Process for increasing the concentration of normal paraffins in a light naphtha stream

Patent metadata

Field	Value
Publication number	US-2023036734-A1
Application number	US-202217859917-A
Country	US
Kind code	A1
Filing date	Jul 7, 2022
Priority date	Jul 15, 2021
Publication date	Feb 2, 2023
Grant date	—

Abstract

A process increases the concentration of normal paraffins in a feed stream comprising separating a naphtha feed stream into a normal paraffin rich stream and a non-normal paraffin rich stream. A naphtha feed stream may be separated into a normal paraffin stream and a non-normal paraffin stream. An isomerization feed stream is taken from the non-normal paraffin stream and isomerized over an isomerization catalyst to convert non-normal paraffins to normal paraffins and produce an isomerization effluent stream. The isomerization effluent stream may be separated into a propane stream and a C4+ hydrocarbon stream optionally in a single column. The C4+ hydrocarbon stream may be recycled to the step of separating a naphtha feed stream.

First claim

1 . A process for increasing the concentration of normal paraffins in a feed stream comprising:
separating a naphtha feed stream into a normal paraffin stream and a non-normal paraffin stream wherein said non-normal paraffin stream further comprises about 1-30 wt % cyclic hydrocarbons; sending said non-normal paraffin stream to be isomerized reacted over an isomerization catalyst in an isomerization zone at a temperature in a range from about 180° C. to 260° C. to convert non-normal paraffins to normal paraffins and produce an effluent stream.

2 . The process of claim 1 wherein said temperature is a range from about 200 to 260° C.

3 . The process of claim 1 wherein said non-normal paraffin stream is isomerized at a liquid space velocity of about 1.5 to 5.0 l/h and a ratio of hydrogen/hydrocarbon of about 0.5 to 2.5 at an inlet.

4 . The process of claim 1 wherein said isomerization effluent stream comprises a normal paraffin/methane selectivity ratio of about 40-55.

5 . The process of claim 1 wherein said isomerization zone maintains a pressure in the range of about 250-500 psig.

6 . The process of claim 1 wherein said isomerization zone produces about 30-65 wt % normal paraffins.

7 . The process of claim 1 wherein said isomerization zone produces about 30-60 wt % C2-C3 normal paraffins.

8 . The process of claim 1 wherein said effluent stream has an effluent molecular weight/feed molecular weight ratio of about 0.70 to 0.80 wherein said feed is said non-normal paraffin stream.

9 . The process of claim 1 wherein said effluent stream has a normal paraffin/iso paraffin ratio of about 0.8-2.0.

10 . The process of claim 1 wherein said effluent stream has a light paraffin (C2-C3) ratio to methane of about 50-60%.

11 . A process for increasing the concentration of normal paraffins in a feed stream comprising:
separating a naphtha feed stream into a normal paraffin stream and a non-normal paraffin stream comprising less than about 0.5 wt % cyclic hydrocarbons; in an isomerization zone isomerizing an isomerization feed stream taken from the non-normal paraffin stream over an isomerization catalyst at a temperature in a range from about 225 to 260° C. to convert non-normal paraffins to normal paraffins and produce an isomerization effluent stream; separating said isomerization effluent stream into a propane stream and a C4+ hydrocarbon stream wherein said isomerization effluent stream has a normal/iso ratio of about 1-1.7.

12 . The process of claim 1 wherein said C4+ hydrocarbon stream is a C4-C6 hydrocarbon stream.

13 . The process of claim 1 wherein said isomerization effluent stream comprises a normal paraffin/methane selectivity ratio of about 40-55.

14 . The process of claim 1 wherein said isomerization zone maintains a pressure in the range of 450-650 psig.

15 . The process of claim 11 wherein said isomerization zone produces about 30-65 wt % normal paraffins.

16 . The process of claim 14 wherein said effluent stream has a light paraffins (C2-C3) over methane selectivity of about 50-60%.

17 . The process of claim 11 wherein said isomerization effluent stream has a molecular weight ratio to said isomerization feed stream of about 0.70 to 0.80.

18 . The process of claim 11 wherein said process is at a LHSV of about 4-7.5.

19 . The process of claim 11 wherein said isomerization feed stream has an inlet mole ratio of H2/hydrocarbon of about 0.5 to 0.6.

20 . A process for treating a naphtha feed stream comprising:
separating a naphtha feed stream into a normal paraffin stream and a non-normal paraffin stream comprising less than about 0.5 wt % cyclic hydrocarbons; and; in an isomerization zone isomerizing an isomerization feed stream taken from the non-normal paraffin stream over a chlorided alumina catalyst at a temperature in a range from about 225 to 260° C. to convert non-normal paraffins to normal paraffins and produce an isomerization effluent stream.

Assignees

• Uop Llc

Inventors

• Lapinski Mark
• Rokkam Ram Ganesh
• Ploentham Cora Wang
• Funk Gregory

Classifications

• C10G2300/1037

  Hydrocarbon fractions · CPC title

• C10G35/06 Primary

  characterised by the catalyst used · CPC title

• C07C5/2724

  with metals · CPC title

• C07C5/2702

  Catalytic processes not covered by C07C5/2732 - C07C5/31; Catalytic processes covered by both C07C5/2732 and C07C5/277 simultaneously · CPC title

• C07C7/13

  by molecular-sieve technique · CPC title