CO2 Utilization via Direct Aqueous Carbonation of Synthesized Concrete Fines under Atmospheric Pressure

Hsing-Jung Ho; Atsushi Iizuka; Etsuro Shibata; Hisashi Tomita; Kenji Takano; Takumi Endo

doi:10.1021/acsomega.0c00985

CO₂ Utilization via Direct Aqueous Carbonation of Synthesized Concrete Fines under Atmospheric Pressure

ACS Omega. 2020 Jun 22;5(26):15877-15890. doi: 10.1021/acsomega.0c00985. eCollection 2020 Jul 7.

Authors

Hsing-Jung Ho¹, Atsushi Iizuka², Etsuro Shibata², Hisashi Tomita³, Kenji Takano³, Takumi Endo³

Affiliations

¹ Department of Environmental Studies for Advanced Society, Graduate School of Environmental Studies, Tohoku University, Aoba-468-1 Aramaki, Aoba-ku, Sendai, Miyagi 980-0845, Japan.
² Center for Mineral Processing and Metallurgy, Institute of Multidisciplinary Research for Advanced Materials, Tohoku University, 2-1-1, Katahira, Aoba-ku, Sendai, Miyagi 980-8577, Japan.
³ Business Development Department, Resources, Energy & Environment Business Area, IHI Corporation, 1-1, Toyosu 3-chome, Koto-ku, Tokyo 135-8710, Japan.

Abstract

Mineral carbonation using alkaline wastes is an attractive approach to CO₂ utilization. Owing to the difference between waste CO₂ and feedstock CO₂, developing CO₂ utilization technologies without CO₂ purification and pressurization is a promising concept. This study investigated a potential method for CO₂ utilization via direct aqueous carbonation of synthesized concrete fines under atmospheric pressure and low CO₂ concentration. The carbonation reaction with different solid-liquid ratios and different concentrations of introduced CO₂ was examined in detail. Under basic conditions, a CO₂ uptake of 0.19 g-CO₂/g-concrete fines demonstrated that direct aqueous carbonation of concrete fines under atmospheric pressure and low CO₂ concentration is effective. The CaCO₃ concentration, degree of carbonation, and reaction mechanism were clarified. Furthermore, characterization of the carbonated products was used to evaluate ways of utilizing the carbonated products.