The selectivities of ring opening were investigated for the hydrocracking of phenanthrene and anthracene under an initial hydrogen pressure of 6 MPa, at the temperature of 430°C and in the time range from 30 to 120min. Major products from phenanthrene were hydrogenated phenanthrenes, butylnaphthalenes, butyltetralins and hydrogenated anthracenes. Major products from anthracene were also hydrogenated anthracenes, butylnaphthalenes, butyltetralins and hydrogenated phenanthrenes. Isomerization was considered to proceed between 1, 2, 3, 4, 5, 6, 7, 8-octahydrophenanthrene and 1, 2, 3, 4, 5, 6, 7, 8-octahydroanthracene via 6-butyltetralin intermediate: 6-butyltetralin intermediate will preferably recyclize to make octahydrophenanthrene or octahydroanthracene before it desorbs from catalyst surface, and between 1, 2, 3, 4-tetrahydrophenanthrene and 1, 2, 3, 4-tetrahydroanthracene via 2-butylnaphthalene intermediate: 2-butylnaphthalene intermediate will preferably recyclize to make tetrahydrophenanthrene or tetrahydroanthracene before it desorbs from catalyst surface.
Ring-opening products were classified into the following two components: 1-buthylnaphthalene derivatives and 2-buthylnaphthalene derivatives. Selectivity to 2-buthylnaphthalene derivatives in phenanthrene reaction was higher than that in anthracene reaction.