# US 4,393,256 A · Hydration of olefins

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- Number: US 4,393,256 A
- Document ID: US4393256A
- Status: Granted
- Kind: A
- Application number: 06/332,042
- Filed: 1981-12-17
- Granted: 1983-07-12
- Earliest claimed: 1981-12-17
- Assignees: Uop LLC
- Inventors: Robert J. Schmidt
- Web page: https://patentgrep.com/patent/US4393256A

## CPC

- C07C 29/06: the acid being sulfuric acid
- C07C 41/01: Preparation of ethers
- C07C 41/34: Separation; Purification; Stabilisation; Use of additives
- C07C: ACYCLIC OR CARBOCYCLIC COMPOUNDS

## Abstract

Alcohols may be obtained by an indirect hydration of olefinic hydrocarbons in which said olefinic hydrocarbon is esterified by treatment with an inorganic acid to form dialkyl and alkyl hydrogen salts. The esters are then hydrolyzed with water, the reconstituted acid is stripped by means of a stripping agent such as nitrogen gas, and the resulting alcohols and ethers are recovered. The alcohol production is separated from the dialkyl ether, the latter then being subjected to further treatment such as thermal decomposition and hydrolysis to form an additional amount of the desired alcohol. The reconstituted inorganic acid may be recycled for use as an esterifying agent without having to reconstitute the acid.

## Claims

### Claim 1

A process for the hydration of an olefinic hydrocarbon which comprises:
(a) esterifying said olefinic hydrocarbon with a concentrated inorganic acid at esterification conditions in an esterification zone to produce alkyl salts of said acid;
(b) hydrolyzing said alkyl salts of said acid by treatment with water at hydration conditions in a hydration zone to form an alcohol and ether hydrolysis product containing reconstituted inorganic acid;
(c) stripping away alcohol and ether hydrolysis product from said reconstituted inorganic acid and removing said reconstituted inorganic acid from said alcohol and ether hydrolysis product;
(d) separating said alcohol from said ether of said hydrolysis product in a separation zone at separation conditions to form a product alcohol stream and an ether stream;
(e) thermally decomposing said ether in a decomposition zone maintained at a temperature in the range of from about 500.degree. C. to about 750.degree. C. and a pressure in the range of from subatmospheric to about 1500 psi to produce an olefinic hydrocarbon and an additional amount of product alcohol;
(f) recovering said additional amount of product alcohol; and
(g) recycling at least a portion of said olefinic hydrocarbon produced in thermal decomposition step (e) to said esterification as a part of said olefinic hydrocarbon.

### Claim 2 (depends on 1)

The process as set forth in claim 1 in which said esterification conditions include a temperature in the range of from about 50.degree. to about 150.degree. C. and a pressure in the range of from about 200 to about 1500 pounds per square inch.

### Claim 3 (depends on 1)

The process as set forth in claim 1 in which said hydration conditions include a temperature in the range of from about ambient to about 200.degree. C. and a pressure in the range of from about atmospheric to about 1500 psi.

### Claim 4 (depends on 1)

The process as set forth in claim 1 in which said separation conditions include a temperature in the range of from about ambient to about 200.degree. C. and a pressure in the range of from about subatmospheric to about 150 psi.

### Claim 5 (depends on 1)

The process as set forth in claim 1 in which said olefinic hydrocarbon of steps (a) and (e) contains from about 2 to about 4 carbon atoms.

### Claim 6 (depends on 5)

The process as set forth in claim 5 in which said olefinic hydrocarbon is ethylene, said alcohol is ethyl alcohol and said ether is diethyl ether.

### Claim 7 (depends on 5)

The process as set forth in claim 5 in which said olefinic hydrocarbon is propylene, said alcohol is isopropyl alcohol and said ether is diisopropyl ether.

### Claim 8 (depends on 5)

The process as set forth in claim 5 in which said olefinic hydrocarbon is butylene, said alcohol is sec-butyl alcohol and said ether is di-sec-butyl ether.

### Claim 9 (depends on 1)

The process as set forth in claim 1 in which said reconstituted inorganic acid is recycled back to said esterification zone.

### Claim 10 (depends on 1)

The process as set forth in claim 1 in which said inorganic acid separation from said hydrolysis product is effected by treatment with a stripping gas.

### Claim 11 (depends on 10)

The process as set forth in claim 10 in which said stripping gas is nitrogen.