Tailao oil shale was subject to step-wise acid washing to eliminate the inherent carbonate and silicate minerals. The pyrolysis experiments of original oil shale and its demineralization products were carried out in an aluminum retort. The composition and property of shale oil and pyrolytic gas were characterized by elemental analysis

chemical class composition

gas chromatography-mass spectrometer (GC-MS) and gas chromatography (GC). The influence of inherent carbonate and silicate minerals on pyrolysis was studied by comparing the product yields and compositions. The results showed that carbonates promoted the formation of shale oil and nitrogen-and oxygen-containing compounds

while silicates inhibited the evolution of oil and oxygenated compounds. Both carbonates and silicates decreased the H/C atomic ratio of shale oil. Furthermore

silicates would catalyze the combination of alkyl free radicals and hydrogen free radicals and cracking of long-chain aliphatic hydrocarbons

which increased the alkanes and short-chain hydrocarbons contents of shale oil

as well as the hydrocarbon gases yields

but decreased the hydrogen yield. On the contrary

carbonates suppressed the combination of free radicals and cracking of long-chain aliphatic hydrocarbons.