Title of Invention

"A PROCESS FOR THE PREPARATION OF >95% PURIFIED WAX FROM WAX-SLUDGE BRAN OIL"

Abstract

A process for the preparation of >95% purified wax from wax-sludge of Bran oil by hydraulic pressing of wax sludge in the pressure range 5-50 psi using hydraulic press, extraction of deoited wax-sludge with non-polar solvent in a ratio of about 1:2 under stirring for a period of about 30 minute at a room temperautre ranging o 25-35 C and collection of wax layer and solvent removal from the said wax layer under 15 inch vacuum to obtain puri¬fied wax. The rice from wax is useful as a substitute for bees" wax and carnauba wax.

Full Text

This invention relates to a process for the prepa¬ration of >95% purified wax from wax-sludge of Bran oil. More particularly the invention relates to a process for purification of wax from rice tonnes would be considered as a major edible oil for the 21st cen¬tury in India. The oil has about 2-5% of wax which has a number of industrial applications, such as for pol¬ishes, ingredient in cosmetics, and food applications. The wax is more or less similar to bees' wax and car-nauba wax in properties and therefore could be used as a substitute for these waxes. Rice bran wax has a potential of 20,000 tonnes and could capture the export and import market of carnauba, bees', and sugarcane waxes. The present production of wax-sludge seems to be 10,000 tonnes per annum (calculated at 4% of the crude oil processed to get the present production figure of 2.5 lakh tonnes of refined rice bran oil) . The chemical composition of Japanese rice bran wax has been cited in the literature. It contains four classes of wax lipids viz., steryl ester (C47), longer alkyl ester (C44 & C54), shorter alkyl ester(C17, C19 & C20) and hydrocarbons(C29, C31 & C33). The main compo¬nent of fatty acids were linoleic, oleic, and palmitic acid for steryl ester; behenic, lignoceric and palmitic acid for longer alkyl ester; and oleic and palmitic acid for shorter alkyl ester. The representative molec¬ular species were sitosteryl linoleate (linoleoyl sitosterol), and sitosteryl oleate (oleoyl sitosterol) for steryl ester; dotriacontanyl behenate (behenoyl dotriacontanol), octacosanyl palmitate (palmitoyl octacosanol) for longer alkyl ester; and methyl oleate, methyl palmitate and ethyl oleate for shorter alkyl ester. Straight-chain and alkene, and branched-chain alkene (squalene) were detected as hydrocarbons. The principal carbon number of alkane was C29 and C31 and that of alkene, 029, 031 and 033. Rice bran wax has been chosen as one of the waxes of the plant source for application as a natural additive in foods, cosmetics and other industries (polishes, carbon paper, lubricants). There are Japanese (patent no.5311013, patent year 1978) and U.S.(patent no.69649, patent year 1979) patents on the use of rice bran wax for coating of fruits and vegetables and as an indirect food additive (release agent) in processing plastics packaging materials intended for food contact applications at a maximum level of 1% of the weight of the plastics. Rice bran wax consists almost exclusively of saturated monoesters with a typical carbon chain length distribution of 046 to 060. This monoester distribution makes it intermediate between the ranges of the esters found in bees's wax and carnauba wax. However, the low level of unsaturation (low iodine value) makes rice bran wax nearly as hard as carnauba, with almost the same melting point. The existing processes on rice bran wax production involves use of low temperature crystallization of wax from the oil followed by filtration using filter presses. The filtered wax is traded as such in India and in developed countriesf the wax-sludge is treated with a number of solvents such as chloroform, isopropanol, acetone and methanol in succession to prepare a wax suitable for the industry. These methods were practised only in advanced countries during 1950-1970*s. Now pure wax is being exported by Japan to other countries. The rice bran wax produced in Japan is prepared by the solvent extraction methods. The solvent(s) used is a trade secret. Even supercritical carbondioxide is being employed to prepare high quality wax. But, there is no process for the preparation of good quality wax in India, although some rice bran oil industries are producing a slightly hard product having entrained oil(upto 30%) which may be called as wax of about 70% purity and not pure rice bran wax which is twice as hard as this wax. Also to our knowledge, no process/patent is making use of hexane at room temperature for wax purification to get a >95% purity hard wax. In the present invention, this soft-wax, termed as wax-sludge has been purified to get a hard wax (by using solvent treatment) which has similar melting profile as that of carnauba wax. Also the present invention is not expensive because about 98-100% of the entrained oil(70% yield) is recovered and can be used for preparing edible oil apart from obtaining 95-98% pure wax (30% yield) which fetches more value compared to wax-sludge. The process can be performed in the industry which produces refined rice bran oil for which the raw material wax-sludge comes from the same industry. The novelty in the process is that the difficult step of percolation of solvent through wax suspension has been eliminated and a new simple method has been used, As per the developed method based on a combination of physical and chemical methods, wax and oil fractions are separated by using low pressure and non-polar solvent treatment for wax-sludge with 80% entrained oil while for sludge with 70% and below of entrained oil, only non-polar solvent treatment can be given avoiding filtration. The wax fraction thus obtained is of >95% purity. The upgraded wax doesnot contain phospholipids and has a melting point, hardness, brittleness comparable to carnauba wax. The wax so prepared in two steps does not need bleaching. The solvent and oil can be recovered and reused, thereby the process is economical. The process is also quick. The rice bran wax in pure form is not available in the country. The objective of the invention was to remove oil from the wax-sludge (50-80% oil) and prepare a wax of >95% purity so that this could be acceptable as an ingredient in many industries. The commercial rice bran wax is soft, with about 50-70% oil in it and can be called as wax-sludge. Therefore, a product of 100% purity is desired which has properties similar to that of carnauba wax. The wax behaved similar to commercial waxes (such as bees' wax, carnauba wax, sugar cane wax, and microcrystalline wax with regard to melting point) marketed in India. The wax prepared with the new methods has the characteristics as given in Table 1. Table 1 Characteristics of purified bran wax prepared by the methods described in this patent Parameter (Table Removed) * The wax on heating melts and sets into a compact pale brown mass on attaining room temperature. Suspending the molten material in hexane(n-hexane, commercial hexane of boiling range 65-70°C or food grade hexane) and cooling to room temperature followed by removal of solvent produces a porous dull-white material same as that of the starting material. Accordingly /'the present^nvention tprov Pre convent&onal hydraulic press Accordingly the present invention provides a process for the preparation of >95% purified wax from wax-sludge of Bran oil which comprises: a) hydraulic pressing of wax sludge in the pressure range 5-50 psi using hydraulic press; b) extraction of deoiled wax-sludge with non-polar solvent of the kind such as herein described in a ratio of about 1:2 under stirring for a period of about 30 minutes at room temperature ranging from 25-35°C; c) collection of wax layer and solvent removal from the said wax layer under 15 inch vacuum to obtain the purified wax. In an embodiment of the present invention, the pressure applied is in the range 5-50 psi. In another embodiment of the present invention, the non-polar aliphatic hydrocarbon solvent is selected from hexane, n-hexane, and any of the C5-C8 carbon chain length aliphatic hydrocarbon solvents viz., petroleum ether, pentane hexane, heptane and octane. In still another embodiment of the present invention, the ratio of deoiled wax-sludge to hexane should be more than 1:2. In another embodiment of the present invention, addition of solvent is effected at room temperature. In another embodiment of the present invention, purified wax is recovered by decantation followed by solvent removal. A process of the example is illustrated by the following example, however, it should not limit the scope of this invention. Example-1 9 kg of wax-sludge was pressed using a low pressure press at 30 psi to get 6.3 kg of partially deoiled wax and 2.2 kg of the oil fraction. Later, 500g of the partially deoiled wax was treated with 2000ml X 4 of the C6 aliphatic hydrocarbon solvent and after 30 minutes, the wax layer and the oil layer were separated at atomospheric pressure, desolventized under 15 inch vacuum to get lOOg of wax of 97.5% purity and 400g of oil fraction respectively (Table 2). Table 2 Use of a combination of physical and chemical principles for the preparation of purified wax from rice bran oil wax-sludge (Table Removed) adetermined as acetone insolubles at room temperature (27-30°C). Similarly, other solvents such as petroleum ether, pentane, heptane and octane also can be used in place of hexane for purification of wax. The advantages of the method are, the wax obtained is of high purity, white powder, brittle in nature, has low acid, iodine and saponification values and therefore could find application in foods (such as confectionery coating), Pharmaceuticals (such as polishing of tablets), cosmetics, lubricants, carbon paper and polish industries. This can also replace carnauba wax by 100% as it has similar melting and hardness profile. In Japan, it is used for coating of fruits and vegetables. In USA it is allowed as a release agent for molds and for coating of candy and chewing gums. Therefore, the wax may be exported to other countries. We claim: 1. A process for the preparation of >95% purified wax from wax-sludge of Bran oil which comprises: a) hydraulic pressing of wax sludge in the pressure range 5-50 psi using hydraulic press; b) extraction of deoiled wax-sludge with non-polar solvent of the kind such as herein described in a ratio of about 1:2 under stirring for a period of about 30 minutes at room temperature ranging from 25-35°C; c) collection of wax layer and solvent removal from the said wax layer under 15 inch vacuum to obtain the purified wax. 2. A process as claimed in claim 1 wherein, the non-polar aliphatic hydrocarbon solvent is selected from hexane, n-hexane, and any of the C5-C8 carbon chain length aliphatic hydrocarbon solvents viz., petroleum ether, pentane hexane, heptane and octane. 3. A process for the preparation of >95% purified wax from wax-sludge of Bran oil substantially as herein described with reference to the example.

Documents:

2162-del-1998-abstract.pdf

2162-del-1998-claims.pdf

2162-del-1998-correspondence-others.pdf

2162-del-1998-correspondence-po.pdf

2162-del-1998-description (complete).pdf

2162-del-1998-form-1.pdf

2162-del-1998-form-2.pdf

2162-del-1998-form-3.pdf