Cement Energy & Environment

51 Carbon-storing and carbon-utilizing cementitious materials: pathways for india’s low-carbon construction future Dr. Mainak Ghosal MAINAK GHOSAL ENTERPRISES OPC Private Limited ABSTRACT The global construction sector contributes 6–8% of global CO 2 emissions, with cement manufacturing being the primary driver. India, the world’s second-largest cement producer (361 million tonnes in 2021–22), accounts for 6–7% of the nation’s industrial emissions. Against India’s Net- Zero 2070 commitment and interim 2047 target, carbon-storing and carbon-utilizing cementitious materials present a transformative pathway for emissions reduction. Recent advances in nanotechnology—nano-silica (nano-SiO 2 ), nano- titaniumdioxide (nano-TiO 2 ), graphene oxide (GO), and carbon nanotubes (CNTs)—enable enhanced carbon sequestration (0.8–1.0 tonnes CO 2 /tonne binder) while improving mechanical and durability properties. This paper synthesizes findings from the U.S. ARPA-E HESTIA study and adapts the framework to India’s cement ecosystem, examining five Department of Science and Technology (DST) Carbon Capture and Utilization testbeds launched May 2025. The analysis identifies India-specific LCA challenges: regional raw material variability, diverseelectricitygrids (45%renewables, 50%coal), biogenic carbon accounting aligned with Indian agricultural practices, and emerging nanomaterial integration strategies. Key findings indicate that combined carbon-storing cement systems (LC3 + biochar + mineral carbonation + nanomaterials) achieve 0.8–1.0 tonnes CO 2 sequestration per tonne binder over 50 years with 25–35% extended service life, positioning nanomaterial-enhanced systems as viable pathways for India’s cement decarbonization. By 2035, systematic adoption could sequester 20–30 million tonnes of CO 2 annually (15–20% of industry emissions) while creating a ₹500–1,000 crore carbon credit market and establishing India as a global leader in low- carbon, nano-enhanced cement innovation.