Catalytic production of light olefins rich in propylene

• US 6,222,087 B1
• Filed: 07/12/1999
• Issued: 04/24/2001
• Est. Priority Date: 07/12/1999
• Status: Expired due to Fees

• Current Assignee: Mobil Oil Corporation (Exxon Mobil Corporation)
• Original Assignee: Mobil Oil Corporation (Exxon Mobil Corporation)
• Inventors: Johnson, David L., Nariman, Khushrav E., Ware, Robert A.
• Primary Examiner(s): Griffin, Walter D.
• Assistant Examiner(s): Dang, Thuan D.
• Application Number:
  US09/351,146
• Time in Patent Office: 652 Days
• Field of Search: 585/653, 585/651, 585/649, 208/114, 208/120.01
• US Class Current: 585/651
• CPC Class Codes: C10G 11/05 Crystalline alumino-silicates, e.g. molecular sieves
• CPC Class Codes: C10G 2400/20 C2-C4 olefins

Abstract

A hydrocarbon feed containing C_4-C₇ olefins and/or paraffins is converted to light olefins, by contacting the feed with a catalyst containing ZSM-5 and/or ZSM-11, having an initial silica to alumina ratio greater than about 300:1, and phosphorus.

Claims

1. A process for converting hydrocarbon feed which includes C₄-C₇ olefins and C₄-C₇ paraffins to a product which includes ethylene and propylene, said process comprising:

contacting said feed with a catalyst which comprises ZSM-5, ZSM-11 zeolites or combination thereof, having an initial silica/alumina ratio greater than 300;

1, and phosphorus under sufficient conditions to convert C₄-C₇ paraffins and C₄-C₇ olefins in said hydrocarbon feed to ethylene and propylene.

2. The process of claim 1 wherein the zeolite makes up about 5 to 75 wt. % of the catalyst, a matrix material makes up about 25 to about 95 wt. % of the catalyst and the phosphorus is present in an amount of about 0.5 to 10 wt. % of the catalyst.

3. The process of claim 2 wherein the matrix material is selected from the group consisting of silica, alumina, silica-alumina, clay and mixtures thereof.

4. The process of claim 1 wherein said contacting is carried out in a dense fluidized bed reactor or a fixed-bed swing reactor.

5. The process of claim 1 wherein said conditions comprise a temperature from about 950°

F. to about 1300°

F., a pressure from about 2 to about 115 psia, a catalyst/hydrocarbon feed weight ratio from about 0.1 to about 10, and a WHSV from about 1 to about 20 hr<sup>−

1</sup>.

6. The process of claim 1 wherein the product comprises propylene and ethylene, with a C₃=/C₂=weight ratio greater than 3, and a C₃ fraction containing greater than 80 wt. % propylene.

7. The process of claim 5 wherein the product has a (C₂=+C₃=)/BTX weight ratio greater than 3.5, based upon a net increase in C₂=, C₃=and BTX relative to the feed.

8. The process of claim 6 wherein the product comprises ethylene plus propylene in an amount greater than 20 wt. % based on total product.

9. The process of claim 6 wherein the product contains less than about 10 wt. % ethane plus propane.

10. The process of claim 1 wherein said

contacting of said feed with said catalyst is carried out in a dense fluidized bed reactor under reaction conditions to produce a product effluent comprising propylene and ethylene; and further comprising;

a. separating the effluent and the catalyst, said catalyst containing coke;

b. regenerating the catalyst containing coke by contact with oxygen-containing gas to produce hot, regenerated catalyst; and

c. recycling the hot, regenerated catalyst to the fluidized bed reactor.