MXPA06011945A

MXPA06011945A - A method for extracting vegetable oils and a counterflow device for performing said method.

Info

Publication number: MXPA06011945A
Application number: MXPA06011945A
Authority: MX
Inventors: Vitaly Nikolaevich Kusnetsov
Original assignee: Stavrulov Igor Anatolievich
Priority date: 2004-04-14
Filing date: 2005-04-04
Publication date: 2007-04-13
Also published as: WO2005100518A1; BRPI0508811A; RU2261269C1; AR048694A1; CN1969031A; CA2562410A1

Abstract

The invention relates to an oil and fat industry, in particular, to production of vegetable oils by a method of extraction by organic solvents. Aim of the invention is to provide such method of the vegetable oils extraction, such device for its implementation, and such extractor of a submersible type being a part of the device, which allow to increase intensity of mass exchange at the extraction stage, to increase concentration and purity of produced miscella, providing heightening output of the extracted oil and improving its quality, and also to obtain defatted meal suitable for further processing. For achieving these aims, the process is carried out at a temperature of phase transformation "fluid-vapor" in conditions of cavitation and intensive mixing of the solvent in non-mixed surrounding of a solid phase of the material under extraction, and solvent vapors, which are produced in this process, are removed, condensed and returned back into the process, providing the re-circulation of the solvent.

Description

A METHOD OF EXTRACTION OF VEGETABLE OILS, A DEVICE FOR THEIR REALIZATION AND A SUBMERSIBLE FLOW EXTRACTOR Field of the invention.

The present . invention relates to a method of extracting vegetable oils, a device for its realization and a submersible counter-flow extractor, applicable in the fats and oils industry and, in particular, to the production of vegetable oils by means of a method of, extraction with organic solvents.

Description of prior art.

The methods of production of vegetable oils by means of application of cold or hot pressure are widely "disclosed at present." By hot pressing the maximum amount of oil is obtained, however, the oils obtained by this method contain many substances The extraction carried out in cold seeds offers less oil, but the oil obtained contains less polluting substances All the oils produced through the application of pressure (or pressing) contain a large quantity of mixtures and require some purification. Obtaining vegetable oils by means of volatile vegetable solvents (often low-boiling benzene proportions) and the subsequent distillation of the solvent are associated with chemical methods. help of organic solvents, these methods provide a preparation treatment of the raw raw materials by the application of solvent vapors, by means of a repeated process of splashing the material extracted with a composition that includes organic solvent. The extraction process is completed by splashing with the organic solvent compound in a vertical column. The distillation of the solvent with respect to the material is provided by the action of superheated solvent vapors that do not leave the device, but instead condense in the ground grain and subsequently return to the extraction process (see Russian Patent No. 2166533, CllB l / 10, 1999) .- The device according to the aforementioned patent comprises a loading column with inlet cavities of the material to be extracted and of the purified gas and the air mixture, in addition to outputs of the purified air; a cross unit with a recirculation unit of organic solvent composition, and a vertical extraction column with an internal screw and cavities for the entry of material subjected to extraction and superheated solvent vapors, in addition to an outlet for the ground grain . Vertical extraction column APEA, this process is built to counter-flow. The main disadvantage of this method and of the device for the extraction - in itself, is its low speed of mass exchange in the extraction process, which requires a rather high proportion of solvent with respect to the material to be extracted, which results in the obtaining compositions with organic solvent of low concentration. The known methods of extraction of vegetable oils influence the load of the material to be extracted, an extraction of the oil by means of solvent in a counter-flow extractor of the submersible type, an extraction of the vapors of solvents, their condensation and re-entry to the process, and the extraction of the composition with vegetable solvent and ground grains. The material to be extracted is impregnated with saturated vapors of organic solvent prior to extraction. The extraction of the solvent oil is carried out in a counter-flow extractor of submersible type and in a vertical counterflow extractor. The extraction of the solvent vapors, their condensation and the re-entry to the process are foreseen in the process. The extraction of the solvent with respect to the processed milled grains is carried out by means of the application thereto of superheated solvent vapors and the heating of the processed grains in the unloading zone. (Russian patent PAC -N "2210589, C11B 1 / 10,2001.) The device for the implementation of the known method is also known.This contains a feed column with an inlet cavity of material to be extracted, inlet cavities. for air formulated with solvent vapors, and output for purified air; a dosing screw; a capacitor; a submersible counter-flow extractor with outlet cavities for the solvent vapors with respect to the extractor inside the. condenser and re-entry for condensed vapors; a unit for heating the ground grains; and solvent entry cavities and. of exit of the compound with organic solvent of the device. The submersible type backflow extractor, which is part of the device, is positioned horizontally. This method, the device and the extractor are the closest in similarity to those proposed. The main disadvantage of this method, the device for its implementation and, according to this the extractor, as well as the previous homologs, is the low mass exchange in the extraction process, produced at a relatively low temperature (45-50). ° C).

Additionally, the cooling of the material under extraction by spraying it with solvent, which is provided in the device, results in obtaining a ground grain with an increased oil content. On the other hand, the use of the pump for the recirculation of composition with organic solvent makes the exploitation conditions difficult (due to the existence in the composition with organic solvent of a large number of particles with highly abrasive properties) which leads to the existence of mechanical mixtures during the extraction of the composition with organic solvent.

SUMMARY OF THE INVENTION It is object of. The present invention provides a method of extracting vegetable oils, a device for its realization and a counterflow submersible extractor, which is part of the device, that allow to increase the intensity of the mass exchange in the extraction stage, increase the concentration and purity of the composition with organic solvent obtained, producing an increase in the extraction of oil and an improvement in its quality, and also obtain a composition with defatted organic solvent of higher quality suitable for further processing. The aforementioned objectives are obtained due to the fact that in the method of extraction of known vegetable oil carried out by organic solvents, which includes the load of material to be extracted, an extraction of the oil by means of a solvent. in a submersible type counter flow extractor, the extraction of solvent vapors, their condensation and re-entry to the process, extraction of the ground grains and the composition with organic solvent, the extraction process is carried out at a transformation temperature. of "liquid-vapor" phase under cavitative conditions.

BRIEF DESCRIPTION OF THE DRAWINGS For greater clarity and understanding of the object of the present invention, it has been illustrated in several figures, in which it has been represented in the preferred forms of embodiment, all by way of example, where: * Figure 1 is a view general representative of the device for the extraction of vegetable oils that includes a counter-flow extractor of submersible type.

Figure 2 shows an example of embodiment of the device of figure 1.

DETAILED DESCRIPTION OF THE INVENTION As mentioned, to achieve the objectives mentioned above this objective with the "known device for extracting vegetable oil by means of organic solvents, which includes a feed column with an inlet cavity of material to be extracted, cavities input for the air used with solvent vapors, and exhaust for the purified air, a dosing screw, a condenser, a counterflow extractor of submersible type with exit cavities for solvent vapors with respect to the extractor inside the condenser and for the re-entry of the condensed vapors, a unit for the heating of the milled grains, cavities of solvent inlet and outlet of the organic solvent composition, the counter-flow extractor of the submersible type is provided with heating means for maintain the interior temperature of the extractor at the "liquid-vapor" phase transformation levels. to conformed in the form of one or more sections. Additionally, a decanter is located prior to the first extractor section including said decanter a loading tube enlarged downward to produce a gas seal. The sections of the submersible backflow extractor can be made horizontally, inclined, vertical, or combination thereof. In an optimal device design for. The extraction of vegetable oils provides an inclination of each section of the extractor against submersible flow towards the loading area of the material to be extracted. Another embodiment of the submersible flow extractor comprises the concept of arranging the first inclined section, regarding the path that the material to be extracted travels, and arrange the next section horizontally. The counterflow extractor of submersible type for the extraction of vegetable oils by means of organic solvents, in order to obtain the previously indicated objective, a box with cavities for the entry of material to be extracted, for the solvent, and an exit For solvent vapors, the organic solvent composition and the milled grains; it also contains heating means for maintaining the inner part of the extractor at a "liquid-vapor" phase transformation temperature. This embodiment is carried out in the form of one or more sections. Numerous researches of the inventor have laid the foundations for this invention. These confirm the fact that the optimum temperature for the process of extraction of vegetable oils by means of organic solvents and the boiling temperature of the solvent at a certain corresponding pressure. to the pressure inside the extractor, for example this temperature is in the range between 68-72 ° C for solvents type "Lephras". The extraction of oil at such temperatures is carried out under conditions of "liquid-vapor" phase transformation and is accompanied by a cavitation process produced by the boiling of the solvent and by the intensive agitation of the extractables in the material layer under extraction. The hydrodynamics of the process is such that each particle of the layer of the unstirred material is washed repeatedly and repeatedly by means of the extracted substance. All this leads to a drastic increase in the warming and a mass exchange and in accordance with this, the intensification of the extraction process. The proposed method is implemented, and the device and the counterflow reactor operate in accordance with the description below: The material to be extracted enters the loading column where it is impregnated with solvent-saturated vapors which bring in formulated air. Then the material is transferred in a decanter by means of a metering screw, and purified by the raw mixes with the organic solvent composition, which comes in counter-flow. Then you come to a counter-flow extractor - of the type, submersible, whose sections are. they are added with heating means. The process of . Extraction is carried out at a temperature, of "liquid-vapor" phase transformation under cavitation conditions. The resulting solvent vapors are removed from the extractor and condensed. The vapors condensed at a temperature close to the boiling temperature are re-inked to the extractor, thus generating a recirculation of the solvent. This allows the reduction of the need to supply fresh solvent in the device, according to the increase in the concentration of the composition with organic solvent; final. The integrity of the extraction of oil is such that virtually defatted milled grains reach the last section of the extractor against flow, where the solvent is removed by means of the supply of vapors of superheated solvents and the heating of the grains. . An exemplary embodiment of this method is described below, which should not be understood as a limitation of the invention. The material has to be extracted, in this case grains of soybean in flakes, it enters the 'column of load where it is impregnated with saturated vapors of solvent that enter together with formulated air. Then the soybean mass is displaced by means of the dosing screw inside the decanter, purifying the composition with organic solvent that enters the counter-flow from the crude mixtures. Subsequently, it enters the submersible counter-flow type extractor. Six sections of the extractor are inclined towards the loading area and are provided with heating elements. The heating elements (or means) are made in the form of steam radiators. These allow to maintain the temperature between 68 ° C and 72 ° C in the inner part of the sections. The extraction process is carried out under "liquid-vapor" and cavitation phase transformation conditions. The produced solvent vapors are removed from the extractor sections and subsequently condensed. The steam condensed at a temperature close to the boiling temperature returns to the last section of the extractor (in the direction of the extracted material), thereby generating the recirculation of the solvent. The ground grain that enters • The last section (seventh section) of the counter-flow extractor for the final extraction and distillation of the solvent, has an oil content between 0.7% and 1.0%. The extraction time is 21 minutes. The concentration of the composition with final organic solvent is between 50% and 70%. For the precise description of the essence of the invention, Figure 1 will first be used, which shows a general scheme of the device for the extraction of vegetable oils that includes a counter-flow extractor of the submersible type. The device for extracting vegetable oils of figure 1 includes a column 1 with a cavity or hopper 2 for the entry of the material to be extracted, a cavity 3 or connector for the entry of air formulated with solvent vapors, a cavity 4 for the removal of the purified air a dosing screw 5 that provides a stable level of material to be extracted in the loading column 1, a decanter 6 that serves for a preliminary purification of the composition with organic solvent, removing it from raw mixtures , and to maintain the constant level of the substance in extraction in the submersible extractor. The submersible extractor is made in the form of several inclined sections 7, 8, 9, 10, 11, 12, connected to each other by means of overload units 13, 14, 15, 16, 17. Each of the inclined sections 7 , 8, 9, 10, 11, 12 is provided with screws or endless screws 18 positioned inside the sections for the transport of the material to be extracted; as well as also means or heating elements represented, for example in this case, by steam radiators 19. Each of the inclined sections 7, 8, 9, 10, 11 t ~ 12 is provided with cavities 20. , 21, 22, 23, 24, 25 for the extraction of solvent vapors produced in the course of extraction, through drop receivers 26, 27, 28, 29, 30, 31 arranged inside the condenser 32, and cavities 33, 34, 35, 36, 37, 38 for the return of the composition with organic solvent within the sections in the agitation box. The last section of the counter-flow extractor is made in the shape of an inclined column 39 with a screw (not illustrated in the figure) disposed therein. The inclined column 39 is provided with a cavity 40 for the removal of the solvent vapors from the condenser 41. Additionally the column 39 includes a cavity 42 for the return of condensing vapors to the. capacitors 32 and 41; , and a cavity 43 for replenishing the • extractor with solvent from the inversion system. The inclined column 39 further has an exit cavity or mouth 44 for permitting the discharge of milled grains from the device; a unit 45 located at the top of the column for heating the milled grains; and a spout for contemplating possible evacuations of "the column 39 if necessary." Figure 2 shows a variant of the device, which includes a loading column 56. with a cavity or hopper 57 for introducing the material to be extracted, one, cavity 58 for introducing the air formulated with solvent vapors, a cavity 59 defining a purified air outlet, a metering screw 60, a decanter 61, and a submersible type extractor having inclined 62 and horizontal sections 63 which house therein respective dosing screws 64 and 65, in turn being disposed respective heating elements or means represented by steam radiators 66 and 67. The counter-flow extractor of the submersible type has another vertical section 68 for the final extraction of the oil For its part, a screw 69 is also positioned inside this section, while a lime element is arranged outside it. This embodiment is represented by a steam radiator 70. The upper part of the section 68 has a cavity 71 for discharging milled grains and a heating unit 72 for heating said ground grains, the lower part has a cavity 73 for deflecting the grains. solvent vapors inside the condenser 74 and a cavity 75 for the return of the cornered vapors, a cavity 76 for the solvent replenishment to the extractor, and finally a cavity 77 for the evacuation of the section 68. The cavity 78 of an inclined section 62 and a decanter 61. The decanter 61 is provided with a cavity. - 73 for the extraction of composition with organic solvents from the device. The loading tube 80, which is widened in the lower part, is positioned inside the decanter, this serves to form a gas seal that prevents passage from the decanter 61 to the column 56 of saturated solvent vapors. The material subjected to extraction coming from the dosing screw 60 descends through the tube. The cavity 81 is located in the upper part of the decanter 61 thus connecting the gaseous space of the decanter with the gaseous space of section 63 (not illustrated in the figure). The device and its part, that is, the submersible counter-flow extractor, according to Figure 1, work in the following manner. The material prepared for the extraction enters the column 1 through the cavity 2. Subsequently, the dosing screw transfers the material into the loading tube 48 of the decanter 6, where it reaches the layer of compound with organic solvent, is saturated by the Composed of organic solvent and is stripped of air, air that penetrates through the cavity 49 into the gaseous space of the inclined sections. The material saturated with organic solvent and stripped of air, goes down through the inclined section and is removed by a screw (not illustrated in the figure) within section 8 through the transfer unit 13. The material during the transfer process reaches the zone of the compound with solvents in the boiling state and saturates it with the oil. This process is repeated in the inclined sections 8, 9, 10, 11, 12 of the submersible counter-flow extractor. The consistency of the compound with solvents (oil content in the solvent) is increased in each consecutive section, while the oil content in hard particles of material is reduced. In the output of section 12 this content is only 1% to 1.5%. The pure solvent in the inclined section 39 washes the material. Then, a screw (not shown in the figure) transports the material from the area where it is immersed in solvent to the vaporization zone of the solvent. Le - extracted material stripped of solvent is discharged through the cavity 4. The solvent vapors generated in the composition of boiling (boiling) solvents in sections 7, 8, 9, 10, 11, Í2, move towards the drop receivers 26, 27, 28, 29, 30, 31 , any type of foam is eliminated, while the drops are charged (transported) by the vapor and condensed in the condenser 32. The solvent vapors produced in the evaporation of the solvent 39 are condensed in the condenser 41. A condensate of the solvent vapors are released through the cavity 42 into the section 39 and are displaced in the direction of the decanter through the inclined sections 12, 11, 10, 9, 8 and 7 towards the material flow under extraction. The solvent from the recycling device (system) is fed through the cavity 43 into the section 39 to replenish the extractor in the amount corresponding to its composition content with organic solvent, which is displaced out of the • extractor through of the cavity 47 of the decanter 6. The mixture of steam and air is transported by additional units from the condensers 32 and 41 through the cavity 3 towards the loading column 1, it is subjected to the elimination of the solvent vapors (by solvent absorption medium? from the oil contained in the material to be extracted) and removed through the cavity 4. The device and the extractor a. Submersible counter-flow according to Figure 2 operates as described below: The material prepared for extraction passes through the cavity 57 within the loading column. 56. Subsequently, the dosing screw 60 transfers it into the charging tube 80 of the decanter 61, where said material comes into contact with the composition layer with organic solvent, is saturated by said composition and removes itself from the air. The removed air passes through the cavity 81 into the gaseous space of section 68. The material, saturated by > the composition with organic solvent and stripped of the air, advances downward within the inclined section 62 and is removed by the screw '64 within the horizontal section 63 of the backflow extractor. During the transfer process the material reaches where the organic solvent composition is in the boiling state, saturating it with oil. The pure solvent washes the material in vertical section .68 of the counter-flow extractor. Then the material is transported from the area where it is submerged in the solvent to the evaporation zone of the solvent.

- The material that has been extracted and released from solvent is discharged through the cavity 71. The solvent vapors that are formed as a result of the boiling of the composition with organic solvents in sections 62 and 63 of the counter-flow extractor, and in section 68 they are condensed in condensing unit 74.

The condensate from the solvent vapors is poured through. of 75 within the __68.y section. displaced in the direction of the decanter through the horizontal section 63 and the inclined section 62 of the counter-flow extractor to the flow of material subjected to extraction. The solvent is sent through the cavity 76 to the section 68 to achieve the replenishment of the extractor from the recirculation system in an amount corresponding to the content of the solvent in the composition with solvent obtained, which is removed from the extractor to through the cavity 79 of the decanter 61. The mixture of air and steam is transported by additional devices from the condenser 74 to the loading column 56 through the cavity 58. In addition, the solvent vapors are eliminated (by absorption of the solvent from the oil contained by the material under extraction) and removed through the cavity 59.

The investigations carried out by the applicant have confirmed that the optimum temperature of the process for extracting vegetable oils by means of organic solvents is a temperature equal to the boiling temperature of the solvent at a pressure corresponding to the pressure of the extractor. These investigations show that at that temperature the extraction of oil takes place under conditions of "liquid-gaseous" phase transformation., accompanied by a cavitation process, conditioned by the boiling of the solvent and by the extensive mixing of the substance extracted in the layer of material to be extracted. The hydrodynamics of the process is such that each particle of the layer of the. Unmixed material is washed intensively and repeatedly by the extracted substance. All these factors lead to a substantial increase in heat and mass exchange, which therefore intensifies the extraction process. In this way, the present invention allows to increase the intensity of the mass exchange in the extraction stage, in order to increase the concentration and purity of the composition with solvent obtained, as well as to provide an increase in the extraction of extracted oil and improve its quality, and in addition it offers a resultant defatted ground grain of high quality.

Claims

CLAIMS Having thus specially described and determined the nature of the present invention and the manner in which it is to be put into practice, it is claimed to claim as property and exclusive right:

1. A method of extracting vegetable oils by means of organic solvents, which includes a charge of material to be extracted, an extraction of oil by the solvent in a submersible counter-flow extractor, a collection of solvent vapors, its condensation and return to the process, a removal of the milled grain and the composition with organic solvents, characterized in that in the same the extraction process is carried out at a "liquid-gas phase" transformation temperature under cavitation conditions.

2. A device for the extraction of vegetable oils by means of organic solvents, which includes a loading column with a cavity to enter the material to be extracted, cavities to enter the air formulated with the solvent vapors, and for the removal of purified air , a dosing screw, a condenser, a submersible counter-flow extractor with cavities for the removal of solvent vapors from the extractor to the condenser and for the re-entry of the condensed vapors, a unit for heating the ground grain and cavities for the entry of solvent and discharge of composition with organic solvents, characterized in that the submersible counter-flow extractor is provided with heating means to maintain inside a "liquid-vapor" phase transformation temperature, carried out in the form of a or more sections, and a decanter that has a widening towards the lower loading tube with the intention of creating a Gas seal is positioned before the first section of the counter-flow extractor. '

3. A device according to claim 2, characterized in that the sections of the counter-flow extractor are positioned with an inclination toward the loading side of the material to be extracted.

4. A device according to claim 2 characterized in that the first section of the counter-flow extractor, in the direction of material movement, is arranged inclined, and the following section is arranged in a horizontal position.

5. A device according to claim 3 or 4, characterized in that therein the unit for warming of ground grain is positioned in the upper part of the last section of the counter-flow extractor, in the direction of movement of the material.

6. A counter-flow-submersible extractor for the extraction of vegetable oils according to claim 1, characterized in that it comprises a body with a cavity for the entry of material to be extracted, a cavity for the entry of solvent, cavities for the discharge of solvent vapors, ground grain and composition of organic solvents, conditioned with means for; maintaining an internal "liquid-gaseous" phase transformation temperature, the extractor being in the form of one or more sections.