Method for the esterification of a fatty acid

• US 20040106813A1
• Filed: 11/12/2003
• Published: 06/03/2004
• Est. Priority Date: 11/28/2002
• Status: Active Grant

• Current Assignee: Sulzer Chemtech AG (Sulzer AG)
• Original Assignee: Sulzer Chemtech AG (Sulzer AG)
• Inventors: Bailer, Oliver, Moritz, Peter, von Scala, Claudia, Faessler, Peter
• Granted Patent: US 7,091,367 B2
• Time in Patent Office: Days
• US Class Current: 554/176
• CPC Class Codes: B01D 3/009 in combination with chemical reactions
• CPC Class Codes: B01D 3/343 the substance being a gas
• CPC Class Codes: B01J 19/249 Plate-type reactors
• CPC Class Codes: B01J 19/32 Packing elements in the form of grids or built-up elements for forming a unit or module inside the apparatus for mass or heat transfer
• CPC Class Codes: B01J 2208/00274 involving reactant vapours
• CPC Class Codes: B01J 2208/00283 involving reactant liquids
• CPC Class Codes: B01J 2219/2453 Plates arranged in parallel
• CPC Class Codes: B01J 2219/2458 Flat plates, i.e. plates which are not corrugated or otherwise structured, e.g. plates with cylindrical shape
• CPC Class Codes: B01J 2219/246 Perforated plates
• CPC Class Codes: B01J 2219/2481 Catalysts in granular from between plates
• CPC Class Codes: B01J 2219/32206 Flat sheets
• CPC Class Codes: B01J 2219/32213 Plurality of essentially parallel sheets
• CPC Class Codes: B01J 2219/32227 Vertical orientation
• CPC Class Codes: B01J 2219/32237 Sheets comprising apertures or perforations
• CPC Class Codes: B01J 2219/32272 relating to blocks in superimposed layers
• CPC Class Codes: B01J 2219/32466 comprising catalytically active material
• CPC Class Codes: B01J 2219/32475 involving heat exchange
• CPC Class Codes: B01J 2219/3325 Counter-current flow
• CPC Class Codes: B01J 8/0426 the beds being superimposed one above the other
• CPC Class Codes: C07C 67/08 by reacting carboxylic acids or symmetrical anhydrides with the hydroxy or O-metal group of organic compounds
• CPC Class Codes: C07C 69/24 : esterified with monohydroxylic compounds
• CPC Class Codes: C07C 69/52 : Esters of acyclic unsaturated carboxylic acids having the esterified carboxyl group bound to an acyclic carbon atom
• CPC Class Codes: Y02P 20/10 : Process efficiency

Abstract

The method for the esterification of a fatty acid F is carried out in a column with a packing. In addition to functioning as a catalytic reactor, the packing functions as a stripping section. A heteregenous catalysis of a fatty acid is carried out with an alcohol used in the same molar ratio or in excess. A gaseous alcohol-rich counter-flow is produced in a sump of the column by vaporisation. Water is removed from the reaction zone by means of the counter-flow acting as a stripping gas. The loaded stripping gas is at least partially liquefied at the head of the column. The head product is separated into a water-rich fraction as well as an alcohol-rich fraction. The alcohol-rich fraction is returned to the process as a starting material for the esterification and for the production of the stripping gas.

Claims

1. A method for the esterification of a fatty acid F in a column with at least one multi-part packing having a catalyst in at least an upper part to define a catalytic reaction zone, a head at an upper end and a sump at an opposite end, said method comprising the steps of

feeding a fatty acid and an alcohol mixture into the catalytic reaction zone;

effecting an esterification of the fatty acid and alcohol mixture in the catalytic reaction zone by a heterogeneous catalysis;

producing an alcohol-rich stripping gas in the sump by vaporisation,

passing the alcohol-rich stripping gas in counter-flow through the catalytic reaction zone to strip water from the reaction zone;

at least partially liquefying the water-loaded gas at the head of the column to form a liquefied head product;

separating the liquefied head product into a water-rich fraction and an alcohol-rich fraction; and

returning the alcohol-rich fraction from the head of the column to the catalytic reaction zone as a starting material for the esterification step and to the sump for the production of the stripping gas.

2. A method in accordance with claim 1 characterised in that water and alcohol separated with the stripping gas out of the liquid mixture which leaves the reaction zone.

3. A method in accordance with claim 1 characterised in that a further packing is incorporated above the stripping section in which fatty acid carried in the stripping gas is transferred to a part of the alcohol-rich fraction returned to the column from the head of the column.

4. A method in accordance with one of the claims 1 to 3 characterised in that alcohol is fed into the reaction zone to contribute to the flow of the stripping gas in vaporized form.

5. A method in accordance with claim 1 wherein said step of separating the liquefied head product into a water-rich fraction and an alcohol-rich fraction is performed by one of pervaporation, phase separation and distillation.

6. A method in accordance with claim 1 further comprising the step of conducting a partial esterification of the fatty acid and an alcohol mixture to form a mixture of fatty acid, alcohol, ester and water and applying said latter mixture into or above the catalytic reaction zone.

7. A method in accordance with claim 1 further comprising the step of separating a part of a mixture from the sump of the column to obtain a fatty acid ester E with a purity of at least 99% by weight.

8. A method in accordance with claim 1 characterised in that the fatty acid is selected from the group consisting of at least one of the C12-, C14-, C16-, C18-, C18′

- and C18″

- fatty acids and the alcohol is selected from the group consisting of at least one of methanol, ethanol, n-propanol, isopropanol, n-butanol, isobutanol and 2-ethyl-hexanol.

9. A method in accordance with claim 8 wherein said fatty acid is at least one of lauric acid, myristic acid, palmitic acid, stearic acid, oleic acid and linoleic acid.

10. A plant for the production of the ester E by means of a heterogeneous catalysis comprising

a column;

a packing disposed in said column for carrying out a heterogeneous catalysis of a fatty acid and alcohol, said packing including porous catalyst supports defining flow channels therebetween for passage of a stripping gas between said catalyst supports and catalyst within said porous catalyst supports;

a distributor for directing a downwardly directed flow of a mixture of fatty acid and alcohol onto said packing for passage through said catalyst supports in counter-flow to an upwardly directed flow of stripping gas with the mixture in direct contact with the gas to allow a material exchange to take place;

a sump below said packing for receiving alcohol from said packing and for generating an upward flow of stripping gas from the alcohol in said sump.

11. A plant as set forth in claim 10 wherein said catalyst is an inorganic catalyst in acidic form and suitable for use in a temperature range of from 150°

to 230°

C.

12. A plant as set forth in claim 10 wherein said catalyst is an ion exchange macroporous resin in acidic form and suitable for use in a temperature range of up to 140°

C.