DE2700302A1 - PROCESS FOR SEPARATING SOLID, PARTICULAR MATERIAL FROM FAT MATERIAL - Google Patents

Description

16. The method according to any one of claims 1 to 15, characterized in that a solvent for the fatty material is present.

17. The method according to any one of claims 1 to 16, characterized in that the solvent comprises hexane, acetone or Ni tropropane.

18. The method according to claim 16, characterized in that the amount of solvent present is 1/2 to 5 parts by weight of the fatty material .

709828/0759

PATENT ANWXLTE

DR. E. WIEGAND DIPL-ING. W. NiEMANN DR. M. KÖHLER DIPL-ING. C. GERNHARDT

MÖNCHEN HAMBURG

V / U0302

PHONE. 55547 «8000 M D N CH E N 2,

TELEGRAMS: CARPATENT. . MATH I LDENSTRASSE 12

TELEX . 529068 K AR PD

W. 42 737/76 7 / hch 5- January 1977

Unilever NV
Rotterdam (Netherlands)

Process for separating solid, particulate material from fatty material

The invention relates to the separation of solid, particulate material from fatty material, in particular Fatty acids and their esters, principally fats. In particular, the invention relates to fractionation processes in application to such substances.

The separation of solid, particulate material of liquid fat material in which it is dispersed becomes in the course of refining and fractionation operations executed. In the latter case, selected fatty acids or glycerides in fats or glyceride oils can be used as solid particles, usually precipitated by cooling and e.g. by filtration of other constituents remaining in the liquid phase

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divide, sometimes dissolved in solvents, separated.

In these operations, the separation of the solid phase and the liquid phase is often slow; Precipitation in the form of particles can hold back a high proportion of the liquid component of the fatty material by adsorption, and drainage or removal of components of the liquid phase therefrom can be difficult to carry out even with centrifugation, especially in recrystallization processes. Frequent washing of the solid material to remove the liquid adhering to it may be necessary, but it takes more time and is costly in terms of solvent consumption.

Thus, although a more complete separation may be very desirable, either for solid phase quality or for yield To improve the liquid phase, the procedure described is in any case time-consuming and expensive and can even be useless.

In the method according to the invention, the particulate Material converted into an aggregate form that is more easily separated from the liquid phase by draining or peeling can be. In this process, the fatty material, which is in liquid form, becomes particulate Contains material dispersed therein, subjected to homogeneous agitation until a substantial amount of the particles have accumulated or aggregated, and the liquid fatty material is separated therefrom.

A homogeneous leadership occurs when the speed gradient is the same between any two particles that are radially adjacent to one another in the mixture. Under the Under the influence of homogeneous stirring, the particles of the

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solid phase to agglomerates, which are much easier from adhering liquid phase can be freed in the subsequent separation processes.

Homogeneous stirring is preferably carried out by a stirrer with a smooth profile. A vortex or turbulence in the fat material experiencing homogeneous agitation should be minimized. A homogeneous stirring, whereby if a streamlined Flu3 results, a stirrer with a smooth and regular profile, such as z.3. durcli a cylindrical stirrer, which is concentric with a chamber containing the fat material and revolves around a vertical, inclined or horizontal axis.

The radial dimensions of the stirrer are not critical, but small stirrers can be slower in terms of bringing about aggregation, while the other conditions are the same. The stirrer preferably has a third to two thirds of the diameter of the agitation chamber, in particular approximately half of its diameter, but preferably extends substantially the full depth of the fat material in the chamber to ensure complete stirring. The depth is not critical in terms of itself radial dimensions, at least in the case of batch operation or batch processes. However, it is anyway preferably at least as large as the radial width of the ring of fatty material between the walls of the Chamber and the stirrer is included, in particular twice as deep or more. There is a special feature of the invention in that no auxiliary medium is required to promote aggregation of the particles.

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The speed of the stirrer should preferably be slow enough to achieve the desired effect can be agreed and preferably 1 to 200, in particular 10 to 100 rpm, preferably corresponding to a speed gradient of 1 to 250 m / min / m, in particular 10 to 100 m / min / ra radial. If the observed aggregation is inadmissibly slow to develop with a small stirrer, it is best to replace the stirrer with a larger stirrer that is the same or a slower speed operated to achieve faster aggregation.

The process is on a batch or continuous basis Works suitable, but in the latter case the chamber is deep in relation to the ring width to various Provide mixing stages in the ring zone which contains the fat material and to ensure good mixing with maximum Combine contact between the liquid and the solid material.

The invention is of particular importance for the fractional crystallization of fatty acids and their esters, in particular Fats. These include glyceride oils, which are usually liquid. Fractional crystallization can be used to remove impurities or to separate special fractions of the fat material with the desired melting properties and can be carried out in the presence or absence of a solvent for the fatty material, although the process is particularly valuable in so-called dry fractionation processes in the absence of a solvent, if essential longer filtration times are required due to the high viscosity of the liquid olein fraction. This can be done by

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see the crystals with an aqueous dispersion of a suitable surfactant, as in the so-called Lanza process, separated. Suitable solvents for the Fat fractionation include acetone, hexane or nitropropane and methanol for fatty acids, preferably containing some water. The amount of solvent can vary from 5: 1 to 1: 2 based on the weight of the fatty material. Other solvents known in the art can also be used.

Preferably, the fractional crystallization is carried out in situ during homogeneous stirring, with the fatty material is cooled from a completely liquid or dissolved state until the crystallization of the fraction to be separated is complete is, at the same time the material is subjected to homogeneous stirring. Includes a device for the purpose preferably a stirring chamber, which is equipped with a coaxial stirrer, both of which have a smooth cylindrical shape and sized as described, and cooling means for cooling the contents of the chamber, preferably through the walls of the chamber and the stirrer. A lower limit on the speed of rotation of the stirrer may be necessary in order to achieve an adequate Ensure heat transfer and excessive deposition of crystal growth on the cooling surfaces, which prevent heat transfer or prevent the transfer of heat. Unlike many forms of crystallization equipment the stirrer should not scrape or scrape the walls of the cooling chamber. Such devices do not provide a homogeneous one Stir.

The cooling rate is also determined by the temperature difference (temperature differential) between the cooling surface and the fat material. Large temperature differences promote one rapid cooling, but with the formation of micro-crystalline growth. On the other hand, small temperature differences generate

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larger crystals, but slower. The temperature differences given in this description are measured with reference to the center of the liquid and are preferably below 10 ° C., measured radially. A temperature difference of 5 to 2O ⁰ C and preferably 5 to 1O ° C, preferably between the coolant and the body of liquid which? cooling is maintained, at least until crystals appear. Thereafter, a higher difference can be provided, but preferably not above 25.degree. C., in particular one in the range from 10.degree. To 20.degree.

The invention applies to both edible and non-edible vegetable. Animal and marine fats, their fractions and hydrogenated and transesterified derivatives and fatty acids, which are a constituent of them, e.g., tallow, palm oil, sunflower oil, safflower oil, peanut oil, soybean oil and lauric oil can be used.

The invention is ^{useful for practicing a V, r} interisaticn This is a form of fractional crystallization that is commonly applied to edible oils, e.g. Use as salad oil or frying and baking oil are intended, is used to prevent the onset of exercise when standing at ambient temperatures as a result of the fractional crystallization of a higher-melting stearin fraction in the oil. In the interization process, the stearin is removed by filtration after the oil has been cooled. However, significant losses can be caused in conventional winterization processes for the reasons mentioned above in the separation of olein and stearin fractions and in any case a small amount of the stearin often remains stubborn in the oil to later crystallize out during storage when the Cl not being chilled to much lower temperatures with the loss of even more oil. The invention provides a technically advanced

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gradual and economical as well as effective winterization process, with minimal oil losses and maximum effectiveness is guaranteed.

The invention is also related to the fractionation of Fat material for the recovery of a substantial portion of a higher melting solid fraction in a single fractionation effective on the order of a quarter of the total weight of the fatty material. Absorbed in normal practice the fixed fraction usually at least twice that their weight of the lower melting liquid fraction · Solid fractions, which, as described above, are about a quarter make up the total weight of the treated material, therefore form sludges, their separation into their constituent parts liquid and solid fractions is extremely difficult, regardless of whether a filtration or a centrifugation is applied · According to the invention, the crystals are aggregated together and retain a much lower one Proportion of the liquid fraction back.

The method according to the invention can be carried out at temperatures of e.g. B. -2O ° C to 50 ° C, the temperature are only limited by the physical limits of solvents, if such are used and the amount of solids to be removed, preferably not more than 35 % . The agglomerated solid material can be separated off, for example, by decanting or by gravity or by pressure filtration or by centrifugation.

The invention is of particular importance for the recovery of fat fractions for use in the food industry have desirable properties. When preparing llargarine fats, for example Fatty mixtures obtained by fractionation processes were manufactured, us: to meet the desired physical or chemical characteristics, e.g. may be required

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be that the fats fill certain melting properties , or that there is a high polyun saturated fatty acid content for dietary purposes. Careful fractionation according to the invention makes it possible to obtain fats which meet such requirements. In the confectionery and confectionery industry, hard butter fats with dex for fats that are used for this purpose are necessary critical melting performance by fractionation according to the invention, in particular from palm oil, but also from other vegetable fats, which can be hardened before or after fractionation , available.

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Accompanying> iel 1

A cylindrical crystallization chamber, equipped with a concave bottom and a cover plate, was used still provided with a cylindrical rotor, which is attached to a vertical rotor shaft extending into the chamber which was attached by .eine above the plate LloiJoreinrichtung turned and in the middle of the Top plate and the concave bottom of the Kainner arranged bearings was supported

The chamber was about half as deep as it was wide and the rotor extended essentially through the entire depth the chamber extended, was half as wide as the chamber The chamber itself was equipped with an external cooling jacket, through which an aqueous ethereal glycol solution cooled to a predetermined temperature is circulated could leave.

Soybean oil became weak to an iodine number of 110 to 112 hydrogenated using a fresh, supported nickel catalyst. This improves the stability did the oil against oxidative deterioration, but leads to cloudiness in the oil on standing due to the crystallization of the stearin fraction. This was made from the oil according to the Invention removed using the device described

After the catalyst was removed, the oil was cooled to 36 ° C and the crystallization chamber was opened with it loaded. The stirrer was turned so that a

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speed gradient of about 15 m / min / m in the liquid in the ring resulted. The aqueous ethylene glycol circulating in the cooling jacket was kept under such conditions that a temperature gradient of 20 ° C / m, measured radially through the oil to a point in the middle between the linden of the vessel and the rotor, was obtained. When the temperature reached 21 ⁰ C, crystals appeared and the temperature difference rose to 35 C / m until a 2nd temperature of 5 ⁰ C was reached. Then the oil was filtered through a standard vacuum filtration unit; 74-ί'ό of an ole was obtained in three hours based on the weight of the hydrogenated oil. The olein remained ^{clear at 0} ° C. for at least 5 hours. On the other hand, the hydrogenated total oil stored even on standing at 2O ⁰ C Stearinkristalle.

In a comparative experiment using conventional fractionation methods were used, with a conventional agitator in the vessel and scraping devices instead of the rotor stirrer used to remove crystalline material that forms on the 7 / and of the vessel conditions were adjusted to give a similar filter time but a yield of only $ 60 was received. The olein product was in both Cases suitable for use as a frying oil and remained clear under ambient conditions on storage.

Example 2

A series of experiments were carried out in which similar hydrogenated soybean oil was fractionated

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ORIGINAL INSPECTED

was, with a similar device, which was equipped with a chamber of 60 cm diameter and 1 m in height and a Rotorrührer 30 cia diameter was charged at 3O ⁰ C. The effect was observed in terms of filtration rate and olein yield at fractionation temperature and the temperature differential, which, however, was constant in each experiment; in all tests the speed of rotation was 42 rpm, corresponding to a speed gradient of 264 m / h / m. The effect was also observed in terms of "stabilization" by keeping the chilled fat at fractionation temperature for 2 hours.

An olein which remained clear for ι 5 h at ^{0 ° C. was obtained from all experiments.} V / pus egg: indicated in the table below.

remained clear after 5 h at ^{0 ° C.} More details are

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1a]

2a]

Cooling conditions

Attempt temp.

• Stabilization time narrow temp

3-4

10 6

Tabel Time
(H)
from •
Oil yield Filtration rate Tight temp. 3O ⁰ C to $> m ³ / m ² / h 10 67.6 5.2 O 12th 65.7 4.0 6th 63.6 0.99 8th 60.8 0.68

- 1.5 61.3

0.63

Experiments 1 and 2 show the marked decrease in the filtration speed and the considerable increase in the olein yield which results when / .t is reduced for the same final temperature. A comparison between experiments 1 and 1a and 2 and 2a surprisingly shows that, in contrast to conventional fractionation practice, a "stabilization" period at the fractionation temperature is detrimental. Finally, experiment 3 also shows that a good olein yield can be obtained , comparable to that of experiment 2a, even at the lower temperature of -1.5 ⁰ G, if a lower Δι is maintained and a prolonged stabilization temperature is avoided.

Example 3

Palm oil (iodine number 53) was stirred at 100 rpm in a cylindrical vessel twice as deep as it was wide, which was equipped with a cooling jacket and a coaxial cylindrical rotor with half the vessel diameter extending essentially through the entire depth of the oil. From 5O ⁰ C, the oil was cooled to ⁰ C per hour of 12 to 28 ⁰ C; it was held at this temperature for 5½ hours with continued stirring, where nuclear magnetic resonance analysis of a sample indicated that 8-6 contaminants had formed. The oil was filtered at the same temperature with a plus rate of above 10 m / m / h and a filter pressure of 0.5 at.

The filtrate was $ 80 of the original palm oil, where-

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if a residue of 20 fo was retained by filtration

The example was repeated in a continuously operating system with the same dimensions, a stirrer speed of 4-0 rpm being used, 9γο solids being reported and the filtrate again 80 $ of the original oil with an iodine number of 57 and a filtering rate of 6.5 m ^ / m / h. The residence time was 2 hours.

In a Kristallisiertemperatur of 13 ⁰ C and a Rührgeachwindigkeit of 80 U / min was a yield of 45 $ liquid fraction from the continuously operating unit having an iodine value of 63, 2 and a Filtrierrate

■ ζ ρ

of 0.5 m / m / h. This is an excellent one Yield considering the heavy residue to be removed. The residence time was 5 hours.

Example 4

Malayan palm oil fraction (iodine value 58.4) obtained by dry fractionation of palm oil was mixed with acetone in a Luenge, which corresponded to four times their weight and fractionated at 3 ⁰ C, wherein, in the batchwise-working, described in Example 3 device, with stirring, at 300 U / min of 50 ⁰ C 3 ⁰ C at a rate of 12 ° C per hour, it was cooled. After stirring for three hours at this temperature, the filtration proceeded rapidly, and the filtration residue was increased four times, each time with 1 1/4 times the weight of the starting oil,

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washed nit acetone, iTach evaporation of the solvent a residue of 36 $ ό (Jodsahl 41.3) was obtained at a Filtratclausbeute of 64 $ (iodine value 68.5) based on the starting oil.

Example 5

Example 4 was repeated at a Tenperatur from -6 ⁰ C, with cooling of 3O ⁰ C under stabilizing 5 h and using hexane as a solvent in the same Ifenge. After washing the piltrate residue twice, each time using hexane in the same amount based on the starting oil, and evaporating the solvent, a piltrate oil of 64.1% by weight of the starting oil was obtained with an iodine number of 67.8 and a residual of $ 35.9 an iodine number of 43.2.

Example 6

Tallow fatty acids with an iodine number of 56 were dissolved in an amount which corresponded to 1 1/2 times their weight from a mixture of 92% methanol and 8% water and fractionated in the device described in Example 3, from 30 ^° C. / was cooled to -7 ⁰ C at a cooling rate of 18 ⁰ C per hour with stirring at 200 rpm; immediately thereafter, as described above, it was filtered and washed twice with the same solvent, each time with 88fo of the original weight of the acid. After evaporation of the solvent, a filtrate with an iodine number of 95.2 was obtained in 5o, Y / o yield together with

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- Vi -

Obtained $ 43.9 piltration residue of an iodine number of 5.8. which was obtained as a free-flowing granular material and of the 92 $ of the particles had a diameter τοπ about 0.5 cm.

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ORIGINAL INSPECTED

Claims (1)

Int. Cl. ² : FEDERAL REPUBLIC OF GERMANY GERMAN PATENT OFFICE C11 B 7/00 Offenlegungsschrift 27 00 302 Union priority: File number: P 27 00 302.7 Registration date: 5. 1.77 Disclosure date: 14th 7.77 8.176 Great Britain 651-76 Description: Process for separating solid, particulate material from fatty material Applicant: Unilever N.V., Rotterdam (Netherlands) Representative: Inventor: Wiegand, E., Dr .; Niemann, W., Dipl.-Ing .; Kohler, M., Dipl.-Chem. Dr .; Gernhardt, C, Dipl.-Ing .; Pat. Attorneys, 8000 Munich and 2000 Hamburg Berg, Hendrikus Jacobus van den, Terheyden (Netherlands) 6 77 709828/769 Claims A method for separating solid particulate material from fatty material in which it is dispersed thereby characterized in that the fatty material which is in liquid form and which contains the particulate material is subjected to homogeneous stirring until a substantial amount of the Particles is aggregated and separates the liquid fatty material therefrom. 2. The method according to claim 1, characterized in that aa.il the homogeneous stirring in a chamber which contains the fat material is carried out by a concentric, cylindrical stirrer. 3. The method according to claim 2, characterized in that the chamber is cylindrical and has a diameter of one and a half times to three times the diameter of the P.üh rers. 4. The method according to claim 2 or 3, characterized in that the chamber is at least as deep as the ra Diale width of the fat material enclosed in the chamber between its walls and the stirrer _# 5. The method according to any one of claims 1 to 4, characterized in that the stirrer is allowed to rotate at a speed which radially delivers a speed gradient of 1 to 250 m / min / m. 6. The method according to claim 5, characterized in that the speed gradient is 10 to 100 m / min / m radially . 709828/0759 ORIGINAL INSPECTSD 7. The method according to any one of claims 1 to 6, characterized characterized in that the stirrer is rotated at a speed of IO to 100 rpm. 8. The method according to any one of claims 1 to 7, characterized in that the particles are components of the fatty material which are selectively precipitated while the Fat material is subjected to homogeneous stirring 9. The method according to claim 8, characterized in that the fat material is cooled to carry out the precipitation. 10. The method according to any one of claims 1 to 9, characterized in that a temperature difference below 10 ⁰ G, measured radially, is applied in order to cool the fat material. 11. The method according to claim 9 or 10, characterized in that the fat material after cooling to constant Temperature is maintained to stabilize the precipitation, 12. The method according to any one of claims 8 to 11, characterized in that 5 to 35% of the let material are precipitated. 13. The method according to any one of claims 1 to 12, characterized characterized in that the fatty material comprises fat. 14. The method according to claim 13, characterized in that the fat comprises palm oil or a fraction thereof. 15. The method according to claim 14, characterized in that the fat comprises soybean oil. 709828/0759