Carbon-Smart Lightweight Aggregates Synthesized From Waste Biomass and Ponded Ash: Sequestering Airborne CO2 and Upcycling Waste Alkali

Climate change poses an increasingly significant risk to human society. In light of the urgent need for climate change mitigation, transformative solutions are desirable to meet the decarbonization goal of civil infrastructure industry. Moreover, innovation is needed to divert industrial wastes, such as ponded ash and waste alkali, towards beneficial uses and minimize their environmental risks. In this context, the proposed Phase I project aims to develop a carbon smart artificial lightweight aggregate by repurposing ponded ash and waste alkali, incorporating carbon negative biochar (produced from pyrolysis of waste biomass), while also sequestering airborne CO 2 This novel approach tackles the immediate environmental challenges posed by ponded ash and waste alkali, helps reduce the fuel load of forested lands and the associated wildfire risk, and greatly advances carbon smart infrastructure solutions through the carbon negative aggregate. This Phase I project involves transformation of biochar and ponded ash to artificial lightweight aggregate, through fabricating alkali activated ponded ash carbonated biochar geopolymer cores, cold bonding the geopolymer to manufacture the aggregate, curing the aggregate with waste heat, and CO 2 curing/ sequestration and storage into the aggregate. The process will be optimized at the laboratory scale and industrial scaling up will be explored to validate the feasibility for future commercialization and implementation. The collaboration with academia and local industries ensures practical testing and adoption pathways. Phase II of this work will further advance the Technology Readiness Level towards commercialization. The successful continuation of this Phase I project into Phase II and III holds the promise of producing lightweight, fire resistant, and soundproof artificial aggregates. This work will contribute to the climate solution related workforce development, help stimulate local economies, create good paying jobs, while drawing down atmospheric CO 2 to produce durable carbon credit in infrastructure applications.