Experimental Study of the Autothermic Pyrolysis In-Situ Conversion Process (Ats) for Oil Shale Recovery

As the most potential supplementary resource of conventional fossil energy, oil shale has attracted unprecedented attention. However, it has not been large-scale industrialization applied due to poor efficiency and high costs. This study develops autothermic pyrolysis in-situ conversion process (ATS) by using its potential heat with the self-designed in-situ conversion experiment. The in-situ pyrolysis of oil shale was successfully triggered at 300 ℃ and the peak surface of ATS can be steadily advanced, which proves the feasibility of the ATS. According to the optical and chemical characteristics in the core sample, the formation during the ATS can be divided into five typical reaction zones: (a) residue zone, (b) autothermic zone, (c) cracking zone, (d) preheating zone, and (e) virgin zone. Compared with in-situ conversion by injecting high-temperature nitrogen (HNICP), oil obtained from ATS contains more light components. When the oil recovery from ATS reaches 97.1% of that from HNICP, the energy efficiency of the former is as high as 3.46, which is much higher than 0.51 of the latter, indicating that the ATS method can not only ensure effective recovery of pyrolysis oil and gas products but also has excellent energy efficiency and significant economic applicability