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Exploring New Secondary Cementitious Materials

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Dr S B Hegde, Visiting Professor, Pennsylvania State University, United States of America, discusses innovations in supplementary cementitious materials in the face of the challenges faced by cement manufacturers to become more sustainable.

Due to rapidly expanding urbanisation, environmental sustainability in the construction industry is facing serious challenges. To put it into perspective, concrete preparation requires a significant quantity of nat ural reserves worldwide and necessitates the development of alternative materials and sources. The manufacturing of concrete needs around 27 billion tonnes of raw material inventory, representing 4 tonnes of concrete per person per year!
By 2050, concrete production will be four times higher than in 1990. Aggregates and cement represent around 60 per cent to 80 per cent and 10 per cent to 15 per cent of the total weight of concrete, respectively.
Along with processing a substantial quantity of aggregates and around 3.5 billion tonnes of cement per year, concrete generates approximately 5 per cent to 7 per cent of the global total carbon dioxide emissions.
By 2025, around 4 billion tonnes of carbon dioxide (approximately) are estimated to be released to the atmosphere during cement production. The possible solution for more sustainable production could be to explore and develop SOPs for utilising the locally available waste materials or recyclable materials. The abundance of these materials and their different chemistries and physics compel the development of a common strategy for their application in concrete production.
Numerous industrial solid by-products containing calcareous siliceous, and aluminium materials (fly ash, ultrafine fly ash, silica fume, etc.), along with some natural pozzolanic materials (volcanic tuffs, diatomaceous earth, sugarcane bagasse ash, palm oil fuel ash, rice husk ash, mine tailings, etc.) can be used as SCM.
Sewage sludge ash (SSA) is an urban waste that may be used as fertiliser, as well as a cement substitute. SSA was not only considered as SCM in blended cements but also in a large scale of building materials like pave-stones, tiles, bricks, light aggregates production.
Marble dust, too, could be explored as one of the SCM. Marble is a finely crystallised metamorphic rock originating from the low-intensity metamorphism of calcareous and dolomitic rocks. Calcium carbonate (CaCO3) can form up to 99 per cent of the total amount of this carbonated rock. Additional phases may also include SiO2, MgO, Fe2O3, Al2O3 and Na2O and, in minor ratio, MnO, K2O, P2O5, F, Cu, S, Pb and Zn.
Construction and demolition debris (CDD) constitute one of the massive flows of solid waste generated from municipal and commercial activities of the modern era. Usually, CDD are in the shape of brick bats, mortars, aggregates, concrete, glass, ceramic tiles, metals and even plastics. The review of these new SCM for life cycle is very much imperative and will mention whether it will be environmentally feasible to apply the SCM for the life cycle of concrete.

Supplementary Cementitious Materials
Supplementary Cementitious Materials (SCM) play a significant role in performance of concrete specially to impart additional durability potential. They encompass a wide spectrum of aluminum-siliceous materials, including natural or processed pozzolans and industrial by-products like ground granulated blast furnace slag (GGBS), fly ash (FA), ultra-fine fly ash (UFFA) and silica fume (SF). Though there is higher fluctuation both in properties and chemistry across the various types of SCM, they share in common capacity to react chemically in concrete and form cementitious binders replacing those obtained by OPC hydration. The key feature of SCM is their pozzolanicity, i.e., their capability to react with calcium hydroxide (portlandite, CH) aqueous solutions to form calcium silicate hydrate (C–S–H).
In the right proportion, SCM can improve the fresh and hardened properties of concrete, especially the long-term durability.
Rice Husk Ash (RHA): An agricultural by-product that is suitable for cement replacement in rice-growing regions is Rice Husk Ash. Various research investigations have demonstrated that the principal chemical composition of rice husk ash consists of biomass-driven silicon dioxide (SiO2) as a result that the nature of silica in rice husk ash is sensitive to processing conditions. The ash obtained through open-field burning or uncontrolled combustion in furnaces generally includes a high percentage of crystalline silica minerals, like tridymite or cristobalite, with inferior reactivity. The highest amount of amorphous silica is obtained when RHA is burnt at temperatures ranging from 500°C to 700°C. The superior reactivity of RHA is due to its large amount of amorphous silica, which has high surface area due to the porous architecture of the host material. RHA can be used as a substitute in Portland cement (acceptable up to 15 per cent), thanks to its pozzolanic activity. Fine RHA can increase the compressive strength of cement paste and can lead to preparation of mortars with low porosity.
As a cement substitute, the usage of RHA in concrete production has advantages and disadvantages. Improved compressive strength of concrete is one of the essential advantages of using RHA as a substitute. Recent studies have highlighted important benefits of replacing cement with RHA in small percentages. In the context of durability, the use of RHA as a substitute in concrete production can lead to notable improved water permeability resistance, Cl penetration and sulphate deterioration.
Sugar cane bagasse: Sugarcane bagasse ash (SBA) is a by-product of producing juice from sugar cane by crushing the stalks of the plants. The addition of SBA in concrete production can decrease the hydration temperature up to 33 per cent, when 30 per cent of OPC is substituted by SBA. Also, water permeability considerably decreases when compared to control concrete samples. With the aim of superior compressive strength, OPC was substituted in the range from 15 per cent to 30 per cent. SBA incorporation has improved concrete durability.
Other wastes: Wastes of different sources have been investigated for their possibility in re-use, to reduce their environmental impact, in landfill volume and decomposition by-products. Sewage sludge ash (SSA) is an urban waste that may be used as fertiliser, as well as a cement substitute. SSA was not only considered as SCM in blended cements but also in a large scale of building materials like pave-stones, tiles, bricks, light aggregates production. The impact of SSA in mortar was a decrease in the compressive strength, when SSA was used as a partial cement substitute. Therefore, use of SSA as an SCM was shown to be limited, in the construction industry. The cement community does not include SSA in the group of pozzolanic materials.
Palm oil fuel ash (POFA): Palm oil is an important cash-crop in tropical countries, especially in Malaysia and Indonesia. For every 100 t of fresh fruit bunches handled, there will be about 20t of nut shells, 7t of fibres and 25t of empty bunches released from the mills. POFA can be used in concrete either as aggregates, SCM or as filler material. Comparable to RHA and SBA, the amorphous SiO2 (around 76 per cent) content of POFA offers relatively high pozzolanic activity, when used as binder in concrete production. Even though a few performance parameters of concrete (especially setting time and strength) are negatively influenced by POFA, several studies claimed that palm oil fuel ash may be appropriate in different applications.
Mining wastes: The quantity of mine wastes has increased hugely due to increasing demand for metal and mineral resources. Mining wastes are produced during mineral extraction by the mining industry and is at present one of the largest waste available worldwide.
At present, they are being used mainly as backfilling both in open cast mines and underground areas. They pose potential long-term risks for environmental pollution. However, use of tailings is not only relevant to environmental conservation, but can also benefit the mining industry. These solid wastes contain compounds with potential pozzolanic properties and can decrease the amount of cement used to produce concrete, reducing simultaneously the ecological impact of the cement and mining industries. An additional benefit of mine tailings is that they are already finely ground. Most of the other SCM require mechanical grinding, as a pre-treatment for use, to improve their reactivity.
Marble powder: Marble is a finely crystallised metamorphic rock of calcareous and dolomitic rocks. Calcium carbonate (CaCO3) can form up to 99 per cent of the total amount of this carbonated rock. Additional phases may also include SiO2, MgO, Fe2O3, Al2O3 and Na2O and, in minor ratio, MnO, K2O, P2O5, F, Cu, S, Pb and Zn.
Through the shaping, sawing and polishing operations, around 20 per cent to 25 per cent of processed marble is converted into powder or lumps. As a result, dumps of marble dust have become an important environmental issue worldwide. Marble powder (MP) has successfully been demonstrated as a viable SCM in self-compacting concrete (SCC). The research proved that marble powder used as a mineral substitute of cement can enhance some properties of fresh concrete and/or hardened concrete.
In the cement-related literature, there are just a few research studies related to the application of marble powder in concrete or mortar production. Thus, more detailed studies are needed in order to define the properties of concrete or mortars with marble powder. The use of marble powder in ternary cementitious blends demands further caution to remove or reduce its adverse effects on the fresh properties of self-compacting concrete and/or mortar.
Construction and demolition debris (CDD): CDD constitute huge solid waste generated from municipal and commercial activities of modern urban styles. Usually, CDD are in the shape of brick bats, mortars, aggregates, concrete, glass, ceramic tiles, metals and even plastics. They must be mechanically sorted according to size and quality level. They are then crushed down to desired size.
There is a need to study the ‘life cycle’ of construction materials to develop a global understanding of sustainable building construction and the feasible use of CDD as SCM for OPC replacement materials.
The materials like low grade/marginal grade limestone, red mud, bio wastes including vegetative wastes calcined under controlled conditions are some examples of potential SCM in future.

Conclusion
Concrete is one of the most widely used materials after water worldwide by volume. Portland cement production is highly energy intensive, and emits significant amounts of CO2 through the calcination process, which contributes substantial adverse impact on global warming. Efforts are needed to produce more ecologically friendly concrete with improved performance and durability.
The conventional SCM are not enough considering the quantity of concrete requirement for infra development world wide and to mitigate global warming issue; there is a pressing need to explore the new SCM, its characterisation, performance evaluation, standardisation and adoption.
However, it is clear that more research is needed to assess the feasibility of long-term performance and to develop a more ecologically sound production SOPs, in addition to quality assessment of these materials.
It is envisaged that introducing new cementitious materials in cement and concrete manufacturing is a time consuming process. Not only from the viewpoints of plants but from standards or codes issuing bodies like Bureau of Indian Standards (BIS) in India, ASTM, EN Standard organisations plus local nodal agencies of the particular countries. Many researches have been done in Universities, and other R&D institutions but issuing relevant codes (specifications) by these organisations for commercial usage is utmost important.

About the author:

DrS B Hegde is a Winner of Global Visionary Award for notable contribution to Cement and currently Visiting Professor, Pennsylvania State University, United States of America. Dr Hegde has more than 30 years of experience in the cement industry both in India and abroad.

References

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By 2050, concrete production will be four times higher than in 1990. Aggregates and cement represent around 60 per cent to 80 per cent and 10 per cent to 15 per cent of the total weight of concrete, respectively.

Concrete

Cement Industry Backs Co-Processing to Tackle Global Waste

Industry bodies recently urged policy support for cement co-processing as waste solution

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Leading industry bodies, including the Global Cement and Concrete Association (GCCA), European Composites Industry Association, International Solid Waste Association – Africa, Mission Possible Partnership and the Global Waste-to-Energy Research and Technology Council, have issued a joint statement highlighting the cement industry’s potential role in addressing the growing global challenge of non-recyclable and non-reusable waste. The organisations have called for stronger policy support to unlock the full potential of cement industry co-processing as a safe, effective and sustainable waste management solution.
Co-processing enables both energy recovery and material recycling by using suitable waste to replace fossil fuels in cement kilns, while simultaneously recycling residual ash into the cement itself. This integrated approach delivers a zero-waste solution, reduces landfill dependence and complements conventional recycling by addressing waste streams that cannot be recycled or are contaminated.
Already recognised across regions including Europe, India, Latin America and North America, co-processing operates under strict regulatory and technical frameworks to ensure high standards of safety, emissions control and transparency.
Commenting on the initiative, Thomas Guillot, Chief Executive of the GCCA, said co-processing offers a circular, community-friendly waste solution but requires effective regulatory frameworks and supportive public policy to scale further. He noted that while some cement kilns already substitute over 90 per cent of their fuel with waste, many regions still lack established practices.
The joint statement urges governments and institutions to formally recognise co-processing within waste policy frameworks, support waste collection and pre-treatment, streamline permitting, count recycled material towards national recycling targets, and provide fiscal incentives that reflect environmental benefits. It also calls for stronger public–private partnerships and international knowledge sharing.
With global waste generation estimated at over 11 billion tonnes annually and uncontrolled municipal waste projected to rise sharply by 2050, the signatories believe co-processing represents a practical and scalable response. With appropriate policy backing, it can help divert waste from landfills, reduce fossil fuel use in cement manufacturing and transform waste into a valuable societal resource.    

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Concrete

Industry Bodies Call for Wider Use of Cement Co-Processing

Joint statement seeks policy support for sustainable waste management

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Leading industry organisations have called for stronger policy support to accelerate the adoption of cement industry co-processing as a sustainable solution for managing non-recyclable and non-reusable waste. In a joint statement, bodies including the Global Cement and Concrete Association, European Composites Industry Association, International Solid Waste Association – Africa, Mission Possible Partnership and the Global Waste-to-Energy Research and Technology Council highlighted the role co-processing can play in addressing the growing global waste challenge.
Co-processing enables the use of waste as an alternative to fossil fuels in cement kilns, while residual ash is incorporated into cementitious materials, resulting in a zero-waste process. The approach supports both energy recovery and material recycling, complements conventional recycling systems and reduces reliance on landfill infrastructure. It is primarily applied to waste streams that are contaminated or unsuitable for recycling.
The organisations noted that co-processing is already recognised in regions such as Europe, India, Latin America and North America, operating under regulated frameworks to ensure safety, emissions control and transparency. However, adoption remains uneven globally, with some plants achieving over 90 per cent fuel substitution while others lack enabling policies.
The statement urged governments and institutions to formally recognise co-processing in waste management frameworks, streamline environmental permitting, incentivise waste collection and pre-treatment, account for recycled material content in national targets, and support public-private partnerships. The call comes amid rising global waste volumes, which are estimated at over 11 billion tonnes annually, with unmanaged waste contributing to greenhouse gas emissions, pollution and health risks.

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Concrete

Why Cement Needs CCUS

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Cement’s deep decarbonisation cannot be achieved through efficiency and fuel switching alone, making CCUS essential to address unavoidable process emissions from calcination. ICR explores if with the right mix of policy support, shared infrastructure, and phased scale-up from pilots to clusters, CCUS can enable India’s cement industry to align growth with its net-zero ambitions.

Cement underpins modern development—from housing and transport to renewable energy infrastructure—but it is also one of the world’s most carbon-intensive materials, with global production of around 4 billion tonnes per year accounting for 7 to 8 per cent of global CO2 emissions, according to the GCCA. What makes cement uniquely hard to abate is that 60 to 65 per cent of its emissions arise from limestone calcination, a chemical process that releases CO2 irrespective of the energy source used; the IPCC Sixth Assessment Report (AR6) therefore classifies cement as a hard-to-abate sector, noting that even fully renewable-powered kilns would continue to emit significant process emissions. While the industry has achieved substantial reductions over the past two decades through energy efficiency, alternative fuels and clinker substitution using fly ash, slag, and calcined clays, studies including the IEA Net Zero Roadmap and GCCA decarbonisation pathways show these levers can deliver only 50 to 60 per cent emissions reduction before reaching technical and material limits, leaving Carbon Capture, Utilisation and Storage (CCUS) as the only scalable and durable option to address remaining calcination emissions—an intervention the IPCC estimates will deliver nearly two-thirds of cumulative cement-sector emission reductions globally by mid-century, making CCUS a central pillar of any credible net-zero cement pathway.

Process emissions vs energy emissions
Cement’s carbon footprint is distinct from many other industries because it stems from two sources: energy emissions and process emissions. Energy emissions arise from burning fuels to heat kilns to around 1,450°C and account for roughly 35 to 40 per cent of total cement CO2 emissions, according to the International Energy Agency (IEA). These can be progressively reduced through efficiency improvements, alternative fuels such as biomass and RDF, and electrification supported by renewable power. Over the past two decades, such measures have delivered measurable gains, with global average thermal energy intensity in cement production falling by nearly 20 per cent since 2000, as reported by the IEA and GCCA.
The larger and more intractable challenge lies in process emissions, which make up approximately 60 per cent to 65 per cent of cement’s total CO2 output. These emissions are released during calcination, when limestone (CaCO3) is converted into lime (CaO), inherently emitting CO2 regardless of fuel choice or energy efficiency—a reality underscored by the IPCC Sixth Assessment Report (AR6). Even aggressive clinker substitution using fly ash, slag, or calcined clays is constrained by material availability and performance requirements, typically delivering 20 to 40 per cent emissions reduction at best, as outlined in the GCCA–TERI India Cement Roadmap and IEA Net Zero Scenario. This structural split explains why cement is classified as a hard-to-abate sector and why incremental improvements alone are insufficient; as energy emissions decline, process emissions will dominate, making Carbon Capture, Utilisation and Storage (CCUS) a critical intervention to intercept residual CO2 and keep the sector’s net-zero ambitions within reach.

Where CCUS stands today
Globally, CCUS in cement is moving from concept to early industrial reality, led by Europe and North America, with the IEA noting that cement accounts for nearly 40 per cent of planned CCUS projects in heavy industry, reflecting limited alternatives for deep decarbonisation; a flagship example is Heidelberg Materials’ Brevik CCS project in Norway, commissioned in 2025, designed to capture about 400,000 tonnes of CO2 annually—nearly half the plant’s emissions—with permanent offshore storage via the Northern Lights infrastructure (Reuters, Heidelberg Materials), alongside progress at projects in the UK, Belgium, and the US such as Padeswood, Lixhe (LEILAC), and Ste. Genevieve, all enabled by strong policy support, public funding, and shared transport-and-storage infrastructure.
These experiences show that CCUS scales fastest when policy support, infrastructure availability, and risk-sharing mechanisms align, with Europe bridging the viability gap through EU ETS allowances, Innovation Fund grants, and CO2 hubs despite capture costs remaining high at US$ 80-150 per tonne of CO2 (IEA, GCCA); India, by contrast, is at an early readiness stage but gaining momentum through five cement-sector CCU testbeds launched by the Department of Science and Technology (DST) under academia–industry public–private partnerships involving IITs and producers such as JSW Cement, Dalmia Cement, and JK Cement, targeting 1-2 tonnes of CO2 per day to validate performance under Indian conditions (ETInfra, DST), with the GCCA–TERI India Roadmap identifying the current phase as a foundation-building decade essential for achieving net-zero by 2070.
Amit Banka, Founder and CEO, WeNaturalists, says “Carbon literacy means more than understanding that CO2 harms the climate. It means cement professionals grasping why their specific plant’s emissions profile matters, how different CCUS technologies trade off between energy consumption and capture rates, where utilisation opportunities align with their operational reality, and what governance frameworks ensure verified, permanent carbon sequestration. Cement manufacturing contributes approximately 8 per cent of global carbon emissions. Addressing this requires professionals who understand CCUS deeply enough to make capital decisions, troubleshoot implementation challenges, and convince boards to invest substantial capital.”

Technology pathways for cement
Cement CCUS encompasses a range of technologies, from conventional post-combustion solvent-based systems to process-integrated solutions that directly target calcination, each with different energy requirements, retrofit complexity, and cost profiles. The most mature option remains amine-based post-combustion capture, already deployed at industrial scale and favoured for early cement projects because it can be retrofitted to existing flue-gas streams; however, capture costs typically range from US$ 60-120 per tonne of CO2, depending on CO2 concentration, plant layout, and energy integration.
Lovish Ahuja, Chief Sustainability Officer, Dalmia Cement (Bharat), says, “CCUS in Indian cement can be viewed through two complementary lenses. If technological innovation, enabling policies, and societal acceptance fail to translate ambition into action, CCUS risks becoming a significant and unavoidable compliance cost for hard-to-abate sectors such as cement, steel, and aluminium. However, if global commitments under the Paris Agreement and national targets—most notably India’s Net Zero 2070 pledge—are implemented at scale through sustained policy and industry action, CCUS shifts from a future liability to a strategic opportunity. In that scenario, it becomes a platform for technological leadership, long-term competitiveness, and systemic decarbonisation rather than merely a regulatory burden.”
“Accelerating CCUS adoption cannot hinge on a single policy lever; it demands a coordinated ecosystem approach. This includes mission-mode governance, alignment across ministries, and a mix of enabling instruments such as viability gap funding, concessional and ESG-linked finance, tax incentives, and support for R&D, infrastructure, and access to geological storage. Importantly, while cement is largely a regional commodity with limited exportability due to its low value-to-weight ratio, CCUS innovation itself can become a globally competitive export. By developing, piloting, and scaling cost-effective CCUS solutions domestically, India can not only decarbonise its own cement industry but also position itself as a supplier of affordable CCUS technologies and services to cement markets worldwide,” he adds.
Process-centric approaches seek to reduce the energy penalty associated with solvent regeneration by altering where and how CO2 is separated. Technologies such as LEILAC/Calix, which uses indirect calcination to produce a high-purity CO2 stream, are scaling toward a ~100,000 tCO2 per year demonstrator (LEILAC-2) following successful pilots, while calcium looping leverages limestone chemistry to achieve theoretical capture efficiencies above 90 per cent, albeit still at pilot and demonstration stages requiring careful integration. Other emerging routes—including oxy-fuel combustion, membrane separation, solid sorbents, and cryogenic or hybrid systems—offer varying trade-offs between purity, energy use, and retrofit complexity; taken together, recent studies suggest that no single technology fits all plants, making a multi-technology, site-specific approach the most realistic pathway for scaling CCUS across the cement sector.
Yash Agarwal, Co-Founder, Carbonetics Carbon Capture, says, “We are fully focused on CCUS, and for us, a running plant is a profitable plant. What we have done is created digital twins that allow operators to simulate and resolve specific problems in record time. In a conventional setup, when an issue arises, plants often have to shut down operations and bring in expert consultants. What we offer instead is on-the-fly consulting. As soon as a problem is detected, the system automatically provides a set of potential solutions that can be tested on a running plant. This approach ensures that plant shutdowns are avoided and production is not impacted.”

The economics of CCUS
Carbon Capture, Utilisation and Storage (CCUS) remains one of the toughest economic hurdles in cement decarbonisation, with the IEA estimating capture costs of US$ 80-150 per tonne of CO2, and full-system costs raising cement production by US$ 30-60 per tonne, potentially increasing prices by 20 to 40 per cent without policy support—an untenable burden for a low-margin, price-sensitive industry like India’s.
Global experience shows CCUS advances beyond pilots only when the viability gap is bridged through strong policy mechanisms such as EU ETS allowances, Innovation Fund grants, and carbon Contracts for Difference (CfDs), yet even in Europe few projects have reached final investment decision (GCCA); India’s lack of a dedicated CCUS financing framework leaves projects reliant on R&D grants and balance sheets, reinforcing the IEA Net Zero Roadmap conclusion that carbon markets, green public procurement, and viability gap funding are essential to spread costs across producers, policymakers, and end users and prevent CCUS from remaining confined to demonstrations well into the 2030s.

Utilisation or storage
Carbon utilisation pathways are often the first entry point for CCUS in cement because they offer near-term revenue potential and lower infrastructure complexity. The International Energy Agency (IEA) estimates that current utilisation routes—such as concrete curing, mineralisation into aggregates, precipitated calcium carbonate (PCC), and limited chemical conversion—can realistically absorb only 5 per cent to 10 per cent of captured CO2 at a typical cement plant. In India, utilisation is particularly attractive for early pilots as it avoids the immediate need for pipelines, injection wells, and long-term liability frameworks. Accordingly, Department of Science and Technology (DST)–supported cement CCU testbeds are already demonstrating mineralisation and CO2-cured concrete applications at 1–2 tonnes of CO2 per day, validating performance, durability, and operability under Indian conditions.
However, utilisation faces hard limits of scale and permanence. India’s cement sector emits over 200 million tonnes of CO2 annually (GCCA), far exceeding the absorptive capacity of domestic utilisation markets, while many pathways—especially fuels and chemicals—are energy-intensive and dependent on costly renewable power and green hydrogen. The IPCC Sixth Assessment Report (AR6) cautions that most CCU routes do not guarantee permanent storage unless CO2 is mineralised or locked into long-lived materials, making geological storage indispensable for deep decarbonisation. India has credible storage potential in deep saline aquifers, depleted oil and gas fields, and basalt formations such as the Deccan Traps (NITI Aayog, IEA), and hub-based models—where multiple plants share transport and storage infrastructure—can reduce costs and improve bankability, as seen in Norway’s Northern Lights project. The pragmatic pathway for India is therefore a dual-track approach: utilise CO2 where it is economical and store it where permanence and scale are unavoidable, enabling early learning while building the backbone for net-zero cement.

Policy, infrastructure and clusters
Scaling CCUS in the cement sector hinges on policy certainty, shared infrastructure, and coordinated cluster development, rather than isolated plant-level action. The IEA notes that over 70 per cent of advanced industrial CCUS projects globally rely on strong government intervention—through carbon pricing, capital grants, tax credits, and long-term offtake guarantees—with Europe’s EU ETS, Innovation Fund, and carbon Contracts for Difference (CfDs) proving decisive in advancing projects like Brevik CCS. In contrast, India lacks a dedicated CCUS policy framework, rendering capture costs of USD 80–150 per tonne of CO2 economically prohibitive without state support (IEA, GCCA), a gap the GCCA–TERI India Cement Roadmap highlights can be bridged through carbon markets, viability gap funding, and green public procurement.
Milan R Trivedi, Vice President, Shree Digvijay Cement, says, “CCUS represents both an unavoidable near-term compliance cost and a long-term strategic opportunity for Indian cement producers. While current capture costs of US$ 100-150 per tonne of CO2 strain margins and necessitate upfront retrofit investments driven by emerging mandates and NDCs, effective policy support—particularly a robust, long-term carbon pricing mechanism with tradable credits under frameworks like India’s Carbon Credit Trading Scheme (CCTS)—can de-risk capital deployment and convert CCUS into a competitive advantage. With such enablers in place, CCUS can unlock 10 per cent to 20 per cent green price premiums, strengthen ESG positioning, and allow Indian cement to compete in global low-carbon markets under regimes such as the EU CBAM, North America’s buy-clean policies, and Middle Eastern green procurement, transforming compliance into export-led leadership.”
Equally critical is cluster-based CO2 transport and storage infrastructure, which can reduce unit costs by 30 to 50 per cent compared to standalone projects (IEA, Clean Energy Ministerial); recognising this, the DST has launched five CCU testbeds under academia–industry public–private partnerships, while NITI Aayog works toward a national CCUS mission focused on hubs and regional planning. Global precedents—from Norway’s Northern Lights to the UK’s HyNet and East Coast clusters—demonstrate that CCUS scales fastest when governments plan infrastructure at a regional level, making cluster-led development, backed by early public investment, the decisive enabler for India to move CCUS from isolated pilots to a scalable industrial solution.
Paul Baruya, Director of Strategy and Sustainability, FutureCoal, says, “Cement is a foundational material with a fundamental climate challenge: process emissions that cannot be eliminated through clean energy alone. The IPCC is clear that in the absence of a near-term replacement of Portland cement chemistry, CCS is essential to address the majority of clinker-related emissions. With global cement production at around 4 gigatonnes (Gt) and still growing, cement decarbonisation is not a niche undertaking, it is a large-scale industrial transition.”

From pilots to practice
Moving CCUS in cement from pilots to practice requires a sequenced roadmap aligning technology maturity, infrastructure development, and policy support: the IEA estimates that achieving net zero will require CCUS to scale from less than 1 Mt of CO2 captured today to over 1.2 Gt annually by 2050, while the GCCA Net Zero Roadmap projects CCUS contributing 30 per cent to 40 per cent of total cement-sector emissions reductions by mid-century, alongside efficiency, alternative fuels, and clinker substitution.
MM Rathi, Joint President – Power Plants, Shree Cement, says, “The Indian cement sector is currently at a pilot to early demonstration stage of CCUS readiness. A few companies have initiated small-scale pilots focused on capturing CO2 from kiln flue gases and exploring utilisation routes such as mineralisation and concrete curing. CCUS has not yet reached commercial integration due to high capture costs (US$ 80-150 per tonne of CO2), lack of transport and storage infrastructure, limited access to storage sites, and absence of long-term policy incentives. While Europe and North America have begun early commercial deployment, large-scale CCUS adoption in India is more realistically expected post-2035, subject to enabling infrastructure and policy frameworks.”
Early pilots—such as India’s DST-backed CCU testbeds and Europe’s first commercial-scale plants—serve as learning platforms to validate integration, costs, and operational reliability, but large-scale deployment will depend on cluster-based scale-up, as emphasised by the IPCC AR6, which highlights the need for early CO2 transport and storage planning to avoid long-term emissions lock-in. For India, the GCCA–TERI India Roadmap identifies CCUS as indispensable for achieving net-zero by 2070, following a pragmatic pathway: pilot today to build confidence, cluster in the 2030s to reduce costs, and institutionalise CCUS by mid-century so that low-carbon cement becomes the default, not a niche, in the country’s infrastructure growth.

Conclusion
Cement will remain indispensable to India’s development, but its long-term viability hinges on addressing its hardest emissions challenge—process CO2 from calcination—which efficiency gains, alternative fuels, and clinker substitution alone cannot eliminate; global evidence from the IPCC, IEA, and GCCA confirms that Carbon Capture, Utilisation and Storage (CCUS) is the only scalable pathway capable of delivering the depth of reduction required for net zero. With early commercial projects emerging in Europe and structured pilots underway in India, CCUS has moved beyond theory into a decisive decade where learning, localisation, and integration will shape outcomes; however, success will depend less on technology availability and more on collective execution, including coordinated policy frameworks, shared transport and storage infrastructure, robust carbon markets, and carbon-literate capabilities.
For India, a deliberate transition from pilots to practice—anchored in cluster-based deployment, supported by public–private partnerships, and aligned with national development and climate goals—can transform CCUS from a high-cost intervention into a mainstream industrial solution, enabling the cement sector to keep building the nation while sharply reducing its climate footprint.

– Kanika Mathur

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