Mild hydrocracking process employing catalysts containing dealuminated y-zeolites

• US 5,342,507 A
• Filed: 04/16/1993
• Issued: 08/30/1994
• Est. Priority Date: 06/11/1992
• Status: Expired due to Fees

• Current Assignee: Texaco Incorporated (Chevron Corp.)
• Original Assignee: Texaco Incorporated (Chevron Corp.)
• Inventors: Sherwood, David E. Jr., Dai, Pei-Shing E., Campbell, Charles N. II, Martin, Bobby R.
• Primary Examiner(s): Myers, Helane
• Application Number:
  US08/046,706
• Time in Patent Office: 501 Days
• Field of Search: 208/111, 208/112
• US Class Current: 208/111.15
• CPC Class Codes: B01J 29/166 Y-type faujasite
• CPC Class Codes: C10G 47/20 the catalyst containing other metals or compounds thereof

Abstract

A mild hydrocracking process for the hydrodemetallation (HDM), hydrodesulfurization (HDS) and hydroconversion (HC) of hydrocarbon feedstocks such as residuum feedstocks which provides increased conversion of heavy hydrocarbons boiling above 1000° F. into products boiling below 1000° F. as well as increased yields of middle distillates is disclosed. The process utilizes a catalyst comprising about 1.0 to about 6.0 wt. % of an oxide of a Group VIII metal, about 12.0 to about 25.0 wt. % of an oxide of molybdenum and 0 to about 5.0 wt. % of an oxide of phosphorus supported on a porous support comprising precipitated alumina or silica-containing alumina and dealuminated Y-zeolite.

Claims

1. A process for mild hydrocracking of a hydrocarbon feedstock having a substantial proportion of components boiling below about 1000°

F., said process comprising contacting said hydrocarbon feedstock under conditions of elevated temperature and a hydrogen pressure of less than about 1500 psig with a particulate catalyst comprising about 1.0 to about 6.0 wt. % of an oxide of a Group VIII metal;

about 12.0 to about 25.0 wt. % of an oxide of molybdenum and 0 to about 5.0 wt. % of an oxide of phosphorus all supported on a porous support comprising (1) a matrix selected from the group consisting of precipitated alumina and silica-alumina containing about 1.0 to about 3.0 wt. % of silica and (2) about 5.0 to about 35 wt. %, based on the weight of the support, dealuminated Y-zeolite having a silica to alumina mole ratio of 10 to 32, a unit cell size of 24.29 to 24.48, in such a manner that the molybdenum gradient of the catalyst ranges from about 1 to about 10, said conditions being such as to yield about a 10 to about a 60 Vol % conversion of the hydrocarbon feedstock boiling above 650°

F. to hydrocarbon products boiling at or below 650°

F., wherein the said catalyst is further characterized by having a total surface area of about 200 to about 350 m² /g and a total pore volume of about 0.55 to about 0.75 cc/g, with a pore volume distribution such that micropores having diameters less than 100 Å

constitute less than 40% pores having diameters of 100-160 Å

constitute about 10 to about 55%, pores having diameters greater than 160 Å

constitute about 25 to about 55%, macropores having diameters greater than 25O Å

constitute about 15 to about 45% of the total pore volume.

2. The process of claim 1 wherein the said hydrocarbon feedstock is contacted with said catalyst in a fixed bed reactor.

3. The process of claim 1 wherein the said hydrocarbon feedstock is contacted with said catalyst in a single ebullated bed reactor.

4. The process of claim 1 wherein the said hydrocarbon feed is contacted with said catalyst in a series of 2-5 ebullated bed reactors.

5. The process of claim 1 wherein the said hydrocarbon feed is contacted with said catalyst in a series of 2-5 continuous stirred tank reactors.

6. The process of claim 1 wherein the said hydrocarbon feed is contacted with said catalyst in a single continuous stirred tank reactor.

7. The process of claim 1 wherein the catalyst is further characterized by having about 40 to about 65% of the total pore volume in pores of diameters from about 20 Angstroms below the pore mode diameter to about 20 Å

above the pore mode diameter and the pore mode diameter is in the range of about 65 to about 120 Å

as measured by mercury porosimetry.