# US 5,705,731 A · Reactivation of hydrocarbon isomerization catalysts

> Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt

- Number: US 5,705,731 A
- Document ID: US5705731A
- Status: Granted
- Kind: A
- Application number: 08/568,109
- Filed: 1995-12-06
- Granted: 1998-01-06
- Earliest claimed: 1995-12-06
- Assignees: Phillips Petroleum Company
- Inventors: Fan-Nan Lin; Johnnie R. Pierce; John D. Cowan
- Web page: https://patentgrep.com/patent/US5705731A

## CPC

- C07C 5/29: changing the number of carbon atoms in a ring while maintaining the number of rings
- B01J 27/13: Platinum group metals
- B01J 27/32: of catalysts comprising compounds of halogens
- C07C 5/2724: {with metals}
- C07C 5/2791: {with metals}
- C07C 2523/42: Platinum
- Y02P 20/584: Recycling of catalysts
- C07C: ACYCLIC OR CARBOCYCLIC COMPOUNDS
- B01J: CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
- Y02P: CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS

## Abstract

In a process for isomerizing C.sub.4 -C.sub.7 alkanes and/or C.sub.6 -C.sub.7 cycloalkanes which is carried out in the presence of hydrogen gas, a chloride additive (e.g., CCl.sub.4 or C.sub.2 Cl.sub.4) and a supported platinum and chlorine-containing catalyst (e.g., Pt/Cl/Al.sub.2 O.sub.3), the catalyst is intermittently reactivated in two steps: first, the hydrogen to feed hydrocarbon ratio is raised (while the chloride level in the feed is either not changed or lowered), and thereafter the chloride level in the feed is increased. Preferably, the fresh catalyst is also preactivated by contacting it with the hydrocarbon feed wherein the hydrogen to feed hydrocarbon ratio is higher and/or the temperature is lower than what is employed in the subsequent isomerization production cycle.

## Claims

### Claim 1

A process for isomerizing saturated hydrocarbons which comprises the steps of:
(A) contacting (a) a fluid feed mixture comprising (i) at least one saturated feed hydrocarbon selected from the group consisting of alkanes containing 4-7 carbon atoms per molecule and cycloalkanes containing 6-7 carbon atoms per molecule, (ii) hydrogen gas and (iii) at least one chlorinated hydrocarbon with (b) an isomerization catalyst comprising platinum, chlorine and an inorganic support material in a reaction zone at effective isomerization conditions comprising a reaction temperature in the range of about 80.degree. F. to about 500 .degree. F., a molar ratio of hydrogen gas to said at least one saturated feed hydrocarbon in the range of about 0.02:1 to about 10:1, and a content of said at least one chlorinated hydrocarbon in said fluid feed mixture equivalent to a chloride level in the range of about 15 ppm Cl to about 800 ppm Cl, so as to convert a portion of said at least one saturated feed hydrocarbon to at least one saturated product hydrocarbon isomer for a prolonged period of time until said catalyst is partially deactivated;
(B) increasing the molar ratio of hydrogen gas to said at least one saturated feed hydrocarbon at least about 10 percent above said molar ratio employed in step (A) while substantially retaining the remaining operating conditions of step (A), and maintaining the operating conditions of this first reactivation step (B) for a time period of at least about 0.1 hour;
(C) increasing the content of said at least one chlorinated hydrocarbon in said fluid feed mixture at least about 10 percent above said content used in steps (A) and (B) while substantially retaining the remaining operating conditions of step (B), and maintaining the operating conditions of this second reactivation step (C) for a time period of at least about 0.1 hour; and
(D) returning to said effective isomerization conditions employed in step (A), and carrying out this isomerization step (D) using the reactivated catalyst from step (C) until said reactivated catalyst is again partially deactivated.

### Claim 2 (depends on 1)

A process in accordance with claim 1, wherein the pressure in steps (A), (B), (C) and (D) is in the range of about 50 psig to about 2,000 psig.

### Claim 3 (depends on 1)

A process in accordance with claim 1, wherein steps (B), (C) and (D) are repeated at least once.

### Claim 4 (depends on 1)

A process in accordance with claim 1, wherein said at least one saturated feed hydrocarbon is selected from the group consisting of n-butane, n-pentane, n-hexane, n-heptane, 2-methylpentane, 2-methylhexane, 3-methylhexane, methylcyclopentane, cyclohexane, methylcyclohexane and mixtures thereof.

### Claim 5 (depends on 4)

A process in accordance with claim 4, wherein said at least one chlorinated hydrocarbon is selected from the group consisting of chloroalkanes, chloroalkenes and chlorocycloalkanes and contains up to 6 carbon atoms and up to 8 chlorine atoms per molecule.

### Claim 6 (depends on 5)

A process in accordance with claim 5, wherein said at least one saturated feed hydrocarbon is n-butane or n-heptane, and said at least one chlorinated hydrocarbon is carbon tetrachloride or perchloroethylene.

### Claim 7 (depends on 5)

A process in accordance with claim 5, wherein said effective isomerization conditions in steps (A) and (D) comprise a reaction temperature of about 100.degree.-450.degree. F., a molar ratio of hydrogen gas to said at least one saturated feed hydrocarbon of about 0.05:1 to about 6:1, a content of said at least one chlorinated hydrocarbon equivalent to a chloride level of about 15-800 ppm Cl, and a reaction pressure of about 100-800 psig.

### Claim 8 (depends on 5)

A process in accordance with claim 5, wherein the molar ratio of hydrogen to said at least one saturated feed hydrocarbon in steps (B) and (C) is about 20-200% higher than said molar ratio employed in step (A) or, alternatively, step (D).

### Claim 9 (depends on 8)

A process in accordance with claim 8; wherein the chloride level in step (C) is about 20-300% higher than said chloride level employed in step (A) or, alternatively, step (D).

### Claim 10 (depends on 9)

A process in accordance with claim 9, wherein the time period of step (B) is about 0.5 hour to about 15 days and the time period of step (C) is about 0.5 hour to about 15 days.

### Claim 11 (depends on 1)

A process in accordance with claim 1, comprising the additional step (X) of preactivating said isomerization catalyst, before it is employed in step (A), by treating of said catalyst with said fluid feed mixture, wherein (.alpha.) the molar ratio of hydrogen gas to said at least one saturated feed hydrocarbon in step (X) is at least about 20 percent higher than said molar ratio employed in step (A), or wherein (.beta.) the reaction temperature in step (X) is at least about 5.degree. F. lower than said reaction temperature employed in step (A), or wherein both operating parameters (.alpha.) and (.beta.) are applied in step (X).

### Claim 12 (depends on 11)

A process in accordance with claim 11, wherein the pressure in steps (X), (A), (B), (C) and (D) is in the range of about 50 psig to about 2,000 psig.

### Claim 13 (depends on 12)

A process in accordance with claim 12, wherein said at least one saturated feed hydrocarbon is selected from the group consisting of n-butane, n-pentane, n-hexane, n-heptane, 2-methylpentane, 2-methylhexane, 3-methylhexane, methylcyclopentane, cyclohexane, methylcyclohexane and mixtures thereof.

### Claim 14 (depends on 13)

A process in accordance with claim 13, wherein said at least one chlorinated hydrocarbon is selected from the group consisting of chloroalkanes, chloroalkenes and chlorocycloalkanes and contains up to 6 carbon atoms and up to 8 chlorine atoms per molecule.

### Claim 15 (depends on 14)

A process in accordance with claim 14, wherein (.alpha.) said molar ratio of hydrogen gas to said at least one saturated feed hydrocarbon in step (X) is about 50-500% higher than said molar ratio employed in step (A) , or wherein (.beta.) said reaction temperature employed in step (X) is about 20.degree.-40.degree. F. lower than said reaction temperature in step (A), or wherein both operating parameters (.alpha.) and (.beta.) are applied in step (X), and wherein step (X) is carried out for at least 4 hours.

### Claim 16

A process for isomerizing saturated hydrocarbons which comprises the steps of:
contacting (a) a fluid feed mixture comprising (i) at least one saturated feed hydrocarbons elected from the group consisting of alkanes containing 4-7 carbon atoms per molecule and cycloalkanes containing 6-7 carbon atoms per molecule, (ii) hydrogen gas and (iii) at least one chlorinated hydrocarbon with (b) an isomerization catalyst comprising platinum, chlorine and an inorganic support material in a reaction zone at effective isomerization conditions comprising a reaction temperature in the range of about 80.degree. F. to about 500.degree. F., a molar ratio of hydrogen gas to said at least one saturated feed hydrocarbon in the range of about 0.02:1 to about 10:1, and a content of said at least one chlorinated hydrocarbon in said fluid feed mixture equivalent to a chloride level in the range of about 15 ppm Cl to about 800 ppm Cl, so as to convert a portion of said at least one saturated feed hydrocarbon to at least one saturated product hydrocarbon isomer for a prolonged period of time until said catalyst is partially deactivated;
(B) increasing the molar ratio of hydrogen gas to said at least one saturated feed hydrocarbon at least about 10 percent above said molar ratio employed in step (A) and lowering by at least about 5 percent the content of said at least one chlorinated hydrocarbon in said fluid feed mixture employed in step (A) while substantially retaining the remaining operating conditions of step (A), and maintaining the operating conditions of this first reactivation step (B) for a period of at least about 0.1 hour;
(C) increasing the content of said at least one chlorinated hydrocarbon in said fluid feed mixture at least about 10 percent above said content used in steps (A) and (B) while substantially retaining the remaining operating conditions of step (B), and maintaining the operating conditions of this second reactivation step (C) for a time period of at least about 0.1 hour; and
(D) returning to said effective isomerization conditions employed in step (A) and carrying out this isomerization step (D) using the reactivated catalyst from step (C) until said reactivated catalyst is again partially deactivated.

### Claim 17 (depends on 16)

A process in accordance with claim 16, wherein the pressure in steps (A), (B), (C) and (D) is in the range of about 50 psig to about 2,000 psig.

### Claim 18 (depends on 16)

A process in accordance with claim 16, wherein steps (B), (C) and (D) are repeated at least once.

### Claim 19 (depends on 16)

A process in accordance with claim 16, wherein said at least one saturated feed hydrocarbon is selected from the group consisting of n-butane, n-pentane, n-hexane, n-heptane, 2-methylpentane, 2-methylhexane, 3-methylhexane, methylcyclopentane, cyclohexane, methylcyclohexane and mixtures thereof.

### Claim 20 (depends on 19)

A process in accordance with claim 19, wherein said at least one chlorinated hydrocarbon is selected from the group consisting of chloroalkanes, chloroalkenes and chlorocycloalkanes and contains up to 6 carbon atoms and up to 8 chlorine atoms per molecule.

### Claim 21 (depends on 20)

A process in accordance with claim 20, wherein said at least one saturated feed hydrocarbon is n-butane or n-heptane, and said at least one chlorinated hydrocarbon is carbon tetrachloride or perchloroethylene.

### Claim 22 (depends on 20)

A process in accordance with claim 20, wherein said effective isomerization conditions in steps (A) and (D) comprise a reaction temperature of about 100.degree.-450.degree. F., a molar ratio of hydrogen gas to said at least one saturated feed hydrocarbon of about 0.05:1 to about 6:1, a content of said at least one chlorinated hydrocarbon equivalent to a chloride level of about 15-800 ppm Cl, and a reaction pressure of about 100-800 psig.

### Claim 23 (depends on 20)

A process in accordance with claim 20, wherein the molar ratio of hydrogen to said at least one saturated feed hydrocarbon in steps (B) and (C) is about 20-200% higher than said molar ratio employed in step (A) or, alternatively, step (D).

### Claim 24 (depends on 23)

A process in accordance with claim 23, wherein the chloride level in step (B) is about 40-90% lower than said chloride level employed in step (A) or, alternatively, step (D), and wherein the chloride level in step (C) is about 20-300% higher than said chloride level employed in step (A) or, alternatively, step (D).

### Claim 25 (depends on 24)

A process in accordance with claim 24, wherein the time period of step (B) is about 0.5 hour to about 15 days and the time period of step (C) is about 0.5 hour to about 15 days.

### Claim 26 (depends on 16)

A process in accordance with claim 16, comprising the additional step (X) of preactivating said isomerization catalyst, before it is employed in step (A), by treating of said catalyst with said fluid feed mixture, wherein (.alpha.) the molar ratio of hydrogen gas to said at least one saturated feed hydrocarbon in step (X) is at least about 20 percent higher than said molar ratio employed in step (A), or wherein (.beta.) the reaction temperature in step (X) is at least about 5.degree. F. lower than said reaction temperature employed in step (A), or wherein both operating parameters (.alpha.) and (.beta.) are applied in step (X).

### Claim 27 (depends on 26)

A process in accordance with claim 26, wherein the pressure in steps (X), (A), (B), (C) and (D) is in the range of about 50 psig to about 2,000 psig.

### Claim 28 (depends on 27)

A process in accordance with claim 27, wherein said at least one saturated feed hydrocarbon is selected from the group consisting of n-butane, n-pentane, n-hexane, n-heptane, 2-methylpentane, 2-methylhexane, 3-methylhexane, methylcyclopentane, cyclohexane, methylcyclohexane and mixtures thereof.

### Claim 29 (depends on 28)

A process in accordance with claim 28, wherein said at least one chlorinated hydrocarbon is selected from the group consisting of chloroalkanes, chloroalkenes and chlorocycloalkanes and contains up to 6 carbon atoms and up to 8 chlorine atoms per molecule.

### Claim 30 (depends on 27)

A process in accordance with claim 27, wherein (.alpha.) said molar ratio of hydrogen gas to said at least one saturated feed hydrocarbon in step (X) is about 50-500 % higher than said molar ratio employed in step (A), or wherein (.beta.) said reaction temperature employed in step (X) is about 20.degree.-40.degree. F. lower than said reaction temperature in step (A), or wherein both operating parameters (.alpha.) and (.beta.) are applied in step (X), and wherein step (X) is carried out for at least for 4 hours.