# US 4,397,737 A · Heat exchanger antifoulant

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- Number: US 4,397,737 A
- Document ID: US4397737A
- Status: Granted
- Kind: A
- Application number: 06/352,817
- Filed: 1982-02-26
- Granted: 1983-08-09
- Earliest claimed: 1982-02-26
- Assignees: Chevron Research Company
- Inventors: Louis R. Kray
- Web page: https://patentgrep.com/patent/US4397737A

## CPC

- C10G 9/16: Preventing or removing incrustation
- 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

Disclosed is a process for reducing the fouling in a heat exchanger in which a hydrocarbon stream is heated or cooled as it passes through the heat exchanger. From 1 to 500 parts per million of poly(oxyalkylene) carbamate is added to the stream to reduce fouling.

## Claims

### Claim 1

A process for reducing heat exchanger fouling in which a liquid hydrocarbon stream is passed through a heat exchanger at a temperature from 0.degree. to 1500.degree. F. wherein from 1 to 500 parts per million of a poly(oxyalkylene) carbamate is added to said hydrocarbon stream.

### Claim 2 (depends on 1)

The process of claim 1 wherein said liquid hydrocarbon stream is crude oil and is passed through said heat exchanger at a temperature from 50.degree. to 500.degree. F.

### Claim 3 (depends on 1)

The process of claim 1 wherein said hydrocarbon stream is a coker feed and is passed through said heat exchanger at a temperature from 600.degree. to 1000.degree. F.

### Claim 4 (depends on 1, 2, 3)

The process of claim 1, 2 or 3 wherein said hydrocarbon stream has a sulfur content of from 0.1 to 5.0 weight percent.

### Claim 5 (depends on 1)

The process of claim 1 wherein 2 to 99 parts per million of said additive are added to said stream.

### Claim 6 (depends on 1)

The process of claim 1 wherein 5 to 29 parts per million of said poly(oxyalkylene) carbamate is added to said stream.

### Claim 7 (depends on 6)

The process of claim 6 wherein said heat exchanger is a shell and tube heat exchanger.

### Claim 8 (depends on 1)

The process of claim 1 wherein said poly(oxyalkylene) carbamate has at least one C.sub.1 -C.sub.30 hydrocarbyloxyterminated poly(oxyalkylene) chain of 2 to 5 carbon oxyalkylene units bonded through an oxycarbonyl group to a nitrogen atom of a polyamine; said polyamine having from 2 to 10 amine nitrogens and from 2 to 40 carbon atoms, said carbamate having a molecular weight of from about 500 to 10,000.

### Claim 9 (depends on 8)

The process of claim 8 wherein the oxyalkylene units contain 3 to 4 carbon atoms.

### Claim 10 (depends on 8)

The process of claim 8 wherein the molecular weight is from about 800 to 5000.

### Claim 11 (depends on 8)

The process of claim 8 wherein the group terminating the poly(oxyalkylene) chain is an alkoxy group containing from 2 to 20 carbon atoms.

### Claim 12 (depends on 8)

The process of claim 8 wherein the group terminating the polyoxyalkylene chain is an aryloxy group of 6 to 20 carbon atoms.

### Claim 13 (depends on 11)

The process of claim 11 wherein the alkoxy group contains 16 to 20 carbon atoms.

### Claim 14 (depends on 13)

The process of claim 13 wherein the alkoxy group comprises a mixture of C.sub.16, C.sub.18 and C.sub.20 carbon groups.

### Claim 15 (depends on 9)

The process of claim 9 wherein the amine is ethylenediamine.

### Claim 16 (depends on 9)

The process of claim 9 wherein the amine is diethylenetriamine.