JPS6197394A - Purification of oils and fats - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a method for refining oils and fats, and more specifically, the present invention relates to a method for refining oils and fats, and more specifically, a method for deodorizing oils and fats and separating components such as tocopherols and fatty acids without deterioration of the oils and fats. I, and with relatively low energy costs and simple operation.

BACKGROUND ART AND TECHNICAL PROBLEMS OF THE INVENTION Oils and fats generally have a unique odor, and also produce odorous components when rancid or decomposed. Furthermore, it is also used in the curing process and deodorizing process in the oil and fat industry.

These odorous components are volatile, and this property is utilized to remove them by steam distillation at high temperature and reduced pressure.For example, recently, Girdler (Qtrd-1t
r) method is widely adopted.

In a typical one-type girder, a tower with five or six chambers is used, and oil is injected into the chamber at the top of the tower and allowed to flow semi-continuously into the chambers below. In the upper two chambers, water vapor is blown into the oil and fat, which is heated by heat exchange with a heating medium (or high-pressure steam), and is allowed to flow down to the lower chamber. In both of the following stages, the fats and oils are stirred by steam purging and steam distillation is performed. A vacuum of several torr salt is maintained in the column by a steam ejector. During steam distillation, a considerable portion of tocopherol (vitamin E) contained in vegetable oils and fats is simultaneously condensed in a condenser and discarded together with the odoriferous components. Most natural vitamin E is produced by recovering this scum and using it as a raw material. However, this steam distillation method is still expensive in terms of thermal energy costs, number of steps, and workability. It has defects.

First, the basic unit of steam used is 50 OKg for blowing and heating and 1500 kg for steam ejector per 1 ton of oil, which requires a large amount of thermal energy cost.

In addition, during steam distillation, not only does the water blown into the residual product fats and oils remain (but also the water content is simultaneously condensed in the distilled volatile components, requiring a water separation operation, and the uncondensed distillate is removed). The components are mixed into the wastewater of the steam ejector and require special wastewater treatment.Furthermore, if water vapor is mixed into the high-temperature fats and oils, there is a risk that some of the fats and oils will deteriorate, such as becoming rancid.

OBJECTS OF THE INVENTION Accordingly, an object of the present invention is to provide a method for refining fats and oils that eliminates the above-mentioned drawbacks of conventional deodorizing methods.

Another object of the present invention is to use an inert gas instead of water vapor as the blowing gas, and to eliminate odorous components contained in oils and fats with low thermal energy cost and without the need for careful separation operations. The object of the present invention is to provide a method for purifying fats and oils in which fatty acids, tocopherols, etc. can be easily separated.

Still another object of the present invention is to provide a method that can easily deodorize oils and fats while preventing thermal deterioration and oxidative deterioration using a relatively compact device and in a closed circuit. It is in.

Structure of the Invention According to the present invention, there is provided a method for distilling and removing odorous components, fatty acids, or tocopherols in oils and fats under reduced pressure. In addition to arranging an inert gas blowing mechanism, a distillate extraction mechanism is arranged at the top of the device, and the vacuum side of the vacuum pump and the distillate extraction mechanism and the normal pressure to high pressure side of the vacuum pump are connected to each other. A gas blowing mechanism is connected to the gas blowing mechanism so that at least one side has a cooling condensing mechanism, and an inert gas is blown into the fats and oils at high temperature and under reduced pressure to eliminate odor components, fatty acids, or tocopherols in the fats and oils. Provided is a method for refining oils and fats, characterized in that the components are distilled together with an active gas, the distilled components are coagulated and separated under cooling, and the separated inert gas is circulated by the blowing mechanism. In the present invention, an inert gas such as nitrogen or carbon dioxide gas is used instead of water vapor as a purge gas for evaporating odorous components, etc. 17 This inert gas is blown into the liquid of oils and fats to be purified, and the above-mentioned I- By lowering the partial pressure of the vapor pressure of the odorous components, etc., the boiling point of the liquid is lowered, and the low volatile components in the liquid, i.e., the odorous components, etc., are reduced at a relatively low temperature and under reduced pressure. Evaporate and separate with inert gas.

The inert gas mixture containing the vaporized components is removed from the evaporative distillation apparatus under reduced pressure and cooled to condense and recover at least a portion of the distilled vapor components. The remaining inert gas mixture is compressed and cooled, and most of the contained distilled vapor components are condensed and liquefied and recovered.

In the present invention, by using a mechanical vacuum pump instead of a steam ejector and providing cooling and condensing mechanisms before and after the pump, this operation can be carried out smoothly [7] without the above-mentioned drawbacks. That is, by connecting the reduced pressure suction side of the vacuum pump to the distillate extracting mechanism of the vacuum evaporation distillation apparatus, and connecting the normal pressure to high pressure discharge side to the blowing mechanism of the liquid reservoir, the inside of the apparatus is While maintaining a predetermined degree of vacuum,
Compression is performed from the reduced pressure suction side to the normal pressure to high pressure discharge side, and by cooling this compressed gas, the contained wet vapor components are condensed and liquefied. The inert gas from which the vapor component has been separated is circulated again to the blowing mechanism of the liquid reservoir to continue the evaporative distillation operation.

In this case, since the inert gas containing the distilled vapor component is compressed in the vacuum pump, the vapor component is condensed. Therefore, it is advantageous to use a liquid ring type (Natsusch type) or mechanical type vacuum pump.

Effects of the Invention According to the present invention, oxidation and deterioration of oils and fats and components to be separated due to heating of the liquid can be effectively prevented by performing evaporative distillation of odorous components etc. in an inert gas. I can do it. In addition, by blowing an inert gas into the liquid, the boiling point can be lowered to a temperature considerably lower than the boiling point of the component to be separated, and the components can be evaporated or distilled at a low temperature. The degree of oxidation and deterioration will be even lower.

Most importantly, the use of an inert gas prevents moisture from being mixed into the product fats and oils and distilled components, and facilitates separation and recovery operations. Oxidative deterioration of oils and fats due to the presence of water vapor can also be effectively eliminated.

However, according to the present invention, in connection with the use of an inert gas, the latent heat of vaporization of water during evaporation as in the case of steam distillation and the latent heat of liquefaction of water during cooling condensation [7] are completely unnecessary. , which simply acts as a purge gas during evaporation to lower the partial pressure of the evaporated components, achieving numerous advantages in terms of thermal economy. Furthermore, the amount of nitrogen blown as a purge gas tends to be smaller than that in the case of steam.

Furthermore, the inert gas blown into the liquid lowers the boiling point of the distillate component, and even if this component exists in the form of small particles in the oil or fat, it can be used as a carrier gas accompanying the gas phase. Therefore, it also has the advantage that the desired components to be separated can be separated and evaporated down to minute particles within a short period of time.

Furthermore, according to the present invention, by combining inert gas injection and gas circulation via a vacuum pump, it is possible to maintain the evaporative distillation apparatus at a predetermined degree of vacuum and to compress the gas containing the eluted vapor component. The condensation by cooling and the circulation blowing of inert gas are carried out smoothly, and the apparatus is compact and can be operated in a closed system.

Preferred embodiments of the invention The present invention will be explained below based on the accompanying drawings.

In FIG. 1, the evaporator main body 1 includes a liquid reservoir section (can section).
2 and a thin film evaporator 3 thereon, each of which is provided with a steam jacket 4, 4' for heating the liquid. This steam jacket 4 (4') is provided with a steam inlet pipe 5 (5'), a valve 6 (6'), and a drain extraction pipe 7 (7'), respectively, to keep each part of the device at a predetermined temperature. Heat to.

A supply pipe 8, a valve 9, and a pipe 10 for the liquid to be treated are provided in the upper part of the thin film evaporator part 2. A liquid extraction pipe 1) is provided in the lower end of the liquid reservoir part 2, A liquid circulation path is formed from this extraction pipe 1) to a valve 12, a circulation pump 13, a circulation pipe 14, a valve 15, and a supply pipe 10.

An inert gas blowing pipe 16 is provided in the liquid reservoir 2, and a take-out pipe 17 for partially containing inert gas is provided at the top of the evaporator main body 1. The extraction pipe 17 passes through the cooling condenser 18 and pipe 19 to the first condensate tank 20, the pipe 21 passes to the low pressure side of the liquid ring vacuum pump 22, and the high pressure side of this pump 22 passes through the cooler 23 to the second condensate tank 20. Inert gas circulation paths are formed from the condensate tank 24 and from the tank 24 to the blowing pipe 16 via a pipe 25 and a pressure reducing valve 26, respectively.

In FIG. 1, 27 and 28 are pipes and valves for gas discharge, 29 and 30 are pipes and valves for supplying inert gas, and 61 is a pulp for switching operations.

First, the valve 15 is closed, the valve 9 is opened, and a predetermined amount of oil and fat to be treated is introduced into the apparatus main body 1 through the pipes 8 and 10. Steam is supplied to the steam jacket 4゜4' to heat the main body of the device, close the valve 9, open the valves 12 and 15, operate the pump 16, and pump the liquid in the liquid reservoir 2 into the pipe 1). ．． Thin film evaporation through 14 and 1o9. Circulation 1 to m3. Continue heating.

Fats and oils to be treated and 1. Includes any oil or fat, safflower oil, soybean oil, sunflower oil, corn oil, cottonseed oil,
Vegetable oils such as sesame oil, rapeseed oil, rice bran oil, kapok oil, peanut oil, olive oil, palm oil, palm kernel oil, coconut oil, linseed oil, castor oil, eno oil, tung oil; beef tallow,
Land animal fats and oils such as lard, mutton fat, and milk fat; water bottle animal fats and fats such as whale oil and fish oil can be magnetized. These fats and oils are subjected to pre-purification steps known per se such as degumming, deacidification, hot water washing, and decolorization with activated clay, or further treatment steps such as hydrogenation if necessary, and then subjected to the purification method of the present invention, that is, the deodorization method. Attach to.

Prior to heating the fats and oils, or at the same time, HaA/
7”!1), open the pulp 30 and open the pipe 29.
An inert gas source (not shown) such as a nitrogen cylinder through the i
Then, the blowing pipe 16 is blown to blow inert gas into the liquid. The pulp 28 is opened and the liquid ring vacuum pump 22 is activated to purge the air in the system with inert gas, after which the pulp 28, 30 is closed and the pulp 31 is opened. The pressure of the inert gas to be blown is regulated by a pressure reducing valve 26.

In the refining method of the present invention, the heating temperature of oils and fats varies depending on the type of oil and fat, and although it cannot be generally specified, if the heating temperature of oil is increased, the vapor pressure of the distillate will increase, resulting in a lower vacuum. But I will leave. Nitrogen is blown into this, and the higher the amount of nitrogen blown, the lower the vacuum (that is, the higher the pressure). If you blow in an amount equal to the amount of steam produced, 2
At 0 Torr, the same is distilled at vapor pressure.
If the vacuum level is high enough, blowing in nitrogen can achieve the same effect as the former at a lower temperature. The amount of inert gas blown is determined so that the above-mentioned degree of vacuum is maintained and the components to be separated, such as odorous components, fatty acids, and tocopherols, are actively evaporated.

The liquid is agitated by the inert gas blown in, and the components in the fats and oils are boiled and evaporated.The inert gas containing steam is drawn out of the device via a pipe 17 and is then stored in a condenser 18. It is cooled, and an amount of steam corresponding to the temperature differential pressure is condensed and collected in the first condensate tank 20. The remaining gas is compressed in the liquid ring vacuum pump 22, its partial pressure is increased, and most of the vapor is condensed and collected and separated in the second condensate tank 24. The inert gas after separation is adjusted to a desired pressure by a pressure reducing valve 26,
It is blown into the liquid through the blowing pipe 16 and the evaporation operation continues.

According to the present invention, by the above-described inert gas circulation operation, the above-described separation and recovery of components and deodorization of fats and oils can be carried out efficiently and almost completely within a short period of time.

Example The invention is illustrated in the following examples.

EXAMPLE 250 Kf of food oil containing malodor components of 0.6K9 was subjected to the refining process of the present invention using the apparatus shown in FIG. 1 to remove malodor. Note that the purification conditions are as follows. .

Blowing purge gas Nisso 6Vn//Ir Nisso blowing time 2r! Heating temperature: 150C Vacuum degree: 20 Torr (%HP) That is, while heating and depressurizing the food oil to 150C, 20)-L, 6 Nd/L of nitrogen gas is blown into the tank, and the malodorous components distilled together with the nitrogen gas are cooled and condensed. Please make sure to recycle the nitrogen gas. A mechanical (roots type) vacuum pump was used as the vacuum pump.

The volume of nitrogen gas used as purge gas was 6#i
/AX2x760/20x (273 plus 150)/275
=706tr? Met.

Comparative Example The same edible oil (250 Ky) used in Example [7] was blown with steam under reduced pressure to remove malodorous components. Purification conditions are as follows.

Blowing steam 150C15 to 9/lr (heated steam is not included) Steam blowing time 3 hrz Heating temperature
150C Vacuum degree 3 torr (%Hf) i.e. 150
C steel A 5 Kg/A r for 3 hours (total 15
Kg) The malodorous components in the oil could be removed by blowing into the oil. The degree of vacuum of 3 Torr was maintained by a steam evaporator, and the amount of steam required for this purpose was 150 to 200 Kp. Steam as purge gas (specific volume 0.4i/150C steam with 9.4.
The volume used was 835 f/d).

From the above results, it is understood that according to the present invention, the purpose can be achieved in a low vacuum with a much smaller amount of nitrogen than steam, and there is no loss due to cyclic use.

[Brief explanation of the drawing]

FIG. 1 is a layout diagram showing an example of the apparatus of the present invention. The number 1 on the side is the device body, 2 is the liquid reservoir, 4 is the heating mechanism, 1
6 inert gas blowing mechanism, 17 and 22I'' inert gas circulation mechanism, 18.20 and 23.24 cooling condensation recovery mechanism.

Claims (1)

[Claims] (1) A method for distilling and removing odorous components, fatty acids, or tocopherols in oils and fats under reduced pressure, which includes a heating mechanism in the liquid distillation section of a vacuum evaporation distillation device and a mechanism for blowing inert gas into the liquid. At the same time, a distillate extraction mechanism is arranged at the top of the device, and the vacuum side of the vacuum pump and the distillate extraction mechanism and the normal pressure to high pressure side of the vacuum pump and the inert gas blowing mechanism are connected. , connected to at least one side with a cooling condensation mechanism, blowing an inert gas into the fats and oils at high temperature and under reduced pressure, and distilling odor components, fatty acids, or tocopherols in the fats and oils together with the inert gas. . A method for refining oils and fats, characterized in that the distilled components are coagulated and separated under cooling, and the separated inert gas is circulated by the blowing mechanism.