Class C Fly Ash-Based Alkali Activated Cement as a Potential Alternative Cement for CO₂ Storage Applications

Author

Priyesh Jani
Abdulmohsin Imqam, Missouri University of Science and TechnologyFollow

Abstract

Long-term storage of carbon dioxide (CO₂) inside depleted reservoirs can help reduce the impact of greenhouse gas emissions. Portland cement has been shown to degrade significantly during long-term contact with CO₂. This research aims to provide a new environmentally friendly, Class C fly ash-based cement as a potential alternative to Portland cement for CO₂ storage wells. This was achieved by comparing the mechanical degradation of Portland cement and Class C fly ash-based alkali-activated cement in a CO₂ environment. A specially designed setup was constructed to create an in situ high pressure and high-temperature CO₂ environment. Seventy-two cores of Portland cement and Class C fly ash-based cement were prepared for this study. The results show that CO₂ reacted with the water in the vessel and formed carbonic acid, which reduced the water pH to 6.8. Millimeter-sized crystals of calcium carbonate (CaCO₃) were observed on the surface of the Portland cement cores after the CO₂ exposure. The surface of the fly ash-based alkali-activated cement cores was not substantively changed after the exposure. No significant change in density was observed for both types of cement during the 14 days of CO₂ exposure. Portland cement showed a significant reduction in compressive strength, and this reduction developed as the exposure time increased. Interestingly, Class C fly ash-based cement showed no reduction in compressive strength, and only a small amount of reduction was observed after 14 days of exposure. This research compared the mechanical degradation of Portland cement and Class C fly ash-based alkali-activated cement in a high-pressure and high-temperature CO₂ environment.

Recommended Citation

P. Jani and A. Imqam, "Class C Fly Ash-Based Alkali Activated Cement as a Potential Alternative Cement for CO₂ Storage Applications," Journal of Petroleum Science and Engineering, vol. 201, Elsevier, Jun 2021.

The definitive version is available at https://doi.org/10.1016/j.petrol.2021.108408

Department(s)

Geosciences and Geological and Petroleum Engineering

Keywords and Phrases

CO2; Fly ash geopolymer cement; Portland cement

International Standard Serial Number (ISSN)

0920-4105

Document Type

Article - Journal

Document Version

Citation

File Type

text

Language(s)

English

Rights

© 2021 Elsevier, All rights reserved.

Publication Date

01 Jun 2021