Hydrocracking of Athabasca asphaltene over ZnCl 2-KCl-NaCl melts with or without an additive of some transition metal chlorides

Abstract

Hydrocracking of Athabasca asphaltene over molten salts has been studied at 400 °C for 1 h at an initial hydrogen pressure of 9.8 M Pa. The hydrocracking over ZnCl 2-KCl-NaCl produced 57.0 wt% of pentanesolubles (PS), 4.7 wt% of benzene-solubles (BS) and 22.7 wt% of gases together with 15.6 wt% of coke. These melts containing NiCl 2 and CuCl, respectively, were examined, the former exerting a little better influence on reducing the coke yield. A small amount of coke (3.7%) and a higher conversion attained with ZnCl 2-KCl-NaCl-MoCl 5 suggested excellent properties of MoCl 5 for the hydrocracking of asphaltene. The sulphur contents of the PS and BS were lowest with melt catalysts containing MoCl 5. A compound-type separation of each pentane-soluble showed that in the presence of melt catalyst, monoaromatic and diaromatic contents increased greatly at the expense of polyaromatics and polar materials. The trend of catalytic activity of each melt for hydrocracking of asphaltene was found to be quite different from that for the decomposition reaction of tetrahydrothiophene in a continuous flow system.