METHOD FOR PRODUCING PLANT-DERIVED SOLID PARAFFIN AND PLANT-DERIVED SOLID PARAFFIN

Abstract

A method for producing a plant-derived solid paraffin and a plant-derived solid paraffin make it possible to reduce the production cost. An alcohol is added to a vegetable oil to obtain a fatty acid ester, and then a solid paraffin is obtained from the fatty acid ester. The fatty acid ester is preferably obtained in the presence of an acid catalyst or a base catalyst. After obtaining the fatty acid ester, the fatty acid ester is preferably cooled to precipitate a solid, followed by separation of the solid to obtain a solid paraffin. The solid paraffin obtained includes a saturated hydrocarbon(s) having an odd number(s) of carbon atoms of C.sub.21 to C.sub.29 in a proportion of not less than 60%.

Claims

1. A method for producing a plant-derived solid paraffin, the method comprising: adding an alcohol to a vegetable oil to obtain a fatty acid ester; and then obtaining a solid paraffin from the fatty acid ester.

2. The method for producing a plant-derived solid paraffin according to claim 1, wherein the fatty acid ester is obtained in the presence of an acid catalyst or a base catalyst.

3. The method for producing a plant-derived solid paraffin according to claim 1, wherein the fatty acid ester is obtained in the presence of a solid acid catalyst or a solid base catalyst.

4. The method for producing a plant-derived solid paraffin according to claim 1, wherein after obtaining the fatty acid ester, the fatty acid ester is cooled to precipitate a solid, followed by separation of the solid to obtain the solid paraffin.

5. The method for producing a plant-derived solid paraffin according to claim 1, wherein the vegetable oil comprises at least one of a crude oil, a deodorizer distillate, and a fatty acid oil.

6. The method for producing a plant-derived solid paraffin according to claim 1, wherein the alcohol is added to the vegetable oil such that the amount of the alcohol is 0.5 to 10 molar equivalents relative to the fatty acid contained in the vegetable oil.

7. A plant-derived solid paraffin comprising a saturated hydrocarbon(s) having an odd number(s) of carbon atoms of C.sub.21 to C.sub.29 in a proportion of not less than 60%.

8. A plant-derived solid paraffin comprising a saturated hydrocarbon(s) having an odd number(s) of carbon atoms of .sub.C21 to C.sub.29 in a proportion of not less than 80%.

9. The plant-derived solid paraffin comprising a saturated hydrocarbon(s) having an odd number(s) of carbon atoms of C.sub.21 to C.sub.29 in a proportion of not less than 60%, produced by the method for producing a plant-derived solid paraffin according claim 1.

Description

BRIEF DESCRIPTION OF THE DRAWING

[0032] FIG. 1 is a flowchart showing a method for producing a plant-derived solid paraffin of an embodiment of the present invention.

DETAILED DESCRIPTION OF THE INVENTION

[0033] An embodiment of the present invention is described below by way of a drawing and Examples.

[0034] FIG. 1 shows a method for producing a plant-derived solid paraffin of an embodiment of the present invention.

[0035] As shown in FIG. 1, in the method of producing a plant-derived solid paraffin according to the embodiment of the present invention, an alcohol is added to a raw material vegetable oil (Step 11), and then an esterification reaction using an acid catalyst or a transesterification reaction using a base catalyst is carried out to obtain a fatty acid ester (Step 12).

[0036] The raw material vegetable oil may be one derived from any plant-related source such as a seed or pulp of palm, soybean, rapeseed, or the like; or rice bran. The raw material vegetable oil preferably contains at least one of a crude oil, a deodorizer distillate, and a fatty acid oil containing a relatively large amount of paraffin. The alcohol may be any alcohol, and its amount relative to the fatty acid contained in the raw material vegetable oil is preferably 0.5 to 10 molar equivalents. The alcohol is preferably a C.sub.1-C.sub.8 alcohol in terms of the carbon chain length. From the viewpoint of the recovery efficiency, the acid catalyst or base catalyst is preferably a solid. The method of contacting the raw material vegetable oil with the alcohol is not limited and may be, for example, a batch method (batch process) or a continuous method (flow process).

[0037] After obtaining the fatty acid ester, the fatty acid ester is cooled to precipitate a solid (Step 13), and then the precipitated solid is separated from the liquid (Step 14). The cooling temperature is preferably 10 C. to 25 C. The solid-liquid separation may be carried out by any method, and examples of the method include filtration, centrifugation, or sedimentation using an apparatus such as a press filter, a filter press, a vacuum filter, a rotary drum, a centrifuge (batch or continuous type), or a sedimentation tank.

[0038] Of the separated liquid (Step 15) and the solid obtained by the solid-liquid separation, the solid is collected to obtain a solid paraffin (Step 16). Thus, a plant- derived solid paraffin of an embodiment of the present invention can be obtained. The solid paraffin obtained comprises a saturated hydrocarbon(s) having an odd number(s) of carbon atoms of C.sub.21 to C.sub.29 in a proportion of not less than 60%, and hardly comprises saturated hydrocarbons having even numbers of carbon atoms. This is in sharp contrast to the fact that petroleum-derived solid paraffins contain a wide range of saturated hydrocarbons having both even and odd numbers of carbon atoms, showing a broad distribution of the number of carbon atoms. The solid paraffin obtained may be washed with a solvent to increase its purity (quality).

[0039] In the method for producing a plant-derived solid paraffin according to the embodiment of the present invention, the conversion of the vegetable oil to the fatty acid ester lowers the melting point, so that solidification of the fatty acid contained in the vegetable oil at room temperature can be prevented. As a result, the resulting fatty acid ester is in a liquid form, and thus only hydrocarbons in the fatty acid ester can be precipitated simply by cooling the fatty acid ester. By separating the resulting solid from the liquid, a solid paraffin can be obtained. Thus, the method for producing a plant-derived solid paraffin according to the embodiment of the present invention can make the production process simpler than the conventional methods using saponification, distillation, and column chromatography. Furthermore, since the present method does not require high temperature and high pressure, the energy consumption and the production cost for the production can be greatly reduced.

[0040] According to the method for producing a plant-derived solid paraffin according to the embodiment of the present invention, the production cost can be reduced to enable low-cost production of a plant-derived solid paraffin. This enables the industrial production of plant-derived solid paraffins and thus the use of the plant- derived solid paraffins for a wide range of applications, including both basic research and industrial use. Thus, by the method for producing a plant-derived solid paraffin according to the embodiment of the present invention, plant-derived solid paraffins can be obtained industrially as alternatives to petroleum-derived solid paraffins.

EXAMPLE 1

[0041] A solid paraffin was produced by the method for producing a plant-derived solid paraffin according to the embodiment of the present invention shown in FIG. 1. As the raw material vegetable oil, a rice bran deodorizer distillate (Sample 1) and a rapeseed deodorizer distillate (Sample 2) were used to produce the solid paraffin. Ethanol was used as the alcohol.

[0042] A commercially available porous resin PK208LH was used as an acid catalyst as shown in Table 1. PK208LH is strongly acidic, has a copolymer of styrene and divinylbenzene as a backbone, and contains a sulfonate group as a functional group. PK208LH is in the form of a gel composed of particles whose inner portions are homogeneous, and has a porous structure in which physical holes (pores) are formed. Before using the acid catalyst PK208LH, it was swollen with the alcohol (ethanol).

TABLE-US-00001 TABLE 1 Resin PK208LH Type Porous Functionality Sulfonic acid Property Strongly acidic Degree of cross-linkage [%] 4 Ion-exchange capacity 1200 [mol/m.sup.3-resin] Particle size [mm] 0.4-0.6

[0043] In the production of the solid paraffin, first, 0.5 kg of the raw material vegetable oil (each deodorizer distillate) was mixed with 0.3 kg of the alcohol (ethanol) (in an amount of three equivalents relative to the fatty acid groups in terms of the molar ratio of the mixture). To the resulting mixture, 0.4 kg of the swollen catalyst was added, and a batch reaction was carried out for 24 hours while maintaining the mixture at 60 C. in order to cause fatty acid esterification reaction. Then, to separate the catalyst from the reaction liquid, filtration was performed through No. 3 filter paper with a particle retention capacity of 5 m, and then the catalyst was washed using 0.5 kg of ethanol as a washing liquid to remove oil adhering to the catalyst surface.

[0044] The reaction liquid and the washing liquid separated by filtration were then cooled at 6 C. overnight. The solid precipitated by the cooling was filtered through No. 3 filter paper with a particle retention capacity of 5 m, and then the filtered solid was washed twice using 0.35 kg of ethanol as a washing liquid, followed by natural drying of the solid. Thus, a solid paraffin was obtained from each vegetable oil.

[0045] Each solid paraffin sample obtained was subjected to evaluation of melting point, purity, and composition. First, about 1 mL of each sample was placed in a 1.5-mL polypropylene microtube and heated sufficiently in a thermostat (ND-M01, manufactured by Nissin Rika Co., Ltd.) to determine the melting point visually. Furthermore, each sample was dissolved in hexane, and then analyzed by gas chromatography using a hydrogen flame ionization detector (FID; GC-4000 Plus, manufactured by GL Sciences Inc.) and a gas chromatograph mass spectrometer (GC-MS; Agilent 5975C Series GC/MSD, manufactured by Agilent Technologies, Inc.), to determine the purity and the composition of the paraffin. Gas chromatography was performed using DB-5ht (film thickness: 0.1 m, inner diameter: 0.32 mm, length: 15 m), manufactured by Agilent Technologies, Inc., as a column. Table 2 shows the analytical conditions for the gas chromatography.

TABLE-US-00002 TABLE 2 carrier gas He split ratio 1:10 injection volume 2.0 10.sup.3 cm.sup.3 injection temperature 370 C. detection temperature 370 C. column temperature 80 C..fwdarw.13 C./min.fwdarw.353 C..fwdarw.12 C./min.fwdarw.365 C., 9 min

[0046] For comparison, a petroleum-derived solid paraffin (mp. 60 to 62 C.; 160-13325, FUJIFILM Wako Pure Chemical Corporation) and a candelilla wax hydrocarbon (MD-21, Yokozeki Oil & Fat Industries Co., Ltd.) were also subjected to the same procedure to determine melting point, purity, and composition. Table 3 shows a summary of color, recovered amount, melting point, purity, total proportion of saturated hydrocarbons having odd numbers of carbon atoms to the total C.sub.21-C.sub.37 saturated hydrocarbons for each solid-paraffin sample. The proportion of saturated hydrocarbons having odd numbers of carbon atoms of C.sub.29 or less to the total C.sub.21-.sub.C37 saturated hydrocarbons is also listed in Table 3.

TABLE-US-00003 TABLE 3 Comparison Comparison Sample 1: Sample 2: Petroleum- Candelilla wax Sample 1 Sample 2 derived paraffin hydrocarbon Vegetable oil Rice bran Rapeseed deodorizer deodorizer distillate distillate Color White to pale Milky white White Pale yellow yellow with pearly luster Recovered amount (g) 7.2 18 Melting point ( C.) 61 63 62 65 Purity (%)*.sup.1 89 61 >97 91 Total proportion of 90 98 49 98 saturated hydrocarbons having odd numbers of carbon atoms (%)*.sup.2 Proportion of saturated 85 93 37 3.5 hydrocarbons having odd numbers of carbon atoms of C.sub.29 or less (%)*.sup.3 *.sup.1(Total peak area of identified saturated hydrocarbons / total peak area) 100 *.sup.2(Total peak area of C.sub.21-C.sub.37 saturated hydrocarbons having odd numbers of carbon atoms / total peak area of all C.sub.21-C.sub.37 saturated hydrocarbons) 100 *.sup.3(Total peak area of C.sub.21-C.sub.29 saturated hydrocarbons having odd numbers of carbon atoms / total peak area of all C.sub.21-C.sub.37 saturated hydrocarbons) 100

[0047] As shown in Table 3, the solid paraffins obtained from the vegetable oils (Sample 1 and Sample 2) have almost the same melting point as that of the petroleum- derived solid paraffin (Comparison Sample 1). However, in the solid paraffins obtained from the vegetable oils, the proportion of C.sub.21-.sub.C37 saturated hydrocarbons having odd numbers of carbon atoms was found to be not less than 90%, and the proportion of C.sub.21-C.sub.29 saturated hydrocarbons having odd numbers of carbon atoms was found to be not less than 85%, indicating that these solid paraffins hardly contain saturated hydrocarbons having even numbers of carbon atoms. As for the candelilla wax hydrocarbon (Comparison Sample 2), the proportion of saturated hydrocarbons having odd numbers of carbon atoms is as high as 98%. However, its main component is C.sub.31, and the proportion of saturated hydrocarbons having odd numbers of carbon atoms of C.sub.29 or less was 3.5%, which is very low. It was also found that the purity of the solid paraffin obtained varies depending on the type of the vegetable oil, and that a solid paraffin can be obtained at a purity of 89% by using a rice bran deodorizer distillate as a raw material.

Comparative Example

[0048] As a Comparative Example, the production of a solid paraffin without esterification was attempted. Rice bran deodorizer distillate was used as the raw material vegetable oil. Ethanol was used as the alcohol. 0.5 kg of the raw material rice bran deodorizer distillate was mixed with 0.3 kg of ethanol, and the resulting mixture was cooled at 6 C. overnight. About 0.4 kg of solid was obtained.

[0049] The solid obtained was found to be a product of the dilution of the original rice bran deodorizer distillate in the ethanol, and not a product obtained by solidification of hydrocarbons. The content of paraffin in the solid obtained was below the detection limit of 0.1%. This result indicates that recovery of solid hydrocarbons was not possible in this Comparative Example due to solidification of fatty acid components. Industrial Applicability

[0050] The plant-derived solid paraffin produced by the method for producing a plant- derived solid paraffin according to the present invention, and the plant-derived solid paraffin according to the present invention, are expected to be highly demanded for the purpose of application to cosmetics and food, which may be brought into contact with the skin or hair, or may be taken into the body. Specific examples of such applications may include cosmetics (creams, lipsticks, hairdressing products, eye shadows, blushers, and facial masks), food (natural coating materials), stationery (crayons, pastel crayons, pencils, and paraffin paper), candle materials, coating materials, and water-proofing materials.