# US 2017/0283358 A1 · (meth)acrylic acid production process

> Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt

- Number: US 2017/0283358 A1
- Document ID: US20170283358A1
- Status: Published application
- Kind: A1
- Application number: 15/452,757
- Filed: 2017-03-08
- Published: 2017-10-05
- Earliest claimed: 2016-03-29
- Assignees: Arkema France
- Applicants: Arkema France
- Inventors: Sandeep Jain; Christian LACROIX
- Web page: https://patentgrep.com/patent/US20170283358A1

## CPC

- C07C 51/252: {of propene, butenes, acrolein or methacrolein}
- C07C 51/42: Separation; Purification; Stabilisation; Use of additives
- C07C 51/44: by distillation
- G09F 7/18: Means for attaching signs, plates, panels, or boards to a supporting structure
- G09F 9/30: in which the desired character or characters are formed by combining individual elements (panels comprising a number of electrodes in a single cell controlling light arriving from an independent light source, e.g. electro-optical or magneto-optical cell, G02F1/00)
- G09F 2007/1865: {on vehicles}
- C07C: ACYCLIC OR CARBOCYCLIC COMPOUNDS
- G09F: DISPLAYING; ADVERTISING; SIGNS; LABELS OR NAME-PLATES; SEALS

## Abstract

The invention relates to the production of (meth)acrylic acid, and to implementation of a step of condensing water contained in a recycled gas effluent and/or in the air feed in a (meth)acrylic acid production process, which further includes a process for purifying a reaction mixture comprising (meth)acrylic acid without using azeotropic solvent and based on the use of two distillation columns.

## Claims

### Claim 1

A process for production of (meth)acrylic acid, comprising at least the following steps:
i) subjecting at least one (meth)acrylic acid precursor to gas-phase oxidation in the presence of an air feed so as to form a gas reaction mixture comprising (meth)acrylic acid;
ii) cooling the gas reaction mixture;
iii) subjecting the gas reaction mixture to dehydration without using azeotropic solvent in a dehydration column, resulting in a first top gas stream and in a first bottom stream;
at least partly subjecting the first top gas stream distilled at the top of the dehydration column to condensation in a top condenser to form condensate, the condensate being returned to the dehydration column in reflux form to absorb acrylic acid, and at least partly returning gas effluent to the oxidation reaction, and subjecting a remainder to thermal and/or catalytic oxidation;
at least partly subjecting, the first bottom stream from the bottom of the dehydration column to distillation in a finishing column, resulting in a second top stream, and in a second bottom stream containing heavy compounds;
vi) recovering a (meth)acrylic acid stream by drawing off (meth)acrylic acid from a side of the finishing column;
and further applying a water condensation step to at least one of two streams selected from the group consisting of: the air feed for the oxidation reaction of step i), and the gas effluent at an outlet of the top condenser of step iv) which is recycled to the oxidation reaction.

### Claim 2 (depends on 1)

The process according to claim 1, wherein the water condensation step is carried out using a single condenser for the two streams or using a condenser for each of the two streams.

### Claim 3 (depends on 1)

The process according to claim 1, wherein the water condensation step is carried out at a temperature ranging from 15° C. to the temperature of the condenser at the top of the dehydration column.

### Claim 4 (depends on 1)

The process according to claim 1 wherein the step of condensing the water for the recycled gas effluent is carried out at a temperature of between 40° C. and 60° C.

### Claim 5 (depends on 1)

The process according to claim 1 wherein the step of condensing the water for the air feed is carried out at a temperature of between 15° C. and 25° C.

### Claim 6 (depends on 1)

The process according to claim 1 wherein the condensed water from the air feed is at least partly recycled to water cooling towers.

### Claim 7 (depends on 1)

The process according to claim 1 wherein the condensed water is partly used to prepare aqueous solutions of polymerization inhibitors.

### Claim 8 (depends on 1)

The process according to claim 1 wherein the condensed water is partly flushed and sent to the treatment of wastewater, or subjected to a thermal oxidation treatment.

### Claim 9 (depends on 1)

The process according to claim 1 wherein the (meth)acrylic acid precursor is acrolein, obtained by oxidation of propylene or by oxydehydrogenation of propane.

### Claim 10 (depends on 1)

The process according to claim 1 wherein the (meth)acrylic acid precursor is methacrolein obtained by oxidation of isobutylene and/or of tert-butanol or from oxydehydrogenation of butane and/or isobutane.

### Claim 11 (depends on 1)

The process according to claim 1 wherein the (meth)acrylic acid precursor is derived from glycerol, from 3-hydroxypropionic acid or from 2-hydroxypropanoic acid.

### Claim 12 (depends on 1)

The process according to claim 1 wherein the (meth)acrylic acid is acrylic acid and the acrylic acid precursor is acrolein obtained by catalytic oxidation of propylene.