Behavior, kinetic and product characteristics of the pyrolysis of oil shale catalyzed by cobalt-montmorillonite catalyst

In this work, the effects of the coupling between montmorillonite and CoCl 2 ·6H 2 O on pyrolysis behavior, products distribution and characteristics of liquid fuel were investigated by the combination of pyrolysis experiment and kinetic analysis. The mass fraction of the MMT in oil shale was 3–9%, and the mass fraction of CoCl 2 ·6H 2 O was 10–25%. The results showed that the coupling effect promoted the formation of shale oil. The maximum yield of shale oil (17.75 wt%) was obtained at 20CoCl 2 ·6H 2 O5MMT. Catalytic pyrolysis behavior and kinetic analysis indicated that the presence of CoCl 2 ·6H 2 O and montmorillonite led to the prominent advance of kerogen decomposition temperature and the decrease of apparent activation energy. Significantly, the addition of the 20CoCl 2 ·6H 2 O5MMT led that the average apparent activation energy was decreased by about 122.42 kJ/mol compared to the catalyst-free pyrolysis. The strong cracking ability produced by their coupling effect was considered to be the main reason. Montmorillonite and CoCl 2 ·6H 2 O enhanced the decarboxylation and free-radical reaction, resulting in a decrease of acids yield and an increase of aliphatic hydrocarbons yield. The relative content of aliphatic hydrocarbons increased from 41.55% to 51.27%. These results demonstrated that the combined use of montmorillonite and CoCl 2 ·6H 2 O was beneficial to the generation of saturated hydrocarbon production.