Title of Invention

A PROCESS FOR REMOVAL OF SULPHUR FROM FATTY ACIDS

Abstract

A process for removal of sulphur from fatty acids comprising of heating the fatty acids at a temperature from 50 - 90 °C; reacting said fatty acids with a hydrogenation catalyst selected from iron, cobalt, nickel, ruthenium, rhodium, palladium, osmium, iridium, platinum, chromium, molybdenum, tungsten, copper, rhenium, vanadium and their alloys, and their compounds, such as oxide, hydroxide, sulphide, palladium black, palladium on carbon, platinum oxide, nickel on kieselguhr, Raney nickel, Raney iron, Raney copper, copper-chromite, molybdenum sulphide in an amount of 0.01 - 5 % by weight for 0.5-5 hours and distilling the treated fatty acid

Full Text

FORM 2 THE PATENTS ACT 1970 (39 of 1970) COMPLETE SPECIFICATION (SECTION-10; RULE 13) "A PROCESS FOR REMOVAL OF SULPHUR FROM FATTY ACIDS" GODREJ SOAPS LTD., AN INDIAN COMPANY INCORPORATED UNDER THE COMPANIES ACT, 1956, HAVING ITS OFFICE AT EASTERN EXPRESS HIGHWAY, VIKHROLI, MUMBAI 400 079, MAHARASHTRA, INDIA. THE FOLLOWING SPECIFICATION PARTICULARLY DESCRIBES THE NATURE OF THIS INVENTION AND THE MANNER IN WHICH IT IS TO BE PERFORMED. ORIGINAL 240/MUM/2000 21-03-2000 The present invention envisages a process of manufacturing sulphur-free fatty acids comprising contacting with hydrogenation catalyst. Impurities in Fatty Acids Refining processes may be used to remove various contaminants and impurities which are undesirable for reasons of health, performance, aesthetics, etc. The fatty acids may contain impurities such as colour bodies, chlorophyll, phospholipids (phosphatides), trace metals, gums, soaps, and/or other impurities. This variety of diverse impurities has led to the development of numerous refining processes involving particular combinations of chemical and / or physical treatment steps. Sulphur as a Contaminant Fatty acids may also comprise sulphur, either in the form of naturally occurring sulphur compounds or in the form of contaminants from various processing or refining steps. For example, certain glyceride oils, most notably canola and rapeseed oils are known to contain small amounts of sulphur in the form of episulfides, isothiocyanates, thiocyanates, oxazolidinethiones, sulphates and sulphur-containing amino acids. These oil soluble sulphur compounds, are the product of enzymatic decomposition of sulphur-containing glucosinolates in the plant seed, which occurs during processing of the seed. Decomposition products of isothiocyanates (hydrogen sulphide and other sulphides) are especially active catalyst poisons and are also considered "sulphur-containing compounds" as that term is used herein. Corn oil also contains sulphur compounds, although from different sources. Natural sulphur compounds may be absorbed and metabolized from the soil as nutrients, In addition, during wet milling, S02 is added as a preservative, and the resulting sulphur content of corn oil may be about 20-30 ppm. The S02 will react with cysteine and cystine to form trace amounts of sulphur-containing proteins in the oil. In coconut oil also there is sulphur contamination of the copra during drying. This results in a marked 'rubbery' off flavour in the deodorised oil within seconds of its exposure to daylight. Effect of Sulphur Poisoning Sulphur compounds present both aesthetic and refining problems, They are implicated in the production of unpleasant odours during heating of the oils or other fatty materials. In addition, these sulphur compounds poison the catafysts used during hydrogenation, resulting in either increased catafysf usage (with a corresponding increase in the disposal burden) or longer hydrogenation times resulting in lower production rates. This is an economically important consideration, since enormous quantities of fatty materials are hydrogenated. Impurities that have a negative effect on catalysts were broken down into poisons, inhibitors and deactivators, with each group acting according to a different mechanism. Poisons such as sulfur and bromine chemically react with the nickel. So the are considered as permanent poisons. Removal of these compounds from fatty acids improves the quality of these materials, since the sulphur compounds cause unpleasant odours upon heating. Important economic benefits can also be realized by the removal of these sulphur compounds, which poison hydrogenation catalysts, particularly nickel hydrogenation catalysts. The result is an improved hydrogenation operation, either by reduction in hydrogenation times or catalyst usage. The Fatty Acids The fatty acid to be applied to the present invention includes fatty acids having about 6-24 carbon atoms, which are obtained by the hydrolysis of naluraliais and oils such as vegetable fats and oils. These fatty acids are, for example canola oil fatty acid, coconut oil fatty acid, corn oil fatty acid, mustard oil fatty acid, palm oil fatty acid, rapeseed oil fatty acid, soybean oil fatty acid, tali oil fatty acid and either their individual fatty acids or their most common fractions like valeric acid, caproic acid, caprylic acid, pelargonic acid, capric acid, caprylic-capric, lauric acid, myristic acid, lauric-myristic, palmitic acid, stearic acid, palmitic-stearic, oleic acid, linoleic acid, linolenic acid, arachidic acid, behenic acid, erucic acid & lignoceric acid. The Hydrogenation Catalyst The hydrogenation catalyst is a catalyst used in the hydrogenation of organic compound, and includes iron, cobalt, nickel, ruthenium, rhodium, palladium, osmium, iridium, platinum, chromium, molybdenum, tungsten, copper, rhenium, vanadium and the like, and their alloys, and their compounds, such as oxide, hydroxide, sulphide and the like. The alloys and compounds are palladium black, palladium on carbon, platinum oxide, nickel on kieselguhr, Raney nickel, Raney iron, Raney copper, copper-chromite, molybdenum sulphide and the like. Prior Art U.S. Patent No. 5298638 discloses a process of removal of sulphur from fatty acids by using a silica hydro gel in 1.5 % - 3.0%. The use of the silica hydro gel in the aforesaid process causes an accumulation of waste. Further, it involves an additional step of bleaching with activated Earth. The present invention obviates the aforesaid drawbacks by providing a process involving no accumulation of waste and having no additional step of bleaching. The present invention relates to a process for removal of sulphur from fatty acids o comprising of heating the fatty acids at a temperature from 50 - 90 C; reacting the fatty acids with said hydrogenation catalyst in an amount of 0.01 - 5% by weight for about 0.5-5 hours and then distilling the treated fatty acids. Although the present invention uses the hydrogenation catalysts, the process does not involve any catalytic hydrogenation. Inventive Step The aspect of the process for purifying fatty acids according to the present invention lies in the combination procedure of a contacting step of a fatty acid with a reducing metal, and a distillation step. The invention relates to the treatment of any fatty acid comprising sulphur-containing compounds where the fatty acid is contacted with a hydrogenation catalyst for purposes of removing sulphur compounds from the fatty acid. More specifically, hydrogenation catalysts have been found to be effective for adsorption of enzymatic decomposition or hydrolysis products of sulphur-containing glucosinolates. The present invention is a process which employs a combination of steps familiar in everyday practices in the refining of fatty acids However, there are certain novel steps ie sequence of steps are modified whereby the resultant combination of steps produces the desired refining treatments without mechanical filtration of the molten fatty acid. Furthermore, substantially small amounts of finely divided solid materials are used and hence their removal is optional to obtain a substantially sulphur free purified fatty acid. In addition, the problems involved with oxidization of the molten fatty acids during mechanical filtration are avoided to ensure optimum product quality of the purified fatty acid. The process of the invention comorises •a. Heaing the fatty acid to 50 - 90 °C depending on the titre of the fatty acid. b. Stirring the molten fatty acid for thorough mixing. c. Adding 0.01 - 5 % of nickel on kieselgur hydrogehation catalyst pellets having 20 - 30 % active nickel content. d. Mixing for sufficient time from 0.5 - 3 hours. e. Recovering the substantially sulphur free purified fatty acid after filtration & difstfflation or only distnllation. The following examples are given for the purpose of illustration of this invention and are not intended as limitations thereof. In the examples, a method, wherein the hydrogenation catalyst is used as a reagent for purifying fatty acid, is referred to as "The Method". Further, in the following examples, the method wherein the hydrogenation catalyst is not used before distillation, is referred to as " The Control ". Further, in the following examples, a distillation fraction up to a bottom temperature of 250°C. at a pressure of 5 mm Hg was gathered and is referred to as "The Distillation". The results are tabulated for all the examples in one common " Table". Example 1 Crude Rapeseed acid oil fatty acid ( RSa/oFA ) was analysed to have 24.5 ppm of total Sulphur content. This was taken in a beaker fitted with a stirring assembly and heated to 90 °C in a constant temperature water bath. The hydrogenation catalyst ( 25% wt. of active nickel adsorbed on paraffin wax and silica ) obtained from standard catalyst manufacturers is added in one lot into the stirred fatty acid and stirring is continued for 1 hr at 90 °C. The RSa/oFA is then filtered through a filter pad consisting of a filter cloth & filter-aid using a Buchner assembly under reduced pressure. The filtered fatty acid is now distilled uridex the nocmal conditions of temoerature and pressure { up. to a maximum of 250 °C as the bottom temperature at a reduced pressure of 5 mm of Hg ) an_d the distilled RSa/oFA is collected As a control experiment, a similar amount of RSa/oFA is identically distilled and the distilled product is collected. Both the samples are then analysed for their Sulphur content by standard method and the results are given in the common table below. Example 2 Similarly a super degummed canola oil fatty acid containing 15.8 ppm total sulphur was used in this example. The same hydrogenation catalyst (.25% wt. of active nickel adsorbed on paraffin wax and silica ) was used. Chemical treatments were conducted by heating the canola oil fatty acid in a glass flask for 20 min. in a water bath to 70 °C. The catalyst was then added to the level indicated in the table and stirred into the fatty acid with a mixer set at 1400 rpm. The flask was transferred to a 100 °C. water bath for 40 min. with continued stirring. The fatty acid was then removed from the bath and cooled to below 70C. while vacuum was maintained. The reaction mixture was distilled, without filtration, at 5 mm of Hg up to a maximum of 250 °C as the bottom temperature. As a control experiment a similar amount of the same canola oil fatty acid is identically distilled and the distilled product is collected. Both the samples are then analysed for their Sulphur content by standard method and the results are given in the common table below. Similarly Examples 3 & 4 are done as per Example 1 and Examples 5 & 6 are done as per Example 2. All the six results are tabulated below in the common table : We claim: 1. A process for removal of sulphur from fatty acids comprising of heating the fatty acids at a temperature from 50 - 90 °C; reacting said fatty acids with a hydrogenation catalyst selected from iron, cobalt, nickel, ruthenium, rhodium, palladium, osmium, iridium, platinum, chromium, molybdenum, tungsten, copper, rhenium, vanadium and their alloys, and their compounds, such as oxide, hydroxide, sulphide, palladium black, palladium on carbon, platinum oxide, nickel on kieselguhr, Raney nickel, Raney iron, Raney copper, copper-chromite, molybdenum sulphide in an amount of 0.01 - 5 % by weight for 0.5-5 hours and distilling the treated fatty acid. 2. A process as claimed in Claim 1, wherein said fatty acids have 6-24 carbon atoms. 3. A process as claimed in Claim 1, wherein said treated fatty acid is filtered and the filtrate is distilled. 4. A process as claimed in Claim 1, wherein said treated fatty acid is directly distilled without filtration. 5. A process for removal of sulphur from fatty acids substantially as herein described with reference to the accompanying examples. Dated this 20th day of June 2001 H. W. Kane Applicant's Agent

Documents:

240-mum-2000-cancelled page(24-11-2004).pdf

240-mum-2000-claim(granted)-(24-11-2004).doc

240-mum-2000-claims(granted)-(24-11-2004).pdf

240-mum-2000-correspondence(12-05-2006).pdf

240-mum-2000-correspondence(ipo)-(26-07-2004).pdf

240-mum-2000-form 1(21-03-2000).pdf

240-mum-2000-form 19(31-07-2003).pdf

240-mum-2000-form 2(granted)-(24-11-2004).doc

240-mum-2000-form 2(granted)-(24-11-2004).pdf

240-mum-2000-form 3(16-03-2000).pdf

240-mum-2000-form 3(21-03-2000).pdf

240-mum-2000-form 4(20-06-2001).pdf

240-mum-2000-form 5(20-06-2001).pdf

240-mum-2000-form 6(10-03-2005).pdf

240-mum-2000-petition under rule 137(24-11-2004).pdf

240-mum-2000-power of authority(21-03-2000).pdf