Extraction and fractionation of organic matters from Jordanian-origin oil shale under different operational parameters

Abstract

Recently, there has been an interest in solvent extraction for extraction organic matter from oil shale. Heating of oil shale in an inert atmosphere facilitated the extraction of the organic matter by solvent extraction. In this research, shale oil obtained by Soxhlet extraction was separated and characterized, and this was not studied previously. The best Soxhlet extraction conditions were 25.0 g oil shale (preheated at 400 °C), particle size of 250–500 µm, 400.0 mL tetrahydrofurane, and 5.0 h extraction time, where 68% of the organic matter was extracted, which is considered a high value compared to published results. Both THF and dichloromethane were effective extractants, the former due to its moderate dipole moment and low hydrophobicity, while the later due to its high solubility factor (20.2) which can swell kerogen and facilitate organic extraction. The significant output of this research is the variability in the composition of oil obtained by solvent extraction compared to conventional thermal retorting, as the first has large fractions of saturated and polar compounds (85%) while small fractions of aromatics (11%). Spectroscopic analysis by FTIR and ¹H-NMR was important in identifying the components of the extracted oil, especially saturated hydrocarbons.

Keywords:

• Jordanian oil shale
• Soxhelt extraction
• kerogen
• retorting
• oil fractionation

Acknowledgments

The authors thanks Mr Bassem Nasrallah for the valuable technical assistance.

Author contributions

Kholoud Mashal, Yahya Al-Degs: conceptualization and supervising; Kholoud Mashal, Yahya Al-Degs, Saif Al-Zawahrah: Methodology, analysis, validation: Yahya Al-Degs, Saif Al-Zawahrah, Abdullah I. Saleh, Kholoud Mashal: Writing-reviewing and editing.

Disclosure statement

The authors declare no conflict of interest.

Additional information

Funding

This research was funded by the Deanship of Graduate Studies, the Hashemite University, Zarqa, Jordan.