Jordan University of Science and Technology
Dielectric properties of Jordanian oil shales
Authors:
Mohammad Al-Harahsheh, Sam Kingman , Abdurrahman Saeid, John Robinson,
Georgios Dimitrakis, Hani Alnawafleh
Abstract:
Microwave heating has been suggested by various authors as a suitable technology for extraction of organic
material from oil shales. However, one of the limiting factors in the development of this technology is a lack of
accurate dielectric property data for design purposes. In this study the dielectric behaviour of El-lajun oil shale is
quantified. The dielectric constant and loss factor of El-lajun oil shalewere measured at 2470 and 912 MHz using
the cavity perturbation technique. The effects of organic content, temperature, and moisture content on the
microwave heating efficiency were quantified. Coaxial probe technique was also employed to study the effect of
frequency on dielectric properties of oil shale.Generally, itwas found that all sampleswere of lowdielectric loss at
room temperature with the imaginary part of permittivity falling significantly after the moisture was removed.
This suggests that the major contribution in the dielectric loss is due to the presence of free and/or interlayer
water. It was found that both the real and imaginary part of complex permittivity increased with a rise in
temperature from 20 up to 80 ?C, then dropped significantly at about 100 ?C before staying approximately
constant up to a temperature of about 480 ?C. Fromthis temperature both the real and imaginary parts of complex
permittivity increased sharply with further increase in temperature. An attempt was also made to correlate the
dielectric properties of the bulk shale sample with the organic content. However, no correlation between
dielectric properties and organic matter content was found.