US3882167A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for the manufacture of acrylic acid esters
Assignee: Hoechst AG
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Filing: 1973-05-25
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Granted: 1975-05-06
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Expires: 1993-05-25
Abstract
Abstract Improved process permitting heterogeneous catalytic reactions to be carried out continuously in liquid phase, wherein a suspension of liquid starting material and fine particulate catalyst together with resulting reaction product is continuously conveyed upwardly in a reaction zone, in accordance with the principle underlying an airlift pump, by the introduction of a gas into, near the bottom of, the reaction zone, and recycled downwardly through a by-pass reflux line to the bottom of the reaction zone, the recycled liquid material passing through an injector system interrupting its flow, the said system being situated in the bypass reflux line in a closed catalyst-separating zone containing reaction product; wherein, following establishment of the reaction equilibrium, starting material is continuously supplied to the reaction zone and crude, catalyst-free reaction product is removed near the head of the catalyst-separating zone; wherein reaction product, which is to be removed from the catalystseparating zone, is caused to flow upwardly through the catalystseparating zone with the injector system therein towards the reaction product outlet at velocity smaller than the sedimentation velocity of the catalyst in the catalyst-separating zone under the operational conditions prevailing. The improved process is more particularly used for esterifying arcylic acid in contact with an acid ion exchanger as a catalyst, at elevated temperature and under pressures substantially between 0.01 and 1 atmosphere absolute. To this end, the reaction zone is continuously supplied with a starting mixture of acrylic acid and an alkanol having between 4 and 6 carbon atoms; an inert gas is introduced into, near the bottom of, the reaction zone; the resulting suspension is heated to boiling; an azeotropic mixture of water originating from the esterification, alkanol and/or ester, is distilled off in a distillation zone placed directly above the head of the reaction zone; the azeotropic mixture is condensed and separated into a specifically lighter, predominantly organic phase and into a specifically heavier, predominantly aqueous phase, the organic phase being recycled to the head of the distillation zone and/or to the reaction zone; and resulting crude alkyl acrylate is removed near the head of the catalyst-separating zone.
Inventors
- 👤 Elmar Lohmar
- 👤 Alexander Ohorodnik
- 👤 Klaus Gehrmann
- 👤 Paul Stutzke
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 14:59
CPC Classifications
B; B01; B01J; B01J19/00; B01J19/18; B01J19/1862; B01J8/00; B01J8/18; B01J8/20; B01J8/22; B01J8/224; B01J8/228; C; C07; C07C; C07C67/00; C07C67/08; B01J2219/00; B01J2219/00049; B01J2219/00051; B01J2219/00074; B01J2219/00087; B01J2219/00094; B01J2219/00101; Y; Y10; Y10S; Y10S203/00; Y10S203/06
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
337 words
A PROCESS PERMITTING HETEROGENEOUS CATALYTIC REACTIONS TO BE CARRIED OUT CONTINUOUSLY IN LIQUID PHASE, WHEREIN A SUSPENSION OF LIQUID STARTING MATERIAL AND FINE PARTICULATE CATALYST TOGETHER WITH RESULTING REACTION PRODUCT IS CONTINUOUSLY CONVEYED UPWARDLY IN A REACTION ZONE, IN ACCORDANCE WITH THE PRINCIPLE UNDERLYING AN AIR-LIFT PUMP, BY THE INTRODUCTION OF A GAS INTO, NEAR THE BOTTOM OF, THE REACTION ZONE, AND RECYCLED DOWNWARDLY THROUGH A BY-PASS REFLUX LINE TO THE BOTTOM OF THE REACTION ZONE, THE RECYCLED LIQUID MATERIAL PASSING THROUGH AN INJECTOR SYSTEM INTERRUPTING ITS FLOW, THE SAID SYSTEM BEING SITUATED IN THE BY-PASS REFLUX LINE IN A CLOSED CATALYSTSEPARATING ZONE CONTAINING REACTION PRODUCT; WHEREIN, FOLLOWING ESTABLISHMENT OF THE REACTION EQUILIBRIUM, STARTING MATERIAL IS CONTINUOUSLY SUPPLIED TO THE REACTION ZONE AND CRUDE, CATALYST-FREE REACTION PRODUCT IS REMOVED NEAR THE HEAD OF THE CATALYST-SEPARATING ZONE; WHEREIN REACTION PRODUCT, WHICH IS TO BE REMOVED FROM THE CATALYST-SEPARATING ZONE, IS CAUSED TO FLOW UPWARDLY THROUGH THE CATALYST-SEPARATING ZONE WITH THE INJECTOR SYSTEM THEREIN TOWARDS THE REACTION PRODUCT OUTLET AT A VELOCITY SMALLER THAN THE SEDIMENTATION VELOCITY OF THE CATALYST IN THE CATALYST-SEPARATING ZONE UNDER THE OPERATIONAL CONDITIONS PREVAILING; WHICH PROCESS COMPRISES ESTERIFYING ACRYLIC ACID IN CONTACT WITH AN ACID ION EXCHANGER AS A CATALYST, AT ELEVATED TEMPERATURES AND UNDER PRESSURES SUBSTANTIALLY BETWEEN 0.01 AND 1 ATMOSPHERE ABSOLUTE BY CONTINUOUSLY SUPPLYING THE REACTION ZONE WITH A STARTING MIXTURE OF ACRYLIC ACID AND AN ALKANOL HAVING BETWEEN 4 AND 6 CARBON ATOMS; INTRODUCING AN INERT GAS INTO, NEAR THE BOTTOM OF, THE REACTION ZONE; HEATING THE RESULTING SUSPENSION TO BOILING; DISTILLING OFF, IN A DISTILLATION ZONE PLACED DIRECTLY ABOVE THE HEAD OF THE REACTION ZONE, AN AZEOTROPIC MIXTURE OF WATER ORIGINATING FROM THE ESTERIFICATION, ALKANOL AND/OR ESTER; CONDENSING THE SAID AZEOTROPIC MIXTURE AND SEPARATING IT INTO A SPECIFICALLY LIGHTER, PREDOMINANTLY ORGANIC PHASE AND INTO A SPECIFICALLY HEAVIER, PREDOMINANTLY AQUEOUS PHASE, THE ORGANIC PHASE BEING RECYCLED TO THE HEAD OF THE DISTILLATION ZONE AND/OR TO THE REACTION ZONE; AND DISCHARGING RESULTING CRUDE ALKYL ACRYLATE, NEAR THE HEAD OF THE CATLAYST-SEPARATING ZONE.
Claim 2
Dependent Claim
337 words
A PROCESS PERMITTING HETEROGENEOUS CATALYTIC REACTIONS TO BE CARRIED OUT CONTINUOUSLY IN LIQUID PHASE, WHEREIN A SUSPENSION OF LIQUID STARTING MATERIAL AND FINE PARTICULATE CATALYST TOGETHER WITH RESULTING REACTION PRODUCT IS CONTINUOUSLY CONVEYED UPWARDLY IN A REACTION ZONE, IN ACCORDANCE WITH THE PRINCIPLE UNDERLYING AN AIR-LIFT PUMP, BY THE INTRODUCTION OF A GAS INTO, NEAR THE BOTTOM OF, THE REACTION ZONE, AND RECYCLED DOWNWARDLY THROUGH A BY-PASS REFLUX LINE TO THE BOTTOM OF THE REACTION ZONE, THE RECYCLED LIQUID MATERIAL PASSING THROUGH AN INJECTOR SYSTEM INTERRUPTING ITS FLOW, THE SAID SYSTEM BEING SITUATED IN THE BY-PASS REFLUX LINE IN A CLOSED CATALYSTSEPARATING ZONE CONTAINING REACTION PRODUCT; WHEREIN, FOLLOWING ESTABLISHMENT OF THE REACTION EQUILIBRIUM, STARTING MATERIAL IS CONTINUOUSLY SUPPLIED TO THE REACTION ZONE AND CRUDE, CATALYST-FREE REACTION PRODUCT IS REMOVED NEAR THE HEAD OF THE CATALYST-SEPARATING ZONE; WHEREIN REACTION PRODUCT, WHICH IS TO BE REMOVED FROM THE CATALYST-SEPARATING ZONE, IS CAUSED TO FLOW UPWARDLY THROUGH THE CATALYST-SEPARATING ZONE WITH THE INJECTOR SYSTEM THEREIN TOWARDS THE REACTION PRODUCT OUTLET AT A VELOCITY SMALLER THAN THE SEDIMENTATION VELOCITY OF THE CATALYST IN THE CATALYST-SEPARATING ZONE UNDER THE OPERATIONAL CONDITIONS PREVAILING; WHICH PROCESS COMPRISES ESTERIFYING ACRYLIC ACID IN CONTACT WITH AN ACID ION EXCHANGER AS A CATALYST, AT ELEVATED TEMPERATURES AND UNDER PRESSURES SUBSTANTIALLY BETWEEN 0.01 AND 1 ATMOSPHERE ABSOLUTE BY CONTINUOUSLY SUPPLYING THE REACTION ZONE WITH A STARTING MIXTURE OF ACRYLIC ACID AND AN ALKANOL HAVING BETWEEN 4 AND 6 CARBON ATOMS; INTRODUCING AN INERT GAS INTO, NEAR THE BOTTOM OF, THE REACTION ZONE; HEATING THE RESULTING SUSPENSION TO BOILING; DISTILLING OFF, IN A DISTILLATION ZONE PLACED DIRECTLY ABOVE THE HEAD OF THE REACTION ZONE, AN AZEOTROPIC MIXTURE OF WATER ORIGINATING FROM THE ESTERIFICATION, ALKANOL AND/OR ESTER; CONDENSING THE SAID AZEOTROPIC MIXTURE AND SEPARATING IT INTO A SPECIFICALLY LIGHTER, PREDOMINANTLY ORGANIC PHASE AND INTO A SPECIFICALLY HEAVIER, PREDOMINANTLY AQUEOUS PHASE, THE ORGANIC PHASE BEING RECYCLED TO THE HEAD OF THE DISTILLATION ZONE AND/OR TO THE REACTION ZONE; AND DISCHARGING RESULTING CRUDE ALKYL ACRYLATE, NEAR THE HEAD OF THE CATLAYST-SEPARATING ZONE.
Claim 3
Dependent Claim
29 words
The process as claimed in claim 1, wherein the reaction zone is operated at temperatures between 45* and 120*C and under pressures between 30 and 500 mm of mercury.
Claim 4
Dependent Claim
36 words
The process as claimed in claim 1, wherein a plurality of analogous reaction zones are series-connected together, each of the individual reaction zones having a distillation zone, a reflux line and a catalyst-separating zone associated therewith.
Claim 5
Dependent Claim
78 words
The process as claimed in claim 1, wherein the crude alkyl acrylate, which is removed near the head of the catalyst-separating zone, is subjected to extraction with water so as to remove residual acrylic acid therefrom; the resulting aqueous phase is separated; and the organic phase is delivered to a second distillation zone and separated therein into a head product coNtaining alkanol, water, dialkyl ether and alkyl acrylate, and into a base product consisting of desirable alkyl acrylate.
Claim 6
Dependent Claim
84 words
The process as claimed in claim 1, wherein the crude alkyl acrylate, which is removed near the head of the catalyst-separating zone, is subjected to extraction with a solution of a base in water so as to remove residual acrylic acid therefrom; the resulting aqueous phase is separated and the organic phase is delivered to a second distillation zone and separated therein into a head product containing alkanol, water, dialkyl ether and alkyl acrylate, and into a base product consisting of desirable alkyl acrylate.
Claim 7
Dependent Claim
188 words
The process as claimed in claim 1, wherein the crude alkyl acrylate, which is removed near the head of the catalyst-separating zone, is subjected to extraction with water so as to remove residual acrylic acid therefrom; the resulting acrylic acid-containing aqueous phase is separated; the organic phase is delivered to a second distillation zone and separated therein into a head product containing alkanol, water, dialkyl ether and alkyl acrylate, and into a base product consisting of desirable alkyl acrylate; the head product originating from the second distillation zone is subjected to condensation to effect separation into an aqueous phase and an organic phase; the aqueous phase is removed and the organic phase is introduced into the lower base portion of an extraction zone; an aqueous, acrylic acid-containing phase separated earlier is introduced, from above, into the extraction zone, countercurrently with respect to the said organic phase; an organic extract containing acrylic acid, alkanol, alkyl acrylate, dialkyl ether and water is removed near the head of the extraction zone and recycled to the reaction zone; and the extracted aqueous phase is removed through the bottom of the extraction zone.
Claim 8
Dependent Claim
59 words
The process as claimed in claim 6, wherein the aqueous phases, originating from the head products coming from the two distillation zones are united with the aqueous phase removed through the bottom of the extraction zone; the united phases are distilled and resulting, predominantly organic head product is equally introduced into the lower base portion of the extraction zone.
Claim 9
Dependent Claim
207 words
The process as claimed in claim 1, wherein the crude alkyl acrylate, which is removed near the head of the catalyst-separating zone, is subjected to extraction with water so as to remove residual acrylic acid therefrom; the resulting aqueous phase is separated and admixed with an alkali metal or alkaline earth metal salt; the organic phase is delivered to a second distillation zone and separated therein into a head product containing alkanol, water, dialkyl ether and alkyl acrylate, and into a base product consisting of desirable alkyl acrylate; the head product originating from the second distillation zone is subjected to condensation to effect separation into an aqueous phase and an organic phase; the aqueous phase is removed and the organic phase is introduced into the lower base portion of an extraction zone; an aqueous, acrylic acid-containing phase separated earlier and admixed with an alkali metal or alkaline earth metal salt is introduced from above into the extraction zone, countercurrently with respect to said organic phase; an organic extract containing acrylic acid, alkanol, alkyl acrylate, dialkyl ether and water is removed near the head of the extraction zone and recycled to the reaction zone; and the extracted aqueous phase is removed through the bottom of the extraction zone.
Claim 10
Dependent Claim
59 words
The process as claimed in claim 8, wherein the aqueous phases separated from the head products coming from the two distillation zones are united with the aqueous phase removed through the bottom of the extraction zone; the united phases are distilled and resulting, predominantly organic head product is equally introduced into the lower base portion of the extraction zone.
Claim 11
Dependent Claim
199 words
The process as claimed in claim 1, wherein the crude alkyl acrylate, which is removed nEar the head of the catalyst-separating zone, is subjected to extraction with a solution of a base in water so as to remove residual acrylic acid therefrom; the resulting aqueous phase is separated and acidified with a mineral acid; the organic phase is delivered to a second distillation zone and separated therein into a head product containing alkanol, water, dialkyl ether and alkyl acrylate, and into a base product consisting of desirable alkyl acrylate; the head product originating from the second distillation zone is subjected to condensation to effect separation into an aqueous phase and an organic phase; the aqueous phase is removed and the organic phase is introduced into the lower base portion of an extraction column; an aqueous phase acidified earlier with a mineral acid is introduced from above into the extraction zone, countercurrently with respect to said organic phase; an organic extract containing acrylic acid, alkanol, alkyl acrylate, dialkyl ether and water is removed near the head of the extraction zone and recycled to the reaction zone; and the extracted aqueous phase is removed through the bottom of the extraction zone.
Claim 12
Dependent Claim
59 words
The process as claimed in claim 10, wherein the aqueous phases separated from the head products coming from the two distillation zones are united with the aqueous phase removed through the bottom of the extraction zone; the united phases are distilled and resulting, predominantly organic head product is equally introduced into the lower base portion of the extraction zone.
References Cited (Backward Citations)
US3037052A
Cited
US3278585A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-05-05 | 1978-11-04 | 1979-05-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-05-05 | 1982-11-04 | 1983-05-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-05-05 | 1986-11-04 | 1987-05-06 | $7700.00 | Window Closed / Lapsed |