Indian Patents. 211495:PROCESS FOR PREPARATION OF FREE FLOWING, NON-STICKY, POROUS AND HIGHLY LOADED SPHERULES

Title of Invention	PROCESS FOR PREPARATION OF FREE FLOWING, NON-STICKY, POROUS AND HIGHLY LOADED SPHERULES
Abstract	Described herein is a process for converting sticky, non-porous and compact physical form of wax into free flowing, non-sticky and porous highly loaded spherules to allow utilization of waxes for extraction of their one or more components having pharmaceutical, cosmoceutical, nutraceuticals, diagnostic and /or agricultural applications using supercritical fluid extraction technology.

Full Text	THE PATENTS ACT, 1970 (39 of 1970) COMPLETE SPECIFICATION [See section 10; rule 13] "PROCESS FOR PREPARATION OF FREE FLOWING, NON-STICKY, POROUS AND HIGHLY LOADED SPHERULES" (a) PATRAVALE VANDANA BHARAT (b) University Institute of Chemical Technology, Nathalal Parikh Marg, Matunga, Mumbai-400 019. India (c) Indian National (a) PIRTHI PAL SINGH PARTAP SINGH (b) University Institute of Chemical Technology, Nathalal Parikh Marg, Matunga, Mumbai-400 019. India (c) Indian National The following specification particularly describes the nature of the invention and the manner in which it is to be performed. Technical Field: The present invention relates to a process for converting sticky, non-porous and compact physical form of wax into free flowing, non-sticky, porous and highly loaded spherules to allow utilization of waxes for extraction of their components using supercritical fluid extraction technology. The invention also relates to a novel process for supercritical fluid extraction of one or more components of wax, using highly loaded spherules, which have one or more pharmaceutical, cosmoceutical, nutraceuticals, diagnostic and/or agricultural applications. Background and Prior Art: Supercritical fluid extraction (SFE) technology has been receiving increasing attention. Supercritical fluid is a gas subjected to temperatures and pressures over limits of critical pressure and critical temperature. Supercritical fluid extraction is a unit operation that exploits the unique properties of solvents above their critical values to extract desired components from a mixture. Supercritical fluids (SF) offer very attractive characteristics owing to its favorable diffusivity, viscosity, surface tension and other physical properties. Various supercritical fluids like ethane, ethylene, propane, trichlorofluoro methane etc., have been used for supercritical fluid extraction. However, carbon dioxide (CO2) is the most widely used SF as it is generally regarded as safe (GRAS), non-toxic, non-corrosive, and easily available at economic price. It has low critical temperature and pressure and also low latent heat of vaporization. Patent CA 2296942 describes extraction of oil from an oil crude product by means of supercritical fluid extraction thus, obtaining a loaded supercritical fluid (SCF). US 2004088926 describes the application of wax as a pore inducer for the fabrication of an abrasive article/tool using supercritical fluid. 2 EP 0438184 describes an apparatus for effecting extraction, chromatographic separation and fractionation in which apparatus is arranged to extract a soluble substance from the sample by the use of a supercritical fluid or a liquefied gas, introduction of the resultant extract into a chromatograph in an on-line manner for separation into individual components and collect them as fractions. The purification of crude vitamin E by selective extraction using supercritical carbon dioxide is known in the art and described in the French patent publication FR 2602772. As described therein, a good separation is effected at a pressure in the range of 80 to 250 bar and at a temperature in the range of 35 to 550 °C. Thus, a supercritical carbon dioxide loaded with vitamin E containing about 60 wt % to about 98 wt % of pure vitamin E is obtained. CA 2296942 describes a process for separation of oil. As described therein, a good separation is effected at a pressure in the range of about 80 to about 310 bar and at a temperature in the range of about 35 DEG C. to about 100 DEG C. Preferred is a temperature of about 60 DEG C. and a pressure of about 140 to about 170 bar. CN 1428408 describes an extraction method for producing essential oil from Jasmine flowers. CN 1242416 describes a process to extract germ oil from wheat germ using supercritical carbon dioxide as solvent. Wheat germ oil dissolved in supercritical fluid flowing out from extractor is then passed through rectification column, so that the germ oil components can be accurately separated according to the solubility so as to implement concentration of object components of vitamin E, etc. CN 1314353 describes a method for simultaneous extraction and purification of vitamin E from soybean oil deodorizing distillate. 3 US 6656358 describes a method for the chromatographic separation of vitamin E isomers such as alpha-tocopherol, beta-tocopherol, gamma-tocopherol, delta-tocopherol, alpha-tocotrienol, beta-tocotrienol, gamma-tocotrienol and delta-tocotrienol from a vitamin E containing mixture using solvent under supercritical conditions. US 6423 851 provides a process for preparing of d,l-alpha-tocopherol by the catalyzed condensation of trimethylhydroquinone with isophytol using metal salt as the catalyst and supercritical carbon dioxide or nitrous oxide as the solvent. EP 0908185 describes a process for preparation of active herbal extracts from plant materials, containing polar or potentially polar components as well as lipophilic active agents, using liquid carbon dioxide under supercritical conditions as extraction solvent in which the lipophilic components are more soluble than the polar components. Supercritical fluid extraction has also been used in a variety of conditions and materials. Supercritical fluid extraction of animal derived materials are reported in US patent 4749522 among other uses in natural products, oils etc. Institute of Thermal Separation Technology has reported fractionation of paraffin mixtures wherein they have compared supercritical fluid extraction with short-path distillation (Cristo Crause and Izak Nienwoudt) However, there have been no reported attempts about the extraction of one or more components of wax using supercritical fluid extraction technology. Waxes as such cannot be used for supercritical fluid extraction of their one or more components because of their inherent non-porous, sticky and compact nature. Objective of the Invention: The objective of the investigation is to extract one or more components of wax by supercritical fluid extraction technology from any synthetic or natural wax hitherto unexploited technique for the above mentioned objective. 4 The another objective of the investigation is to provide a process for converting sticky, non-porous and compact physical form of wax into free flowing, non-sticky and porous spherules without affecting its chemical properties. These free flowing, non-sticky and porous spherules of wax are used as a feed for extraction of one or more component of wax using supercritical fluid extraction technology. Yet another objective of the investigation is to provide an inert adsorbent which converts the physical form of wax into free flowing, non-sticky and porous spherules. A further objective of this investigation is to provide the adsorption conditions during formation of free flowing, non-sticky and porous spherules of wax. These conditions will depend on the type of wax and inert adsorbent used. Another objective of the investigation is to provide a larger surface area of the wax for efficient transport of wax component(s) to the bulk of supercritical fluid Yet another objective of the investigation is to optimize the loading of the adsorbent with wax so as to obtain free flowing, non-sticky and porous spherules of waxes. A further objective of the investigation is to provide with an optimum particle size range of the adsorbent to obtain free flowing, non-sticky and porous spherules of waxes. Another objective of the investigation is to provide extraction conditions for the extraction of required one or more component of wax using free flowing, non-sticky and porous spherules of wax by supercritical fluid extraction technology. The extraction conditions will depend on the physico-chemical properties of the compound to be extracted. Yet another objective of the investigation is to provide extraction conditions that will result into the selective extraction of desired component in pure form. 5 Summary of the Invention Sticky, non-porous and compact nature of waxes limits their application in supercritical fluid extraction of either one or more of its components. The present invention relates to a process for converting sticky, non-porous and compact physical form of wax into free flowing, non-sticky and porous spherules. The process comprises of dissolving wax in a solvent at higher temperature; adding inert adsorbent to the wax solution and loading wax onto adsorbent to form highly loaded spherules; forming a semi-solid mass by cooling the above mixture under stirring; removing residual solvent under vacuum and drying the highly loaded spherules. These highly loaded spherules have larger surface area for faster extraction; high porosity that helps in better diffusivity of supercritical fluid leading to efficient extraction; are non-sticky and free flowing that helps in better packaging of extraction device and easy cleaning of extraction device thus preventing cross contamination in successive experiments. The highly loaded spherules formed act as a feed for the supercritical fluid extraction of one or more components of wax having pharmaceutical, cosmoceutical, nutraceuticals, diagnostic and/or agricultural applications. Detailed Description of the Invention Over the past decade, several noteworthy consumer trends have emerged such as enhanced concern for the quality and safety of foods and medicines, regulation for nutritive and toxicity levels and increased preference for "natural" as opposed to synthetic substances. "Mother Nature" is considered a highly efficient synthesizer of desirable blends of constituents ideally suitable for human consumption. Safety of both producers and consumers is now a major requirement of any new product or process. Accordingly, compelling regulations on the usage of hazardous, carcinogenic and toxic solvents as well as high energy costs for solvent regeneration have curtailed the growth of natural extract industries. Alternative extraction methodologies that comply with both consumer preference and regulatory control and that are cost effective are becoming popular. One such major technology that has emerged over the last two decades as the alternative to the traditional solvent extraction of natural products is the Supercritical Fluid Extraction technique. The supercritical fluid extraction is a known process which is 6 Supercritical fluid extraction technology is thus gaining importance over the conventional techniques for extraction of natural products. Part of the reason for recent interest in the supercritical fluid extraction is that it offers a potential advantage of higher yield and better quality products. One particular application, where the process may prove to be useful, is for recovery of high value and low volume products. Waxes are one such group of example which contains many pharmaceutical, cosmoceutical, nutraceuticals, diagnostic and/or agriculturally important constituents. The term wax generally refers to a substance which is a plastic solid at room temperature and a liquid of low viscosity above its melting point. It is chemically defined as esters of fatty acid with fatty alcohols, having 36-50 carbon atoms. However, Supercritical fluid extraction technology has not been extended to waxes for extraction of their one or more components as they posed several mechanical and thermodynamic problems during extraction. 1. The inherent non-porous and compact nature of waxes does not make them an ideal candidate for supercritical fluid extraction of components of waxes, as waxes caused thermodynamic problems during supercritical fluid extraction. Their non-porous and compact nature hampers the diffusivity of supercritical fluid leading to inefficient extraction. Also lesser surface area is exposed to supercritical fluid to extract wax component(s). 2. Another limitation of waxes is their sticky nature that results in clogging of the tubing connected to the extraction vessel. The internal diameter of tubing being as small as that of 1/16th of an inch, it led to the blocking the flow of supercritical fluid, making the supercritical fluid extraction instrument inoperable. 3. At high pressure waxes adhered strongly to the metal surface of extraction vessel making it very difficult for cleaning. Traces of wax, which could not be removed during cleaning, led to contamination in the successive batches. 8 The present invention is focused on changing the sticky, non-porous and compact physical form of wax into a free flowing, non-sticky, porous spherules, to extract any component of wax from any wax. As used herein the term "wax" refers to any wax which is synthetic (such as modified wax, compound wax etc.) or of natural origin (animal wax, insect wax, mineral wax, vegetable wax, etc.). The term wax generally refers to a substance which is a plastic solid at room temperature and a liquid of low viscosity above its melting point. It is chemically defined as esters of fatty acid with higher fatty alcohols. As used herein the term "adsorbent" refers, e.g., to kaolin, aluminum hydroxide, zeolites, activated carbon, hydrophobic starch, molecular sieves, fuller"s earth, bentonite, hectorite, silicon dioxide gel, silica, colloidal magnesium-aluminum silicate, activated alumina, magnesium tri silicate, magnesium hydroxide, magnesium oxide, and the like. As used herein the term "highly loaded spherules" refers to a loading of the adsorbent with the wax. The percentage loading should be less than 1000%. Preferably the percentage loading should be less than 500%. Most preferably the percentage loading should be less than 200%. These highly loaded spherules are free flowing, non-sticky and porous spherules. As used herein the term "conditions of adsorption" does not refer to fixed conditions. The conditions depend on the kind of wax and the desired loading of the adsorbent. As used herein the term "wax component(s)" refers to one or more constituents of wax to be extracted such as, but not limited to, vitamin A, D, E or K, carotenoids, fatty alcohols, hydroxy aromatic acids, saturated, monounsaturated or polyunsaturated fatty acids, squalene, sterols, oryzanols etc. 9 As used herein the term "supercritical fluid" refers to carbon dioxide, methane, ethane, ethylene, propane, propylene, n-butane, acetone, chlorotrifluoromethane, trichlorofluoromethane, nitrous oxide, ammonia, benzene, toluene and mixtures thereof. As used herein the term "extraction conditions" does not refer to fixed conditions. The conditions of extraction depend on the kind of wax, supercritical fluid used and the component of wax to be extracted. Extraction pressure and extraction temperature must have a value above the critical pressure and critical, temperature respectively, or at least in the near critical region. The process for preparing highly loaded spherules is as follows A supersaturated solution of wax in a solvent is prepared at temperature where the clear solution is formed. Inert adsorbent is added to the above solution. The resultant mixture is allowed to cool under stirring conditions. Residual solvent is removed by vacuum drying to obtain highly loaded spherules. Highly loaded spherules are inert adsorbents loaded with wax in such a fashion that they inherit favorable physical characters such as free flowing, non-sticky and porous so that they can be subjected to supercritical fluid extraction of one or more component of wax. Wax is treated with inert adsorbents in presence of a solvent to obtain highly loaded spherules. The conditions of formation of highly loaded spherules cannot be fixed. These conditions may vary depending upon the nature of wax and nature of adsorbent. The solvent that can be used, for the preparation of highly loaded spherules, in the present invention are low molecular weight alkanes such as hexane, heptane, petroleum fractions; alkyl halides such as chloroform, carbon tetrachloride, dichloro methylene; ether such as di ethyl ether, petroleum ether; ketone such as acetone; aromatic compounds such as benzene, toluene, pyridine; esters such as ethyl acetate; alcohol 10 (primary, secondary or tertiary) such as ethanol, methanol, propanol, iso-propanol, butanol, iso-butanol etc. Preferred solvents are those in which wax shows intermediate solubility. Most preferred solvents are that exhibiting temperature dependent solubility for wax. The solubility of wax in solvent should increase with increase with temperature and vice-versa. Most preferred solvents are those which give a clear solution with wax at higher temperature and on cooling precipitate the wax in the form of small fluffy particles. Also the solvent should be such that the adsorbent should be insoluble in solvent. The temperature range required for the formation of highly loaded spherules would depend upon the wax component(s) to be extracted. At the maximum limit of temperature, the wax component(s) to be extracted should not degrade. The experiment for the formation of highly loaded spherules is carried out under stirring conditions of more than 10 RPM, preferably more than 100 RPM. The particle size and loading of adsorbent determines the free flowing and non-sticky nature of highly loaded spherules. Not more than 10% of particles should pass through 400 # sieve. Preferably not more than 10% of particles should pass through 200 # sieve. Most preferably not more than 10% of particles should pass through 100 # sieve. The percentage loading of wax onto adsorbents to yield highly loaded spherules is calculated by the following formula: (Weight of spherules - Weight of adsorbent) X 100 Percentage Loading = Weight of adsorbent Weight of spherules is the weight of wax loaded onto adsorbents and the weight of adsorbents. The percentage loading should be less than 1000%. Preferably the percentage 11 loading should be less than 500%. Most preferably the percentage loading should be less than 200%. Highly loaded spherules, thus formed, will act as a feed for the extraction of one or more constituents/components of wax, having one or more pharmaceutical, cosmoceutical, nutraceuticals, diagnostic and/or agricultural applications, using supercritical fluid extraction technology. Highly loaded spherules are subjected to different conditions of extraction pressure, extraction temperature, flow rate of supercritical fluid etc., in order to extract the desired wax component(s) from highly loaded spherules. When the feed is in the form of a solid, the supercritical fluid extraction process is carried out from a fixed bed of solids with a continuous flow of supercritical fluid. Alternatively moving solid bed can also be used but they are difficult to handle continuously in pressurized vessels. For extraction from fixed bed of solid particles loaded in a batch extractor, the supercritical fluid solvent is continuously passed through the extractor and evenly, either in the downward or upward direction with a fixed flow rate of supercritical fluid. The pressure and temperature are of the extractor are maintained constant and these parameters should be decided such that the supercritical fluid has sufficient solvent capacity for the wax component(s) to be extracted. The wax component(s) must be readily transported from the highly loaded spherules to the bulk of supercritical fluid When highly loaded spherules are in contact with supercritical fluid at selected supercritical conditions, the extraction of wax component(s) takes place in the following sequential and parallel steps: 1. Diffusion of supercritical fluid into the pores and adsorption of supercritical fluid on the solid surface of highly loaded spherules 2. Transport of wax component(s)to the outer layer and formation of a thin liquid film around the highly loaded spherules 3. Dissolution of wax component(s) in supercritical fluid 4. Convective transport of the wax component(s) to the bulk of supercritical fluid 12 The process for extraction of wax component(s) will now be set forth in great detail with reference to figure 1, showing schematically supercritical fluid extraction equipment. The four primary steps involved are extraction, expansion, separation and solvent conditioning, and the four corresponding critical components needed are a high pressure extractor (1), a pressure reduction valve (2), a low pressure separator (3) and a pump (4) for intensifying the pressure of the recycled solvent The process starts by feeding the highly loaded spherules into the extraction device (1). The supercritical fluid, at pressure above critical pressure and temperature above critical temperature of supercritical fluid, is fed into the extraction device (1). Depending upon the extraction pressure, extraction temperature and flow rate of supercritical fluid the wax component(s) is dissolved and extracted, thereby obtaining supercritical fluid loaded with the wax component(s). The loaded supercritical fluid is then expanded in a separator (3) by passing through pressure reduction valve (2) to a pressure where the solubilisation capacity of the supercritical fluid is reduced to obtain a reduced supercritical fluid and wax component(s). The pressure reduction depends on the applied supercritical fluid and on the extraction conditions. The appropriate reduction of pressure can be determined by phase equilibria measurements. At reduced pressure and temperature conditions, the wax component(s) precipitates in a separator (3). The separated wax component(s) is collected from separator (3) and may be further processed for purification to obtain wax component(s) with high purity. Alternatively, the supercritical fluid may be recycled to the extractor via a pump (4). Because of the pressure drop, the temperature is also reduced. Therefore the recycled in-loading supercritical fluid is passed through the heater (5) before it is fed again to the extraction device (1). Thus the present invention comprises of a process of supercritical fluid extraction of one or more component from wax by 1. Dissolving wax in a solvent at higher temperature; 13 2. Adding inert adsorbent to the wax solution and loading wax onto adsorbent to form highly loaded spherules; 3. Forming a semi-solid mass by cooling the above mixture under stirring; 4. Removing residual solvent under vacuum and drying the highly loaded spherules; 5. Feeding the highly loaded spherules to the extraction device of supercritical fluid extraction unit; 6. Packing the extraction device with silica and glass wool; 7. Adjusting solvent capacity of supercritical fluid by adjusting the extraction pressure, extraction temperature and flow rate of supercritical fluid; 8. Passing supercritical fluid over the bed of highly loaded spherules; 9. Extracting the wax component(s) in supercritical fluid; 10. Expanding supercritical fluid loaded with wax component(s); 11. Separating wax component(s) from reduced supercritical fluid; and 12. Optionally purifying the wax component(s) to get the required quality product. Suitable wax includes any wax of natural or synthetic origin. Preferred wax includes wax containing one more components of pharmaceutical, cosmoceutical, nutraceuticals, diagnostic and/or agricultural applications. Suitable solvents includes low molecular weight alkanes such as hexane, heptane, petroleum fractions; alkyl halides such as chloroform, carbon tetrachloride, dichloro methylene; ether such as di ethyl ether, petroleum ether; ketone such as acetone; aromatic compounds such as benzene, toluene, pyridine; esters such as ethyl acetate; alcohol (primary, secondary or tertiary) such as ethanol, methanol, propanol, iso-propanol, butanol, iso-butanol etc. Suitable adsorbent is any inert to kaolin, aluminum hydroxide, zeolites, activated carbon, hydrophobic starch, molecular sieves, fuller"s earth, bentonite, hectorite, silicon dioxide gel, silica, colloidal magnesium-aluminum silicate, activated alumina, magnesium tri silicate, magnesium hydroxide, magnesium oxide, and the like. Preferred is silica. 14 Suitable particle size of adsorbent is such that not more than 10% of particles should pass through 400 # sieve. Preferably not more than 10% of particles should pass through 200 # sieve. Most preferably not more than 10% of particles should pass through 100 # sieve. The percentage loading should be less than 1000%. Preferably the percentage loading should be less than 500%. Most preferably the percentage loading should be less than 200%. The adsorption conditions include temperature more than 25 °C and stirring speed more than 10 RPM. Preferably temperature more than 30 °C and stirring speed more than 100 RPM. Suitable supercritical fluid is carbon dioxide, methane, ethane, ethylene, propane, propylene, n-butane, acetone, chlorotrifluoromethane, trichlorofluoromethane, nitrous oxide, ammonia, benzene, toluene and mixtures thereof. Preferred supercritical fluid is carbon dioxide. The extraction conditions include extraction pressure and extraction temperature. Extraction pressure and extraction temperature should be more than critical pressure and critical temperature of supercritical fluid respectively. Preferably the extraction pressure is 80 to 1000 bar. Most preferably the extraction pressure is between 100 to 750 bar. Preferably the extraction temperature is between 35 to 350 °C. Most preferably the extraction temperature is between 35 to 150 °C. The following examples illustrate the invention but do not limit its scope in any manner Example 1 Preparation of highly loaded spherules Wax was dissolved in a solvent at a temperature of 40 - 70 °C. A supersaturated clear solution was formed. Inert adsorbent, silica, was added to the above solution and the mixture was stirred at the speed of more than 200 RPM to get highly loaded spherules. 15 Not more than 10% of particles of adsorbent passed through 100 # sieve. The percentage loading of highly loaded spherules was less than 200%. The mixture was allowed to cool till a semi solid mass of adsorbents loaded with wax was obtained. Residual solvent was evaporated by vacuum drying to obtain dried highly loaded spherules. Example 2 Optimization of particle size of adsorbent used in example 1 Adsorbent of various particle sizes such as 20-100 #, 100-200# and 200-400# mesh was used for the preparation of highly loaded spherules. They were assessed on the basis of sphericity, flow properties and adherence time to metal surface. The effect of particle size of adsorbent on various parameters was as follows: Parameters Adsorbent 20-100# 100-200# 200-400# Sphericity 90-100 80-90 70-80 Adherence Time on Metal Surface (sec) Bulk density (gm/cc) 0.4-0.5 0.4-0.5 0.4-0.5 True density (gm/cc) 0.5-0.6 0.5-0.6 0.5-0.6 Angle of Repose (6) 20-30 25-35 30-40 Flow Rate (gm /sec) 15-25 10-20 5-15 Hausner"s ratio NLT1.2 NLT1.2 NLT1.2 Highly loaded spherules prepared using adsorbent of particle size of 20-100 # mesh sieve were more spherical as compared to the spherules prepared using 100-200# or 200-400# mesh sieve. The spherules prepared using adsorbent of particle size of 20-100 # mesh showed better flow properties, like flow rate, angle of repose, when compared to spherules prepared using 100-200# or 200-400# mesh sieve. 16 No difference was observed when adherence to metal surface was considered. Example 3 Optimization of percentage loading of highly loaded spherules used in example 1 Highly loaded spherules were prepared with different percentage loading of wax (less than 200%). They were assessed on the basis of spherecity, flow properties and adherence time to metal surface. The effect of percentage loading of highly loaded spherules on various parameters was as follows: PARAMFTFRS Percentage Loading Wax 200% 100% 66.66% 50% Flow Time (gm/sec) * * * 10- 15 10-15 Angle of Repose (°) * * * 20-30 20-30 Sphericity # # 65-75 75-85 85-95 Adherence Time on Metal Surface (sec) 14 4 * Poor flow # Semi solid mass, no spherules were formed Based on flow properties, sphericity and adherence time on metal surface, percentage loading of less than 100% gave better result. For a particular adsorbent selected, flow properties, sphericity and adherence time to metal surface was improved, as the percentage loading of highly loaded spherules was decreased. It should also be considered that as the percentage loading is decreased the feed sample weight will increase. However an optimum percentage loading should be considered which gives satisfactory results with the added advantage of low feed sample weight. 17 Example 4 Supercritical fluid extraction of vitamin E from oilseed wax The extraction of vitamin E from oilseed wax was carried out by forming highly loaded spherules of wax using inert adsorbent, silica. The percentage loading of highly loaded spherules was less the 200%. The particle size of adsorbent was such that not more than 10% of the particles were passed through 100#. The said highly loaded spherules formed were fed into the extraction device of supercritical fluid extraction unit. Carbon dioxide was used as a supercritical fluid. Vitamin E was extracted at extraction pressure ranging from 100 to 550 bar, extraction temperature ranging from 35 to 80 °C and flow rate of supercritical fluid ranging from 0.1 to 0.8 L/min. Vitamin E extracted using this technology was five times more than conventional extraction Example 5 Extraction of pure vitamin E in one single step The purity of the wax component(s) being extracted by supercritical fluid extraction technology decreases as the values of extraction conditions increases, whereby its yield increases. 100%o pure natural vitamin E was obtained at extraction pressure ranging from 100 to 300 bar, extraction temperature of 40 to 60 °C, flow rate of supercritical fluid of 0.1 to 0.3 L/min. Description of drawings: Figure 1, shows supercritical fluid extraction equipment. The process starts with feeding the highly loaded spherules followed by the supercritical fluid, at pressure above critical pressure and temperature above critical temperature of supercritical fluid, is fed into the extraction device (1). Depending upon the extraction pressure, extraction temperature and flow rate of supercritical fluid, the wax component(s) is dissolved and extracted, thereby obtaining supercritical fluid loaded with the wax component(s). The loaded supercritical fluid is then expanded in a separator (3) by passing through pressure reduction valve (2) to a pressure where the solubilisation capacity of the supercritical fluid is reduced to obtain a reduced supercritical fluid and wax component(s). At reduced pressure and temperature conditions, the wax component(s) 18 precipitates in a separator (3). The separated wax components) is collected from separator (3) and may be further processed for purification to obtain wax component(s) with high purity. Alternatively, the supercritical fluid may be recycled to the extractor via a pump (4). Because of the pressure drop, the temperature is also reduced. Therefore the recycled in-loading supercritical fluid is passed through the heater (5) before it is fed again to the extraction device (1). While the present invention is described above in connection with preferred or illustrative embodiments, these embodiments are not intended to be exhaustive or limiting the scope of the invention. Rather, the invention is intended to cover all alternatives, modifications and equivalents included within its spirit and scope, as defined by the appended claims. We claim, 1. A process for preparation of free flowing, non-sticky, porous and highly loaded spherules of wax for supercritical fluid extraction of one or more component of wax, wherein the said process comprises: a. Dissolving wax in a solvent at higher temperature; b. Adding inert adsorbent to the wax solution and loading wax onto adsorbent to form highly loaded spherules; c. Forming a semi-solid mass by cooling the above mixture under stirring; d. Removing residual solvent under vacuum and drying the highly loaded spherules; e. Feeding the said highly loaded spherules to the extraction device of supercritical fluid extraction unit; f. Packing the extraction device with silica and glass wool; g. Adjusting solvent capacity of supercritical fluid by regulating the extraction pressure, extraction temperature and flow rate of supercritical fluid; h. Passing supercritical fluid over the bed of highly loaded spherules; i. Extracting the wax component(s) in supercritical fluid; j. Expanding supercritical fluid loaded with wax component^s); k. Separating wax component(s) from reduced supercritical fluid; and 1. Optionally purifying the wax component(s) using conventional purification techniques. 2. The process according to claim 1, wherein said wax is of synthetic or of natural origin. 3. The process according to claim 1 and 2, wherein said synthetic wax includes modified wax and compound wax. 4. The process according to claim 1 and 2, wherein said natural wax includes animal wax, insect wax, mineral wax, or vegetable wax. 5. The process according to any of the preceding claims, wherein preferred wax is a natural oilseed wax. 20 6. The process according to claim 1, wherein the inert adsorbent is selected from one or more adsorbent such as kaolin, aluminum hydroxide, zeolites, activated carbon, hydrophobic starch, molecular sieves, fuller"s earth, bentonite, hectorite, silicon dioxide gel, silica, colloidal magnesium-aluminum silicate, activated alumina, magnesium tri silicate, magnesium hydroxide, magnesium oxide, and the like. 7. The process according to claims 1 and 6, wherein the preferred inert adsorbent is silica. 8. The process according to claim 1, wherein said solvent selected from low molecular weight alkanes such as hexane, heptane, petroleum fractions; alkyl halides such as chloroform, carbon tetrachloride, dichloro methylane; ethers such as diethyl ether, petroleum ether; ketone such as acetone; aromatic compounds such as benzene, toluene, pyridine; esters such as ethyl acetate; alcohol (primary, secondary or tertiary) such as ethanol, methanol, propanol, iso-propanol, butanol and iso-butanol. 9. The process according to claim 1 and 8, wherein said solvent is an alcohol. 10. The process according to claim 1, 8 and 9, wherein said solvent is secondary alcohol. 11. The process according to claim 1, 8, 9 and 10, wherein said preferred solvent is iso-propanol. 12. The process according to claim 1, 6 and 7 wherein the particle size of said adsorbent is such that not more than 10% of particles should pass through 400 # sieve. 13. The process according to claim 1, 6, 7 and 12, wherein particle size of said adsorbent is such that not more than 10% of particles should pass through 200 # sieve, 14. The process according to claim 1, 6, 7, 12 and 13, wherein the preferred particle size of adsorbent is such that not more than 10% of particles should pass through 100 # sieve. 15. The process according to claim 1, wherein the percentage loading of highly loaded spherules is less than 1000%. 16. The process according to claims 1 and 15, wherein the percentage loading of highly loaded spherules is less than 500% 21 17. The process according to claims 1, 15 and 16, wherein the preferred percentage loading of highly loaded spherules is preferably less than 200% 18. The process according to claim 1, wherein the adsorption conditions includes temperature more than 25 °C and stirring speed more than 10 RPM. 19. The process according to claim 1 and 18, wherein the preferred adsorption conditions includes temperature adjusted to more than 30 °C and stirring speed adjusted to more than 100 RPM. 20. The process according to claim 1, wherein the highly loaded spherules are made to have more surface area as compared to wax, for efficient and faster extraction of wax component(s). 21. The process according to claim 1, wherein the highly loaded spherules are made more porous as compared to wax, for better diffusivity of supercritical fluid leading to efficient and faster extraction of wax component(s). 22. The process according to claim 1, wherein the highly loaded spherules are made more free-flowing as compared to wax, resulting in better packaging of extraction device. 23. The process according to claim 1, wherein the highly loaded spherules are made less sticky as compared to wax that prevents the adherence of wax onto extraction device at high pressure, thus preventing chances of cross contamination during successive experiments. 24. V The process according to claim 1, wherein said extracted wax component(s) refers to one or more constituents of wax having pharmaceutical, cosmoceutical, nutraceuticals, diagnostic and/or agricultural applications. 25. The process according to claim 1 and 24, wherein said extracted wax component(s) includes, but not limited to vitamin A, D, E or K, carotenoids, fatty alcohols, hydroxy aromatic acids, saturated, monounsaturated or polyunsaturated fatty acids, squalene, sterols, and oryzanols 26. The process according to claim 1, 24 and 25, wherein the preferred extracted wax component is vitamin E. 27. The process according to claim 1, wherein said supercritical fluid used for extraction of wax component(s) is selected from carbon dioxide, methane, ethane, 22 ethylene, propane, propylene, n-butane, acetone, chlorotrifluoromethane, trichlorofluoromethane, nitrous oxide, ammonia, benzene, toluene and mixtures thereof. 28. The process according to claim 1 and 27, wherein said preferred supercritical fluid used for extraction of wax component(s) is carbon dioxide. 29. The process according to claim 1, wherein said wax component(s) are extracted at extraction pressure of about 80 to 1000 bar. 30. The process according to claim 1 and 29, wherein said wax component(s) are preferably extracted at extraction pressure of about 100 to 550 bar. 31. The process according to claim 1, wherein said wax component(s) are extracted at extraction temperature of about 35 to 350 °C. 32. The process according to claim 1 and 31, wherein said wax component(s) are preferably extracted at extraction temperature of about 35 to 150 °C. 33. The process according to claim 1, wherein said wax components) are extracted at flow rate of supercritical fluid of about 0.01 to 10.00 L/min 34. The process according to claim 1 and 33, wherein said wax component(s) are preferably extracted at flow rate of supercritical fluid of about 0.1 to 1.0 L/min 35. The process according to any of the preceding claims, wherein the extraction of vitamin E from natural oilseed wax is carried out at extraction pressure ranging from 100 to 550 bar, extraction temperature ranging from 35 to 80 °C and flow rate of carbon dioxide in the range from 0.1 to 0.8 L/min. 36. The process according to any of the preceding claims, wherein said extraction of vitamin E from natural oilseed wax is carried out at preferred extraction pressure ranging from 200 to 550 bar, preferred extraction temperature ranging from 40 to 60 °C and preferred flow rate of carbon dioxide in the range from 0.1 to 0.6 L/min. 37. The process according to any of the preceding claims, wherein the extraction of said vitamin E is five times higher using supercritical fluid technology from natural oilseed within 90 minutes, as compared to conventional extraction. 38. The process according to any of the preceding claims, wherein said extracted wax component is 100% pure, extracted in a one single step. 24 39. The process according to claim 1 and 38, wherein said 100% pure vitamin E is extracted from natural oilseed wax at extraction pressure ranging from 100 to 350 bar, extraction temperature ranging from 35 to 80 °C and flow rate of carbon dioxide in the range from 0.1 to 0.6 L/min. 40. The process according to claim 1 and 39, wherein said 100% pure vitamin E is extracted from natural oilseed wax at preferred extraction pressure ranging from 200 to 300 bar, preferred extraction temperature ranging from 40 to 60 °C and preferred flow rate of carbon dioxide in the range from 0.1 to 0.3 L/min. 41. The process according to any of the preceding claims, wherein said extracted wax component(s) were further optionally purified by conventional purification techniques. 42. A process for preparing highly loaded spherules of wax and supercritical fluid extraction of wax component(s) from highly loaded spherules of wax as substantially described herein with reference the foregoing examples 1 to 5.

Full Text

THE PATENTS ACT, 1970
(39 of 1970)
COMPLETE SPECIFICATION
[See section 10; rule 13]
"PROCESS FOR PREPARATION OF FREE FLOWING, NON-STICKY, POROUS AND HIGHLY LOADED SPHERULES"
(a) PATRAVALE VANDANA BHARAT
(b) University Institute of Chemical Technology, Nathalal Parikh Marg, Matunga, Mumbai-400 019. India
(c) Indian National

(a) PIRTHI PAL SINGH PARTAP SINGH
(b) University Institute of Chemical Technology, Nathalal Parikh Marg, Matunga, Mumbai-400 019. India
(c) Indian National
The following specification particularly describes the nature of the invention and the manner in which it is to be performed.

Technical Field:
The present invention relates to a process for converting sticky, non-porous and compact physical form of wax into free flowing, non-sticky, porous and highly loaded spherules to allow utilization of waxes for extraction of their components using supercritical fluid extraction technology. The invention also relates to a novel process for supercritical fluid extraction of one or more components of wax, using highly loaded spherules, which have one or more pharmaceutical, cosmoceutical, nutraceuticals, diagnostic and/or agricultural applications.
Background and Prior Art:
Supercritical fluid extraction (SFE) technology has been receiving increasing attention. Supercritical fluid is a gas subjected to temperatures and pressures over limits of critical pressure and critical temperature. Supercritical fluid extraction is a unit operation that exploits the unique properties of solvents above their critical values to extract desired components from a mixture.
Supercritical fluids (SF) offer very attractive characteristics owing to its favorable diffusivity, viscosity, surface tension and other physical properties.
Various supercritical fluids like ethane, ethylene, propane, trichlorofluoro methane etc., have been used for supercritical fluid extraction. However, carbon dioxide (CO2) is the most widely used SF as it is generally regarded as safe (GRAS), non-toxic, non-corrosive, and easily available at economic price. It has low critical temperature and pressure and also low latent heat of vaporization.
Patent CA 2296942 describes extraction of oil from an oil crude product by means of supercritical fluid extraction thus, obtaining a loaded supercritical fluid (SCF).
US 2004088926 describes the application of wax as a pore inducer for the fabrication of an abrasive article/tool using supercritical fluid.
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EP 0438184 describes an apparatus for effecting extraction, chromatographic separation and fractionation in which apparatus is arranged to extract a soluble substance from the sample by the use of a supercritical fluid or a liquefied gas, introduction of the resultant extract into a chromatograph in an on-line manner for separation into individual components and collect them as fractions.
The purification of crude vitamin E by selective extraction using supercritical carbon dioxide is known in the art and described in the French patent publication FR 2602772. As described therein, a good separation is effected at a pressure in the range of 80 to 250 bar and at a temperature in the range of 35 to 550 °C. Thus, a supercritical carbon dioxide loaded with vitamin E containing about 60 wt % to about 98 wt % of pure vitamin E is obtained.
CA 2296942 describes a process for separation of oil. As described therein, a good separation is effected at a pressure in the range of about 80 to about 310 bar and at a temperature in the range of about 35 DEG C. to about 100 DEG C. Preferred is a temperature of about 60 DEG C. and a pressure of about 140 to about 170 bar.
CN 1428408 describes an extraction method for producing essential oil from Jasmine flowers.
CN 1242416 describes a process to extract germ oil from wheat germ using supercritical carbon dioxide as solvent. Wheat germ oil dissolved in supercritical fluid flowing out from extractor is then passed through rectification column, so that the germ oil components can be accurately separated according to the solubility so as to implement concentration of object components of vitamin E, etc.
CN 1314353 describes a method for simultaneous extraction and purification of vitamin E from soybean oil deodorizing distillate.
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US 6656358 describes a method for the chromatographic separation of vitamin E isomers such as alpha-tocopherol, beta-tocopherol, gamma-tocopherol, delta-tocopherol, alpha-tocotrienol, beta-tocotrienol, gamma-tocotrienol and delta-tocotrienol from a vitamin E containing mixture using solvent under supercritical conditions.
US 6423 851 provides a process for preparing of d,l-alpha-tocopherol by the catalyzed condensation of trimethylhydroquinone with isophytol using metal salt as the catalyst and supercritical carbon dioxide or nitrous oxide as the solvent.
EP 0908185 describes a process for preparation of active herbal extracts from plant materials, containing polar or potentially polar components as well as lipophilic active agents, using liquid carbon dioxide under supercritical conditions as extraction solvent in which the lipophilic components are more soluble than the polar components.
Supercritical fluid extraction has also been used in a variety of conditions and materials. Supercritical fluid extraction of animal derived materials are reported in US patent 4749522 among other uses in natural products, oils etc.
Institute of Thermal Separation Technology has reported fractionation of paraffin mixtures wherein they have compared supercritical fluid extraction with short-path distillation (Cristo Crause and Izak Nienwoudt)
However, there have been no reported attempts about the extraction of one or more components of wax using supercritical fluid extraction technology. Waxes as such cannot be used for supercritical fluid extraction of their one or more components because of their inherent non-porous, sticky and compact nature.
Objective of the Invention:
The objective of the investigation is to extract one or more components of wax by supercritical fluid extraction technology from any synthetic or natural wax hitherto unexploited technique for the above mentioned objective.
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The another objective of the investigation is to provide a process for converting sticky, non-porous and compact physical form of wax into free flowing, non-sticky and porous spherules without affecting its chemical properties. These free flowing, non-sticky and porous spherules of wax are used as a feed for extraction of one or more component of wax using supercritical fluid extraction technology.
Yet another objective of the investigation is to provide an inert adsorbent which converts the physical form of wax into free flowing, non-sticky and porous spherules.
A further objective of this investigation is to provide the adsorption conditions during formation of free flowing, non-sticky and porous spherules of wax. These conditions will depend on the type of wax and inert adsorbent used.
Another objective of the investigation is to provide a larger surface area of the wax for efficient transport of wax component(s) to the bulk of supercritical fluid
Yet another objective of the investigation is to optimize the loading of the adsorbent with wax so as to obtain free flowing, non-sticky and porous spherules of waxes.
A further objective of the investigation is to provide with an optimum particle size range of the adsorbent to obtain free flowing, non-sticky and porous spherules of waxes.
Another objective of the investigation is to provide extraction conditions for the extraction of required one or more component of wax using free flowing, non-sticky and porous spherules of wax by supercritical fluid extraction technology. The extraction conditions will depend on the physico-chemical properties of the compound to be extracted.
Yet another objective of the investigation is to provide extraction conditions that will result into the selective extraction of desired component in pure form.
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Summary of the Invention
Sticky, non-porous and compact nature of waxes limits their application in supercritical fluid extraction of either one or more of its components.
The present invention relates to a process for converting sticky, non-porous and compact physical form of wax into free flowing, non-sticky and porous spherules. The process comprises of dissolving wax in a solvent at higher temperature; adding inert adsorbent to the wax solution and loading wax onto adsorbent to form highly loaded spherules; forming a semi-solid mass by cooling the above mixture under stirring; removing residual solvent under vacuum and drying the highly loaded spherules. These highly loaded spherules have larger surface area for faster extraction; high porosity that helps in better diffusivity of supercritical fluid leading to efficient extraction; are non-sticky and free flowing that helps in better packaging of extraction device and easy cleaning of extraction device thus preventing cross contamination in successive experiments. The highly loaded spherules formed act as a feed for the supercritical fluid extraction of one or more components of wax having pharmaceutical, cosmoceutical, nutraceuticals, diagnostic and/or agricultural applications.
Detailed Description of the Invention
Over the past decade, several noteworthy consumer trends have emerged such as enhanced concern for the quality and safety of foods and medicines, regulation for nutritive and toxicity levels and increased preference for "natural" as opposed to synthetic substances. "Mother Nature" is considered a highly efficient synthesizer of desirable blends of constituents ideally suitable for human consumption. Safety of both producers and consumers is now a major requirement of any new product or process. Accordingly, compelling regulations on the usage of hazardous, carcinogenic and toxic solvents as well as high energy costs for solvent regeneration have curtailed the growth of natural extract industries. Alternative extraction methodologies that comply with both consumer preference and regulatory control and that are cost effective are becoming popular. One such major technology that has emerged over the last two decades as the alternative to the traditional solvent extraction of natural products is the Supercritical Fluid Extraction technique. The supercritical fluid extraction is a known process which is
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Supercritical fluid extraction technology is thus gaining importance over the conventional techniques for extraction of natural products. Part of the reason for recent interest in the supercritical fluid extraction is that it offers a potential advantage of higher yield and better quality products. One particular application, where the process may prove to be useful, is for recovery of high value and low volume products. Waxes are one such group of example which contains many pharmaceutical, cosmoceutical, nutraceuticals, diagnostic and/or agriculturally important constituents.
The term wax generally refers to a substance which is a plastic solid at room temperature and a liquid of low viscosity above its melting point. It is chemically defined as esters of fatty acid with fatty alcohols, having 36-50 carbon atoms.
However, Supercritical fluid extraction technology has not been extended to waxes for extraction of their one or more components as they posed several mechanical and thermodynamic problems during extraction.
1. The inherent non-porous and compact nature of waxes does not make them an ideal candidate for supercritical fluid extraction of components of waxes, as waxes caused thermodynamic problems during supercritical fluid extraction. Their non-porous and compact nature hampers the diffusivity of supercritical fluid leading to inefficient extraction. Also lesser surface area is exposed to supercritical fluid to extract wax component(s).
2. Another limitation of waxes is their sticky nature that results in clogging of the tubing connected to the extraction vessel. The internal diameter of tubing being as small as that of 1/16th of an inch, it led to the blocking the flow of supercritical fluid, making the supercritical fluid extraction instrument inoperable.
3. At high pressure waxes adhered strongly to the metal surface of extraction vessel making it very difficult for cleaning. Traces of wax, which could not be removed during cleaning, led to contamination in the successive batches.
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The present invention is focused on changing the sticky, non-porous and compact physical form of wax into a free flowing, non-sticky, porous spherules, to extract any component of wax from any wax.
As used herein the term "wax" refers to any wax which is synthetic (such as modified wax, compound wax etc.) or of natural origin (animal wax, insect wax, mineral wax, vegetable wax, etc.). The term wax generally refers to a substance which is a plastic solid at room temperature and a liquid of low viscosity above its melting point. It is chemically defined as esters of fatty acid with higher fatty alcohols.
As used herein the term "adsorbent" refers, e.g., to kaolin, aluminum hydroxide, zeolites, activated carbon, hydrophobic starch, molecular sieves, fuller"s earth, bentonite, hectorite, silicon dioxide gel, silica, colloidal magnesium-aluminum silicate, activated alumina, magnesium tri silicate, magnesium hydroxide, magnesium oxide, and the like.
As used herein the term "highly loaded spherules" refers to a loading of the adsorbent with the wax. The percentage loading should be less than 1000%. Preferably the percentage loading should be less than 500%. Most preferably the percentage loading should be less than 200%. These highly loaded spherules are free flowing, non-sticky and porous spherules.
As used herein the term "conditions of adsorption" does not refer to fixed conditions. The conditions depend on the kind of wax and the desired loading of the adsorbent.
As used herein the term "wax component(s)" refers to one or more constituents of wax to be extracted such as, but not limited to, vitamin A, D, E or K, carotenoids, fatty alcohols, hydroxy aromatic acids, saturated, monounsaturated or polyunsaturated fatty acids, squalene, sterols, oryzanols etc.
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As used herein the term "supercritical fluid" refers to carbon dioxide, methane, ethane, ethylene, propane, propylene, n-butane, acetone, chlorotrifluoromethane, trichlorofluoromethane, nitrous oxide, ammonia, benzene, toluene and mixtures thereof.
As used herein the term "extraction conditions" does not refer to fixed conditions. The conditions of extraction depend on the kind of wax, supercritical fluid used and the component of wax to be extracted. Extraction pressure and extraction temperature must have a value above the critical pressure and critical, temperature respectively, or at least in the near critical region.
The process for preparing highly loaded spherules is as follows
A supersaturated solution of wax in a solvent is prepared at temperature where the clear solution is formed. Inert adsorbent is added to the above solution. The resultant mixture is allowed to cool under stirring conditions. Residual solvent is removed by vacuum drying to obtain highly loaded spherules.
Highly loaded spherules are inert adsorbents loaded with wax in such a fashion that they inherit favorable physical characters such as free flowing, non-sticky and porous so that they can be subjected to supercritical fluid extraction of one or more component of wax. Wax is treated with inert adsorbents in presence of a solvent to obtain highly loaded spherules.
The conditions of formation of highly loaded spherules cannot be fixed. These conditions may vary depending upon the nature of wax and nature of adsorbent.
The solvent that can be used, for the preparation of highly loaded spherules, in the present invention are low molecular weight alkanes such as hexane, heptane, petroleum fractions; alkyl halides such as chloroform, carbon tetrachloride, dichloro methylene; ether such as di ethyl ether, petroleum ether; ketone such as acetone; aromatic compounds such as benzene, toluene, pyridine; esters such as ethyl acetate; alcohol
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(primary, secondary or tertiary) such as ethanol, methanol, propanol, iso-propanol,
butanol, iso-butanol etc.
Preferred solvents are those in which wax shows intermediate solubility. Most preferred
solvents are that exhibiting temperature dependent solubility for wax. The solubility of
wax in solvent should increase with increase with temperature and vice-versa. Most
preferred solvents are those which give a clear solution with wax at higher temperature
and on cooling precipitate the wax in the form of small fluffy particles.
Also the solvent should be such that the adsorbent should be insoluble in solvent.
The temperature range required for the formation of highly loaded spherules would depend upon the wax component(s) to be extracted. At the maximum limit of temperature, the wax component(s) to be extracted should not degrade.
The experiment for the formation of highly loaded spherules is carried out under stirring conditions of more than 10 RPM, preferably more than 100 RPM.
The particle size and loading of adsorbent determines the free flowing and non-sticky nature of highly loaded spherules.

Not more than 10% of particles should pass through 400 # sieve. Preferably not more than 10% of particles should pass through 200 # sieve. Most preferably not more than 10% of particles should pass through 100 # sieve.
The percentage loading of wax onto adsorbents to yield highly loaded spherules is calculated by the following formula:
(Weight of spherules - Weight of adsorbent) X 100
Percentage Loading =
Weight of adsorbent
Weight of spherules is the weight of wax loaded onto adsorbents and the weight of adsorbents. The percentage loading should be less than 1000%. Preferably the percentage
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loading should be less than 500%. Most preferably the percentage loading should be less than 200%.
Highly loaded spherules, thus formed, will act as a feed for the extraction of one or more constituents/components of wax, having one or more pharmaceutical, cosmoceutical, nutraceuticals, diagnostic and/or agricultural applications, using supercritical fluid extraction technology.
Highly loaded spherules are subjected to different conditions of extraction pressure, extraction temperature, flow rate of supercritical fluid etc., in order to extract the desired wax component(s) from highly loaded spherules.
When the feed is in the form of a solid, the supercritical fluid extraction process is carried out from a fixed bed of solids with a continuous flow of supercritical fluid. Alternatively moving solid bed can also be used but they are difficult to handle continuously in pressurized vessels. For extraction from fixed bed of solid particles loaded in a batch extractor, the supercritical fluid solvent is continuously passed through the extractor and evenly, either in the downward or upward direction with a fixed flow rate of supercritical fluid. The pressure and temperature are of the extractor are maintained constant and these parameters should be decided such that the supercritical fluid has sufficient solvent capacity for the wax component(s) to be extracted. The wax component(s) must be readily transported from the highly loaded spherules to the bulk of supercritical fluid
When highly loaded spherules are in contact with supercritical fluid at selected supercritical conditions, the extraction of wax component(s) takes place in the following sequential and parallel steps:
1. Diffusion of supercritical fluid into the pores and adsorption of supercritical fluid on the solid surface of highly loaded spherules
2. Transport of wax component(s)to the outer layer and formation of a thin liquid film around the highly loaded spherules
3. Dissolution of wax component(s) in supercritical fluid
4. Convective transport of the wax component(s) to the bulk of supercritical fluid
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The process for extraction of wax component(s) will now be set forth in great detail with reference to figure 1, showing schematically supercritical fluid extraction equipment. The four primary steps involved are extraction, expansion, separation and solvent conditioning, and the four corresponding critical components needed are a high pressure extractor (1), a pressure reduction valve (2), a low pressure separator (3) and a pump (4) for intensifying the pressure of the recycled solvent
The process starts by feeding the highly loaded spherules into the extraction device (1). The supercritical fluid, at pressure above critical pressure and temperature above critical temperature of supercritical fluid, is fed into the extraction device (1). Depending upon the extraction pressure, extraction temperature and flow rate of supercritical fluid the wax component(s) is dissolved and extracted, thereby obtaining supercritical fluid loaded with the wax component(s).
The loaded supercritical fluid is then expanded in a separator (3) by passing through pressure reduction valve (2) to a pressure where the solubilisation capacity of the supercritical fluid is reduced to obtain a reduced supercritical fluid and wax component(s). The pressure reduction depends on the applied supercritical fluid and on the extraction conditions. The appropriate reduction of pressure can be determined by phase equilibria measurements. At reduced pressure and temperature conditions, the wax component(s) precipitates in a separator (3). The separated wax component(s) is collected from separator (3) and may be further processed for purification to obtain wax component(s) with high purity. Alternatively, the supercritical fluid may be recycled to the extractor via a pump (4). Because of the pressure drop, the temperature is also reduced. Therefore the recycled in-loading supercritical fluid is passed through the heater (5) before it is fed again to the extraction device (1).
Thus the present invention comprises of a process of supercritical fluid extraction of one
or more component from wax by
1. Dissolving wax in a solvent at higher temperature;
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2. Adding inert adsorbent to the wax solution and loading wax onto adsorbent to form highly loaded spherules;
3. Forming a semi-solid mass by cooling the above mixture under stirring;
4. Removing residual solvent under vacuum and drying the highly loaded spherules;
5. Feeding the highly loaded spherules to the extraction device of supercritical fluid extraction unit;
6. Packing the extraction device with silica and glass wool;
7. Adjusting solvent capacity of supercritical fluid by adjusting the extraction pressure, extraction temperature and flow rate of supercritical fluid;
8. Passing supercritical fluid over the bed of highly loaded spherules;
9. Extracting the wax component(s) in supercritical fluid;
10. Expanding supercritical fluid loaded with wax component(s);
11. Separating wax component(s) from reduced supercritical fluid; and
12. Optionally purifying the wax component(s) to get the required quality product.
Suitable wax includes any wax of natural or synthetic origin. Preferred wax includes wax containing one more components of pharmaceutical, cosmoceutical, nutraceuticals, diagnostic and/or agricultural applications.
Suitable solvents includes low molecular weight alkanes such as hexane, heptane, petroleum fractions; alkyl halides such as chloroform, carbon tetrachloride, dichloro methylene; ether such as di ethyl ether, petroleum ether; ketone such as acetone; aromatic compounds such as benzene, toluene, pyridine; esters such as ethyl acetate; alcohol (primary, secondary or tertiary) such as ethanol, methanol, propanol, iso-propanol, butanol, iso-butanol etc.
Suitable adsorbent is any inert to kaolin, aluminum hydroxide, zeolites, activated carbon, hydrophobic starch, molecular sieves, fuller"s earth, bentonite, hectorite, silicon dioxide gel, silica, colloidal magnesium-aluminum silicate, activated alumina, magnesium tri silicate, magnesium hydroxide, magnesium oxide, and the like. Preferred is silica.
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Suitable particle size of adsorbent is such that not more than 10% of particles should pass through 400 # sieve. Preferably not more than 10% of particles should pass through 200 # sieve. Most preferably not more than 10% of particles should pass through 100 # sieve.
The percentage loading should be less than 1000%. Preferably the percentage loading should be less than 500%. Most preferably the percentage loading should be less than 200%.
The adsorption conditions include temperature more than 25 °C and stirring speed more than 10 RPM. Preferably temperature more than 30 °C and stirring speed more than 100 RPM.
Suitable supercritical fluid is carbon dioxide, methane, ethane, ethylene, propane, propylene, n-butane, acetone, chlorotrifluoromethane, trichlorofluoromethane, nitrous oxide, ammonia, benzene, toluene and mixtures thereof. Preferred supercritical fluid is carbon dioxide.
The extraction conditions include extraction pressure and extraction temperature. Extraction pressure and extraction temperature should be more than critical pressure and critical temperature of supercritical fluid respectively. Preferably the extraction pressure is 80 to 1000 bar. Most preferably the extraction pressure is between 100 to 750 bar. Preferably the extraction temperature is between 35 to 350 °C. Most preferably the extraction temperature is between 35 to 150 °C.
The following examples illustrate the invention but do not limit its scope in any manner
Example 1
Preparation of highly loaded spherules
Wax was dissolved in a solvent at a temperature of 40 - 70 °C. A supersaturated clear
solution was formed. Inert adsorbent, silica, was added to the above solution and the
mixture was stirred at the speed of more than 200 RPM to get highly loaded spherules.
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Not more than 10% of particles of adsorbent passed through 100 # sieve. The percentage loading of highly loaded spherules was less than 200%. The mixture was allowed to cool till a semi solid mass of adsorbents loaded with wax was obtained. Residual solvent was evaporated by vacuum drying to obtain dried highly loaded spherules.
Example 2
Optimization of particle size of adsorbent used in example 1
Adsorbent of various particle sizes such as 20-100 #, 100-200# and 200-400# mesh was
used for the preparation of highly loaded spherules. They were assessed on the basis of
sphericity, flow properties and adherence time to metal surface. The effect of particle size
of adsorbent on various parameters was as follows:

Parameters Adsorbent

20-100# 100-200# 200-400#
Sphericity 90-100 80-90 70-80
Adherence Time on Metal Surface (sec) Bulk density (gm/cc) 0.4-0.5 0.4-0.5 0.4-0.5
True density (gm/cc) 0.5-0.6 0.5-0.6 0.5-0.6
Angle of Repose (6) 20-30 25-35 30-40
Flow Rate (gm /sec) 15-25 10-20 5-15
Hausner"s ratio NLT1.2 NLT1.2 NLT1.2
Highly loaded spherules prepared using adsorbent of particle size of 20-100 # mesh sieve were more spherical as compared to the spherules prepared using 100-200# or 200-400# mesh sieve.
The spherules prepared using adsorbent of particle size of 20-100 # mesh showed better flow properties, like flow rate, angle of repose, when compared to spherules prepared using 100-200# or 200-400# mesh sieve.
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No difference was observed when adherence to metal surface was considered.
Example 3
Optimization of percentage loading of highly loaded spherules used in example 1 Highly loaded spherules were prepared with different percentage loading of wax (less than 200%). They were assessed on the basis of spherecity, flow properties and adherence time to metal surface. The effect of percentage loading of highly loaded spherules on various parameters was as follows:

PARAMFTFRS Percentage Loading
Wax 200% 100% 66.66% 50%
Flow Time (gm/sec) * * * 10- 15 10-15
Angle of Repose (°) * * * 20-30 20-30
Sphericity # # 65-75 75-85 85-95
Adherence Time on Metal Surface (sec) 14 4 * Poor flow
# Semi solid mass, no spherules were formed
Based on flow properties, sphericity and adherence time on metal surface, percentage loading of less than 100% gave better result.
For a particular adsorbent selected, flow properties, sphericity and adherence time to metal surface was improved, as the percentage loading of highly loaded spherules was decreased. It should also be considered that as the percentage loading is decreased the feed sample weight will increase. However an optimum percentage loading should be considered which gives satisfactory results with the added advantage of low feed sample weight.
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Example 4
Supercritical fluid extraction of vitamin E from oilseed wax
The extraction of vitamin E from oilseed wax was carried out by forming highly loaded
spherules of wax using inert adsorbent, silica. The percentage loading of highly loaded
spherules was less the 200%. The particle size of adsorbent was such that not more than
10% of the particles were passed through 100#. The said highly loaded spherules formed
were fed into the extraction device of supercritical fluid extraction unit. Carbon dioxide
was used as a supercritical fluid. Vitamin E was extracted at extraction pressure ranging
from 100 to 550 bar, extraction temperature ranging from 35 to 80 °C and flow rate of
supercritical fluid ranging from 0.1 to 0.8 L/min. Vitamin E extracted using this
technology was five times more than conventional extraction
Example 5
Extraction of pure vitamin E in one single step
The purity of the wax component(s) being extracted by supercritical fluid extraction
technology decreases as the values of extraction conditions increases, whereby its yield
increases. 100%o pure natural vitamin E was obtained at extraction pressure ranging from
100 to 300 bar, extraction temperature of 40 to 60 °C, flow rate of supercritical fluid of
0.1 to 0.3 L/min.
Description of drawings:
Figure 1, shows supercritical fluid extraction equipment. The process starts with feeding the highly loaded spherules followed by the supercritical fluid, at pressure above critical pressure and temperature above critical temperature of supercritical fluid, is fed into the extraction device (1). Depending upon the extraction pressure, extraction temperature and flow rate of supercritical fluid, the wax component(s) is dissolved and extracted, thereby obtaining supercritical fluid loaded with the wax component(s).
The loaded supercritical fluid is then expanded in a separator (3) by passing through pressure reduction valve (2) to a pressure where the solubilisation capacity of the supercritical fluid is reduced to obtain a reduced supercritical fluid and wax component(s). At reduced pressure and temperature conditions, the wax component(s)
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precipitates in a separator (3). The separated wax components) is collected from separator (3) and may be further processed for purification to obtain wax component(s) with high purity. Alternatively, the supercritical fluid may be recycled to the extractor via a pump (4). Because of the pressure drop, the temperature is also reduced. Therefore the recycled in-loading supercritical fluid is passed through the heater (5) before it is fed again to the extraction device (1).
While the present invention is described above in connection with preferred or illustrative embodiments, these embodiments are not intended to be exhaustive or limiting the scope of the invention. Rather, the invention is intended to cover all alternatives, modifications and equivalents included within its spirit and scope, as defined by the appended claims.

We claim,
1. A process for preparation of free flowing, non-sticky, porous and highly loaded
spherules of wax for supercritical fluid extraction of one or more component of
wax, wherein the said process comprises:
a. Dissolving wax in a solvent at higher temperature;
b. Adding inert adsorbent to the wax solution and loading wax onto adsorbent to
form highly loaded spherules;
c. Forming a semi-solid mass by cooling the above mixture under stirring;
d. Removing residual solvent under vacuum and drying the highly loaded
spherules;
e. Feeding the said highly loaded spherules to the extraction device of
supercritical fluid extraction unit;
f. Packing the extraction device with silica and glass wool;
g. Adjusting solvent capacity of supercritical fluid by regulating the extraction
pressure, extraction temperature and flow rate of supercritical fluid;
h. Passing supercritical fluid over the bed of highly loaded spherules; i. Extracting the wax component(s) in supercritical fluid; j. Expanding supercritical fluid loaded with wax component^s); k. Separating wax component(s) from reduced supercritical fluid; and 1. Optionally purifying the wax component(s) using conventional purification techniques.
2. The process according to claim 1, wherein said wax is of synthetic or of natural origin.
3. The process according to claim 1 and 2, wherein said synthetic wax includes modified wax and compound wax.
4. The process according to claim 1 and 2, wherein said natural wax includes animal wax, insect wax, mineral wax, or vegetable wax.
5. The process according to any of the preceding claims, wherein preferred wax is a natural oilseed wax.
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6. The process according to claim 1, wherein the inert adsorbent is selected from one or more adsorbent such as kaolin, aluminum hydroxide, zeolites, activated carbon, hydrophobic starch, molecular sieves, fuller"s earth, bentonite, hectorite, silicon dioxide gel, silica, colloidal magnesium-aluminum silicate, activated alumina, magnesium tri silicate, magnesium hydroxide, magnesium oxide, and the like.
7. The process according to claims 1 and 6, wherein the preferred inert adsorbent is silica.
8. The process according to claim 1, wherein said solvent selected from low molecular weight alkanes such as hexane, heptane, petroleum fractions; alkyl halides such as chloroform, carbon tetrachloride, dichloro methylane; ethers such as diethyl ether, petroleum ether; ketone such as acetone; aromatic compounds such as benzene, toluene, pyridine; esters such as ethyl acetate; alcohol (primary, secondary or tertiary) such as ethanol, methanol, propanol, iso-propanol, butanol and iso-butanol.
9. The process according to claim 1 and 8, wherein said solvent is an alcohol.
10. The process according to claim 1, 8 and 9, wherein said solvent is secondary alcohol.
11. The process according to claim 1, 8, 9 and 10, wherein said preferred solvent is iso-propanol.
12. The process according to claim 1, 6 and 7 wherein the particle size of said adsorbent is such that not more than 10% of particles should pass through 400 # sieve.
13. The process according to claim 1, 6, 7 and 12, wherein particle size of said adsorbent is such that not more than 10% of particles should pass through 200 # sieve,
14. The process according to claim 1, 6, 7, 12 and 13, wherein the preferred particle size of adsorbent is such that not more than 10% of particles should pass through 100 # sieve.
15. The process according to claim 1, wherein the percentage loading of highly loaded spherules is less than 1000%.
16. The process according to claims 1 and 15, wherein the percentage loading of highly
loaded spherules is less than 500%
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17. The process according to claims 1, 15 and 16, wherein the preferred percentage loading of highly loaded spherules is preferably less than 200%
18. The process according to claim 1, wherein the adsorption conditions includes temperature more than 25 °C and stirring speed more than 10 RPM.
19. The process according to claim 1 and 18, wherein the preferred adsorption conditions includes temperature adjusted to more than 30 °C and stirring speed adjusted to more than 100 RPM.
20. The process according to claim 1, wherein the highly loaded spherules are made to have more surface area as compared to wax, for efficient and faster extraction of wax component(s).
21. The process according to claim 1, wherein the highly loaded spherules are made more porous as compared to wax, for better diffusivity of supercritical fluid leading to efficient and faster extraction of wax component(s).
22. The process according to claim 1, wherein the highly loaded spherules are made more free-flowing as compared to wax, resulting in better packaging of extraction device.
23. The process according to claim 1, wherein the highly loaded spherules are made less sticky as compared to wax that prevents the adherence of wax onto extraction device at high pressure, thus preventing chances of cross contamination during
successive experiments.
24. V The process according to claim 1, wherein said extracted wax component(s) refers
to one or more constituents of wax having pharmaceutical, cosmoceutical,
nutraceuticals, diagnostic and/or agricultural applications.
25. The process according to claim 1 and 24, wherein said extracted wax component(s) includes, but not limited to vitamin A, D, E or K, carotenoids, fatty alcohols, hydroxy aromatic acids, saturated, monounsaturated or polyunsaturated fatty acids, squalene, sterols, and oryzanols
26. The process according to claim 1, 24 and 25, wherein the preferred extracted wax component is vitamin E.
27. The process according to claim 1, wherein said supercritical fluid used for extraction of wax component(s) is selected from carbon dioxide, methane, ethane,
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ethylene, propane, propylene, n-butane, acetone, chlorotrifluoromethane, trichlorofluoromethane, nitrous oxide, ammonia, benzene, toluene and mixtures thereof.
28. The process according to claim 1 and 27, wherein said preferred supercritical fluid used for extraction of wax component(s) is carbon dioxide.
29. The process according to claim 1, wherein said wax component(s) are extracted at extraction pressure of about 80 to 1000 bar.
30. The process according to claim 1 and 29, wherein said wax component(s) are preferably extracted at extraction pressure of about 100 to 550 bar.
31. The process according to claim 1, wherein said wax component(s) are extracted at extraction temperature of about 35 to 350 °C.
32. The process according to claim 1 and 31, wherein said wax component(s) are preferably extracted at extraction temperature of about 35 to 150 °C.
33. The process according to claim 1, wherein said wax components) are extracted at flow rate of supercritical fluid of about 0.01 to 10.00 L/min
34. The process according to claim 1 and 33, wherein said wax component(s) are preferably extracted at flow rate of supercritical fluid of about 0.1 to 1.0 L/min
35. The process according to any of the preceding claims, wherein the extraction of vitamin E from natural oilseed wax is carried out at extraction pressure ranging from 100 to 550 bar, extraction temperature ranging from 35 to 80 °C and flow rate of carbon dioxide in the range from 0.1 to 0.8 L/min.
36. The process according to any of the preceding claims, wherein said extraction of vitamin E from natural oilseed wax is carried out at preferred extraction pressure ranging from 200 to 550 bar, preferred extraction temperature ranging from 40 to 60 °C and preferred flow rate of carbon dioxide in the range from 0.1 to 0.6 L/min.
37. The process according to any of the preceding claims, wherein the extraction of said vitamin E is five times higher using supercritical fluid technology from natural oilseed within 90 minutes, as compared to conventional extraction.
38. The process according to any of the preceding claims, wherein said extracted wax component is 100% pure, extracted in a one single step.

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39. The process according to claim 1 and 38, wherein said 100% pure vitamin E is extracted from natural oilseed wax at extraction pressure ranging from 100 to 350 bar, extraction temperature ranging from 35 to 80 °C and flow rate of carbon dioxide in the range from 0.1 to 0.6 L/min.
40. The process according to claim 1 and 39, wherein said 100% pure vitamin E is extracted from natural oilseed wax at preferred extraction pressure ranging from 200 to 300 bar, preferred extraction temperature ranging from 40 to 60 °C and preferred flow rate of carbon dioxide in the range from 0.1 to 0.3 L/min.
41. The process according to any of the preceding claims, wherein said extracted wax component(s) were further optionally purified by conventional purification techniques.
42. A process for preparing highly loaded spherules of wax and supercritical fluid extraction of wax component(s) from highly loaded spherules of wax as substantially described herein with reference the foregoing examples 1 to 5.

Documents:

1235-mum-2003- abstract.doc

1235-mum-2003- claims.doc

1235-mum-2003-abstract.pdf

1235-mum-2003-claims.pdf

1235-mum-2003-correspondence.pdf

1235-mum-2003-correspondence[ipo].pdf

1235-mum-2003-description(granted).doc

1235-mum-2003-description[granted].pdf

1235-mum-2003-form 18.pdf

1235-mum-2003-form 1[12-oct-2007].pdf

1235-mum-2003-form 1[28-nov-2003].pdf

1235-mum-2003-form 2(granted).doc

1235-mum-2003-form 2(provisional).pdf

1235-mum-2003-form 26.pdf

1235-mum-2003-form 2[granted].pdf

1235-mum-2003-form 2[title page].pdf

1235-mum-2003-form 3.pdf

1235-mum-2003-form 5.pdf

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Patent Number

211495

Indian Patent Application Number

1235/MUM/2003

PG Journal Number

04/2008

Publication Date

25-Jan-2008

Grant Date

01-Nov-2007

Date of Filing

28-Nov-2003

Name of Patentee

PIRTHI PAL SINGH PARTAP SINGH

Applicant Address

UNIVERSITY INSTITUTE OF CHEMICAL TECHNOLOGY, NATHALAL PARIKH MARG, MATUNGA, MUMBAI-400019

Inventors:

#	Inventor's Name	Inventor's Address
1	PATRAVALE VANDANA BHARAT	UNIVERSITY INSTITUTE OF CHEMICAL TECHNOLOGY, NATHALAL PARIKH MARG, MATUNGA, MUMBAI-400019
2	PIRTHI PAL SINGH PARTAP SINGH	UNIVERSITY INSTITUTE OF CHEMICAL TECHNOLOGY, NATHALAL PARIKH MARG, MATUNGA, MUMBAI-400019

PCT International Classification Number

C07C9/14

PCT International Application Number

N/A

PCT International Filing date

PCT Conventions:

#	PCT Application Number	Date of Convention	Priority Country
1			NA