Laser-Induced Voltage of Oil Shale during Retorting

Abstract

In this study, a 248 nm laser was used to analyze oil shale at different pyrolysis temperatures. An induced voltage was obtained when the ultraviolet laser irradiated the oil shale surface. The laser-induced voltage (LIV) peak decreases with temperatures below 200 °C, increases with temperatures in the range 200–400 °C, and then decreases above 400 °C. The critical temperatures of 200 and 400 °C corresponded well with the points conformed using thermogravimetry and differential scanning calorimetry (TGA-DSC), gas chromatography and gas chromatography coupled (TG-FTIR-MS), and scanning electron microscopy (SEM). Our research suggested that an LIV method could be applied to the analysis of the oil shale pyrolysis process.

Mechanism of the Laser-Induced Voltage Generated in Oil Shale under the Irradiation of a 532 nm Laser

“…Previously, the LIV measurements were employed to characterize both the oil yield and the pyrolysis process of the oil shale. 26,27,31 Here, we aim to discuss the interaction between oil shale and the 532 nm laser. The laser power and bias-voltage-dependent LIV response were determined, in which the LIV signal increased linearly with the power and the current increased nonlinearly with the bias voltage.…”

“…With the advantage of noncontact and insensitive to harsh environments, optical techniques can be served as an appropriate means to promote the development of the unconventional petroleum industry. Previously, the LIV measurements were employed to characterize both the oil yield and the pyrolysis process of the oil shale. ,, Here, we aim to discuss the interaction between oil shale and the 532 nm laser. The laser power and bias-voltage-dependent LIV response were determined, in which the LIV signal increased linearly with the power and the current increased nonlinearly with the bias voltage.…”

“…We have investigated the oil shale sample, which contains different contents of organic matter and generates different values of excitons when irradiated by laser. 26 Positively related relationships were observed between the voltage (V p ) response and the oil yield of oil shale, in which V p was directly affected by the organic matter content. 27 With the pyrolysis of the oil shale, its surface became rougher, and more pores and cracks were observed.…”

“…When the shale has different bedding directions, and its LIV response changes periodically with direction changes. We have investigated the oil shale sample, which contains different contents of organic matter and generates different values of excitons when irradiated by laser . Positively related relationships were observed between the voltage ( V p ) response and the oil yield of oil shale, in which V p was directly affected by the organic matter content .…”

Simultaneous Determination of Organic Distribution and Content in Oil Shale by Terahertz Imaging

“…Seeking a means for the rapid determination of oil distribution and content in oil shale will be of great help in optimizing the pyrolysis conditions and improving economic benefits. Optical techniques, with the advantages of requiring no contact, being nondestructive, and being impervious to Earth’s magnetic field, can be served as appropriate means to promote the development of the petroleum industry. − Various optical technologies, including optical fibers and infrared spectroscopy, have made great progress in the exploration of unconventional oil gas resources. Because of its unique advantages, THz spectroscopy is a promising method for the characterization of oil gas reservoirs.…”