Epoxidized oil production from olive pomace oil and waste edible oils with the help of boric / perboric acid

Abstract

The invention relates to a method for obtaining and producing epoxy triglycerides (oils) from olive pomace oil or waste edible triglycerides (oils), which are among the renewable sources.

Description

[0001] EPOXIDIZED OIL PRODUCTION FROM OLIVE POMACE OIL AND WASTE EDIBLE OILS

[0002] WITH THE HELP OF BORIC / PERBORIC ACID

[0003] Technical Field

[0004] The invention relates to the production of epoxidized oil.

[0005] The invention relates in particular to a method for obtaining and producing epoxy triglycerides (oils) from olive pomace oil or waste edible triglycerides (oils), which are among the renewable sources.

[0006] State of the Art

[0007] The fats are the substances, which dissolve in the solvents referred to as the fat solvents, such as acetone, diethyl ether, dichloromethane, ethyl acetate, and chloroform. Said fats are divided into two main groups, namely the simple and the compound fats. Triglycerides, which are among the simple fats, are glycerin triesters of the long carbon-chain carboxylic acids called the fatty acids. Their structural representation is provided below. The saturated fatty acids such as lauric, myristic, palmitic, and stearic acid and the unsaturated fatty acids such as palmitoleic, oleic, linoleic, linolenic, gadoleic, and behenic acid can be found in the structure of edible triglycerides.

[0008] Triglyceride

[0009] Although the fatty acids containing the hydroxyl and epoxy groups, such as ricinoleic acid and vemolic acid, exist in nature, these do not join in the structure of the edible oils.

[0010] When the reactive portions of the triglycerides are examined, it can be seen that they have roughly 4 reactive positions or groups, namely ester groups, a methylene groups, double bonds, and allyl groups. A wide variety of monomers or polymers may be obtained by reacting these groups. Industrially, the most common practice involves obtaining the alkyd resins through the modification of the ester groups. The alkyd resins are the resins obtained with an excess of glycerin and in the presence of various carboxylic acids. They are very widely used in the production of the oil paints. It is also possible to obtain many industrial materials by way of the modification of the double bonds, besides the modification of the ester group. The brominated oils are the substances, which are obtained, for example, via the reaction of the triglycerides with the element bromine and which are widely used in the food industry.

[0011] Other than the halogenated oils, the epoxidized oils are another important raw material used again on the industrial basis. When the double bonds in the triglycerides react with the epoxidizing agents (e.g., m- chloroperbenzoic acid, performic acid, and peracetic acid), they convert into the rings referred to as epoxide or oxirane consisting of three members, where one of the members is the oxygen atom. The triple rings are the structures with ring strain due to their bond angles and they are the reactive groups as a result of said ring strain.

[0012] Epoxidized Vegetable Triglyceride

[0013] The reaction mechanism (the mechanism of the epoxidation reaction with peroxy formic acid) is shown below. According to this, the epoxidation reaction is a reaction that occurs in tandem (with the bond rupture and the bond formation occurring simultaneously). The double bond group is rich in electrons and interacts with one of the oxygens other than the carbonyl oxygen in the peroxy acid; meanwhile, the bond

[0014] The patent application no. TR 2022 / 011717 was found in the state of the art. Said patent application relates to a method developed for producing polyol (oleopolis, oleo milk) from the renewable sources. Consequently, the problems described above and the inadequacy of the existing solutions have made it necessary to perform an improvement in the relevant technical field.

[0015] Brief Description of the Invention

[0016] The present invention relates to the production of epoxidized oil that satisfies the above-mentioned requirements, eliminates all the disadvantages, and provides some additional advantages.

[0017] The invention aims at resolving the above-mentioned drawbacks by providing a solution that is inspired by the current situations.

[0018] The main object of the invention is to develop a method for obtaining and producing epoxy triglycerides (oils) from olive pomace oil or waste edible triglycerides (oils), which are among the renewable sources. The waste edible oils, especially the olive oil obtained from the olive pomace waste, or the waste oils (tallow oil, suet, etc.) possible to be considered within this class, are used for this purpose. The triglycerides obtained from said sources contain nothing other than the above-mentioned 4 main reactive groups or positions.

[0019] According to the invention, it is enabled to obtain and produce epoxy triglycerides (oils) especially from the olive pomace oil or waste edible triglycerides (oils), with the help of a perboric acid complex. According to this, the oils are first freed from the solid particles and water they contain. In the next process step, the iodine index and the acid number are determined. An acid number determined to be below 10 does not cause any problem. If above 10, the acid number is reduced by way of mixing with a waste oil with low acid number, an edible oil with low acid number, or an oil with low acid number obtained from another source. The iodine index is checked and in case it is found to be below 100, an oil with high iodine index is added to ensure an iodine index of 100. An iodine index of above 100 does not cause any problem. If desired, an oil with high iodine index is used as it is. The waste oil, which has been subjected to the preliminary processes, is subsequently mixed first with the acids (such as acetic acid, formic acid, phosphoric acid, boric acid, etc.) having the ability to form complexes with hydrogen peroxide. If deemed suitable, a boric acid or perboric acid solution may be added to these acids, or the boric acid solution or the perboric acid solution may be mixed with the oil without using these acids. Subsequently, a concentrated hydrogen peroxide solution (minimum 10% and maximum 80%) is slowly added to the mixture of oil and acid. While the reaction may be performed at the room temperature, it is also possible to perform the same at higher temperatures. At the end of the process, the triglycerides where the double bonds have converted into the epoxide groups are obtained from the waste edible oils or olive pomace oil.

[0020] In the following section entitled “Detailed Description of the Invention ”, the process steps for obtaining and producing epoxy triglycerides (oils) from the olive pomace oil or the waste edible triglycerides (oils) with the help of a perboric boric acid complex for being used partly or fully along with the other epoxidation reagents are described along with the respective examples of said process steps.

[0021] The structural and characteristic features and all the advantages of the invention will become more clearly understood owing to the enclosed figures and the detailed description written with reference to said figures, and therefore, the evaluation must be made taking these figures and the detailed description into consideration.

[0022] Detailed Description of the Invention

[0023] In this detailed description, the preferred embodiments of the invention will be described only to enable a better understanding of the subject matter.

[0024] The invention relates to a method for the production of epoxidized oil. In said production method, first the waste oil is filtered to be freed from the foreign particles it contains. In the next process step, the water content of the waste oil is removed. This process step may be realized by one or more of the methods of holding in an oven, heating, and adding water retaining material (anhydrous sodium sulphate, dried sawdust, molecular sieve, etc.). Since the free fatty acids in the waste oil do not have any detrimental effect on the process, no extra process step is required in order to remove the same. Then, the iodine index and the acid index are checked for the oil, which has been subjected to the preliminary processes like drying and filtration.

[0025] The iodine index is an indicator of unsaturation and is preferred to be at least around 80-100. Even though the free fatty acids do not impair the epoxidation reaction, they have an effect of decreasing the epoxy amount as they join in the formed epoxy rings and convert into the products of the ring opening. For this reason, it is not desirable to have an acid number of 10 and above. According to the invention, an oil sample whose iodine index and acid number have also been adjusted is taken, and in case it is desired to reduce the viscosity of the oil sample, the low-boiling aliphatic solvents such as ethyl acetate, dichloromethane, and hexane, or aromatic solvents such as toluene, said solvents being not affected by the epoxidation reaction, are added. In the next process step of the method according to the invention, a suitable acid is added to the mixture. The boric, carboxylic or phosphoric acid may be used as the acid. While these acids may be used alone, it is also possible to use the same in the form of a mixture. In an alternative embodiment, it is also possible to add sulphonic acids to the oil / oil -solvent mixture. However, sulphonic acids cause blackening. Accordingly, it is recommended to avoid using them, if possible. If deemed appropriate, the obtained mixture of oil and acid is epoxidized by the addition of hydrogen peroxide preferably at around the room temperature or at a temperature of 60°C. The reaction takes about 16 hours at the room temperature and about 8 hours at the temperature of 60°C.

[0026] The examples of the process steps that constitute the method within the scope of the invention are presented below. These examples, which do not imply any limitation, exemplify the implementation and the effectiveness of the invention.

[0027] Example 1. Standardization of the Waste Oils

[0028] Determination of the acid number: 1 g oil is taken and is thoroughly mixed with 50 ml ethanol and 50 ml diethyl ether. 1-2 drops of phenolphthalein indicator (1% solution in ethanol) is added to this mixture. Then, the mixture is titrated with 0,1 N NaOH, which has been adjusted with potassium hydrogen phthalate. The acid number becomes 5,6 for the consumption of 1 ml of 0, 1 N NaOH.

[0029] Determination of the iodine index: The determination of the iodine index is performed according to Hanns method. In this method, a blank solution and a sample solution are prepared. For the sample solution, about 0,25 g of the oil sample is dissolved in 15 ml chloroform and 20 ml of an IBr solution in acetic acid is added to the same. The solution is kept in the dark for 1 hour. For the blank sample, the solutions are mixed without weighing the oil and the same process steps are performed. Then, both samples are taken, 20 ml of 10% sodium iodide and 1% starch are added to each sample, and the samples are titrated with a 0,1 N sodium thiosulfate solution. The consumption of 20 ml of 0.1 N thiosulfate corresponds to an iodine index of 100.

[0030] Example 2, Epoxidation of the Standardized Oils (with Formic Acid-Peroxide Complex)

[0031] 50 liters of standardized olive pomace oil is added to a 100-liter reactor equipped with temperature control and a stirrer and 20 kg of pure formic acid is added to the same. The mixture is cooled down to around 10°C. Then, 12 kg of 50% hydrogen peroxide is slowly added to this mixture at high speed (500- 1000 rpm; optimal value 750 rpm). The process of hydrogen peroxide addition is stopped after about 1 hour and the mixture is kept in this state at 750 rpm for at least 16 hours. The reaction mixture is then transferred to the 100-liter conical separators and washed 5 times with 15 liters of water. The contaminated water is removed from the bottom and the top phase is the epoxidized vegetable oil. Afterwards, the obtained raw oil is introduced to the drying ovens and dried at a temperature in the range of 20-50°C, optimally at a temperature of 30°C.

[0032] Example 3 , Epoxidation of the Standardized Oils (with Phosphoric Acid-Peroxide Complex)

[0033] 50 liters of standardized olive pomace oil is added to a 100-liter reactor equipped with temperature control and a stirrer and 10 kg of 85% phosphoric acid is added to the same. The mixture is heated to around 60°C. Then, 10 kg of 50% hydrogen peroxide is slowly added to this mixture at high speed (500- 1000 rpm; optimal value 750 rpm). The process of hydrogen peroxide addition is stopped after about 3 hours and the mixture is kept in this state at 750 rpm for maximum 8 hours. The reaction mixture is then transferred to the 100-liter conical separators and washed 5 times with 15 liters of water. The contaminated water is removed from the bottom and the top phase is the epoxidized vegetable oil. Afterwards, the obtained raw oil is introduced to the drying ovens and dried at a temperature in the range of 20-50°C, optimally at a temperature of 30°C.

[0034] Example 4, Epoxidation of the Standardized Oils (with Boric Acid / Formic Acid-Peroxide Complex) 50 liters of standardized olive pomace oil is added to a 100-liter reactor equipped with temperature control and a stirrer and 5 kg of boric acid and 15 kg of formic acid are added to the same. The mixture is cooled down to around 10°C. Then, 12 kg of 50% hydrogen peroxide is slowly added to this mixture at high speed (500-1000 rpm; optimal value 750 rpm). The process of hydrogen peroxide addition is stopped after about 1 hour and the mixture is kept in this state at 750 rpm for at least 16 hours. The reaction mixture is then transferred to the 100-liter conical separators and washed 5 times with 15 liters of water. The contaminated water is removed from the bottom and the top phase is the epoxidized vegetable oil. Afterwards, the obtained raw oil is introduced to the drying ovens and dried at a temperature in the range of 20-50°C, optimally at a temperature of 30°C.

[0035] Example 5 , Epoxidation of the Standardized Oils (with Boric Acid / Phosphoric Acid-Peroxide Complex) 50 liters of standardized olive pomace oil is added to a 100-liter reactor equipped with temperature control and a stirrer and 1 kg of boric acid and 9 kg of 85% phosphoric acid are added to the same. The mixture is heated to around 60°C. Then, 10 kg of 50% hydrogen peroxide is slowly added to this mixture at high speed (500-1000 rpm; optimal value 750 rpm). The process of hydrogen peroxide addition is stopped after about 3 hours and the mixture is kept in this state at 750 rpm for maximum 8 hours. The reaction mixture is then transferred to the 100-liter conical separators and washed 5 times with 15 liters of water. The contaminated water is removed from the bottom and the top phase is the epoxidized vegetable oil. Afterwards, the obtained raw oil is introduced to the drying ovens and dried at a temperature in the range of 20-50°C, optimally at a temperature of 30°C.

Claims

CLAIMS1. A method for the production of epoxidized oil characterized in that the method comprises the process steps of• filtering the waste oil to remove the foreign particles it contains,• removing the water from the waste oil,• checking and adjusting the iodine index and the acid index of said oil,• adding an appropriate acid to the resulting mixture, and• epoxidizing the resulting oil -acid mixture.

2. A method according to Claim 1 characterized in that, in the process step of removing the water from the waste oil, one or more of the methods of holding in an oven, heating, and adding water retaining material (anhydrous sodium sulphate, dried sawdust, molecular sieve, etc.) are implemented.

3. A method according to Claim 2 characterized in that anhydrous sodium sulphate, dried sawdust and / or molecular sieve is / are used as the water retaining material.

4. A method according to Claim 1 characterized in that the method comprises the process step of adding the low-boiling aliphatic solvents such as ethyl acetate, dichloromethane, and hexane, or aromatic solvents such as toluene, said solvents being not affected by the epoxidation reaction, in order to reduce the viscosity of the oil sample whose iodine index and acid number have also been adjusted.

5. A method according to Claim 1 characterized in that boric, carboxylic and / or phosphoric acid is / are added as the acid in the process step of acid addition.

6. A method according to Claim 1 characterized in that the mixture is epoxidized by the addition of hydrogen peroxide.

7. A method according to Claim 6 characterized in that the mixture is epoxidized for 16 hours at the room temperature.

8. A method according to Claim 6 characterized in that the mixture is epoxidized for 8 hours at a temperature of 60°C.

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