DE1767866A1 - Process for preventing discoloration and darkening of first-run fatty acids - Google Patents

Description

Method of preventing discoloration and darkening

of initial fatty acids · / D / O D D

The invention relates to a method of preventing discoloration and the darkening of the first runners produced by the distillation of refined fatty acids from split soapstock or from fission fatty acids obtained from coconut oil and palm kernel fat.

It is known that inorganic and organic compounds of the Bors can be used to prevent discoloration.

The prior art is found in U.S. Patent No. 2,862,943 and from the German Auslegeschrift 1 214 212 from “In the latter the disadvantages of these known methods are set out: When using the organic and inorganic compounds of the Boric acid accumulates in the distillation residue, unsaponifiable condensation products of the fatty acids. In DAS 1 073 663 a Process described which has the production of these condensation products from fatty acids as an object, with oxygen-containing Boron compounds are used as condensation catalysts. The yield of unsaponifiable condensation products according to this method is up to £ 92. The USA patent 2,583,028 and British patent specification 1,081,522 describe the treatment of fatty acids with boron trifluoride and with its ether complex »With these processes, however, the most severe corrosion problems arise.

A process has now been found for preventing the discoloration and darkening of the first-run fatty acids having 8 to 12 carbon atoms, which is characterized in that the fatty acids are 0.2 to 2, preferably 0.5 to 1% by weight , based on the fatty acid used, an alkyl ester of silicic acid or polysilicic acid and / or carbonic acid for 0.5 to 8 hours, preferably 2 to 4 hours, to temperatures of 180 to 250 ^° C., preferably to 200 to 240 ^° C. under normal pressure, if appropriate when using a low-boiling alkyl ester of silicic acid and / or carbonic acid, heated under a slight excess pressure to about 5% and then the fatty acids

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The method has the particular advantage that after the Treatment with the alkyl esters of silicic or polysilicic acid and / or carbonic acid and subsequent distillation present Distillate of the first run fatty acids no longer unsaponifiable Compounds as the distillate of the untreated fatty acid. The distillation residue also contains the according to of the present invention, fatty acids did not treat newly formed condensation products of the fatty acids as in the Use of boric acid or boric acid esters is the case, which act as Lewis catalysts and the formation of condensation products support financially. After the distillation, non-distillable silica and / or carbonic acid derivatives are found in the distillation residue.

The first run fatty acid to be treated in accordance with the present invention occurs as a preliminary run in the distillation of the fission fatty acids from coconut oil or palm kernel fat. One distinguishes between Refined fatty acid from split soapstock during refining of coconut oil or palm kernel fat and split fatty acids from the pressure splitting of coconut oil or palm kernel fat.

The refined fatty acid has a poorer color quality than fission fatty acid and tends to discolour and darken to an even greater extent than the latter.

In Examples 1 to 4 below, leader fatty acids were used relatively poor quality used, made from refined fatty acids came from. It goes without saying that the color stability of first runnings fatty acids, which are derived from the split fatty acid from coconut oil or palm kernel fat is significantly higher. Compare Examples 5 and 6.

The color stability of the treated according to the invention and the untreated leader fatty acids was obtained by heating Samples in a glass tube with a diameter of 14 millimeters and a filling height of 115 millimeters at 200 C during 6 hours noted. This heating test was carried out in one thermostated drying cabinet which was not opened for the entire duration of the test. The test tube

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Each was covered with a cap. The color intensity was measured in iodine color units, with the iodine color number indicating how many milligrams of free iodine are contained in 100 milliliters of aqueous iodine-iodine potassium solution with the same color depth, if is measured at a layer thickness of 25 millimeters.

The process according to the present invention can be both batchwise as well as continuously.

example 1

According to the gc analysis, the untreated first-run fatty acid used had the following composition (figures: weight ^); Cg acid: 0.2; C _g acid: 68.4; C ₁₀ acid: 23.5; Cg acid: 7; Cj acid: 0.5; Cj acid: 0.2; also 0.2 methylheptyl and methylnonyl ketones.

2400 parts by weight of fractionated fatty acid containing about 2% water was drained while stirring, and at a bottom temperature of 240 ⁰ C with 0.5 weight ^ Kieselsäuretetrabutylester or Kohlensäuredibutylester. The duration of the treatment was 3 hours. A temperature of 240 ° C. was maintained during this time. Then, the bottom temperature was lowered by cooling to 100 ⁰ C and the flask contents in the vacuum of 3 to 5 Torr over a small distillation column is distilled within about 2 hours, whereby 3 fractions were collected. For comparison, 2400 parts by weight of untreated first-run fatty acid were distilled under the same conditions. (Example la)

Fraction 1 fell from 8 to 10 percent by weight, fraction 2 from 76 bis 78 weight- ^, as fraction 3 5 to 7 weight-Jt, based on the use of anhydrous first run fatty acid. The amount of residue was 7 to 9% by weight.

Table I summarizes the values. Example 2

Except for the treatment duration, which was 8 hours, all others are Conditions are the same as those in Example 1. Table I.

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contains the measured values.

Example 3

Dewatered vurden 2400 parts by weight Vorlauffetteäure and 1 weight-ji-Polykieselsäurete fcTÄäthylester added at 200 ⁰ C. The batch was kept at 200 ° C. for 6 hours and then distilled under vacuum. 3 fractions were obtained.

The test data are entered in Table II. Example 4

5 tons of first run fatty acid were dewatered at 450 torr. At 220 ° C., 0.7% by weight of tetra-butyl silica was added and the temperature of the batch was kept at 220 to 240 ^° C. for three hours. The batch was then ^{cooled to 100 °} C. and fractionally distilled in a continuous distillation plant in a vacuum of 5 Torr. The characteristics of the three fractions obtained are entered in Table II.

Example 5

a) 2400 parts by weight of first run fatty acid from coconut fission fatty acid were dehydrated and 0.5 weight ^ polysilicic acid ethyl ester at 240 ° C. was added. The approach was at for three hours 240 C held and then distilled under vacuum. The key figures of the three fractions and the residue are the table III refer to.

b) For comparison, 2400 parts by weight of untreated coconut fatty acid were obtained under the same conditions as in a) in three fractions distilled.

Example 6

2400 parts by weight of first run fatty acid, which originated from the split fatty acid of coconut oil and pala kernel fat, were dehydrated with 0.8% by weight of ethyl butyl carbonate at 180 ° C. The temperature was increased to 240 ^° C. within 6 hours and the batch was then distilled in vacuo. The characteristic numbers of the three fractions and the residue are entered in Table III. 109839/0482

additive - 5 - 3 Group I. SZ. JFZ. 1767866 Table 1 8th lot
Gew.-Jf 380 5.2 example without addition Treatment
duration 8th 8.8 378 1.0 Hours. 9.0 377 1.5 JFZ. after 6 hours
at 200 ^° C 1 a 0 9.8 381 1 10U 1 b Weight %
0.5 % ortho- 3
silicic acid
tetraburyl ester 8.6 379 1.3 38 1 c Weight *
0.5 35 carbon
s acid dibutyl
ester 8.1 kB 2 a 0.5 wt .- *
Ortho pebble
acid tetra-
butyl ester 33 2 B 0.5 wt -.%
Carbonic acid-
dibutyl ester

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Group II Group III Quantity of SZ, JFZ. JFZ, after 6 hours quantity SZ, JFZ, JFZ. after 6 hours Weight g at 200 ⁰ C wt .- * at 200 ° C

77.5 376 2.1 51 5.5 315 3.5 60

77.3 375 1 6.1 »5.3 313 2.6 15.2

76.7 37b 1 9.6 5.9 317 2.3 1 \ 3

76.0 376 1 7.0 6.7 31U 2, U 17.0

77 ,? 375 1 9.3 5.6 318 2.7 31.6

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Residue

Amount of UV content

Weight i %

B, 2 3.2

7.U 3.9

7.6 3.5

3.3

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Table II

fraction

SZ. JFZ.

JFZ. After 6 hours 200 ⁰ C

UV-treated Ge * .- ^

example 3 1 7th ,8th 381 <1 2 18.0 0.8 2 79 , 5 375 <1 6.2 0.6 3 5 , 5 312 2, 2 15.3 1.0 Residue 7th , 2 252 - - 3.6 example 4 1 6th 384 1" 1 53 0.9 2 78 376 <1 7.8 0.6 3 12th 320 2, 18.2 0.5 Residue 4th 248 - - 6.6

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fraction Tabel SZ. III JFZ. , 2 JFZ. To
6 hours
200 ⁰ C UV content
Weight -j » , 6 a I lot
Weight % 360 12th 0 , 3 Example 5 2 5.2 353 <1 , 2 4.2 0 , 4 3 83.2 256 1 ,8th 14th 0 , 5 Backlog 6.4 242 - , 0 - 1 , 6 b 1 5.2 359 2, 60 O , 3 Example 5 2 5.0 352 I ₁ 35 O ₁ , 4 3 83.4 254 I ₁ 20th O ₁ , 6 Residue 6.8 241 - 3 - I ₁ , 7 1 4.8 340 15th O ₁ 2 Example 6 2 5.3 335 <1 3.8 O, 2 3 83.0 242 1. 13th O, 8th Buckstand 6.6 230 - - 1. 5.1

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Claims (2)

Claims 1. Method of preventing discoloration and darkening of first run fatty acids of 8 to 12 carbon atoms, characterized in that the fatty acids - With 0.2 to 2, preferably 0.5 to 1% by weight, based on the fatty acid used, of an alkyl ester of silica or polysilicic acid and / or carbonic acid for 0.5 to 8 hours, preferably 2 to 4 hours, heated to temperatures of 180 to 250 ^° C., preferably 200 to 240 ^° C., under normal pressure, optionally when using a low-boiling alkyl ester of silica and / or carbonic acid under a slight excess pressure of up to about 5 atmospheres, and the fatty acids are then distilled. 2. The method according to claim 1, characterized in that the method is carried out continuously. Pat.-Dept. Dr.We / Si
June 24, 1968 109839/0482