Claims
- 1. In a process for the manufacture of lower alkyl esters by the reaction of fatty acid triglycerides containing less than 1% free fatty acid with a lower alcohol at a temperature up to 100.degree. C. and at a pressure up to 10 bar in the presence of a homogeneous alkaline catalyst, the improvement wherein the reaction mixture is passed through at least two stages in which in each stage the reaction mixture is passed through a single horizontally oriented tubular reactor and a following static separator in which glycerol is removed from the reaction mixture, and wherein the Reynolds number of the flow of the reaction mixture at the entrance of the first tubular reactor is greater than 2,300, the Reynolds number being calculated from the formula ##EQU4## in which Re is the Reynolds number, .zeta. is the density of the mixture, v is the average tube velocity, d is the internal tube diameter and .eta. is the viscosity of the mixture.
- 2. The process of claim 1 wherein the Reynolds number is greater than 4,000.
- 3. The process of claim 1 wherein the Reynolds number is greater than 10,000.
- 4. The process of claim 1 wherein the residence time of the reaction mixture in the static separators is from 0.1 to 5 hours and wherein the reaction mixture is kept at the reaction temperature in the static separators.
- 5. The process of claim 4 wherein the lower alcohol is methanol and the residence time of the reaction mixture in the static separators is from 1 to 2 hours.
- 6. The process of claim 1 wherein the static separators are tubular horizontal separators into one end of which the reactor mixture enters, then separates into an ester upper phase and a glycerol lower phase, and the two phases leave separately at the opposite end from which the reaction mixture enters.
- 7. The process of claim 1 wherein the residence time of the reaction mixture in each tubular reactor is from 1 to 10 minutes.
- 8. The process of claim 1 wherein the lower alcohol is methanol and the residence time of the reaction mixture in each tubular reactor is from 2 to 5 minutes.
- 9. The process of claim 1 wherein in each stage the lower alcohol and fatty acid triglycerides are present in a ratio of from 4.5 to 7.5 mols of alcohol per mole of triglycerides.
- 10. The process of claim 9 wherein the lower alcohol is methanol and said ratio is from 5.1 to 6.9 mols of methanol per mole of triglycerides.
- 11. The process of claim 1 wherein the total concentration of alkaline catalyst in the at least two stages is less than 0.25% by weight, based on the weight of neutral triglycerides, and wherein the total quantity of alkaline catalyst and lower alcohol used in the process is divided among the stages so that a conversion to lower alkyl ester of at least 85% is obtained in each stage.
- 12. The process of claim 1 wherein the reaction mixture used in the first stage is mixed prior to use in a static mixer.
- 13. The process of claim 1 wherein the lower alcohol is methanol; the Reynolds number is greater than 10,000; the residence time of the reaction mixture in each tubular reactor is from 2 to 5 minutes and the residence time of the reaction mixture in the static separators is from 1 to 2 hours; the static separators are tubular horizontal separators; and the ratio of methanol to triglycerides in each stage is from 5.1 to 6.9 moles of methanol per mole of triglycerides.
Priority Claims (1)
Number |
Date |
Country |
Kind |
39 32 514.8 |
Sep 1989 |
DEX |
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Parent Case Info
This application is a continuation of application Ser. No. 07/844,625 filed on Jun. 1, 1992, now abandoned.
US Referenced Citations (1)
Number |
Name |
Date |
Kind |
2360844 |
Bradshaw et al. |
Nov 1941 |
|
Foreign Referenced Citations (3)
Number |
Date |
Country |
0131991 |
Jan 1985 |
EPX |
3020612 |
Dec 1980 |
DEX |
634411 |
Mar 1950 |
GBX |
Non-Patent Literature Citations (1)
Entry |
Seifen, Ole, Fette, Wachse, Modern Production Technology for Fatty Acid Methylester--Derived Surfactants and Soap, 1988, pp. 595-600. |
Continuations (1)
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Number |
Date |
Country |
Parent |
844625 |
Jun 1992 |
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