Quantitative Review of Olivine Carbonation Kinetics: Reactivity Trends, Mechanistic Insights, and Research Frontiers

Journal Article · Tue Aug 13 04:00:00 EDT 2019 · Environmental Science & Technology Letters

DOI:https://doi.org/10.1021/acs.estlett.9b00301· OSTI ID:1572497

Miller, Quin RS ^[1]; Schaef, Herbert T. ^[1]; Kaszuba, John ^[2]; Gadikota, Greeshma ^[3]; McGrail, Bernard P. ^[1]; Rosso, Kevin M. ^[1]

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1. BATTELLE (PACIFIC NW LAB)
2. University of Wyoming
3. UNIVERSITY OF WISCONSIN

Magnesium-dominant olivine (Mg2SiO4) has received considerable attention for geologic and ex situ carbon mineralization due to its reaction potential with CO2 and its abundance in mafic and ultramafic rocks. To enable better predictions and optimization of its carbonation rate, here we compile the results of 15 separate studies into an internally consistent kinetic framework. Time-dependent transformation curves were determined, analyzed, and used to calculate temperature-dependent carbonation rate constants from 50-300 °C. The unified results clearly show that olivine carbonation is optimized at 185-200 °C, and indicate a change in the carbonation reaction mechanism above 90 °C. By comparison with related efforts focused solely on olivine dissolution rates, we demonstrate that the kinetics are controlled by growth of magnesium carbonates. Additional outcomes include the identification of important knowledge gaps and research frontiers for carbon mineralization, including those related to unraveling competitive serpentinization reactions, H2O-saturated supercritical CO2 (wet scCO2) reactivity, and the formation and impacts of secondary surface coatings. In addition to supporting the deployment of carbon storage technologies in a climate-responding world, the findings may help improve understanding of how carbonation and serpentinization processes influence critical geochemical cycles.

• Research Organization: Pacific Northwest National Laboratory (PNNL), Richland, WA (United States)
• Sponsoring Organization: USDOE
• DOE Contract Number: AC05-76RL01830
• OSTI ID: 1572497
• Report Number(s): PNNL-SA-143712
• Journal Information: Environmental Science & Technology Letters, Journal Name: Environmental Science & Technology Letters Journal Issue: 8 Vol. 6
• Country of Publication: United States
• Language: English