DE1617019C3 - Process for the alkali refining of glyceride oils - Google Patents

Description

contain.

The invention relates to alkali refining in German Offenlegungsschrift 1,300,999

of glyceride oils, the free fatty acids and others a method of reducing refining impurities contain. The eligible losses are described at which the oil and alkaline The glyceride oils comprise both normally solid solutions in a bed of chemically inert fillers normally liquid, animal and plant materials are also continuously brought into contact borrowed glyceride oils. become random by making each of the fluids

Glyceride oils, as they are brought into contact with the other liquid by solvent extraction, Squeezing or other methods from animal while they are on curved paths through the bed or vegetable raw materials are obtained flow away; below are the oily and aqueous always hold a larger or smaller amount of liquids due to their different specificities Fatty acids. Before using these oils for making fish weights separately.

of foods, such as margarine, shortening, in this way the speed of the oil

Mayonnaise and the like, can be used, and alkaline currents are reduced so that the emuldie Impurities are removed. It is common for yaw to be pushed down to a minimum; these impurities from treatment result in significantly lower refining depressants or to remove the oil with losses.

aqueous alkali at temperatures below the In German Auslegeschrift 1120 623 is a

Boiling point of water and generally in processes and apparatus for neutralization Atmospheric pressure is 40 described by fats and fatty oils in which one and the so formed soap together with others the fat continuously in the form of practically the same Reaction products of initially present large drops with their own buoyancy by a impurities in solution removed and then kept at an approximately constant height vertical for the recovery of fat materials from it split lye column while avoiding turbulence. It is known that 45 bubbles during the neutralization, the droplet size being at least a combination of about 0.5 mm, in particular 1 mm, is kept with an alkaline solution, effect with regard to cleaning, removal of gum and although with the described known processes

partial discoloration can occur as a number slightly offsets the usual refining losses undesirable substances that can be put in the crude oil occur various essentials present are to be absorbed into the soap. However, 5 ° borrowed disadvantages. So it is very difficult to get droplets in this process there are still considerable comparisons of the same size; there is this desire for Ford of neutral oil. These losses are very severe due to the fact that smaller droplets are undesirable in the alkali Causes side reactions that rise in the caustic solution at a slower rate than The course of neutralization will occur. larger ones and, due to their small size, faster

Sometimes emulsions of oil in water will be de-acidified. As soon as the fatty acid is formed, which are stabilized by the soap solution. is distant, the degree of saponification increases. About these Emulsions can be very persistent; this is the complete avoidance of turbulence The result is that during the separation of the two or vortexing is very difficult. These factors Phases of oil are carried along with the soap solution lead to an increase in the saponification loss can. 60 A reduced path length increases the

In the processes previously used, it was the free fatty acid content of the neutralized oil that not possible to avoid any oil loss as larger droplets of complete neutralization for example, by suppressing one of the original can completely escape. Even slight turbulence Stuff of oil leakage can prevent other unwanted minor droplets, even of the same kind Reactions are promoted or other undesirable factors, the same residence time in the alkali Process conditions may be necessary. If have and causes some of the droplets that they accordingly, the soap solution is subsequently subject to excessive saponification by acid. This is hydrolysis for the extraction of fat materials reduces their size and also makes them more sensitive

³ 4

versus turbulence. In addition, the concentrated alkaline solution decreases. In general, oils,

tration of the alkali lye during neutralization, in which the predominant free fatty acids min-

so that a longer path is required for the droplets to contain at least 16 carbon atoms, and in the case of oils,

is to complete a neutralization at the end of where the free fatty acid content is high,

Ensure treatment. 5 ζ. B. 8 to 10% or more, relatively high

certain oils give rise to difficulties due to a ·; Temperatures, e.g. B. 130 or 140 to 150 or 160 ⁰ C,

unsatisfactory coalescence or coalescence is most advantageous, but even at temperatures

flow of the droplets at the upper part of the column temperatures between 105 and 130 ⁰ C, for example 110 to

walk. 120 ⁰ C, achieved some advantages with such oils.

It has now been found that even if the io on the other hand results in connection with oils, in O! and the aqueous liquid in one of the ones in the free fatty acids those lesser built or obstacles free space, which predominate a chain length, z. B. coconut oil, palm linear movement of one of the liquids kernel oil and other oils of the lauric acid group, were brought into contact with each other at temperatures of 105 to 110 or 120 ° C, a considerable reduction in emulsion results, even if the initial one alloy and consequently a substantial reduction in the free fatty acid content is high, e.g. 8%. The refining losses can be achieved when temperature should not be higher than the one the two liquids is ^ at a temperature necessary for the desired reduction deir not below 105 ⁰ C, but not high enough uir. To achieve refining losses, and generally to bring about a substantial saponification of the oil, ao it has not proven to be desirable to work at temperatures and at a superatmospheric pressure which is higher than about 160 or 170 ⁰ C to the temperatures. Prevention of boiling is sufficient to keep them in contact with one another. The pressure should be so with respect to the temperature. be chosen that the formation of steam bubbles

The object of the invention is to create one that is completely avoided. Higher pressures than them

improved refining process, which requires the usual 15 to achieve this purpose,

Refining losses reduced considerably should generally be avoided, in particular

and no need to perform the operation to achieve the desired total pressure

Fahrcns consists in a complicated way. an inert gas is used. At unreasonably high

The method according to the invention is based on pressures, the consumption of such gas becomes easy

the realization that the neutralization process is almost 30 too expensive.

is completely regulated by the processes that are The method according to the invention can be applied to numerous

ar. the oil-lye interface. rich ways to be carried out. So both

For example, the oil enters a stirrer at this interface during the transfer passage of fatty acids from the oil into the aqueous pressurized cylindrical kettle with cone phase local differences in interfacial tension 35 shaped soil are neutralized, the on. This difference in interfacial tension alkali is sprayed onto the oil. According to another cause currents in the immediate vicinity more recently described method can the oil the interface, which can be so violent that it is in the form of droplets in a vessel, the invented interface Oil droplets become unstable and spontaneously kept at a suitable pressure and torn off which is then heated by the aqueous phase 40, by a resting body of aqueous be included; this means that in an alkali are allowed to rise, greater or lesser extent a spontaneous Another advantageous way of carrying out Emulsification takes place. When examining the method according to the invention is The phenomenon has been found to emulsify at appropriately elevated temperatures and pressures oil droplets are extremely small, so that they do not 45 do the things described in German patent 1 287 241, even in a very strong gravitational field. to apply neutralization processes in which These oil droplets are lost even if they are in the same or in the oil and the aqueous solution not be saponified by the alkali. opposite directions by a sequence of

It has also been found that the currents are made to flow treatment zones; in each

in the immediate vicinity of the interface and the 50 of these treatment zones, the oil flows evenly,

so-called spontaneous emulsification from the process - horizontally or at a small angle upwards

rene conditions and on the type of applied on the surface of the aqueous solution, and the

Are dependent on oil. Overpass between each such zone and

The method according to the invention for the alkali of the next zone is effected in such a way that each refining of glyceride oils with an aqueous layer of aqueous soap solution, which is immediately

Liquid formed by bringing the oil into contact with bar below the oil layer, displaced

Aqueous alkali in one of internals or hindrances will bring the oil into direct contact with aqueous

nissen free space that bring a linear movement of alkaline solution, the less soap and

of either the oil or the aqueous liquid contains more unreacted alkali than in one would prevent, and removal of the formed soap 60 such layer is present, and consistently «ine

in aqueous solution is characterized in that significant mixing of the aqueous and oily

one the oil and the aqueous liquid is avoided at one temp phase.

temperature from 105 to 170 ° C under a pressure of 1 The method according to the invention is also

up to 10 atm in contact with each other. applicable to the continuous alkali refining of

The optimum temperature depends primarily on 65 glyceride oils with the help of centrifuges. Furthermore is

the nature of the treated crude oil, in particular which the method according to the invention is applicable to

Chain length and the proportion of predominant refining processes other than neutralization,

free fatty acids, and the strength of the used which a treatment with aqueous alkaline liquid

and accordingly to refined vegetable oils such as cottonseed oil, soybean

tend to losses as a result of emulsification. To such bean oil, peanut oil, olive oil, sunflower oil,

Procedures include B. the degumming of such safflower oil, sesame oil, linseed oil, rapeseed or

oils that still contain certain amounts of mucilage; rapeseed oil and mustard seed oil, which are predominant

by treating these oils with suitable S fatty acids with a chain length of 16 carbon

aqueous alkaline liquids, e.g. B. Sodium atoms and more, which contain unsaturated bonds

silicate. have fertilize included.

The effectiveness and efficiency of the process according to the invention are surprising, since oils of the second and third groups in particular lead to the saponification at higher reaction temperatures, leading to many difficulties during the reaction being accelerated and the refining, like the one above, was to be expected was stated, the losses due to saponification in the oil as a result of spontaneous emulsification. It can be seen that surface areas increase rapidly with increasing temperature, and many oils, in particular, would assume an intermediate position. It would appear, therefore, that one of the last two types of oil mentioned.
direct saponification does not lead to any appreciable 15 The superatmospheric pressure can simply contribute to the refining losses. The greater part is based on the vapor pressure of the aqueous liquid, the refining losses appear to be due to emulsification or it can be caused by an inert gas such as nitrogen, but not by saponification. If saponification occurs, this will generally be above the saturation vapor pressure of the water at which takes place in the form of indirect saponification, ie at ao treatment temperature. The total pressure, ie the surface area of the emulsified oil particles which follows the sum of the vapor pressure and the pressure of the spontaneous uptake of oil by the inert gas interface, is in the range of 1 to 10 atmospheres, of the alkaline phase. especially 3 to 5 atmospheres, depending on the

The method according to the invention is at processing temperature.

Of particular importance for use on oils 35 The use of more concentrated alkaline types which tend to dissolve during neutralization, for example higher than 0.3N, is of the formation of emulsions, especially spontaneous significance, especially with regard to the lower emulsions. Amount of heat which is required to warm up the aqueous The differences in behavior during the neural alkaline solution. It has been observed that the oils are observed, in particular, that if the concentration of the type of free fatty acid prevailing in the oil is increased, an alkali from 0.1 η to 0.4 η, for example, determines a temperature. temperature increase of about 20 ⁰ C above the tempera-It has been found that in general the refining, which are conventionally used in refining with losses with decreasing chain length of a 0.1 η alkaline solution, predominant free fatty acids in the oil an- 35 is required to reduce the refining losses on which it is essential. Also the presence of more dilute caustic soda to unsaturated bonds in the free fatty acids is reducing. Thus, when relatively influential, oils operating at single or high temperature free fatty acids will contain a small amount of raffi two unsaturation, will show less nation loss compared to more dilute emulsification than oils which are predominantly saturated alkali and a significantly better one Contains fatty acids that are not subject to heat management. Achieved with a higher chain link.

length of the free fatty acids, the losses as a result. In the process, aqueous sodium carbonate spontaneous emulsification can be markedly greater. In particular solution can be used. This type of alkali leads to oils which contain free fatty acids with a high chain length in general to the occurrence of strong spontaneousness and which have a pronounced tendency to emulsify. This stronger emulsification of emulsification during refining, carbonate in relation to sodium hydroxide can be effectively neutralized by increasing the temperature during the refining if the nitralization temperature is chosen well above 100 ° C, compared to that when using Nag . Contrary to all expectations, trium hydroxide maintained temperature, the losses are overcome in the neutralization of such 50 and eliminated. In general, 0.05 to oil types are considerably reduced, and final 2.0 molar sodium carbonate solutions are suitable,
High quality products are obtained when the reaction is neutralized using a Tem temperatures at high temperatures. temperature is carried out, which is about 25 ° C above the general, the various oils can be below the conventional temperature for application of Na Sodium carbonate are completely eliminated, can be summarized: and the same low refining

Losses as when using sodium hydroxide

oils such as coconut oil, palm kernel oil and babassu.

Nut oil, the predominantly free fatty acids with _6o It is known that the refining of glycerides of a chain length below 16 carbon atoms which contain a relatively large amount of free fatty acids, for example 1 to 5% or oils such as palm oil, hydrogenated fats and oils , Cocoa more, often encounters many difficulties. Such butters, Borneo algae, Illipe butter, lard and oils lead to strong spontaneous emulsification, sebum, which is predominantly free fatty acids with a 65 which causes relatively high oil losses. The chain length of 16 carbon atoms or more, the process according to the invention is well suited and which contain a substantial proportion of saturated effective for this type of oils by having at through fatty acids, and carrying out the refining treatment at temperatures

a- well above 100 ⁰ C the refining losses are high temperature the extent of the hydrolysis reaction decreases

il, to be lowered and then comparable with those, equally strong and compete with them

; r as when refining oils of the same kind, reduced loss as a result of avoiding the spontaneous

td which, however, have a much lower level of free tan emulsification. When sebum containing

have n-fatty acid can be achieved. Generally 5 5% free fatty acids, consisting of about 50% ge

n- should be the temperature during the refining of oils, saturated C _{6 -C 18} fatty acids and 50% unsaturated

which have a free fatty acid content significantly above 1% C ₁₈ fatty acids, in a kettle with stirring

have, to achieve lower refining losses 90 ° C is refined, the oil loss amounts to

p- about 25 ° C higher, compared to about 1 kg of oil per kg of fatty acid removed. Another-

id those with a free fatty acid glyceride with io hand, is at a temperature of 14O ⁰ C under

e, content below 1% can be obtained. ■ the same reaction conditions of oil loss

If oils are to be treated, the ratio is about 0.4 kg of oil per kg of fatty acid removed.

ic; contain moderately large amounts of free fatty acids, neutral sodium

I it is advantageous to find the initial content of free salts, especially sodium chloride, application

to reduce fatty acids by using the crude oil 15 den, for example in an amount of 0.3 to 3%

n, before neutralization with an oil - preferably and in particular 0.5 to 2%, dissolved in the alkaline

j- of the same kind - mixed, which is a ratio- solution to the separation of the oil phase from the soap-

; h contains a moderately small amount of free fatty acids. solution to promote. However, it was observed that

_är This may be an oil Also, loading salt favors the spontaneous emulsification and

!1. has already been subjected to alkali refining, since the oil emulsified in this way is no longer of the

Surprisingly, the final refining salt can be separated as the influence of the

r) ₍ losses are noticeably less than the sum of the salt does not extend to spontaneously emulsified oil;

_r . Refining losses in the case of separate treatment of this are accordingly lost. The related

both oils. adverse influence of salt can be reduced,

^ _n When the refining process is carried out continuously, in order to reduce the spontaneous emul-

«. In the process, it is advantageous to continuously select a part of the neutralization temperature.

e of the refined oil after this from the soaps- In this way the advantage of the salt is given in the

η solution has been separated, in the crude oil stream separation of oil and aqueous phase upright-

v to return the received in the room or container, but without the disruptive effect of a

. _s occurs in which the refining takes place. This proportion is increased spontaneous emulsification. For example, if

,. depending on the \ n of the raw safflower oil to be treated, which contains 3 " ₀ free fatty acids, with a

! _ Oil, the amount and the type of 0.1 n alkali solution treated in the crude oil at 60 C, is

i _t essential free fatty acids, as well as other ver the refining factor 1.15. If under otherwise the same

^ driving conditions, such as alkali concentration and conditions safflower oil with a 0.1 η liquor, the 2 ° _o

Ie - as already discussed - the choice of temperature 35 contains salt, at a temperature of over 100 ⁰ C

_r . in the method according to the invention. is treated, the refining loss lies in the

■ g Good results are achieved when the amount of the same amount.

■ :. proportion is chosen so that the content of free fat The method according to the invention is particular

T ₁ acids in the oil, which can be used with the aqueous alkaline oils, such as soybean oil, rapeseed or

t_ solution comes into contact, to such an extent 40 rapeseed oil, cottonwood arnen oil, linseed oil and

Is decreased that the soap content of the refined peanut oil, which is usually a relatively

». Oil does not contain more than about 0.1 percent by weight with a high proportion of mucilage.

_rt wears. This mucus is usually removed by an ent-

_n . The type of free fat slime treatment present in the crude oil removes, e.g. B. by treatment

_{) n} acids depends largely on the glyceride structure of the crude oil with hot water in order to

_In oil as these fatty acids hydrate and precipitate ab- phaticle to a large extent. However,

! j. This treatment does not remove all phosphatides from building products of the triglycerides present in the oil, and

j. are. As indicated above, in the case of soybean oil, for example, the

_n Oil fatty acids generally present in acids that are still about 0.3 percent by weight phosphatide

j _s contain a long carbon chain, and acids that 50 are present. During the neutralization, the dei

have a relatively short carbon chain, remove a larger proportion of the remaining mucilage,

j. can be distinguished. but in general there is so much slime left in it

_iT The relatively high refining losses in the case of oil mean that subsequent degumming is necessary

I. the refining of glyceride oils, which is long-chain when very pure oils are to be produced.

Containing free fatty acids can effectively 55 A significant advantage of the method according to dei

! At the level of, for example, coconut oil, the invention is that a subsequent degumming

'can be done by avoiding the refining if the slimy oil

(j process selects a temperature which is about 40 ° C higher with an aqueous acid, preferably 1 to 5 n-salt

than the temperature normally used. acid in an amount ranging from 1 to 5% of the

j. The long-chain free fatty acids lead to the oil weight, which is mixed and this mixture ohms

. _n contact higher refining losses at application removal of the acid neutralization unterworfer

L _r higher alkali concentrations than the short chain being obtained by putting the mixture under the process

j _e free fatty acids, so that the application of stronger conditions according to the invention with an alka

^ alkaline solutions bring a further increase in the tem- plic remedies in contact. At application

ζ ^ temperature required in order to cope with the adverse influences of such an acid pretreatment, it is particularly:

_ic j to counteract. In these cases it becomes necessary, desirable, the subsequent neutralization after the

_v the maximum allowable temperature in the range of 160 method according to the invention in one completely

to choose up to 170 ⁰ C; in the case of the last-mentioned tem- perature-free or obstacle-free space

The invention is illustrated further with reference to the following exemplary embodiments.

example 1

In order to reduce the losses in the refining, which are achieved by compliance of refining temperatures well over 100 ⁰ C, to illustrate, a tallow with a free fatty acid content of 4.9% was treated at a temperature of 90 ° C, and then a treated further portion of the same oil at 130 ⁰ C.

At a temperature of 90 ⁵ C, crude tallow (free fatty acid content 4.9%) was deacidified in a stirred cylindrical kettle with a conical bottom, with an alkaline solution of 0.8 η in an excess of 10% over the theoretically required Crowd. The oil was then aftertreated with 15 percent by volume of a dilute 0.2 N alkali solution, followed by 3 washing treatments with water in an amount of 10%, based on the amount of oil. The following results were achieved:

final free fatty acid content 0.1%, final soap content 0.15%,
Neutralization factor 1.8, this corresponds to a loss of neutral oil of 0.8 kg per kg of fatty acid removed.

An equal amount of sebum v / urde then treated (along with water vapor, nitrogen) in the same apparatus at a temperature of 130 ⁰ C and a pressure of 4 atmospheres.

After neutralization, a final free fatty acid content of 0.07% became a neutralization factor of 1.4, corresponding to an oil loss of 0.4 kg per kg of fatty acid removed, and a soap content of 0.1% achieved so that washing treatment was no longer required. From the reduction of the Neutralization factor, it can be seen that the neutral oil loss had been reduced to 50%.

Example 2

A batch of 16 kg of crude safflower oil was in the same device as in Example 1 at one temperature of 90 ° C neutralized with a 0.8 n alkali solution. This was followed by an after-treatment with a 0.2 N alkali solution, followed by 3 water washes, required to remove the soap formed by neutralization.

The neutralization factor was 1.6, so that 0.6 kg of neutral oil was lost for every kg of fatty acids removed.

If in the same device another batch of 16 kg with the same alkali solution at was treated at a temperature of 125 ° C and a pressure of 4 atmospheres was none Washing treatment with water is necessary to remove the soap.

In this case, the final free fatty acid content was 0.05%, the soap content was 0.05% and the neutralization factor 1.2, corresponding to an oil loss of 0.2 kg per kg of fatty acid removed; this means that the loss of neutral oil is reduced from 0.6 kg per kg of free fatty acids removed to 0.2 kg had been.

Example 3

From a comparison of the neutralization losses when using a calcined soda or an alkali solution it can be seen that at the same temperature and the same conditions the treatment with Lye results in considerably less refining losses than treatment with soda ash. Through Choosing a higher temperature when treating with soda ash can be essentially comparable Results are achieved. A sebum with a free fatty acid content of 4.5% was used in one Tower neutralized, the one with filling panels in a zigzag arrangement was provided, as described in German Patent 1,287,241.

The device consisted of 36 zigzag mounted sensing plates with a length of 18 cm and a width of 5 cm, which were mounted at an inclination of 5 ° in a housing with a length of 18 cm, a width of 5 cm and a height of 100 cm . In each plate, a tube was mounted in a 0.9 cm diameter hole in the center of the plate at a distance of 1 cm from the end of the plate. The tube has to lead the alkaline solution upwards through the oil layer on the plate below. In this device, a batch of tallow with a free fatty acid content of 4.5% was ^{neutralized at 110 °} C. with a 0.1 n alkali solution in an excess of 25% over the theoretically required amount; no washing treatments were required at all. The following results were obtained: soap content 0.02%, final free fatty acid content 0.3%, neutralization factor 1.05.

With a 1/2 molar solution of soda ash, a soap content of 0.1% became a final one Free fatty acid content of 0.6% and a neutralization factor of 1.3 under identical conditions achieved.

If, however, the treatment with calcined soda was carried out at a temperature of 140 ^° C., the result was a final free fatty acid content of 0.4% and a neutralization factor of 1.05.

B e i s ρ i e 1 4

The negative influence of a high concentration of sodium hydroxide solution on the neutralization can be caused by Increase in temperature during neutralization can be compensated for. This can be seen, for example in the neutralization of tallow with a free fatty acid content of 4.5% at 95 ° C with a 0.1 N sodium hydroxide solution (25% excess over the theoretically required amount) in the same device as in example 3 and comparison of the results obtained with those of a similar treatment, but using a stronger sodium hydroxide solution.

The neutralization factor was 1.10 while when neutralized under the same conditions

a neutralizing factor of 1.45 was obtained with a 0.4 N sodium hydroxide solution. A temperature of 140 ^° C. was required when neutralizing tallow with 0.4 N sodium hydroxide solution in order to achieve a neutralization factor which was the same as when using 0.1 N sodium hydroxide solution

Example 5

There were three approaches of tallow using a 0.1 η solution of caustic soda, the 1 ° Sodium chloride contained, neutralized in the device according to Example 3, the first being a free one Fatty acid content of 1% and the other two had a free fatty acid content of 0.5%. attempt

with the sebum low and the sebum high content of free fatty acids showed that the neutralization factor was much higher in the latter case. at Neutralizing sebum with a high content of free fatty acids under the same conditions, except that the temperature was selected 20 ° C higher during the neutralization, a The neutralization factor obtained is that of the neutralization of a sebum with a low content of free Fatty acids was the same. The following results were achieved:

gen that the presence of salt reduces the loss of neutralization increased considerably when sebum was treated at a temperature of 95 ° C. When on the other hand, the treatment was carried out at a temperature of 130 ° C., was the adverse influence the addition of salt eliminated.

In detail, the following results were obtained:

temperature Content of
free fatty acid Neutralizing
factor 95 ° C
95 ° C
115 ° C 1.0%
5.0%
5.0% 1.35
1.6
1.35

IO temperature C. 0.1 η alkali 1% salt Neutralizing
factor 95 ° C. 0.1 η 1% salt 1.2 95 ° C. 0.1 η With 1.6 '5 130 ° With 1.2

Example 6

The influence of the presence of salt in the neutralization of sebum (free fatty acid content 5%) is apparent from the 3 experiments listed below, which are listed in the device according to Example 3 became.

The results summarized in a table are shown in the table below game 7

To get the same results in neutralizing safflower oil and sebum as below Similar conditions were achieved when neutralizing coconut oil, the temperature had to be the Neutralization treatment can be much higher. The device according to Example 3 used.

In detail, the following results were achieved in the tests:

oil temperature Free fatty acid
salary
g-equiv. / kg 0.1 η
0.1η
0.1η
0.1η
0.1η alkali salt
salt
salt
salt
salt Neutralizing
factor Coconut
Valley 95 ⁰ C
95 ⁰ C
95 ° C
140 ° C
120 ° C 0.17
0.17
0.17
0.17
0.17 with 1%
with 1%
with 1 %
with 1 %
with 1 % 1.1
1.6
1.25
1.1
1.1 Safflower. .. Tallow. Safflower

Example 8

This example illustrates the implementation of the neutralization according to the invention in one completely free of obstacles. In a stainless steel column with a height of 160 cm and a diameter of 10 cm, which had a conical bottom, a sebum was neutralized. The column was closed to the atmosphere and the neutralization was carried out under a pressure of about 5 atm, the gas phase consisting of nitrogen saturated with water vapor. The oil and the alkaline solution flowed countercurrently, the oil being introduced at and from the bottom numerous small openings flowed upwards, so that a dispersed phase was present; the alkaline Solution flowed downwards. The soap solution formed was continuously from the bottom below deducted from the oil inlet. The alkaline solution had a concentration of 0.3 η and was in one 25% excess present. The temperature was kept at 140 ° C. during the neutralization. The oil throughput was 4 t / m * / h. The initial free fatty acid content was 5.62%. The

neutralized oil had a free fatty acid hue of 0.15% and a soap content of 0.08%. The neutralization factor was 1.16.

Claims (1)

ζ. will split, there is a considerable amount of Claim: Neutraiol in the acidic oil, resulting in a reduction the yield of neutral oil leads. Generally are acidic Process for the alkali refining of glyceride oils which contain 30 to 40% or more neutral oil, oiling with an aqueous liquid by means of In- 5 is still quite common. It is possible to bring the neutral oil into contact with aqueous alkali of usable quality from the soap solution back in a place free of internals or obstacles, but this is quite expensive and the space that a straight line movement of accordingly technically and economically unsatisfactory, In the literature, various methods have been used that would prevent, and removal of the io formed, in order to reduce the inherent soap in aqueous solution, which is characteristic of alkali refining, in order to reduce losses, for example the use of draws the oil and the aqueous less alkaline compounds, such as calcined liquid at a temperature of 105 to soda and ammonia, and the use of centrifugal 170 ⁰ C under a pressure of 1 to 10atü, which very short contact times between each other brings. 15 to the oil and the alkaline solution. When If certain improvements can be achieved with such working methods, the oil losses are still very considerably, especially when refining glyceride oils which are predominantly fatty acids with a chain length of 16 carbon atoms or more