About the Talk 

The trapping of carbon dioxide (CO₂) as an aqueous (bi)carbonate ion (e.g., HCO₃^–, CO₃^2–) or as a mineral solid is attractive because of favorable thermodynamics, and the durability and permanence of storage. Here, I will describe an approach to rapidly precipitate Ca- and Mg- carbonates and hydroxides from seawater to achieve large-scale, cost-effective CO₂ removal. This Equatic process electrolytically forces mineral carbonate precipitation – from seawater – thereby consuming CO₂ that is dissolved in seawater by locking it within carbonate minerals, and simultaneously producing alkaline mineral hydroxides that when (re)dissolved in seawater enable the drawdown of atmospheric CO₂. Specifically, 1 mol of CO₂ is captured per 2 mol of OH^– produced by the formation of 1 mol CaCO₃. In addition, only 1.2 mol of OH⁻ are required per 1 mol CO₂ stored as dissolved HCO₃^– and CO₃^2– ions. This is because when dissolved into seawater, every mol of Mg(OH)₂ leads to the absorption of up to ~1.7 mol of CO₂. In addition, I will describe the translational design, fabrication, commissioning and operations of pilot plants in Singapore and Los Angeles which demonstrate a net energy intensity (NEI) of ~1-to-1.5 MWh per tonne of atmospheric CO₂ removal.

About the speaker:

Gaurav is a Professor and the Pritzker Endowed Chair in Sustainability at the Samueli School of Engineering at the University of California, Los Angeles (UCLA). He holds faculty appointments in the Departments of Civil and Environmental Engineering, Materials Science and Engineering, and the California Nanosystems Institute. Gaurav has published over 200 publications and has an h-index of 55. He is also the Director of UCLA's Institute for Carbon Management (ICM): a cross-campus technology translation institute. Gaurav is the Co-Founder of SeaChange Inc., the Grand Prize Winner of the Temasek Foundation’s 2021 Liveability Challenge, the Co-Founder of Concrete-AI Inc., the Co-Founder of Nextli Technologies Inc., the Co-Founder of x/44, and the Founder of CarbonBuilt Inc., a Grand Prize Winner of the NRG COSIA Carbon XPRIZE, and a GlobalTop10 Innovation selected at The International Cool Earth Forum 2018. Gaurav has served as an expert providing: a) testimony to the U.S. Senate, U.S. House of Representatives, and the California State Senate, and b) strategic consulting, core R&D, and innovation support to Fortune500 corporations, government agencies, foundations, and industry organizations globally. Gaurav earned his B.S. (2006), M.S. (2007), and Ph.D. (2009) from Purdue University.