# US 11,078,140 B2 · Process for producing 1,3-butanediol and for optionally further producing (R)-3-hydroxybutyl (R)-3-hydroxybutyrate

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- Number: US 11,078,140 B2
- Document ID: US11078140B2
- Status: Granted
- Kind: B2
- Application number: 17/008,640
- Filed: 2020-09-01
- Published: 2020-12-24
- Granted: 2021-08-03
- Earliest claimed: 2016-01-06
- Assignees: Archer Daniels Midland Company
- Applicants: Archer Daniels Midland Company
- Inventors: Paul D. Bloom; Chi-Cheng Ma; Kevin J. Martin; Brennan Smith
- Web page: https://patentgrep.com/patent/US11078140B2

## CPC

- C07C 29/149: with hydrogen or hydrogen-containing gases
- B01J 23/72: Copper
- B01J 25/00: Catalysts of the Raney type
- B01J 25/02: Raney nickel
- C07C 67/03: by reacting an ester group with a hydroxy group
- C07C 67/08: by reacting carboxylic acids or symmetrical anhydrides with the hydroxy or O-metal group of organic compounds
- C07B 2200/07: Optical isomers
- C07C: ACYCLIC OR CARBOCYCLIC COMPOUNDS
- B01J: CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
- C07B: GENERAL METHODS OF ORGANIC CHEMISTRY; APPARATUS THEREFOR (preparation of carboxylic acid esters by telomerisation C07C67/47; telomerisation C08F)

## Abstract

A process is described for producing 1,3-butanediol, wherein an ester of poly-(R)-3-hydroxybutyrate such as formed by transesterification with an alcohol is reduced by hydrogenation in the presence of a skeletal copper-based catalyst to provide 1,3-butanediol. The 1,3-butanediol may be transesterified by reaction with additional poly-(R)-3-hydroxybutyrate ester to produce (R)-3-hydroxybutyl (R)-3-hydroxybutyrate.

## Claims

### Claim 1

A process for producing 1,3-butanediol, comprising contacting an ester of poly-(R)-3-hydroxybutyrate with a source of hydrogen in the presence of a skeletal copper-based catalyst under elevated temperature conditions, wherein the term ester of poly-(R)-3-hydroxybutyrate refers to an ester formed by reaction of poly-(R)-3-hydroxybutyrate with an alcohol and wherein the term skeletal copper-based catalyst refers to a porous catalytic alloy based material comprising copper and aluminum.

### Claim 2 (depends on 1)

The process of claim 1, wherein the ester of poly-(R)-3-hydroxybutyrate is a methyl, ethyl, propyl, butyl, pentyl or hexyl ester.

### Claim 3 (depends on 2)

The process of claim 2, wherein the ethyl ester is used.

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

The process of any one of claims 1-3, wherein the process is conducted continuously, using a fixed catalyst bed.

### Claim 5 (depends on 4)

The process of claim 4, wherein the skeletal copper-based catalyst is a promoted or unpromoted copper-aluminum alloy catalyst containing from 10 to 60 weight percent of aluminum and with the balance consisting of copper and any promoters present.

### Claim 6 (depends on 5)

The process of claim 5, wherein the catalyst contains from 20 to 55 weight percent of aluminum.

### Claim 7 (depends on 1)

The process of claim 1, conducted at a reactor temperature between 120 degrees Celsius and 220 degrees Celsius, a liquid hourly space velocity of from 0.1 hr−1 to 2 hr−1 and a hydrogen supply at a pressure of from 5.5 MPa, gauge to 17.2 MPa, gauge.

### Claim 8 (depends on 7)

The process of claim 7, conducted at a reactor temperature between 150 degrees Celsius and 220 degrees Celsius, a liquid hourly space velocity of from 0.2 hr−1 to 1 hr−1 and a hydrogen supply at a pressure of from 8.3 MPa, gauge to 12.4 MPa, gauge.

### Claim 9 (depends on 8)

The process of claim 8, conducted at a reactor temperature between 160 degrees Celsius and 200 degrees Celsius, a liquid hourly space velocity of from 0.2 hr−1 to 1 hr−1 and a hydrogen supply at a pressure of from 9.7 MPa, gauge to 12.4 MPa, gauge.

### Claim 10 (depends on 1, 2, 3, 4, 5, 6, 7, 8, 9)

A process for producing (R)-3-hydroxybutyl (R)-3-hydroxybutyrate, comprising:
contacting poly-(R)-3-hydroxybutyrate with an alcohol under transesterification conditions for transesterifying the poly-(R)-3-hydroxybutyrate and producing an ester of the alcohol and poly-(R)-3-hydroxybutyrate;
separating the product of the transesterification step into first and second portions comprising the ester of the alcohol and poly-(R)-3-hydroxybutyrate;
reducing the first portion of the poly-(R)-3-hydroxybutyrate ester through a process according to any one of claims 1-9 to produce 1,3-butanediol;
contacting the 1,3-butanediol with the second portion of the poly-(R)-3-hydroxybutyrate ester under transesterification conditions for producing (R)-3-hydroxybutyl (R)-3-hydroxybutyrate.