Development of Hydrocracking Catalyst to Produce High Quality Clean Middle Distillates

A novel hydrocracking Ni-W binary catalyst was tentatively designed and prepared by means of impregnation on mixed supports of modified Y zeolite and amorphous aluminosilicate. The structure and properties of catalyst were extensively characterized by XRD, NH3-TPD, IR and XRF techniques. The performance of catalyst was evaluated by a 100-ml hydrogenation laboratory test unit with two single-stage fixed-bed reactors connected in series. The characterization results showed that the catalyst has a developed and concentrated mesopores distribution, suitable acid sites and acid strength distribution, and uniform and high dispersion of metal sites. Under a high conversion rate of 73.8% with the ＞350℃ feedstock, a 98. 1m% of C5+yield and 83.5% of middle distillates selectivity were obtained. The yield of middle distillates boiling between 140℃and 370℃ was 68.70m% and its quality could meet the WWFC category Ⅲ specification. It means that this catalyst could be used to produce more high quality clean middle distillates derived from heavy oil hydrocracking. The potential aromatic content of heavy naphtha from 65℃ to 140℃ was 37.5m%. The BMCI value of ＞370℃ tail oil was 6.6. The heavy naphtha and tail oil are premium feedstocks for catalytic reforming and steam cracker units.