Esterification unit for producing crude methyl methacrylate, esterification process using said unit and plant comprising said unit

Patent metadata

Field	Value
Publication number	US-11084774-B2
Application number	US-201816159802-A
Country	US
Kind code	B2
Filing date	Oct 15, 2018
Priority date	Oct 18, 2013
Publication date	Aug 10, 2021
Grant date	Aug 10, 2021

Abstract

The invention relates to an esterification unit (150) and esterification process for producing crude methyl methacrylate (MMA) from methacrylamide (MAM), which enable particularly to improve the yield, meaning that the organics spent acids are low; and at the same time, providing crude MMA with rather good quality, meaning that MMA concentration in crude MMA is rather high and preferably from 50 wt % to 80 wt %. According to the invention, the esterification unit comprises esterification reactors (1, . . . , 5 (or 6) set up in a serial way so that there is a counter current flow between gaseous phase and liquid phase, the liquid phase flowing from first reactor (1) of the series to last reactor (5 (or 6)), and the gaseous phase flowing from reactor to first reactor (1).

First claim

What is claimed is:

1. An esterification process for producing crude methyl methacrylate (MMA) from methacrylamide (MAM), and at least methanol and water comprising a series of linked reactors ( 1 , n, n+1, . . . N) wherein “n” represents the number of each reactor in the series of reactors ( 1 , 2 , 3 , 4 , 5 etc.), and “N” represents the last reactor in the series, each reactor having an upper part and a lower part, wherein the reactors are set up in a serial way so that there is a counter current flow between a gaseous phase and a liquid phase, the liquid phase flowing from a first reactor ( 1 ) of the series toward a last reactor (N), and the gaseous phase flowing from the last reactor (N) toward the first reactor ( 1 ), the first reactor of the series comprising:
methacrylamide, methanol and water lateral inlets,

the last reactor comprising a lateral steam inlet located at the lower part,
and each reactor also comprising:
at least a liquid phase outlet located at the bottom of the lower part,
at least a gaseous phase outlet, at the top of the upper part,
at least a gaseous phase inlet at the lower part, the reactors being connected in such a manner that the gaseous phase outlet of reactor (n+1) is linked to the gaseous phase inlet of reactor (n) with the exception of the last reactor, wherein the at least a gaseous phase inlet is the lateral steam inlet,
at least a lateral liquid phase inlet located at the lower part, the reactors being connected in such a manner that the liquid phase outlet of reactor (n) is linked to the lateral liquid phase inlet of the reactor (n+1) with the exception of the first reactor, wherein the at least a lateral liquid phase inlet includes the methacrylamide, methanol, and water lateral inlets,
at least another lateral liquid phase inlet located at the lower part, the liquid phase
outlet of reactor (n) being linked to said another lateral liquid phase inlet of said reactor (n);
wherein said series of linked reactors further comprises an additional reactor (N+1) comprising:
at least a first and a second lateral liquid phase inlet located at the lower part,
at least a gaseous phase outlet at the top of the upper part,
at least a liquid phase outlet located at the bottom of the lower part, and
at least a lateral steam inlet located at the lower part,
said additional reactor (N+1) being connected in a parallel way to the last reactor (N) of the series in such a manner that said additional reactor (N+1) is alternatively linked to a penultimate reactor (N−1), the gaseous phase outlet of the additional reactor (N+1) being linked to a gaseous phase inlet at the lower part of said penultimate reactor (N−1), a liquid phase outlet at the bottom of the lower part of said penultimate reactor (N−1) being linked to the first lateral liquid phase inlet of the additional reactor (N+1), and the liquid phase outlet of said additional reactor (N+1) being linked to the second lateral liquid phase inlet of said additional reactor (N+1);
said process comprising the steps of:
a) introducing methacrylamide, methanol and water through the lateral inlets, wherein the inlets are located in a lower part of the first reactor,
b) extracting a gaseous phase from the top of the reactors via the at least a gaseous phase outlets and introducing said gaseous phase of reactor (n+1) into the at least a gaseous phase inlet at the lower part of reactor (n), with a distributor located inside reactor (n) for mixing said gaseous phase with the liquid flow, wherein said distributor comprises a pipe running horizontally from a lateral wall of the reactor to the middle of the reactor with the end located in the middle of the reactor comprising at least three nozzles in the liquid phase, with at its end at least three nozzles in the liquid phase, wherein said distributor,
c) extracting the liquid phase from the bottom of the reactors via the liquid phase outlets,
d) introducing at least a portion of said liquid phase of reactor (n) into the reactor (n+1) via the at least a lateral liquid phase inlet located at the lower part of reactor (n+1), and
e) introducing steam laterally into the last reactor via the lateral steam inlet located in the lower part of the last reactor.

2. The esterification process for producing crude methyl methacrylate according to claim 1 further comprising the step of partially recycling the liquid phase of reactor (n) to the same reactor (n) via the at least another lateral liquid inlet located at the lower part of same reactor (n to ensure miring of the liquid phase and the gaseous phase and, transferring the remaining part of the liquid phase to the next reactor (n+1) after filtering small polymers from said liquid phase.

3. The esterification process for producing crude methyl methacrylate according to claim 1 , comprising the steps of separating in a first separation, liquid methacrylic acid from crude MMA in the gaseous phase obtained from the gaseous phase outlet at the top of the upper part of the first reactor and recycling said methacrylic acid by feeding through a lateral liquid inlet of said first reactor, thereby providing 60 to 70 wt % crude MMA, and separating in a second separation of methacrylic acid from the gaseous phase after the first separation to get crude MMA containing mainly 50 wt % to $0 wt % of MMA, 10 wt % to 20 wt % of water and 10 wt % to 20 wt % of the total of methanol and impurities.

4. The esterification process for producing crude methyl methacrylate according to claim 1 comprising the step of: controlling a liquid level (L) of each reactor, and maintaining said liquid level by regulating the flow introduction of the liquid phase to each reactor and controlling said liquid level (L) to between 25% to 75% of the total height of the reactor.

5. The esterification process for producing crude methyl methacrylate according to claim 1 , comprising the step of controlling the steam flow into the last reactor according to a predetermined flowrate.

6. The esterification process for producing crude methyl methacrylate according to claim 3 , further comprising the steps of introducing an anti-fouling additive and/or polymerization inhibitors, to at least said first reactor, said polymerization inhibitors comprising water soluble or alcohol soluble polymerization inhibitors, and introducing said polymerization inhibitors at the first separation of acids-methacrylic acid from crude MMA.

Assignees

• Arkema France
• Trinseo Europe Gmbh

Inventors

• Bernardin Yves
• Billon Romain
• Marcarian Xavier
• Vallet Florent

Classifications

• B01J10/00

  Chemical processes in general for reacting liquid with gaseous media other than in the presence of solid particles, or apparatus specially adapted therefor (B01J19/08 takes precedence; separation, e.g. distillation, also combined with chemical reactions B01D, {e.g. B01D3/009}) · CPC title

• B01J19/245

  placed in series · CPC title

• B01J19/1862

  placed in series · CPC title

• B01J4/002

  Nozzle-type elements (nozzle-type reactors B01J19/26) · CPC title

• C07C67/20 Primary

  from amides or lactams · CPC title