ABSTRACT
This study explored the vast scale of produced brine available and novel pathways to convert offshore carbon dioxide (CO2) to valuable products. Carbonate structures were selected as host materials with monohydrocalcite (MHC) as the target product. Laboratory simulates comprising carbonate salts of group two metal ions were titrated against CO2 absorbed into dilute alkali solution. The rapid mixing of reactants at pH >9 is essential. Thermal and spectroscopic analyses revealed the product forms and purity of MHC and residual magnesium ions. MHC readily forms at low temperatures and ionic strengths and yet is a feasible material for larger-scale production. Barium and strontium in produced brine depress MHC formation slightly. MHC has low solubility and requires about 5 mole% partial substitutions of calcium by magnesium. The fine-grained and non-agglomerating MHC crystals have beneficial uses. MHC synthesis at room temperature ensures an energy-efficient process and environmentally benign products, forming a basis of a carbon capture process.
Graphical Abstract
Highlights
Synthesis of monohydrocalcite, MHC, from produced water simulates and dilute carbon dioxide.
Magnesium stabilizes MHC production, enabling its ready formation over a range of aqueous solution compositions and temperatures.
Aqueous barium and strontium have a negligible impact on MHC synthesis and NaCl up to 2M does not interfere with MHC precipitation.
MHC is an article of commerce and forms the basis of a carbon capture process and upgrades the status carbon dioxide.
Acknowledgments
The University of Aberdeen, the Schools of Engineering and Natural and Computing Science, supported this work. Many thanks to Prof. Fredrik Glasser and Dr. Marcus Campbell Bannerman for their kind support. Many thanks to Mr. Jacob Kwame Kholi for his immense support and motivation.
Author contributions
Foster designed and coordinated this research. Hariharan and Grace carried out the experiments and data analysis. Min critically revised the paper. All authors wrote parts of the manuscript. The authors read and approved the final manuscript.
Correction Statement
This article has been republished with minor changes. These changes do not impact the academic content of the article.
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Notes on contributors
Foster Kwame Kholi
Foster Kwame Kholi received his B.S in Industrial Chemistry from the University of Cape-Coast, Ghana, M.S in Oil and Gas Engineering from the University of Aberdeen, Scotland, and M.S. in Chemical Engineering from Imperial College London, London. He received his Ph.D. from the School of Mechanical Engineering, Pusan National University, in Busan, South Korea. His research interests include energy systems related to thermal and environmental sustainability management.
Grace Esu-Ejemot Aquah
Grace Esu-Ejemot Aquah received her B. Tech in Chemical Engineering from Ladoke Akintola University of Technology, Oyo, Nigeria, and M.S in Chemical Engineering from Imperial College London, London. Currently, she is a lecturer at the Department of Chemical Engineering, University of Calabar, Nigeria. Her research focuses on applying chemical engineering frameworks to biological systems and environmental remediation.
Hariharan Kallath
Hariharan Kallath received his M.S. in Ocean Engineering from the Indian Institute of Technology, Chennai, and Mechanical Engineering degree from The Institution of Engineers (India), Kolkata. He received his Ph.D. from the School of Mechanical Engineering, Pusan National University, in Busan, South Korea. His research interests include energy systems related to aircraft thermal management.
June Kee Min
June Kee Min received his Ph.D. degree from the Korea Advanced Institute of Science and Technology, Korea, in 1999. Currently, he is a professor at the School of Mechanical Engineering at Pusan National University in Busan, Korea. His research interest is in developing advanced CFD models for various complicated flow and heat transfer problems.