Abstract: A process for the selective surface dealumination of a zeolite having a Constraint Index greater than 1 by contacting the zeolite with dicarboxylic acid, such as oxalic acid.

Abstract: A process for the dealumination of a zeolite having the structure of mordenite by contacting the zeolite with dicarboxylic acid, such as oxalic acid, and steaming. The process is useful for the dealumination of TEA mordenite.

Abstract: A process for the selective surface dealumination of organic-containing zeolites by contacting the zeolite with dicarboxylic acid, such as oxalic acid. The treatment results in a reduction in surface acidity without a significant reduction in overall activity. The organic may be a directing agent used in the zeolite synthesis or introduced into the pores of the zeolite after thermal treatment.

Abstract: Hydroprocessing catalysts of high metal content and surface area are based on a support material comprising a non-layered, ultra-large pore crystalline material. The crystalline material exhibits unusually large pores of at least 13 .ANG. diameter and a high sorption capacity demonstrated by its benzene adsorption capacity of greater than about 15 grams benzene/100 grams at 50 torr and 25.degree. C. and may be characterized by an X-ray diffraction pattern with at least one d-spacing greater than about 18 .ANG.. In a particularly preferred form, the crystalline material has a hexagonal arrangement of pores of at least 13 .ANG. diameter which has an electron diffraction pattern with one line at a d.sub.100 value greater than about 18 .ANG.. The catalysts based on these materials are capable of accommodating high metal loadings while retaining a high surface area with high pore volume and low density.

Abstract: A process for the dealumination of a zeolite having the structure of zeolite Beta by contacting the zeolite with dicarboxylic acid, such as oxalic acid.

Abstract: The equilibration of a zeolitic hydrocracking catalyst is accelerated by the addition of nitrogen compounds to the hydrocracker feed during the start of cycle (SOC). Addition of the nitrogen compounds reduces the exotherm, indicative of a decrease in the hydrogenation activity of the catalyst consequent upon the addition of the nitrogen. The reduced hydrogenation level decreases hydrogen consumption at this point in the cycle so that units which are hydrogen constrained may be operated under more favorable conditions. In addition, the attainment of equilibrium or lineout conditions is accelerated and yield benefits, particularly in the production of middle distillates are observed.