US 10,894,223 B2Granted

Process for isolating pure 2-ethylhexyl acrylate or pure 2-propylheptyl acrylate from the corresponding crude alkyl acrylate by distillation

AssigneeBASF SE

InventorsOrtmund Lang, Bernd Metzen, Claus Hechler

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Abstract

Process for isolating pure 2-ethylhexyl acrylate or pure 2-propylheptyl acrylate from the corresponding crude alkyl acrylate by distillation, wherein the process is carried out in a dividing wall column (1) which has separation-active internals and vaporizer (7) and in which a dividing wall (8) is arranged in the longitudinal direction of the column to form an upper joint column region (9), a lower joint column region (14), an inflow section (10, 12) having a side feed point (2) and an offtake section (11, 13) having a side offtake point (3), the column has a number of theoretical plates in the range from 10 to 60, where the number of theoretical plates of the dividing wall column (1) relates to the sum of the theoretical plates in the joint upper column region (9), the joint lower column region (14) and the inflow section (10, 12), the side feed point (2) for the corresponding crude alkyl acrylate is arranged at a theoretical plate in the region commencing at least two theoretical plates above the bottommost theoretical plate and ending at least two theoretical plates below the uppermost theoretical plate, the side offtake point (3) for the pure 2-ethylhexyl acrylate or pure 2-propylheptyl acrylate is arranged at a theoretical plate in the region commencing at least two theoretical plates above the bottommost theoretical plate and ending at least two theoretical plates below the uppermost theoretical plate and the dividing wall (8) is arranged in the column in the region commencing at least one theoretical plate above the bottommost theoretical plate and ending at least one theoretical plate below the uppermost theoretical plate, where the ratio of amount of liquid at the upper end of the dividing wall (8) going to the enrichment section (10) and the stripping section (11) of the column is set in the range from 1:0.2 to 1:5.

Claims41

Dependent claims

A process for purifying 2-propylheptyl acrylate from a corresponding crude alkyl acrylate, the process comprising:

distilling the corresponding crude alkyl acrylate in a dividing wall column,
wherein the dividing wall column has separation-active internals and a vaporizer and in which a dividing wall is arranged in a longitudinal direction of the dividing wall column to form an upper joint column region, a lower joint column region, an inflow section having a side feed point and a side offtake section having a side offtake point,
wherein the dividing wall column has a number of theoretical plates in the range from 10 to 60, where the number of theoretical plates of the dividing wall column relates to the sum of the theoretical plates in the joint upper column region, the joint lower column region and the inflow section,
wherein in the dividing wall column the side feed point for the corresponding crude alkyl acrylate is arranged at a theoretical plate in a region commencing at least two theoretical plates above a bottommost theoretical plate and ending at least two theoretical plates below an uppermost theoretical plate, the side offtake point for a distilled 2-propylheptyl acrylate is arranged at a theoretical plate in the region commencing at least two theoretical plates above the bottommost theoretical plate and ending at least two theoretical plates below the uppermost theoretical plate, and the dividing wall is arranged in the dividing wall column in a region commencing at least one theoretical plate above the bottommost theoretical plate and ending at least one theoretical plate below the uppermost theoretical plate,
where a ratio of an amount of liquid at the upper end of the dividing wall going to an enrichment section and an amount of liquid at a stripping section of the dividing wall column is in the range from 1:0.2 to 1:5 and a ratio of amounts of a vapor stream at the lower end of the dividing wall going to the stripping section and a vapor stream at the enrichment section of the dividing wall column is in the range from 1:0.5 to 1:2.0, wherein the upper end is above the side feed point and the lower end is below the side offtake point;
and
wherein the distilling includes isolating 2-propylheptyl acrylate having a purity of ≥98.5% by weight from the corresponding crude alkyl acrylate.

4 more elements

A process for purifying 2-ethylhexyl acrylate from a corresponding crude alkyl acrylate, the process comprising:

distilling the corresponding crude alkyl acrylate in a dividing wall column,
wherein the dividing wall column has separation-active internals and a vaporizer and in which a dividing wall is arranged in a longitudinal direction of the dividing wall column to form an upper joint column region, a lower joint column region, an inflow section having a side feed point and a side offtake section having a side offtake point,
wherein the dividing wall column has a number of theoretical plates in the range from 10 to 60, where the number of theoretical plates of the dividing wall column relates to the sum of the theoretical plates in the joint upper column region, the joint lower column region and the inflow section,
wherein in the dividing wall column the side feed point for the corresponding crude alkyl acrylate is arranged at a theoretical plate in a region commencing at least two theoretical plates above a bottommost theoretical plate and ending at least two theoretical plates below an uppermost theoretical plate, the side offtake point for a distilled 2-ethylhexyl acrylate is arranged at a theoretical plate in the region commencing at least two theoretical plates above the bottommost theoretical plate and ending at least two theoretical plates below the uppermost theoretical plate, and the dividing wall is arranged in the dividing wall column in a region commencing at least one theoretical plate above the bottommost theoretical plate and ending at least one theoretical plate below the uppermost theoretical plate,
where a ratio of an amount of liquid at the upper end of the dividing wall going to an enrichment section and an amount of liquid at a stripping section of the dividing wall column is in the range from 1:0.2 to 1:5 and a ratio of amounts of a vapor stream at the lower end of the dividing wall going to the stripping section and a vapor stream at the enrichment section of the dividing wall column is in the range from 1:0.5 to 1:2.0, wherein the upper end is above the side feed point and the lower end is below the side offtake point;
and
wherein the distilling includes isolating 2-ethylhexyl acrylate having a purity of ≥98.5% by weight from the corresponding crude alkyl acrylate, and
wherein the corresponding crude alkyl acrylate has the following composition:
from 40 to 99% by weight of 2-ethylhexyl acrylate,
from 0.1 to 10% by weight of 2-ethylhexanol,
from 0.1 to 10% by weight of high boilers having a boiling point greater than the boiling point of 2-ethylhexyl acrylate, and
from 0.1 to 10% by weight of low boilers having a boiling point less than the boiling point of 2-ethylhexyl acrylate.

9 more elements

Dependencies are inferred from the claim text.

Facts

Application: 16/472,054Filed 11 Dec 2017
Priority: EP 1620596821 Dec 2016
Published: US 2020/0094160 A126 Mar 2020
Granted: 19 Jan 2021
Term ends: Not estimatedThe source records don’t support an estimate.

Classification7 codes

B01D 3/141
Fractional distillation or use of a fractionation or rectification column: where at least one distillation column contains at least one dividing wall
B01D 3/00
Distillation or related exchange processes in which liquids are contacted with gaseous
B01D 3/225
With horizontal sieve plates or grids; Construction of sieve plates or grids: dual-flow sieve trays
B01D 3/4283
Of columns: bottom stream