Applying Laser-induced Voltage To Characterize And Evaluate Potential Oil Content Of Oil Shale

As an important unconventional resource,oil shale can generate pyrolysis tar,dry distillation gas,semi-coke and other substances after high temperature pyrolysis.Oil yield is an important parameter for evaluating the industrial value of oil shale.Aiming at the urgent need for environmental protection,rapidity,convenience and accuracy in the detection of oil shale oil content,a laser-induced voltage（LIV）detection system was developed for oil content.The following results were found:（1）Under the irradiation of ultraviolet（UV）pulsed laser,the LIV peak value was positively correlated with the incident laser energy:V_p（?）k E_in,k～8.3 m V/m J.The peak sensitivity did not depend on the energy density and was about 8.3 m V/m J.Organic and inorganic minerals in oil shale form a complex band gap structure.The HOMO-LUMO model shows that the photogenerated carriers excited in the oil shale are responsible for the UV LIV response;（2）When the 532 nm steady-state laser irradiated the oil shale surface,the electron-hole pairs were generated,while most of the laser energy was absorbed in the oil shale to increased its surface temperature,which enhanced the LIV response.When the near-infrared laser was applied the LIV response of oil shale came from the temperature change caused by the photothermal effect;（3）The oil yield analysis software was designed according to the functional relationship between the oil yield and LIV peak value,which consists of four parts of data file reading,waveform display,parameter input and result analysis,to realize the measurement and processing analysis of oil shale oil content;（4）Based on the characteristics of high speed and short time of pulsed UV LIV response,a detection system with real-time characterization and rating of oil yield was designed in combination with the host computer module,which realized serial communication with the detection circuit and could display,analyze and process test results.This system not only simplified the analysis and detection process,but also ensured the detection accuracy and stability.