydrothermal Liquid-phase Densification
This type of cement is produced using the same raw materials as ordinary Portland cement, but at lower temperature and through a different chemical reaction that produces less CO2 compared with traditional Portland cement production process.
This cement is blended with water and CO2 and reacts with CO2 to produce calcium carbonate and silica, which eventually hardens to make concrete. This type of green cement is produced by Solidia Technology Company based in the United States, and has partnership with Lafarge to commercialise the cement production technology.

Advantages

Lowers carbon dioxide emission as it does not require as much heat during its production, releasing up to 80 per cent less carbon dioxide.
Makes use of industrial waste such as fly ash, silica fume and blast furnace slag that may require several hectares of land for disposal. As a result, it protects land from becoming a dumping ground and ultimately being destroyed.
Requires less energy. Since industrial by-products present in green cement, the energy needed in production is greatly reduced. Additionally, it withstands temperature fluctuations and
hence decreases costs related to both heating and cooling.

Efforts Towards Going Green
Decarbonising the cement industry is likely to require significant advances on three fronts: operational efficiency, technological innovation, and business model reorientation. More collaboration across the cement ecosystem will be pivotal. Despite the increasing complexity and challenges each ecosystem player faces, first movers may gain the upper hand by taking immediate action across the value chain to help the industry reach its decarbonisation targets. These green-cement disruptors are likely to capture headwinds as sustainability becomes increasingly urgent.

Operational Efficiency
Even after decades of effort to make cement production more efficient, the industry still has considerable room for efficiency improvements. McKinsey analysis suggests that continued application of proven emissions-abatement methods could reduce emissions by about one-fifth by 2050.
These methods include using clinker substitutes more widely, increasing plant utilisation (which can lower energy intensity), and boosting the effectiveness of equipment. Other opportunities include applying advanced analytics and replacing fossil fuels with alternatives such as biomass-based fuels.

Technological Innovation
Promising changes in the formulation of cement have begun to emerge. For example, lowering the proportion of limestone in cement can result in fewer process and fuel emissions. Adding CO2 to concrete as it cures can strengthen the solid material, reduce the amount of cement needed, and sequester captured CO2. And improving carbon-capture technology would make it more economical to keep process emissions from entering the atmosphere. Coolbrook technology for calciner and kiln electrification using rotodynamic reactors can be a game changer in future.

Business Model Reorientation
Cement-based concrete will probably remain the construction industry’s preferred material. But if engineers, technologists, construction companies and building-materials businesses (which account for about 30 per cent of construction emissions) work together more closely, they could optimise the design of buildings and infrastructure to use less cement overall.
This might involve rethinking structures and shapes, altering the material mix and replacing cement with alternative materials such as cross-laminated timber and employing novel methods such as prefabrication and 3-D printing.
Star Cement has started using green fuel i.e. bamboo for its power plant and clinkerisation unit thus enhancing the green fuel efficiency in the plant, and aiding in the green growth initiative of the country.
Star Cement is adding waste heat recovery systems (WHRS) with existing clinker production lines. It promises to bring the latest technologies for reducing carbon emissions to all the upcoming/existing plants and to bring green cement to the market.

ABOUT THE AUTHOR:
Pankaj Kejriwal, Whole Time Director and COO, Star Cement, has been responsible for conceptualising, engineering, implementation and commissioning of all cement projects.

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Concrete

The primary high-power applications are fans and mills

Published

2 days ago

October 10, 2025

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Alex Nazareth, Whole-time Director and CEO, Innomotics India, explains how plants can achieve both cost competitiveness and sustainability by lowering emissions, reducing downtime and planning for significant power savings.

As one of the most energy-intensive industries, cement manufacturing faces growing pressure to optimise power consumption, reduce emissions and improve operational reliability. Technology providers like Innomotics India are enabling this transformation by combining advanced motors, AI-driven digital solutions and intelligent monitoring systems that enhance process stability and reduce energy costs. From severe duty motors built for extreme kiln environments to DigiMine AI solutions that optimise pyro and mill operations, Alex Nazareth, Whole-time Director and CEO, Innomotics India, explains how the company is helping cement plants achieve measurable energy savings while moving closer to their sustainability goals.

How does your Energy Performance Contracting model typically reduce power consumption in cement plants—e.g., MWh saved?
Our artificial intelligence-based DigiMine AI Pyro and Mill solutions developed specifically for the cement industry, supports our customers in improving their process stability, productivity and process efficiency. In Pyro, this is achieved by optimising fuel consumption (Coal / AFR), reducing Specific Heat Consumption and reduction in emissions (CO2, SOx and NOx) through continuous monitoring of thermodynamics in pyro and recommending set-points of crucial parameters in advance for maintaining stable operations.
Within the mill, this is achieved by improving throughput, reduce energy / power consumption and maintaining stable operations on a continuous basis. Our ROI-based value proposition captures the project KPIs like reduction of coal usage, increase of AFR, reduction of specific heat consumption (Kcal / Kg), reduction of specific power consumption (KWH / tonne), reduction of emissions, etc., by a specific percentage. This gives clarity to our customers to understand the investment vis-à-vis savings and estimate the recovery time of their investment, which typically is achieved within one year of DigiMine AI Pyro and Mill solutions implementation.

What role do digitalisation and motor monitoring play in overall plant energy optimisation?
Motors are being used extensively in cement production, and their monitoring play crucial role in ensuring continuous operation of applications. The monitoring system can automatically generate alerts for any anomaly / abnormalities in motor parameters, which allows plant team to take corrective actions and avoid any major equipment damage and breakdown. The alerts help maintenance team to plan maintenance schedule and related activity efficiently. Centralised and organised data gives overview to the engineers for day-to-day activities. Cement is amongst the top energy intensive industries in comparison to other industries. Hence, it becomes critically important to optimise efficiency, productivity and up-time of plant equipment. Motor monitoring and digitalisation plays a vital role in it. Monitoring and control of multiple applications and areas
within the plant or multiple plants becomes possible with digitalisation.
Digitalisation adds a layer on top of OT systems, bringing machine and process data onto a single interface. This solves the challenges such as system silo, different communications protocol, databases and most importantly, creates a common definition and measurement to plant KPIs. Relevant stakeholders, such as engineers, head of departments and plant heads, can see accurate information, analyse it and make better decisions with appropriate timing. In doing so, plant teams can take proactive actions before machine breakdown, enable better coordination during maintenance activities while improving operational efficiency and productivity.
Further using latest technologies like Artificial Intelligence can even assist operators in running their plant with minimal requirement of human intervention, which allows operators to utilise their time in focusing on more critical topics like analysing data to identify further improvements in operation.

Which of your high-efficiency IEC low-voltage motors deliver the best energy savings for cement mills or fans?
Innomotics India offers a range of IEC-compliant low-voltage motors engineered to deliver superior performance and energy savings, particularly for applications such as cement mills, large fans, and blowers. Innomotics has the complete range of IE4 motors from 0.37kW to 1000kW to meet the demands of cement industry. The IE5 range is also available for specific requirements.

Can safe area motors operate safely and efficiently in cement kiln environments?
Yes, safe area motors are designed to operate reliably in these environments without the risk of overheating. These motors have ingress protection that prevents dust, moisture ingress and can withstand mechanical stress. These motors are available in IE3 / IE4 efficiency classes thereby ensuring lower energy consumption during continuous operation. These motors comply with relevant Indian as well as international standards.

How do your SD Severe Duty motors contribute to lower emissions and lower cost in heavy duty cement applications?
Severe duty motors enhances energy efficiency and durability in demanding cement applications, directly contributing to lower emissions and operational costs. With high-efficiency ratings (such as IE3 or better), they reduce power consumption, minimising CO2 output from energy use. Their robust design handles extreme heat, dust and vibration—common in cement environments—ensuring reliable performance and fewer energy losses.
These motors also lower the total cost of ownership by reducing downtime, maintenance and replacement frequency. Their extended service life and minimal performance degradation help cement plants meet sustainability targets, comply with emissions regulations and improve overall energy management—all while keeping production consistent and cost-effective.

What pump, fan or compressor drive upgrades have shown approximately 60 per cent energy savings in industrial settings and can be replicated in cement plants?
In the cement industry, the primary high-power applications are fans and mills. Among these, fans have the greatest potential for energy savings. Examples, the pre-heater fan, bag house fan, and cooler fans. When there are variations in airflow or the need to maintain a constant pressure in a process, using a variable speed drive (VSD) system is a more effective option for starting and controlling these fans. This adaptive approach can lead to significant energy savings. For instance, vanes and dampers can remain open while the variable frequency drive and motor system manage airflow regulation efficiently.

Concrete

We conduct regular internal energy audits

Published

2 days ago

October 10, 2025

admin

Shaping the future of low-carbon cement production involves integrating renewables, digitalisation and innovative technologies. Uma Suryam, SVP and Head Manufacturing – Northern Region, Nuvoco Vistas, gives us a detailed account of how.

In an industry where energy consumption can account for a significant portion of operating costs, cement manufacturers are under increasing pressure to adopt sustainable practices without compromising efficiency. Nuvoco Vistas has taken a decisive step in this direction, leveraging digitalisation, renewable energy and innovative technologies to drive energy efficiency across its operations. In this exclusive conversation, Uma Suryam, SVP and Head Manufacturing – Northern Region, Nuvoco Vistas, shares its approach to energy management, challenges of modernising brownfield plants and its long-term roadmap to align efficiency with India’s net-zero vision.

How has your company improved energy efficiency over the past five years?
Over the past five years, we have prioritised energy conservation by enhancing operational efficiency and scaling up renewable energy adoption. Through strategic fuel mix optimisation, deployment of cleaner technologies, and greater integration of renewables, we have steadily reduced our environmental footprint while meeting energy needs sustainably.
Technological upgrades across our plants have further strengthened efficiency. These include advanced process control systems, enhanced trend analysis, grinding media optimisation and the integration of solar-powered utilities. Importantly, grid integration at our key plants has delivered significant cost savings and streamlined energy management.
A notable milestone has been the expansion of our solar power capacity and Waste Heat Recovery Systems (WHRS). Our solar power capacity has grown from 1.5 MW in FY 2021–22 to 5.5 MW, while our WHRS capacity has increased from 44.7 MW to 49 MW, underscoring our commitment to sustainable energy solutions.

What technologies or practices have shown the highest energy-saving potential in cement production?
One of our most significant achievements in advancing energy efficiency has been the successful commissioning of a 132 KV Grid Integration Project, which unified three of our major manufacturing units under a single power network. This milestone, enabled by a dedicated transmission line and a state-of-the-art Line-In Line-Out (LILO) substation, has transformed our energy management and operational capabilities.
With this integration, we have substantially reduced our contract demand, eliminated power disruptions, and enhanced operational continuity. Supported by an optical fibre network for real-time communication and automation, this project stands as a testament to our innovation-led manufacturing excellence and underscores Nuvoco’s vision of building a safer, smarter, and sustainable world.

What role does digitalisation play in achieving energy efficiency in your operations?
Digitalisation plays a transformative role in driving energy efficiency across our operations. At Nuvoco, we are leveraging cutting-edge technologies and advanced digital tools to enhance productivity, optimise energy consumption and strengthen our commitment to sustainability and employee safety.
We are developing AI-enabled dashboards to optimise WHRS and kiln operations, ensuring maximum efficiency. Additionally, our advanced AI models evaluate multiple operational parameters — including fuel pricing, moisture content and energy output — to identify the most cost-effective fuel combinations in real time. These initiatives are enabling data-driven decision-making, improving operational excellence and reducing our environmental footprint.

What is your long-term strategy for aligning energy efficiency with decarbonisation goals?
As part of India’s climate action agenda, the cement sector has laid out a clear decarbonisation roadmap to achieve net-zero CO2 emissions by 2070. At Nuvoco, we view this as both a responsibility and an opportunity to redefine the future of sustainable construction. Our long-term strategy focuses on aligning energy efficiency with decarbonisation goals by embracing innovative technologies, alternative raw materials and renewable energy solutions.
We are making strategic investments to scale up solar power installations and enhance our renewable energy mix significantly by 2028. These initiatives are a key part of our broader vision to reduce Scope 2 emissions and strengthen our contribution to India’s net-zero journey, while continuing to deliver innovative and sustainable solutions to our customers.

How do you measure and benchmark energy performance across different plants?
We adopt a comprehensive approach to measure and benchmark energy performance across our plants. Key metrics include Specific Heat Consumption (kCal/kg of clinker) and Specific Power Consumption (kWh/tonne of cement), which are continuously tracked against Best Available Technology (BAT) benchmarks, industry peers and global standards such as the WBCSD-CSI and CII benchmarks.
To ensure consistency and drive improvements, we conduct regular internal energy audits, leverage real-time dashboards and implement robust KPI tracking systems. These tools enable us to compare performance across plants effectively, identify optimisation opportunities and set actionable targets for energy efficiency and sustainability.

What are the key challenges in adopting energy-efficient equipment in brownfield cement plants?
Adopting energy-efficient technologies in brownfield cement plants presents a unique set of challenges due to the constraints of working within existing infrastructure. Firstly, the high capital expenditure and relatively long payback periods often require careful evaluation before investments are made. Additionally, integrating new technologies with legacy equipment can be complex, requiring significant customisation to ensure seamless compatibility and performance.
Another major challenge is minimising production disruptions during installation. Since brownfield plants are already operational, upgrades must be planned meticulously to avoid affecting output. In many cases, space constraints in older facilities add to the difficulty of accommodating advanced equipment without compromising existing layouts.
At Nuvoco, we address these challenges through a phased implementation approach, detailed project planning and by fostering a culture of innovation and collaboration across our plants. This helps us balance operational continuity with our commitment to driving energy efficiency and sustainability.

Concrete

Enlight Metals Supplies 3,200 Tonne of Steel for Navi Mumbai Airport

The airport is set to become Asia’s largest air connectivity hub.

Published

2 days ago

October 10, 2025

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Enlight Metals has supplied 3,200 metric tonne of steel for the newly inaugurated Navi Mumbai International Airport, marking a major contribution to one of India’s largest infrastructure projects and reinforcing the company’s commitment to supporting national development.

The Navi Mumbai International Airport, developed under a Public-Private Partnership led by the Adani Group, was inaugurated today by Prime Minister Narendra Modi. The airport is set to become Asia’s largest air connectivity hub, enhancing regional connectivity, boosting economic growth, and expanding trade opportunities. Prime Minister Modi described the project as a “glimpse of Viksit Bharat,” highlighting its transformative impact on infrastructure and development in the region.

“The supply of 3,200 metric tonne of steel for this key project aligns with our focus on supporting critical infrastructure development through reliable and timely metal sourcing. Enlight Metals is committed to enhancing transparency and efficiency in the steel supply chain, contributing to projects integral to India’s growth objectives,” said Vedant Goel, Director, Enlight Metals.

Enlight Metals has implemented technology-driven solutions to strengthen supply chain efficiency, ensuring consistent availability of construction materials for large-scale projects nationwide. Its contribution to the Navi Mumbai International Airport underscores the company’s growing role in supporting India’s infrastructure development initiatives.

This milestone reflects Enlight Metals’ ongoing engagement in delivering quality materials and timely services for major national projects, further cementing its position as a reliable partner in India’s infrastructure sector