Title of Invention

"A PROCESS AND AN APPARATUS FOR SEPARATION OF EDIBLE OIL AND EDIBLE SOL VENT FROM MISCELLA"

Abstract

A process for separation of edible oil and edible solvent from miscelia comprising in the steps of pumping miscelfa to a filter (13), for removal of impurities (2), the miscelia being Introduced through an economizer (4, 15), for counter flow of hot vapour and cold miscelia (2), the miscelia discharged from the economizer (4, 15), allowed to flow through a preheater (16) and flasher (17), at a temperature 90°C (4), lower than the miscelia from said flasher subjected to step of azeotropic distillation at a temperature not exceeding 90°C.

Full Text

FIELD OF INVENTION This invention relates to a process and an apparatus for separation of oil and hexane from miscella at low temperatures. In particular, this invention relates to a process and apparatus for causing a separation a oil and hexane from miscella in a solvent extraction process of oil from oil seeds or any oil bearing material PRIOR ART In the known process for the extraction of oil from seeds or oil bearing material using an edible solvent, it was known to first prepare the raw materials, which are then mixed with hexane to form a miscella. Oil is separated from hexane at a temperature of 120°C and then subjected to the step of stripping in a stripping column and in the presence of steam to obtain a first fraction of oil and a second fraction of hexane, Several distinct disadvantages are associated with such a known process. One such disadvantage is the increase of non hydiatable phosphatides during the step of oxidation. Thus, non hydratable phosphatides, which is not an impurity but an undesired fraction, increases from approximately 0,2% to 0 .5%. In a likewise manner, the free fatty acids increase from 02 to 0.4% and the peroxide value from 100 to approximately 500 ppm Yet another disadvantage is that of colour fixation and a reduction in bleachability Such increase in the levels of undesirecl fractions may be attributed to various reasons. One such reason is the preparation of raw material. It is known that the seeds consist of different types of enzymes, which have a tendency to hydrolyze in the presence of moisture. Such a reaction increases the free fatty acids and resulting in an increase of glycerides. Referring to the non hydratable phosphatides and with reference to the step of preparation of raw materials, it has been found that the broken seeds present in the raw material hydrolyzes in the presence of heat and moisture and increases, though not significantly, the level of non hydratable phosphatides. Further, a colour fixation takes place during storage, and whereby chemical consumption increases. Yet another disadvantage is the operating temperature during the steps of separation and stripping. In the known process, separation of hexane from oil was carried out at 120°C. In a likewise manner, the step of stripping was also carried out at an elevated temperature of 120-180°C, It has now been found that such steps carried out at elevated temperatures contributed to the increase in levels of non hydratable phosphatides, free fatty acids and gycerides. Further, an increase in the level of peroxide value is also attributed to the high temperatures employed during the process of separation and stripping. Specifically, the known apparatus and process consisted in passing the miscella through a first stage preheater and flasher at a temperature of 80 to 100°C and then through a second stage preheater and flasher at a temperature of 100-120°C, and then finally through, a stripper at a temperature of 120-180°C. The disadvantages of employing such elevated temperatures during the steps of separation and stripping have been described hereinabove. OBJECTS OF THE INVENTION An object of this invention is to propose an improved process and apparatus for separation of oil and solvent from miscella in a solvent extraction process. Another object of this invention is to propose a process and apparatus for separation of oil and solvent in miscella at temperatures lower than those employed in the known art. Yet another object of this invention is to propose a process and apparatus for separation of oil and solvent in miscella having a reduced level of non hydratable phosphatides in comparison to the known art Still another object of this invention is to propose a process and apparatus for separation of oil and solvent in miscella and wherein the peroxide value does not increase in the step of separation and stripping. A further object of this invention is to propose a process and apparatus for separation of oil and solvent in miscella and wherein the level of free fatty acids does not increase. A still further object of this invention is to propose a process and apparatus for separation of oil and solvent in miscella and wherein there is a substantial saving of stream and reduced consumption of edible solvent Yet a further object of this invention is to propose a process and apparatus for separation of oil and solvent in miscella having a reduced colour fixation in comparison to the prior art. DESCRIPTION OF INVENTION According to this invention there is provided a process for separation of edible oil and edible solvent from miscella comprising in the steps of pumping miscella to a filter for removal of impurities, the miscella being introduced through an economizer for counter flow of hot vapour and cold miscella, the miscella discharged from the economizer allowed to flow through a preheater and flasher at a temperature 90°C, lower than the miscella from said flasher subjected to step of azeotropic distillation at a temperature not exceeding 90°C. Further, according to this invention there is provided an apparatus for separation of edible oil and edible solvent from miscella comprising of miscella tank connected to a filter, said filter causing a removal of impurities, an economizer connected to the outlet of said filter, a first stage preheater and flasher connected to said economizer, the outlet of said flasher connected to a reflux filter to produce an entrainer with miscella, said miscella and entrainer being introduced into a reflux column. DESCRIPTION WITH REFEFENCE TO DRAWINGS Further objects and advantages of this invention will be more apparent from the ensuing description when read in conjunction with the accompanying drawings and wherein :- Fig 1 shows the miscella separation apparatus of the known art; Fig. 2 shows the miscella separation apparatus of the present i Fig 3 shows the azeotropic distillation employed in the apparatus of the present invention; Referring to Fig 1, the apparatus of the known art comprises an extractor 1, and where hexane as a solvent is pumped onto the raw materials to extract oil from said materials The miscella comprising hexane and oil is introduced into a miscella tank 2. A pump 4 pumps miscella from tank 2 to a filter 3 having vanes 3a held to a shaft 3b and driven by a motor 3c so as to cause a removal of the impurities present in miscella Filter 3 has an outlet 3d for discharge of filtered miscolla, which is introduced through inlet 4a located at the bottom of an economizer 4 The impurities present in miscella introduced in filter 3 have a level of 5 to 6% Filter 3 reduces the impurities to a level of 0.2 to 2 % Economiser 4 has an outlet 4b which is connected to a first stage preheater 5a and flasher 6a, the temperature within preheater 5a is betweeen 85 to 100°C, and the heated miscella from preheater 5a is fed to a first stage flasher 6 Miscella from first stage flasher 6a is fed to a second stage heater 5b and flasher 6b, the temperature being maintained at 100-120°C Miscella from flasher 6b is fed by a pump 4a to a stripper which causes a separation of oil from hexane at a temperature of 120 to 180°C Reference is now made to the apparatus 10 of the present invention of Fig.2 which also comprises an extractor 11, and miscella produced in extractor 11 is fed into a miscella tank 12. Reference is now made to the ratio of solvent to oil present in miscella. Such a reference is only by way of example and without intending to imply any limitation. Miscella from tank 12 is pumped through a pump 14 into a filter for removal of impurities. Thus, if the ratio of hexane to oil of the miscella introduced into filter 13 is 4:1, the filtered miscella continues to have such a ratio, except that the impurities are removed therefrom. In accordance with this invention, compressed coir is the filtering media employed in filter 13, and it has now been found that the impurity level is reduced from 5 to 6% to approximately 0.05% in comparison to 0.2 to 2% of the known art. Miscella having a solvent to oil ration of 4:1 is discharged from filter 13 and introduced into an economizer and where the solvent to oil ratio discharged therefrom is 2:1. Economizer 15 has an outlet 15a for introduction of miscella into a preheater 16 and a flasher 17, and where the solvent to oil rat io is further reduced to 1:1. Specifically, in accordance with this invention, only a single stage heater and flasher is employed in comparison to two stage heater and flasher. Further, the temperature within heater 16 is maintained below 90°C. In the instance of frothing oil, the temperature in preheater 16 and the subsequent reflux column is maintained preferably in the vicinity of 80°C and in the instance of non frothing oil at 75°C. Such a low temperature at preheater 16 and in the reflux column 20 has the advantage of reduction in the level of free fatty acids, non hydratable phosphilites and peroxide value Yel another advantage, and which applies to the step of refinement, is that a degumming may be effected with water. Hitherto, only a degumming with water could only be effected with respect to hydratable phosphatides, but which is now possible also with respect to non hydratable phosphatides The solvent to oil ratio of the miscella discharged from flasher 17 is 1:1 which is then pumped to a reflux filter 19 through a pump 18. An entrainer is produced in filter 19 as a first liquid phase and the miscella as the second liquid phase The temperature in reflux filter 19 is maintained below 90°C. The; entrainer and miscella is fed to a reflux column 20, the oil being discharged by a pump 21. Reference is made to Fig. 3 which illustrates reflux column 20 to consist of a plurality of trays 22 stacked within column 20. Column 20 has an inlet 23 for introduction of water as a binary mixer or entiainer and an inlet 24 for introduction of miscella. A first outlet 25 for the discharge of hexane vapours is provided at the upper end of column 20, and an oil discharge outlet 26 is provided at the lower end of column 20. A reflux is added through inlet 27 at start up conditions. Column 20 has a vacuum gauge 28. A jacket 29 is provided with column 20 for flow of a heating media, if required. Jacket 29 has an inlet 30 and an outlet 31. WE CLAIM 1. A process for separation of edible oil and edible solvent from miscella comprising in the steps of pumping miscella to a filter (13), for removal of impurities (2), the miscella being introduced through an economizer (4, 15), for counter flow of hot vapour and cold miscella (2), the miscella discharged from the economizer (4, 15), allowed to flow through a preheater (16) and flasher (17), at a temperature 90°C (4), tower than the miscella from said flasher subjected to step of azeotropic distillation at a temperature not exceeding 90°C. 2. The process as claimed in claim 1, which comprises in passing the miscella from the economizer into a preheater and flasher at a temperature of upto 65°C for non frothing oil. 3. The process as claimed in claim 1, which comprises in passing the miscella from the economizer (15), to a preheater (16) and flasher (17) at a temperature of lower than 90°C for frothing oil. 4. The process as claimed in claim 1, which comprises in passing the miscella from said flasher to a reflux fitter (19), to produce an entrainer and miscella. 5. The process as claimed in claim 4, wherein said entrainer is fed to a stripping column (20). 6. The process for extraction of edible oil from misceNa substantially as herein described and illustrated. 7. An apparatus for separation of edible oil and edible solvent from miscella comprising a miscella tank (12) counter to a filter (13) said fitter (13), causing removal of impurities, an economizer (15) counter to the outlet of said fitter, a preheater (16) and flasher (17) counted to said economizer, the outlet of said flasher counted to a reflux fitter (19) to produce an entrainer being introduced into reflux column (20). 8. The apparatus as claimed in claim 7, wherein said filter (13) comprises compressed coir as the filtering medium for removal of impurities. 9. The apparatus for extraction of edible oil from miscella substantially as herein described and illustrated.

Documents:

66-del-2001-abstract.pdf

66-del-2001-claims.pdf

66-DEL-2001-Correspondence-Others-(22-11-2010).pdf

66-del-2001-correspondence-others.pdf

66-del-2001-correspondence-po.pdf

66-del-2001-description (complete).pdf

66-del-2001-drawings.pdf

66-del-2001-form-1.pdf

66-DEL-2001-Form-15-(22-11-2010).pdf

66-del-2001-form-19.pdf

66-del-2001-form-2.pdf

66-del-2001-form-3.pdf

66-del-2001-gpa.pdf