PROCESS FOR INCREASING PRODUCTION OF LIGHT OLEFINS FROM HYDROCARBON FEEDSTOCK IN CATALYTIC CRACKING

• US 20070083071A1
• Filed: 06/01/2006
• Published: 04/12/2007
• Est. Priority Date: 10/07/2005
• Status: Active Grant

• Current Assignee: SK Innovation Company Limited
• Original Assignee: SK Corporation (Kimberly-Clark Corporation)
• Inventors: Kim, Yong, Choi, Sun, Kim, Suk, Park, Deuk, Yang, Il
• Granted Patent: US 7,939,702 B2
• Time in Patent Office: Days
• US Class Current: 585/652
• CPC Class Codes: C10G 11/10 with stationary catalyst bed
• CPC Class Codes: C10G 2300/1044 Heavy gasoline or naphtha having a boiling range of about 100 - 180 °C
• CPC Class Codes: C10G 2300/1051 Kerosene having a boiling range of about 180 - 230 °C
• CPC Class Codes: C10G 2300/301 Boiling range
• CPC Class Codes: C10G 2300/4081 Recycling aspects
• CPC Class Codes: C10G 2300/807 Steam
• CPC Class Codes: C10G 2400/20 C2-C4 olefins
• CPC Class Codes: C10G 51/04 including only thermal and catalytic cracking steps
• CPC Class Codes: Y02P 30/40 Ethylene production

Abstract

Disclosed is a process for increasing production of light olefinic hydrocarbons from hydrocarbon feedstock by catalytic cracking. In the process, an effective separation process structure and recycle method of light olefins are used not only to increase the productivity and efficiency of an overall process, thus effectively increasing the production of light olefins, but also to simplify the overall process.

Claims

1. A process for increasing production of light olefinic hydrocarbons from hydrocarbon feedstock by catalytic cracking, the process comprising the steps of:

(a) feeding hydrocarbon feedstock and steam into a catalytic cracking furnace where the hydrocarbon feedstock is subjected to a catalytic cracking reaction in the presence of a catalyst;

(b) regenerating the catalyst used in the catalytic cracking reaction by a continuous or periodic regeneration procedure and recycling the regenerated catalyst into the catalytic cracking furnace;

(c) quenching, compressing and separating the product of the catalytic cracking reaction, to separate and recover each of hydrogen, methane and C2-C3 olefinic hydrocarbons and to separate into a stream containing C2-C3 paraffinic hydrocarbons and a stream containing C4+ hydrocarbons;

(d) feeding the stream containing C2-C3 paraffinic hydrocarbons into a recycling furnace where it is converted to C2-C3 olefinic hydrocarbons by a thermal cracking reaction, and recycling the converted C2-C3 olefinic hydrocarbons to the quenching step; and

(e) recycling at least a portion of the stream containing C4+ hydrocarbon to the catalytic cracking reaction step, the catalyst regeneration step or both steps.

2. The process of claim 1, wherein the stream containing C4+ hydrocarbons is separated into a stream containing C4-C5 hydrocarbons and a stream containing C6+ hydrocarbons.

3. The process of claim 2, wherein the stream containing C4-C5 hydrocarbons is recycled to the catalytic cracking reaction step.

4. The process of claim 2, wherein a portion of the stream containing C6+ hydrocarbons is recycled to the catalytic cracking reaction step, and the remaining portion can be separated into a stream containing C6-C8 hydrocarbons and a stream containing C9+ hydrocarbons.

5. The process of claim 4, wherein a portion of the stream containing C6-C8 hydrocarbons is recycled to the catalytic cracking reaction step, and the remaining portion is recovered after conversion to an aromatic fraction by hydrodesulfurization.

6. The process of claim 4, wherein a portion of the stream containing C9+ hydrocarbons is recycled to the catalytic cracking reaction, and the remaining portion is recycled to the catalyst regeneration step.

7. The process of claim 1, wherein the hydrocarbon feedstock is naphtha or kerosene.

8. The process of claim 1, wherein the hydrocarbon feedstock is a hydrocarbon mixture having a boiling point of 30-350°

C.

9. The process of claim 1, wherein the catalyst is a zeolite compound.

10. The process of claim 9, wherein the zeolite compound is ZSM-5 zeolite.

11. The process of claim 1, wherein the catalytic cracking reaction is carried out at a temperature of 500-750°

C. and a hydrocarbon feedstock/steam weight ratio of 0.01-10.

12. The process of claim 1, wherein the catalytic cracking reaction is carried out in a fixed-bed reactor or a fluidized-bed reactor.

13. The process of claim 12, wherein, if the catalytic cracking reaction is carried out in the fixed-bed reactor, the catalytic cracking reaction will be carried out at a hydrocarbon feedstock residence time of 0.1-600 seconds.

14. The process of claim 12, wherein, if the catalytic cracking reaction is carried out in the fluidized-bed reactor, the catalytic cracking reaction will be carried out at a hydrocarbon feedstock residence time of 0.1-600 seconds and a catalyst/hydrocarbon feedstock weight ratio of 1-100.