# US 2018/0022680 A1 · Method for producing acrylic acid

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- Number: US 2018/0022680 A1
- Document ID: US20180022680A1
- Status: Published application
- Kind: A1
- Application number: 15/548,538
- Filed: 2016-01-26
- Published: 2018-01-25
- Earliest claimed: 2015-02-05
- Assignees: Nippon Shokubai Co., Ltd.
- Applicants: Nippon Shokubai Co., Ltd.
- Inventors: Toyofumi SAKAI; Masashi MUKAE; Yasutaka TAKEMOTO
- Web page: https://patentgrep.com/patent/US20180022680A1

## CPC

- C07C 51/44: by distillation
- B01D 3/26: Fractionating columns in which vapour and liquid flow past each other, or in which the fluid is sprayed into the vapour, or in which a two-phase mixture is passed in one direction
- B01D 3/40: Extractive distillation
- C07C 57/04: Acrylic acid; Methacrylic acid
- B01D 3/322: {Reboiler specifications}
- B01D 3/324: {Tray constructions}
- C07C 31/202: {Ethylene glycol}
- C07D 307/60: Two oxygen atoms, e.g. succinic anhydride
- C07C: ACYCLIC OR CARBOCYCLIC COMPOUNDS
- B01D: SEPARATION (separating solids from solids by wet methods B03B, B03D; by pneumatic jigs or tables B03B; by other dry methods B07; magnetic or electrostatic separation of solid materials from solid materials or fluids, separation by high-voltage electric fields B03C; centrifuges, vortex apparatus B04; presses per se for squeezing-out liquid from liquid-containing material B30B9/02; treatment of water C02F, e.g. softening by ion-exchange C02F1/42; {arrangements of air intake cleaners in gas turbine plants F02C7/05} ; arrangements or mounting of filters in air-conditioning, air-humidification or ventilation F24F13/28)
- C07D: HETEROCYCLIC COMPOUNDS (macromolecular compounds C08)

## Abstract

The objective of the present invention is to provide a method for efficiently producing acrylic acid while troubles not only in a waste oil handling after distillation of acrylic acid but also in a purification system of acrylic acid during distillation are reduced. The method for producing acrylic acid according to the present invention is characterized in comprising the step of supplying at least crude acrylic acid and an alcohol solvent to an acrylic acid distillation apparatus to distill acrylic acid, wherein a boiling point of the alcohol solvent is higher than a boiling point of acrylic acid by not lower than 50° C.

## Claims

### Claim 1

A method for producing acrylic acid,
comprising the step of supplying at least crude acrylic acid and an alcohol solvent to an acrylic acid distillation apparatus to distill acrylic acid,
wherein a boiling point of the alcohol solvent is higher than a boiling point of acrylic acid by not lower than 50° C.

### Claim 2 (depends on 1)

The method according to claim 1, wherein the crude acrylic acid and the alcohol solvent are mixed to obtain a mixture and the mixture is supplied to the acrylic acid distillation apparatus.

### Claim 3 (depends on 1)

The method according to claim 1, wherein the crude acrylic acid and the alcohol solvent are separately supplied to the acrylic acid distillation apparatus.

### Claim 4 (depends on 1)

The method according to claim 1, wherein a supply amount of the alcohol solvent is adjusted to 1.0 mass % or more to a total amount of maleic acid and maleic anhydride in the crude acrylic acid.

### Claim 5 (depends on 1)

The method according to claim 1, wherein a polyhydric alcohol is used as the alcohol solvent.

### Claim 6 (depends on 5)

The method according to claim 5, wherein ethylene glycol is used as the alcohol solvent.

### Claim 7 (depends on 2)

The method according to claim 2, wherein a supply amount of the alcohol solvent is adjusted to 1.0 mass % or more to a total amount of maleic acid and maleic anhydride in the crude acrylic acid.

### Claim 8 (depends on 3)

The method according to claim 3, wherein a supply amount of the alcohol solvent is adjusted to 1.0 mass % or more to a total amount of maleic acid and maleic anhydride in the crude acrylic acid.

### Claim 9 (depends on 4)

The method according to claim 4, wherein a polyhydric alcohol is used as the alcohol solvent.

### Claim 10 (depends on 9)

The method according to claim 9, wherein ethylene glycol is used as the alcohol solvent.