the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
The influence of various solvents extraction on chemical properties on Chang 7 shale, Ordos Basin, China
Yan Cao
Zhijun Jin
Rukai Zhu
Kouqi Liu
Abstract. To explore the effect of various solvents extraction on the chemical property of shales, several lacustrine shales from Chang 7 member of the Upper Triassic Yanchang Formation, Ordos Basin with maturities from marginally mature (Tmax = 439 ℃) to late mature (Tmax = 456 ℃) were extracted by using acetone, tetrahydrofuran (THF), carbon disulfide (CS2), and benzene, respectively. Fourier transform infrared spectroscopy (FTIR) was employed to examine the functional groups of the samples before and after extraction with different solvents. The results showed that the extraction yield from shale with THF is significantly higher than that of other solvents, which may be related to the properties of the THF, including the aromatic structure, high boiling point, excellent Hansen solubility parameters, and strong polarity. The TOC-normalized yield of the mature sample J1 is significantly higher than that of other samples, which may be related to that the J1 sample is at the peak of hydrocarbon generation, thus a large number of kerogens were cracked into oil and bitumen. The aromaticity of organic matter (OM) increases with the increase of maturity. The length of the aliphatic chains of the organic matter first increased with the increase of maturity before late maturity stage, and then decreased in late maturity stage. The extraction of shales with solvents hardly changes the length of aliphatic chains. Higher aromaticity is observed in shale residues after THF extractions than other solvents (i.e., acetone, CS2, benzene).
Yan Cao et al.
Status: open (until 14 Jun 2023)
-
CC1: 'Comment on egusphere-2023-272', jiangming tian, 06 May 2023
reply
This paper focuses on exploring the influence of various solvents extraction on chemical properties of shales. It is a topic of interest to the researchers in the fossil energy areas, the manuscript is well written. Moreover, this well-designed research paper contains interesting results which merit publication, the chemical characterization of shales with different maturities is attractive. For the benefit of the readers, however, there are still some problems need be clarified after reading this paper. I suggest some minor modifications before publication and I would be happy to review the revised article.
1: You took the 60 mesh as the optimal particle size in extraction process of shale. However, some groups have suggested 200 mesh for the shale extraction. This analytical condition could have substantial influences on subsequent shale characterization.
2: The conclusions of this paper don’t refer to the mineral composition of shale. Is XRD experiment redundant in your research?
Citation: https://doi.org/10.5194/egusphere-2023-272-CC1 -
AC1: 'Reply on CC1', Yan Cao, 06 May 2023
reply
Response 1: Thank you for pointing this out. Our research is a continuation of previous research and previous work mainly evaluated the changes in pore structure of shale before and after solvent extraction using N2 sorption. Coincidentally, Wei et al. (2014) indicated that a grain size of 60-mesh is beneficial for efficient solvent extraction of soluble OM and is more appropriate for gas adsorption porosimetry for both unextracted and extracted shales. Therefore, we took the 60 mesh as the optimal particle size for the shale analysis in this research.
Wei, L., Mastalerz, M., Schimmelmann, A., Chen, Y., 2014. Influence of Soxhlet-extractable bitumen and oil on porosity in thermally maturing organic-rich shales. Int. J. Coal Geol. 132, 38–50.
Response 2: Thank you for pointing this out. XRD experiments of shale samples are necessary and the FTIR results of those samples can provide a reference for shale samples of similar mineral composition.
Citation: https://doi.org/10.5194/egusphere-2023-272-AC1 -
CC6: 'Reply on AC1', san zhang, 07 May 2023
reply
I agree with the replies and recommend this paper to be published in Solid Earth.
Citation: https://doi.org/10.5194/egusphere-2023-272-CC6
-
CC6: 'Reply on AC1', san zhang, 07 May 2023
reply
-
AC1: 'Reply on CC1', Yan Cao, 06 May 2023
reply
-
CC2: 'Comment on egusphere-2023-272', san zhang, 06 May 2023
reply
The author employed four polar solvents (acetone, tetrahydrofuran (THF), carbon disulfide (CS2), and benzene) for extracting lake-type shales at different maturity levels. The extraction yield of various solvents were compared, while Fourier-transform infrared spectroscopy (FTIR) was used to examine functional group characteristics pre- and post-extraction. The experimental design was intriguing, demanding significant effort, and yielded compelling results. However, there are still unresolved inquiries that require clarification from the author. I suggest considering minor revisions to the article.
1. I would like to suggest that the TOC should be written in full name where this word appeared for the first time in the manuscript.
2. The calculation of extraction yields involves the quality of the residual sample. How to judge the effect of extraction, and is it enough to extract 150 hours?Citation: https://doi.org/10.5194/egusphere-2023-272-CC2 -
AC2: 'Reply on CC2', Yan Cao, 06 May 2023
reply
Response 1: Thank you for pointing this out. The TOC has been written in full name where this word appeared for the first time in the manuscript (see lines 14 and 15).
Response 2: Thank you for pointing this out. In our study, the time of the experiment is constant, each studied sample was extracted for 150 hours. In previous studies of this kind, shale samples were extracted for 72 hours (Wei et al., 2014; Guo et al., 2014; Furmann et al., 2013). Although we cannot be sure that the shale-soluble organic matter has been completely extracted, we believe that 150 hours is close to the time when the organic matter has been completely extracted.
Wei, L., Mastalerz, M., Schimmelmann, A., Chen, Y., 2014. Influence of Soxhlet-extractable bitumen and oil on porosity in thermally maturing organic-rich shales. Int. J. Coal Geol. 132, 38–50.
Guo, H., Jia, W., Peng, P., Lei, Y., Luo, X., Cheng, M., Wang, X., Zhang, L., Jiang, C., 2014. The composition and its impact on the methane sorption of lacustrine shales from the Upper Triassic Yanchang Formation, Ordos Basin, China. Mar. Petrol. Geol. 57, 509–520.
Furmann, A., Mastalerz, M., Brassell, S. C., Schimmelmann, A., Picardal, F., 2013. Extractability of biomarkers from high- and low-vitrinite coals and its effect on the porosity of coal. Int. J. Coal. Geol. 107, 141–151.-
CC7: 'Reply on AC2', san zhang, 07 May 2023
reply
The points raised in the previous review have been satisfactorily addressed and I agree that this work can be accepted for publication on Solid Earth.
Citation: https://doi.org/10.5194/egusphere-2023-272-CC7
-
CC7: 'Reply on AC2', san zhang, 07 May 2023
reply
-
AC2: 'Reply on CC2', Yan Cao, 06 May 2023
reply
-
CC3: 'Comment on egusphere-2023-272', san zhang, 06 May 2023
reply
The author employed four polar solvents (acetone, tetrahydrofuran (THF), carbon disulfide (CS2), and benzene) for extracting lake-type shales at different maturity levels. The extraction yield of various solvents were compared, while Fourier-transform infrared spectroscopy (FTIR) was used to examine functional group characteristics pre- and post-extraction. The experimental design was intriguing, demanding significant effort, and yielded compelling results. However, there are still unresolved inquiries that require clarification from the author. I suggest considering minor revisions to the article.
1. I would like to suggest that the TOC should be written in full name where this word appeared for the first time in the manuscript.
2. The calculation of extraction yields involves the quality of the residual sample. How to judge the effect of extraction, and is it enough to extract 150 hours?Citation: https://doi.org/10.5194/egusphere-2023-272-CC3 -
AC3: 'Reply on CC3', Yan Cao, 06 May 2023
reply
Response 1: Thank you for pointing this out. The TOC has been written in full name where this word appeared for the first time in the manuscript (see lines 14 and 15).
Response 2: Thank you for pointing this out. In our study, the time of the experiment is constant, each studied sample was extracted for 150 hours. In previous studies of this kind, shale samples were extracted for 72 hours (Wei et al., 2014; Guo et al., 2014; Furmann et al., 2013). Although we cannot be sure that the shale-soluble organic matter has been completely extracted, we believe that 150 hours is close to the time when the organic matter has been completely extracted.
Wei, L., Mastalerz, M., Schimmelmann, A., Chen, Y., 2014. Influence of Soxhlet-extractable bitumen and oil on porosity in thermally maturing organic-rich shales. Int. J. Coal Geol. 132, 38–50.
Guo, H., Jia, W., Peng, P., Lei, Y., Luo, X., Cheng, M., Wang, X., Zhang, L., Jiang, C., 2014. The composition and its impact on the methane sorption of lacustrine shales from the Upper Triassic Yanchang Formation, Ordos Basin, China. Mar. Petrol. Geol. 57, 509–520.
Furmann, A., Mastalerz, M., Brassell, S. C., Schimmelmann, A., Picardal, F., 2013. Extractability of biomarkers from high- and low-vitrinite coals and its effect on the porosity of coal. Int. J. Coal. Geol. 107, 141–151.-
CC8: 'Reply on AC3', san zhang, 07 May 2023
reply
The questions I have pointed out have been carefully revised or answered and I now agree to publish the paper.
Citation: https://doi.org/10.5194/egusphere-2023-272-CC8
-
CC8: 'Reply on AC3', san zhang, 07 May 2023
reply
-
AC3: 'Reply on CC3', Yan Cao, 06 May 2023
reply
-
CC4: 'Comment on egusphere-2023-272', Peng Pang, 06 May 2023
reply
The experiments seem well-designed, the data are convincing, and the entire article is clear and scholarly. The specific comments, which have to be addressed before the article can be recommended for publication are: 1. The OM should be written in full name where this word appeared for the first time in the manuscript. 2. The discussion regarding the extraction of organic matter may be strengthened by the use of NMR analyses of the samples if available.
Citation: https://doi.org/10.5194/egusphere-2023-272-CC4 -
AC4: 'Reply on CC4', Yan Cao, 06 May 2023
reply
Response 1: Thank you for pointing this out. The OM has been written in full name where this word appeared for the first time in the manuscript (see line 17).
Response 2: Thank you for pointing this out. It is our negligence of our experimental design and we are sorry about this. We agree the reviewer’s point. Strictly speaking, the discussion regarding the extraction of organic matter may be strengthen by use of NMR analyses of the samples in addition to FTIR if available. Althrough Both Nuclear Magnetic Resonance (NMR) and Infrared Spectroscopy contribute to our understanding of shale's organic properties to some extent, this study primarily focuses on discussing the results obtained from infrared spectroscopy testing, which provides insights into the organic features of shale. In addition, there are no samples left for this experiment, so we cannot do the experiment suggested by reviewers. Furthermore, the review's comments about the use of NMR analyses of the samples would be a new direction for our next phase of research.
-
CC5: 'Reply on AC4', Peng Pang, 06 May 2023
reply
The authors have responded well to previous comments. I have no additional comments, and agree to the acceptance of the article for publication in Solid Earth.
Citation: https://doi.org/10.5194/egusphere-2023-272-CC5
-
CC5: 'Reply on AC4', Peng Pang, 06 May 2023
reply
-
AC4: 'Reply on CC4', Yan Cao, 06 May 2023
reply
Yan Cao et al.
Yan Cao et al.
Viewed
| HTML | XML | Total | BibTeX | EndNote | |
|---|---|---|---|---|---|
| 270 | 98 | 31 | 399 | 4 | 4 |
- HTML: 270
- PDF: 98
- XML: 31
- Total: 399
- BibTeX: 4
- EndNote: 4
Viewed (geographical distribution)
| Country | # | Views | % |
|---|
| Total: | 0 |
| HTML: | 0 |
| PDF: | 0 |
| XML: | 0 |
- 1