Molecular simulation for catalytic hydrotreatment of coker heavy gas oil derived from Athabasca bitumen

Abstract

The average molecular structure of coker heavy gas oil (HGO) from Athabasca bitumen was derived from both elemental properties and 1H and 13C NMR spectra. The optimized 3D structure of the most stable conformation was obtained by quantum chemistry calculations, together with molecular mechanics and molecular dynamics simulation methods. The relative structural parameters and characteristics were simulated through a quantum chemistry study. The adsorption and hydrotreatment of HGO molecules on catalyst surfaces were studied in combination with the nano minicrystal catalyst model. The stable minimum of adsorption was reached when the HGO molecule was 0.22 nm from the catalyst surface. The exothermic heat of adsorption is 378.0 kcal/mol. Molecular simulation of HGO hydrotreatment shows that the total system energy changes as a hydrogen atom approaches the reaction site of an HGO molecule. The activation energy and the heat of reaction for the initial hydrotreatment reaction are 133.8 and −176.0 kcal/mol, respectively.