Impact of variables on the naphthalene hydrogenation for the tetralin formation towards BTX production

To achieve high naphthalene conversion and selectivity to tetralin as a first step for BTX production, experiments were carried out in a bench-scale setup processing four model mixtures with a commercial CoMo/Al2O3 catalyst at 250°C-375°C, 1.96-7.84 MPa, and 0.7-1.4 h−1. Model mixtures were prepared by dissolving in n-hexadecane: naphthalene (10 wt%), dibenzothiophene (1.5 wt%) and carbazole (0.05 wt%). Without dibenzothiophene and carbazole, naphthalene conversion and selectivity to tetralin reached 95.6 and 97.2wt%, respectively at 250°C, 1.96 MPa and 1.2 h−1. With dibenzothiophene and carbazole, naphthalene conversion dropped to 38.3 wt% (selectivity to tetralin = 99.6 wt%) at the same experimental conditions. Temperature and pressure were increased to 300°C and 2.94 MPa to enhance naphthalene conversion (97.4 wt%); (selectivity to tetralin = 87.0 wt%). HDS and HDN were complete yet accompanied by a loss in the catalyst activity due to deactivation by coke. [Received: December 11, 2017; Accepted: May 9, 2018]