WO2010098651A1

WO2010098651A1 - Method for epoxidation of plant oil

Info

Publication number: WO2010098651A1
Application number: PCT/MY2009/000033
Authority: WO
Inventors: Mohd Basyaruddin Abdul Rahman; Asrul Farrish O K R Udaiyappan; Mahiran Basri; Abu Bakar Salleh; Raja Noor Zaliha Raja Abdul Rahman
Original assignee: Universiti Putra Malaysia
Priority date: 2009-02-26
Filing date: 2009-02-26
Publication date: 2010-09-02

Abstract

The present invention provides a method for epoxidation of plant oil, particularly to epoxidized palm oil and palm kernel oil. The chemo-enzymatic method of epoxidation of palm oil and palm kernel oil were performed with the presence of lipase as biocatalyst. The method for epoxidation of plant oil, comprising the steps of dissolving a mixture of oil in a non-polar solvent, adding enzymes to the mixture, adding hydrogen peroxide gradually at a time interval, stirring the mixture, filtering the mixture for removal of enzyme, washing the mixture with a polar solvent and removing the solvent by evaporation.

Description

METHOD FOR EPOXIDATION OF PLANT OIL

Description

FIELD OF THE INVENTION

[1] The present invention relates to a method for synthesising epoxidized plant oils, particularly to epoxidized palm oil and palm kernel oil.

BACKGROUND OF THE INVENTION

[2] Epoxidized plant oils which are derived from the reaction plant oils containing unsaturated moiety with hydrogen peroxide are attracting significant interest since they can be alternative for the petroleum-derived chemicals. The high reactivity of oxirane ring in epoxides due to its polarity and ring strain makes them useful in organic synthesis since they can undergo various reactions.

[3] Currently, in-situ epoxidation is used in standard industrial production, where peracid is generated, by reacting acetic or formic acid with hydrogen peroxide in the presence of strong mineral acids. However, the use of strong mineral acid catalyst such as sulphuric acid and phosphoric acid has several drawbacks. They are non-selective, can cause equipment corrosion, and must be treated before discharging it into the environment. Another disadvantage is that strong acids can set off undesirable ring- opening reactions with water, which leads to formation of secondary hydroxyl groups on the fatty acid backbone or oligcmerization through the ether linkage. In addition, the formation of high molecular- weight side products requires expensive purification.

[4] Many disadvantages of acid-catalyzed epoxidation process causes the chemo- enzymatic epoxidation to emerge as an alternative method tq produce epoxidized plant oils with high selectivity in a more environmental friendly way. In this method, the inorganic acid catalyst is replaced by imnobilized lipase as the catalyst and the reaction is done in mild conditions.

[5] Most researchers synthesized epoxide using acid catalyst. Goud et al. (2006) synthesized epoxidized mahua oil using sulphuric acid as catalyst. Meanwhile, Turner and Casper (2005) successfully prepared epoxidized functional vegetable oil by contacting a raw vegetable oil with hydrogen peroxide and an organic acid.

[6] Renewable resources such as fats and oils can be chemically or enzytratically reacted to produce alternatives for petroleum-derived materials. The application of modified plants oils in chemical industry is attracting more interest because of their availability from renewable resource. Using these raw materials from plants can contribute towards global sustainability without depletion of limited resources especially petroleum. Furthermore, seme of these materials are less expensive than petrochemicals.

[7] Green alternative route in conjunction with biotechnological methods, becomes interesting features in modern technology. The green route involves en∑jmatic synthesis which offers mild reaction conditions and environmentally benign process. Thus, it is necessary to develop highly stable biopatalyst such as immobilized enzyme for the synthesis of epoxides. The use of imnobilized enzjαne has become a valid approach due to its special features which allow the reutilization of the enzyme and better separation of products.

[8] Enzjme-catalyzed reactions operate at mild conditions, which prevent degradation of starting materials and reduce side reactions. Application of Upases in various biochemical modifications of fats and oils is well established, and the biocatalytic activity of Upases towards acid has been studied by various parties.

[9] Rusch gen. Klaas and Marwel (1999) reported the chemo-enzjmatic epoxidation of rapeseed oil, sunflower oil, soybean oil and Unseed oil using Novozjin 435 as biocatalyst. Hilker et al. (2001) successfully produced epoxidized Unseed oil by chemo-enzjinatic epoxidation process in an enzyme-recycle reactor system. Tornvall et al. (2007) prepared epoxidized fatty acids using the chemo-enzjmatic process. Disclosure of Invention

SUMMARY OF THE INVENTION

[10] It is an object of the present invention to provide a method for producing a high quaUty and purity epoxidized palm oil and palm kernel oil, which are epoxides with high oxirane number.

[11] Another object of the present invention is to produce a high yield of epoxidized palm oil and palm kernel oil by reaction of the oil with hydrogen peroxide and fatty acids in the presence of immobilized Upase.

[12] The present invention related to a process for producing epoxidized palm oil and palm kernel oil by chemo-enz>τnatically epoxidiang the oil with hydrogen peroxide and fatty acid preferably oleic acid (at least five mol percent frαn the total concentration of double bonds in the oil used.

[13] Epoxidized palm oil and palm kernel oil are accomplished in agreement with the present invention that the oil and hydrogen peroxide are stirred continuously at temperature in the range from about 25 *C to 60 Xl. The epoxidation reaction is carried out with organic solvent as a medium and with enzjme as the biocatalyst. Preferably immobiUzed Upase is chosen as the biocatalyst in the reaction mixture to facilitate the epoxidation reaction. The immobilized lipase is recycled with the selectivity of the immobilized lipase and purity of the product is controlled.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[14] According to present invention, process for producing epoxidized palm oil and palm kernel oil comprise epoxidizing the oil with at least five mol percent of oleic acid and hydrogen peroxide in the presence of immobilized lipase as a catalyst and an organic solvent as the medium.

[15] Continuous stirring is applied to the reaction mixture and the mixture is allowed to proceed for 16 hours. Later, the reaction mixture is separated frαn the biocatalyst by filtration. The separated biocatalyst is then recycled and washed with organic solvent.

[16] In the preferred embodiment of the present invention, the immobilized lipase is used. Immobilized lipase has the advantages by easy separation from the product and the reusability. Lipase is highly selective towards certain bond* and specific with respect to their substrates. Easy separation will permit efficient handling of the process while the reusability of lipase will allow for cost reduction and higher production.

[17] The palm oil used in the present invention has the composition of 40% palmitic acid, 5% stearic acid, 44% oleic acid and 10% linoleic acid. [18] The palm kernel oil used in the present invention has the following composition:

[19] The immobilized lipases used are Candida antartica (Novozjin 435) and Rhizømucor miehei (Lipozjme RM IM). The protein content of the mixture is controlled to maximize the epoxide product.

[20] IQ the preferred embodiment of the present invention, the five mole percent fatty acid used is oleic acid since it has the largest unsaturated fatty acid composition in palm oil and palm kernel oil. [21] The ratio of double bond in the palm oil to hydrogen peroxide is set to 1 : 1.5 (molar) so that the hydrogen peroxide will supply enough to substitute the double bond. [22] The reaction is carried out in temperature with range from 25 *C to 60 Xl with preferably 30 ⁰C. In the present invention, the mixture undergoes continuous stirring in controlled temperature. Changing in the reaction temperature can be assigned to its effect on substrate solubility as well as its direct influences on the reaction rate, enzyme stability and activity.

[23] The oxirane number, which is the measure of epoxide oxygen is determined by adding tetraethyl ammonium bromide and titration with mixture of perchloric acid in acetic acid, whereby the HBr formed reacts with the epoxide group.

[24] The product from the reaction is characterized by various techniques. TMn Layer

Chromatography (TLC) is done first to confirm the presence of the product. The product is also analyzed by High Performance Liquid Chromatography (HPLC) and Gas Chromatography (GC) to calculate the yield. The structure and purity of the product is determined with Fourier Transform-Infrared (FT-IR) and Gas Chro- matography-Mass Spectrometry (GC-MS).

[25] The present invention can be performed in various ways, but certain detailed routes embodying the present invention will be illustrated in the following example.

EXAMPLE 1

[26] 30 DHCI C=C of palm oil and the 1.5 mmol of oleic acid were dissolved in 100 ml tolune. After addition of 600 mg Novozym 435, 46 portions of 100 μl hydrogen peroxide (30% w/w) each after 7.5 min were added by a Metrohm Dosino, which has been modified to work automatically and time dependently. Afterwards the mixture was stirred for another 10 hours, the lipase was then removed by filtration and set aside for further use. The crude reaction product was washed with water to remove the excess H O , optionally with 5% Na CO to remove the free fatty acids and finally the

2 2 2 3 solvent was removed by evaporation.

[27] It is to be understood that the present invention may be embodied in other specific forms and is not limited to the sole embodiment described above. However modification and equivalents of the disclosed concepts such as those which readily occur to one skilled in the art are intended to be included within the scope of the claims which are appended thereto.

Claims

[I] Method of synthesis of epoxidized plant oil using chemoenzymatic epoxidation reaction of oil and hydrogen peroxide with enzyme as biocatalyst.

[2] The method of claim. 1 consists of palm oil, palm kernel oil, oleic acid and hydrogen peroxide. [3] The method of claim 1 consists of immobilized Upases including Rhizomucor miehei (Lipozjme RM IM) and Candida antartica (Noa>∑3m 435). [4] The method of claim 1 wherein the enzyme is reusable.

[5] A method for epoxidation of plant oil, comprises the steps of:

(a) dissolving a mixture of oil in a non-polar solvent,

(b) adding enzjmes to the mixture,

(c) adding hydrogen peroxide gradually at a time interval,

(d) stirring the mixture,

(e) filtering the mixture for removal of enzyme,

(f) washing the mixture with a polar solvent,

(g) removing the solvent by evaporation.

[6] The method of claim 5 wherein the mixture of oil consists of palm oil and palm kernel oil.

[7] The method of claim 5 wherein the non-polar solvent is toluene.

[8] The method of claim 5 wherein the enzymes are inxnobilized lipases.

[9] The method of claim 8 wherein the inrnobilized lipases are Rhizomucor miehei and Candida antartica. [10] The method of claim 5 wherein adding hydrogen peroxide of step (c) gradually at 75 minutes interval.

II 1] The method of claim 5 wherein stirring the mixture of step (d) is for 10 hours. [12] The method of claim 5 wherein the enzymes are reusable.

[13] The method of claim 5 wherein in the washing step (f), the polar solvent is water.