# US 4,396,492 A · Method for retarding corrosion in petroleum processing operation using N-methyl pyrrolidone

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- Number: US 4,396,492 A
- Document ID: US4396492A
- Status: Granted
- Kind: A
- Application number: 06/317,760
- Filed: 1981-11-03
- Granted: 1983-08-02
- Earliest claimed: 1981-11-03
- Assignees: Exxon Research & Engineering Co.
- Inventors: Ewa A. Bardasz
- Web page: https://patentgrep.com/patent/US4396492A

## CPC

- C10G 21/20: Nitrogen-containing compounds
- C10G 21/12: Organic compounds only
- C10G: CRACKING HYDROCARBON OILS; PRODUCTION OF LIQUID HYDROCARBON MIXTURES, e.g. BY DESTRUCTIVE HYDROGENATION, OLIGOMERISATION, POLYMERISATION (cracking to hydrogen or synthesis gas C01B; cracking or pyrolysis of hydrocarbon gases to individual hydrocarbons or mixtures thereof of definite or specified constitution C07C; cracking to cokes C10B); RECOVERY OF HYDROCARBON OILS FROM OIL-SHALE, OIL-SAND, OR GASES; REFINING MIXTURES MAINLY CONSISTING OF HYDROCARBONS; REFORMING OF NAPHTHA; MINERAL WAXES

## Abstract

This invention is directed to a method of reducing the amount of corrosion resulting in a petroleum process operation wherein N-methyl pyrrolidone is utilized as one of the components by adding an effective corrosion inhibiting amount of an ester additive formed from a polycarboxylic acid and glycol or glycerol, preferably a dimer acid of linoleic acid and diethylene glycol.

## Claims

### Claim 1

In a petroleum process operation wherein N-methyl pyrrolidone is used as one of the components in a hydrocarbon system, the improvement comprising adding an effective corrosion inhibiting amount of an ester additive formed from the combination of a polycarboxylic acid with glycol or glycerol to reduce the formation of corrosion.

### Claim 2 (depends on 1)

The process of claim 1 wherein said ester additive is used in an amount of from about 0.001 to about 10% by weight based on the total weight of the hydrocarbon system.

### Claim 3 (depends on 2)

The process of claim 2 wherein said ester additive is formed from a dicarboxylic acid having from about 9 to about 42 carbon atoms between carboxylic acid groups and a glycol which is selected from the group consisting of alkane diols having from about 2 to about 12 carbon atoms or an oxane-alkane diol having from about 4 to about 200 carbon atoms.

### Claim 4 (depends on 3)

The process of claim 3 wherein said ester additive is used in an amount of from about 0.01 to about 5% by weight based on the total weight of the hydrocarbon system.

### Claim 5 (depends on 4)

The process of claim 4 wherein said ester additive is formed from a dimer acid of a conjugated fatty acid having from about 16 to about 22 carbon atoms between carboxylic acid groups.

### Claim 6 (depends on 5)

The process of claim 5 wherein said ester is formed by esterification of a dimer acid of linoleic acid and diethylene glycol.

### Claim 7 (depends on 6)

The process of claim 6 wherein said ester additive is used in an amount of from about 0.02 to about 3% by weight based on the total weight of the hydrocarbon composition.

### Claim 8 (depends on 4)

The process of claim 4 wherein said process operation is an extraction operation.

### Claim 9 (depends on 8)

The process of claim 8 wherein said ester additive is formed from a dimer acid of a conjugated fatty acid having from about 16 to about 22 carbon atoms between carboxylic acid groups.

### Claim 10 (depends on 9)

The process of claim 9 wherein said ester is formed by esterification of a dimer acid of linoleic acid and diethylene glycol.