MM Rathi, Joint President – Power Plants, Shree Cement, suggests CCUS is the indispensable final lever for cement decarbonisation in India, moving from pilot-stage today to a policy-driven necessity.

In this interview, MM Rathi, Joint President – Power Plants, Shree Cement, offers a candid view on India’s CCUS readiness, the economic and technical challenges of integration, and why policy support and cluster-based infrastructure will be decisive in taking CCUS from pilot stage to commercial reality.

How critical is CCUS to achieving deep decarbonisation in cement compared to other levers?
CCUS is critical and ultimately indispensable for deep decarbonisation in cement. Around 60 per cent to 65 per cent of cement emissions arise from limestone calcination, an inherent chemical process that cannot be addressed through energy efficiency, renewables, or alternative fuels. Clinker substitution using fly ash, slag, and calcined clay can reduce emissions by 20 per cent to 40 per cent, while energy transition measures can abate 30 per cent to 40 per cent of fuel-related emissions. These are cost-effective, scalable, and form the foundation of decarbonisation efforts.
However, these levers alone cannot deliver reductions beyond 60 per cent. Once they reach technical and regional limits, CCUS becomes the only viable pathway to address residual
process emissions. In that sense, CCUS is not an alternative but the final, non-negotiable step toward net-zero cement.

What stage of CCUS readiness is the Indian cement sector currently at?
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.

What are the biggest technical challenges of integrating CCUS into existing Indian kilns?
Retrofitting CCUS into existing Indian cement plants presents multiple challenges. Many plants have compact layouts with limited space for capture units, compressors, and CO2 handling systems, requiring modular and carefully phased integration.
Kiln flue gases contain high CO2 concentrations along with dust and impurities, increasing risks of fouling and corrosion and necessitating robust gas pre-treatment. Amine-based capture systems also require significant thermal energy, and improper heat integration can affect clinker output, making waste heat recovery critical.
Additional challenges include higher power and water demand, pressure drops in the gas path, and maintaining kiln stability and product quality. Without careful design, CCUS can impact productivity and reliability.

How does the high cost of CCUS impact cement pricing, and who bears the cost?
At capture costs of US$ 80-150 per tonne of CO2, CCUS can increase cement production costs by US$ 30-60 per tonne, potentially raising cement prices by 20 to 40 per cent. Initially, producers absorb the capital and operating costs, which can compress margins. Over time, without policy support, these costs are likely to be passed on to consumers, affecting affordability in a highly price-sensitive market like India. Policy mechanisms such as subsidies, tax credits, carbon markets, and green finance can significantly reduce this burden and enable cost-sharing across producers, policymakers, and end users.

What role can carbon utilisation play versus geological storage in India?
Carbon utilisation can play a supportive and transitional role, particularly in early CCUS deployment. Applications such as concrete curing and mineralisation can reuse 5 to 10 per cent of captured CO2 while improving material performance. Fuels and chemicals offer niche opportunities but depend on access to low-cost renewable energy. However, utilisation pathways are limited in scale and often involve temporary carbon storage. With India’s cement sector emitting over 200 million tonnes of CO2 annually, utilisation alone cannot deliver deep decarbonisation.
Long-term geological storage offers permanent sequestration at scale. India has significant potential in deep saline aquifers and depleted oil and gas fields, which will be essential for achieving net-zero cement production.

How important is government policy support for CCUS viability?
Government policy support is central to making CCUS commercially viable in India. Without intervention, CCUS costs remain prohibitive and adoption will remain limited to pilots.
Carbon markets can provide recurring revenue streams, while capital subsidies, tax incentives, and concessional financing can reduce upfront risk. Regulatory mandates and green public procurement can further accelerate adoption by creating predictable demand for low-carbon cement. CCUS will not scale through market forces alone; policy design will determine its pace and extent of deployment.

Can CCUS be scaled across mid-sized and older plants?
In the near term, CCUS is most viable for large, modern integrated plants due to economies of scale, better layout flexibility, and access to waste heat recovery. Mid-sized plants may adopt CCUS selectively over time through modular systems and shared CO2 infrastructure, though retrofit costs can be 30 to 50 per cent higher. For older plants nearing the end of their operational life, CCUS retrofitting is generally not economical, and decarbonisation efforts are better focused on efficiency, fuels, and clinker substitution.

Will CCUS become a competitive advantage or a regulatory necessity?
Over the next decade, CCUS is expected to shift from a competitive advantage to a regulatory necessity. In the short term, early adopters can access green finance, premium procurement opportunities, and sustainability leadership positioning. Beyond 2035, as emissions regulations tighten, CCUS will become essential for addressing process emissions. By 2050, it is likely to be a mandatory component of the cement sector’s net-zero pathway rather than a strategic choice.

– Kanika Mathur