Experimental Investigation of the Characteristics and Transformation Mechanism of Jimsar Oil Shale and Derived Shale Oil

An experimental investigation of the characteristics and transformation mechanism of Jimsar oil shale and derived shale oil was conducted using a solid-state nuclear magnetic resonance spectrometer (C-13 NMR), Fourier transform infrared spectroscopy (FT-IR), liquid H-1 NMR, and gas chromatography-mass spectrometry (GC-MS) techniques. The carbon skeleton structure of Jimsar oil shale is mainly composed of aliphatic carbons (70.5%), mostly containing straight-chain methylene (CH2), and aromatic carbon (29.31%). Derived shale oil is primarily made of aliphatic compounds that are dominated by n-alkanes and alkenes (comprising more than 70%). The nature of the conversion of oil shale to shale oil is the decomposition of aliphatic groups dominated by methylene structures in organic matter. Additionally, as the heating rate is increased, the secondary cracking reactions in shale oil could increase the contents of short-chain alkanes and alkenes, which could then enhance the secondary polymerization reactions that increase the generation of cycloalkanes and aromatic compounds. Shale oil demonstrates a maximum yield value of 6.32%, the largest carbon, hydrogen, and nitrogen contents, and a minimum oxygen content at the pyrolysis heating rate of 5 degrees C/min.

Automated summary

An experimental investigation was conducted to study the characteristics and transformation mechanism of Jimsar oil shale and derived shale oil. Solid-state nuclear magnetic resonance spectrometer, Fourier transform infrared spectroscopy, liquid H-1 NMR, and gas chromatography-mass spectrometry techniques were used. The carbon skeleton structure of Jimsar oil shale is mainly composed of aliphatic carbons and aromatic carbon. Derived shale oil is primarily made of aliphatic compounds dominated by n-alkanes and alkenes. The conversion process involves decomposition of aliphatic groups with methylene structures. Increasing the heating rate promotes secondary cracking reactions in shale oil and enhances the generation of cycloalkanes and aromatic compounds. Shale oil has the maximum yield value, the highest contents of carbon, hydrogen, and nitrogen, and the lowest oxygen content at a pyrolysis heating rate of 5 degrees C/min.