Abstract
While hydrocrackers have an excellent track record processing VGOs and lighter feedstocks, feedstocks heavier than VGO pose significant challenges resulting in diminished unit performance and processing efficiency. Therefore,it has long been the objective of Saudi Aramco to enable its Riyadh Refinery hydrocracker to handle more Demetallized Oil (DMO) and much work has been carried out over the last few years to enhance this capability through process and catalyst modifications. Saudi Aramco’s R&DC and JGC C&C have collaborated to develop a catalyst system to enable the Riyadh Refinery hydrocracking unit to process a blend of VGO and demetalized oil, targeting the extended cycle while increasing or maintaining distillate yields and quality. The developed catalysts are based on Y-zeolite, which is post-treated to improve its performance. The post-treatment methods include dealumination to create meso porosity, and transition metal, i.e., Ti, Zr, insertion into the zeolite lattice to modify the zeolite acidity to enhance distillate selectivity. After extensive R&D work, some formulations were identified as candidates for scale- up and commercialization and the best placement of the selected catalyst prototype in the unit was determined. The catalyst was loaded into the Riyadh Refinery hydrocracking unit in May 2014 and has been performing exceptionally well.
