Delayed coking process and method of formulating delayed coking feed charge

• US 6,048,448 A
• Filed: 07/01/1997
• Issued: 04/11/2000
• Est. Priority Date: 07/01/1997
• Status: Expired due to Fees

• Current Assignee: El Paso CGP Company LLC (El Paso Corporation)
• Original Assignee: Coastal
• Inventors: Nirell, Kai G.
• Primary Examiner(s): GRIFFIN, WALTER DEAN
• Application Number:
  US08/886,594
• Time in Patent Office: 1,015 Days
• Field of Search: 208/131, 208/50, 208/67, 208/48 R, 208/40, 208/76
• US Class Current: 208/67
• CPC Class Codes: C10G 51/023 only thermal cracking steps
• CPC Class Codes: C10G 9/005 Coking (in order to produce liquid products mainly)
• CPC Class Codes: C10G 9/007 Visbreaking

Abstract

A process for upgrading petroleum residua to more valuable products by visbreaking or otherwise thermally cracking a petroleum residuum to produce a thermally cracked bottoms stream, vacuum distilling at least a portion of the thermally cracked bottoms stream to produce a vacuum distilled thermally cracked pitch, blending a portion of the pitch with a hydrocarbon residuum that is not a vacuum distilled thermally cracked pitch to produce a delayed coker feed component, producing a delayed coker heater charge having a recycle ratio, by weight, of less than about 1.27:1, and introducing the coker heater charge into a delayed coker.

Claims

1. A process for upgrading hydrocarbon residua to more valuable products, comprising:

thermally cracking a petroleum residuum selected from the group consisting of atmospheric-reduced crudes, virgin-reduced crudes, vacuum tower bottoms, and mixtures thereof to produce a thermally cracked bottoms stream;

vacuum distilling at least a portion of said thermally cracked bottoms stream to produce a vacuum distilled thermally cracked pitch (VFP) stream;

blending at least a portion of said VFP stream with at least one of said petroleum residua to produce a delayed coker feed component, the concentration of said VFP stream in said delayed coker feed component being from about 15% by weight to about 85% by weight, said blending being conducted under conditions to maintain said delayed coker feed component substantially homogeneous;

producing a delayed coker heater charge having a recycle weight ratio of less than about 1.27;

1; and

introducing said coker heater charge into a delayed coker.

2. The process of claim 1 wherein said petroleum residuum comprises a vacuum towers bottoms stream.

3. The process of claim 1 wherein the concentration of said VFP stream in said delayed coker feed component is from about 25% by weight to about 75% by weight.

4. The process of claim 1 wherein said recycle ratio is less than about 1.22:

1.

5. The process of claim 1 wherein said thermally cracked bottoms stream is a visbreaker bottoms stream.

6. In a process of delayed coking wherein a coker charge is fed to a delayed coker to produce coke and a recycle stream containing heavy coker gas oil that is fed to a coker fractionator, the improvement comprising:

thermally cracking a petroleum residuum selected from the group consisting of atmospheric-reduced crudes, virgin-reduced crudes, vacuum tower bottoms, and mixtures thereof to produce a thermally cracked bottoms stream;

vacuum distilling at least a portion of said thermally cracked bottoms stream to produce to a vacuum distilled thermally cracked pitch (VFP) stream;

blending at least a portion of said VFP stream with at least one of said petroleum residua to produce a delayed coker feed component, the concentration of said VFP stream in said delayed coker feed component being from about 15% by volume to about 85% by weight, said blending being conducted under conditions to maintain said delayed coker feed component substantially homogeneous;

forming a delayed coker heater charge comprising said delayed coker feed component and at least a portion of the heavy coker gas oil in said recycle stream, said coker charge comprising a weight ratio of coker feed component plus said portion of said heavy coker gas oil to said coker feed component of less than about 1.27;

1.

7. The process of claim 6 wherein said petroleum residuum comprises a vacuum towers bottoms stream.

8. The process of claim 6 wherein the concentration of said VFP stream in said delayed coker feed component is from about 25% by weight to about 75% by weight.

9. The process of claim 6 wherein said recycle ratio is less than about 1.22:

1.

10. The process of claim 6 wherein said thermally cracked bottoms stream is a visbreaker bottoms stream.