Built Environment
Problem Overview: High usage of clinker in Indian cement industry
About 60% of cement CO₂ emissions comes from the calcination of limestone - the chemical decomposition of CaCO₃ into CaO (clinker) and CO₂. This reaction is endothermic and unavoidable within conventional Portland cement chemistry. Today, India’s average clinker factor is already comparable to global standards (~0.7), but has the potential to move towards ~ 0.5 through next-generation cement pathways.
While blended cement (blending SCMs like fly ash and GGBS in cement) now makes up over 70% of India's output, dominated by Portland Pozzolana Cement (PPC), there is a structural ceiling to this. Developers and structural engineers mainly steer towards OPC 53 grade (high clinker factor) for most high-cycle, high-load applications that represent the fastest-growing segment of India's construction market. Growth in high-performance structural applications could increase India’s clinker intensity.
Core Bottlenecks: Performance constraints and cost/infrastructure challenges for novel solutions
Several scaling challenges exist in solutions being explored today:
1. Compressive Strength Gain
Blended cements like PPC and PSC are already cost-effective, but take longer to gain compressive strength. Cycle time is essential for high-rise construction.
2. Quality Constraints
Variability in substitutes is quite wide. Blending creates performance constraints limiting usage (eg. 35% limits of fly ash in codes).
3. Lack of Standards
No BIS code for geopolymer concrete as a structural material. No codified design basis.
4. Retrofitting Needs
Novel solutions like LC3 need retrofitting and upfront capex investments.
Existing Approaches and Technology Readiness
Existing SCMs
Fly ash faces (limited substitution) & GGBS (limited supply)
Limestone Calcined Clay
Blended cement reducing clinker with low-grade clays and limestone
Silicate based approach
Calcium silicates to replace limestone (~75% lower emissions)
Electrochemical
Replacing combustion kiln with electrochemical process
Where is the white-space for innovation?
The technologies and solutions above, which if implemented at scale, can enable wider replacement of clinker/cement across urban and rural housing and infrastructure like roads. There is a need for innovation on three fronts:
Science Breakthrough
Creating novel SCMs, geopolymers, blended cements which can give high performance including workability, setting time, strength, etc. Current activators also need to be made safer and eco-friendly for mainstream site use.
Engineering Innovation
Building modular infrastructure for production of alternate cement; Bringing down the cost of production for alternate cement production pathways.
Business model / Financial
Specifically for Limestone Calcined Clay (LC3): solving for retrofitting and clay quality variation; improving standardised testing and confidence.
How we identify climate innovation opportunities?
- Decarbonization Roadmap for the Indian Cement Sector, TERI and GCCA India
- Tracking cement, IEA
- Guynn, J., & Kline, J. (2015, April). Maximizing SCM content of blended cements. In 2015 IEEE-IAS/PCA Cement Industry Conference.. IEEE.
- IPCC Cement Emissions Publication
- Calculated based on cost saved in cement production in India (blended vs ordinary cement)
- Calculated based on cost saved in cement production globally (blended vs ordinary cement)
- Calculated based on 15% clinker abatement in 2025, 20% clinker abatement in 2030
Last Updated On: June 5, 2026
Economic Potential
- India, 20258,300Mn USD[5]
- India, 203011,750Mn USD
- Global, 2025292,000Mn USD[6]
Impact Potential
- India, 202579 Mt CO2e[7]
- India, 2030163 Mt CO2e
- Global, 2025753 Mt CO2e[8]
Waste
Air Pollution
p-ARL Score
9/12
Regulatory Outlook
Implemented
Spotlight for innovation in India
Research
IIT Delhi: develop the standard LC3 mix containing roughly 50% clinker, 30% calcined clay, and 15% limestone
IIT Indore: Alkali-activated cement systems
CarbonStrong: Engineered SCM to enhance performance with reduced cement usage
EcoPath: Cement free geopolymers as alternate binders
GreenJams: Carbon-negative building blocks from crop residues & industrial waste
- Decarbonization Roadmap for the Indian Cement Sector, TERI and GCCA India
- Tracking cement, IEA
- Guynn, J., & Kline, J. (2015, April). Maximizing SCM content of blended cements. In 2015 IEEE-IAS/PCA Cement Industry Conference.. IEEE.
- IPCC Cement Emissions Publication
- Calculated based on cost saved in cement production in India (blended vs ordinary cement)
- Calculated based on cost saved in cement production globally (blended vs ordinary cement)
- Calculated based on 15% clinker abatement in 2025, 20% clinker abatement in 2030
Last Updated On: June 5, 2026