Kerogen nanoscale structure and CO2 adsorption in shale micropores

Gonciaruk, Aleksandra; Hall, Matthew R; Fay, Michael W.; Parmenter, Christopher D J; Vane, Christopher H; Khlobystov, Andrei N.; Ripepi, Nino

Abstract

Gas storage and recovery processes in shales critically depend on nano-scale porosity and chemical composition, but information about the nanoscale pore geometry and connectivity of kerogen, insoluble organic shale matter, is largely unavailable. Using adsorption microcalorimetry, we show that once strong adsorption sites within nanoscale network are taken, gas adsorption even at very low pressure is governed by pore width rather than chemical composition. A combination of focused ion beam with scanning electron microscopy and transmission electron microscopy reveal the nanoscale structure of kerogen includes not only the ubiquitous amorphous phase but also highly graphitized sheets, fiber- and onion-like structures creating nanoscale voids accessible for gas sorption. Nanoscale structures bridge the current gap between molecular size and macropore scale in existing models for kerogen, thus allowing accurate prediction of gas sorption, storage and diffusion properties in shales.

Citation

Gonciaruk, A., Hall, M. R., Fay, M. W., Parmenter, C. D. J., Vane, C. H., Khlobystov, A. N., & Ripepi, N. (2021). Kerogen nanoscale structure and CO2 adsorption in shale micropores. Scientific Reports, 11, Article 3920. https://doi.org/10.1038/s41598-021-83179-z

• Journal Article Type: Article
• Acceptance Date: Jan 18, 2021
• Online Publication Date: Feb 16, 2021
• Publication Date: Feb 16, 2021
• Deposit Date: Jan 29, 2021
• Publicly Available Date: Feb 16, 2021
• Journal: Scientific Reports
• Electronic ISSN: 2045-2322
• Publisher: Nature Publishing Group
• Peer Reviewed: Peer Reviewed
• Volume: 11
• Article Number: 3920
• DOI: https://doi.org/10.1038/s41598-021-83179-z
• Public URL: https://nottingham-repository.worktribe.com/output/5275490
• Publisher URL: https://www.nature.com/articles/s41598-021-83179-z