In-situ catalytic pyrolysis of oil shale over metal-loaded silicon nanoparticles

Oil shale, as an abundant unconventional energy resource, offers significant potential for mitigating the shortage of conventional fossil fuels. However, challenges such as the complex and costly synthesis of catalysts capable of being injected into the shale reservoirs, along with an insufficient understanding of the underlying catalytic mechanisms, continue to hinder the commercial application of in-situ catalytic pyrolysis. In this study, we synthesized three metal-loaded silica nanoparticle catalysts (M/SiO 2 , M=Ni, Mn and Cu), and comprehensively investigated their catalytic efficiency in oil shale pyrolysis under varying conditions. GC-MS and simulated distillation results demonstrated that the pyrolysis of kerogen was significantly facilitated by the M/SiO 2 catalysts. This enhancement leads to increased concentrations of hydrogen, carbon dioxide, and methane in the shale gas, while the quality of the product oil is also improved. Notably, Cu/SiO 2 exhibited the best catalytic performance, boosting the yields of product oil and gas by 9.38% compared to non-catalytic pyrolysis. Kinetic analysis indicated a reduction of 13.83% in the average apparent activation energy. Furthermore, semi-coke characterization revealed an approximately 15.55% decrease in weight loss, with the calorific value dropping from 1727 J/g in non-catalyst pyrolysis to 1444 J/g in the catalyst-assisted system. These findings underscore the excellent catalytic performance of the metal-loaded SiO 2 catalysts and provide crucial insights for optimizing in-situ oil shale conversion and product upgrading.