Process Know-how for the Development of CO2 Sequestered Artificial Autoclaved Lightweight Aggregates

The technology delivers a dual-impact solution for industries seeking sustainable, economical, and regulatory-compliant pathways for waste management and carbon reduction. By converting siliceous and calcareous industrial wastes into high-performance lightweight aggregates, we enable industries to permanently sequester 8–10% CO₂ while producing a value-added construction material. The developed ALWAs offer superior strength (5–7 MPa), reduced water absorption, and up to 50% lower density, outperforming several commercially available lightweight aggregates. Industries adopting this technology can significantly cut waste disposal costs, accelerate their ESG and carbon neutrality goals, and unlock new revenue streams in the growing green construction market. ALWAs are compliant with IS 9142 (Part 2):2018 and suitable for structural and non-structural applications, enabling immediate deployment in precast, insulation, and smart-city infrastructure. This technology provides a scalable, future-ready pathway to meet emerging carbon taxation and sustainability mandates.

CSIR-CBRI has developed an innovative CO₂-sequestered autoclaved artificial lightweight aggregate (ALWA) technology that addresses carbon emissions while converting industrial wastes into high-value construction materials. Using siliceous and calcareous waste, the aggregates are autoclaved and then carbonated, enabling 8–10% permanent CO₂ uptake, significantly enhancing sustainability. The produced ALWAs are 4–16 mm, rounded, and up to 50% lighter than natural aggregates. A major breakthrough is the reduction in water absorption due to pore refinement during carbonation, improving concrete performance. The aggregates comply with IS 9142 (Part 2):2018 and outperform commercial LWAs, achieving 5–7 MPa pellet strength, 920–930 kg/m³ bulk density, and good durability. This technology supports waste valorization, ESG compliance, and carbon-neutral construction, offering applications in precast elements, green blocks, and lightweight structural components. It provides industries with a scalable pathway for carbon utilization, revenue generation, and circular economy integration.

• Carbon Utilization: Up to 8-10% CO₂ by weight of aggregates can be sequestered permanently. 
• Waste Valorization: Turns siliceous and calcareous rich industrial wastes and similar residues into high-value aggregates, reducing disposal costs. 
• Revenue Generation: The product is suitable for structural and non-structural lightweight concrete, especially in urban high-rise construction and precast panels. 
• Regulatory Compliance: Supports industries in meeting Environmental, Social, and Governance (ESG) goals and upcoming carbon taxation norms.