ABSTRACT
Yoshida et al. (1982) studied the changes that asphaltenes experience after hydrogenolysis at 400°C and 22 MPa using red mud (Fe2O3 [~60%], Al2O3 [~20%], SiO2 [10%] and other oxides) as the catalyst. After the reaction, it was observed that residual asphaltenes increased their hydrogen content and, at the same time, there was an increase of aliphatic carbon, which indicated that aromatics hydrogenation occurred. It seemed that aromatic systems with more than two rings were more easily hydrogenated. But, on the contrary, systems having only two aromatic rings were hardly hydrogenated. Changes in asphaltenes are mainly found in hydrogen to carbon (H/C) atomic ratio, aromaticity factor, molecular weight, and an average degree of cross linking. Regarding the degree of cross linking, hydrogenolysis is responsible for heteroatoms removal, which produces oil composed by two condensed aromatic rings. The remaining asphaltenes are formed by two or more condensed aromatic rings that cross link.
