Catalytic pyrolysis of oil shale using tailored Cu@zeolite catalyst and molecular dynamic simulation

Abstract

This study synthesized a novel Cu@4 A zeolite nano-catalyst, which exhibited excellent catalytic pyrolysis performance on oil shale. The catalytic pyrolysis behaviors of oil shale were investigated, results show the initial pyrolysis temperature of organics decreased from 410 °C to 360 °C after catalytic treatment, and the activation energy declined from 190.73 to 147.95 kJ/mol. The oil and gas yields increased by 7.61% and 19.69% after catalysis treatment by Cu@4 A, respectively; the yields of H2 and ethylene catalyzed by Cu@4 A zeolite climbed to 15% and 21%. Cu@4 A shows a prominent selectivity on light alkanes and alkenes compared with metal catalysts. The configurations of hydrocarbons in nano-pore were investigated by Molecular Dynamics simulations, the first density peak of C3H6 declined by 68.3% after catalyzed by Cu@4 A at a temperature of 573 K. The interaction energy of hydrocarbon would decrease when the system temperature increases. Finally, the catalytic mechanism was elucidated, kerogen would decompose into macromolecule aromatic hydrocarbons via the β-cleavage of carbenium ions over the acidic sites of the prepared catalyst, then followed by the dehydrocyclization, oligomerization, and aromatization.