![Author ORCID: We display the ORCID iD icon alongside authors names on our website to acknowledge that the ORCiD has been authenticated when entered by the user. To view the users ORCiD record click the icon. [opens in a new tab]](https://chemrxiv.org/engage/assets/public/chemrxiv/images/logos/orcid.png)
Abstract
We report a highly efficient approach to carbon capture and sequestration via the water catalyzed conversion of basic oxygen steel (BOS) slag and CO2 into CaCO3 and volumetrically stable aggregate for road construction using the Zero-Air-Pollution-Carbon-Capture-Capsule (ZAP-C3) units. The overall transformation is accomplished in a 2-step process. In the first component pH 7 water is sprayed through CO2 containing vapor, forming an acidic solution (pH <4), onto BOS slag or other suitable mineral resulting in a leachate with a pH >10 and a volumetrically stabilized slag with chemically incorporated CO2. In the second stage the 55% decreased CO2 containing vapor out of the first reactor is passed through the leachate using a micro bubble system, causing CaCO3 to precipitate from pH 7 water, yielding a total carbon sequestration of 309 kg CO2 per ton of slag. Over 95% of the water in the process is recycled in a system that total CO2 sequestration of ca. 1,900 ton/year of CO2 in the present configuration and an estimated CO2 sequestration of ca. 2,600 ton/year with the proposed dual reactor set-up.
