Title
Pore morphology in thermally-treated shales and its implication on CO2 storage applications: A gas sorption, SEM, and small-angle scattering study
Author
Chandra, D. (TU Delft Applied Geophysics and Petrophysics; Indian Institute of Technology Bombay) 
Bakshi, Tuli (Indian Institute of Technology Bombay)
Bahadur, Jitendra (Bhabha Atomic Research Centre; Homi Bhabha National Institute, Mumbai)
Hazra, Bodhisatwa (Central Institute of Mining and Fuel Research)
Vishal, Vikram (Indian Institute of Technology Bombay)
Kumar, Shubham (Indian Institute of Technology Bombay)
Sen, Debasis (Bhabha Atomic Research Centre; Homi Bhabha National Institute, Mumbai)
Singh, T. N. (Indian Institute of Technology Bombay)
Date
2023
Abstract
A combination of high-resolution imaging, low-pressure gas adsorption, and small-angle X-ray and neutron scattering quantifies changes in the pore characteristics of pulverized shale samples under oxic and anoxic environments up to 300 ℃. Clay-rich early-mature shales have a fair potential to generate hydrocarbons, the total organic carbon content of which lies within a range of 2.9 % to 7.4 %. High-resolution imaging indicates restructuring and coalescence of Type III kerogen-hosted pores due to oxic heating, which causes up to 580 % and 300 % increase in the surface area and pore volume of mesopores respectively. Similarly, up to 300 % and 1200 % increase in micropore surface area and pore volume is observed post oxic heating. However, during anoxic heating, bitumen mobilizes, leads to pore-blockage, and reduces the surface area and pore volume up to 45 % and 12 % respectively without any significant mass loss up to 350 °C. Between 400 and 550 °C, considerable loss in mass occurred due to breaking of organic matter, facilitated by the presence of siderite that caused up to 30 % loss in mass. The test conditions display starkly opposite effects in pores that have a width of < 100 nm when compared to the larger macropore domain, which has a pore width in the range of 100 to 700 nm as inferred from their small-angle X-ray (SAXS) and neutron (SANS) scattering behaviour, respectively. Despite the formation of new mesopores or the creation of new networks of pores with rougher surfaces, the fractal behavior of accessible mesopores in combusted shales minimally increase mesopore surface roughness. The pyrolyzed shales exhibit decreased mesopore surface roughness at higher temperatures, which indicates smoothening of pores due to pore blocking. Increase in pore volume and surface area due to oxic-heat treatment enhances the feasibility of long-term CO2 storage in shales.
Subject
CO storage
Combustion & inert heating
Organic matter
Pore characteristics
SANS
SAXS
To reference this document use:
http://resolver.tudelft.nl/uuid:73ff6d13-04a1-44cf-aa5a-dcf347311577
DOI
https://doi.org/10.1016/j.fuel.2022.125877
Embargo date
2023-07-01
ISSN
0016-2361
Source
Fuel: the science and technology of fuel and energy, 331
Bibliographical note
Green Open Access added to TU Delft Institutional Repository 'You share, we take care!' - Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.
Part of collection
Institutional Repository
Document type
journal article
Rights
© 2023 D. Chandra, Tuli Bakshi, Jitendra Bahadur, Bodhisatwa Hazra, Vikram Vishal, Shubham Kumar, Debasis Sen, T. N. Singh