Method for extracting essential oils and the extracted essential oils and aromatic distilled water

Abstract

This aims to make effective use of the central part of the log and to provide a novel and useful method for extracting essential oils. [Solution] An essential oil extraction method comprising the following steps: measuring the cross-sectional shape 2 of a log 1 to set an inscribed circle 3; cutting the log to obtain a central part of the log 6 whose cross-section is all or part of a concentric circle 5 with a diameter of 30 to 60 mm relative to the inscribed circle; crushing the central part of the log to obtain crushed material; distilling the crushed material to obtain a distillate; and separating the distillate into essential oil and aromatic distilled water. The core of the log can be the peeled core remaining after obtaining veneers 9 continuously with a rotary lathe. The essential oil and aromatic distilled water obtained through the separation process according to the present invention can be used for the same purposes as in the conventional method. The crushed material after essential oil extraction can be reused alone or mixed with other materials in the manufacture of wood fiberboard such as MDF or wood board such as particleboard.

Description

Technical Field

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[0001] The present invention relates to an essential oil extraction method for extracting essential oil from wood, the extracted essential oil, and aromatic distilled water.

Background Art

[0006] Therefore, the problems that this invention aims to solve are to make effective use of the central part of the raw wood and to provide a novel and useful method for extracting essential oils. [Means for solving the problem]

[0007] To solve this problem, the invention according to claim 1 of the present application is an essential oil extraction method characterized by comprising: an inscribed circle setting step of measuring the cross-sectional shape of a log and setting the inscribed circle of the cross-section; a log center preparation step of cutting the log to obtain a log center whose cross-section is all or part of a range of concentric circles with a diameter of 30 to 60 mm with respect to the inscribed circle set in the setting step; a crushing step of crushing the log center to obtain crushed material; a distillation step of distilling the crushed material to obtain a distillate; and a separation step of separating the distillate into essential oil and aromatic distilled water.

[0008] The invention according to claim 2 of this application is characterized in that, in the essential oil extraction method described in claim 1, it further comprises a water removal step for removing water contained in the essential oil obtained in the separation step.

[0009] The invention according to claim 3 of this application is an essential oil extraction method according to claim 2, characterized in that the water removal step comprises a step of cooling the essential oil obtained in the separation step to a temperature below the freezing point of water and higher than the freezing point of the essential oil components, and then removing the frozen water.

[0010] The invention according to claim 4 of this application is an essential oil extraction method according to claim 1, characterized in that the pulverized material obtained by the pulverization step is an elongated, thin plate-shaped pulverized material having dimensions of an average length of 10 to 30 mm, an average width of 3 to 10 mm, and an average thickness of 1 to 2 mm.

[0011] The invention according to claim 5 of this application is an essential oil obtained after the separation step in the essential oil extraction method described in any one of claims 1 to 4.

[0012] The invention according to claim 6 of this application is aromatic distilled water obtained after the separation step in the essential oil extraction method described in any one of claims 1 to 4.

[0013] The invention according to claim 7 of this application is an essential oil extracted from the central part of a log, with a cross-section that is all or part of a concentric circle having a diameter of 30 to 60 mm with respect to the inscribed circle of the log.

[0014] The invention according to claim 8 of this application is aromatic distilled water extracted from the central part of a log, with a cross-section that is all or part of a concentric circle having a diameter of 30 to 60 mm with respect to the inscribed circle of the log. [Effects of the Invention]

[0015] The core of a log, such as the peeled heart, which remains in large quantities after peeling the log to obtain veneers, has traditionally had limited uses. However, according to the present invention, new uses for the core of the log are provided, thereby expanding its effective utilization. Furthermore, since the core of the log contains more essential oil than other parts of the log, a high essential oil recovery rate can be obtained by extracting essential oil from the core of the log.

[0016] Furthermore, in the present invention, by performing a water removal step of removing water contained in the essential oil obtained in the separation step, an essential oil with high purity can be extracted. Also, as the water removal step, after cooling the essential oil obtained in the separation step to a temperature below the freezing point of water and higher than the freezing point of the essential oil components, and then performing a step of removing the frozen fine water, the water in the essential oil can be efficiently removed in a short time.

[0017] In addition, in the present invention, by using an elongated thin plate-shaped pulverized material having dimensions of an average length of 10 to 30 mm, an average width of 3 to 10 mm, and an average thickness of 1 to 2 mm as the pulverized material obtained by the pulverization step, the essential oil recovery efficiency can be further increased.

[0018] The essential oil and aromatic distilled water obtained after the separation step according to the present invention can be used for the same applications as in the prior art. Also, the pulverized material after essential oil extraction can be reused as a single material or mixed with other materials in the production of wood-based fiberboards such as MDF and wood-based boards such as particle boards.

Brief Description of the Drawings

[0019] [Figure 1] It is a cross-sectional view explaining a method of measuring the cross-sectional shape of a log and setting an inscribed circle. [Figure 2] As an example of a method of obtaining a central part of a log with a circle having a predetermined diameter as a cross section from the center of the inscribed circle of the log, it is a side view schematically showing that after continuously obtaining veneers with a rotary lathe, the central part of the log (core) remains. [Figure 3] As another example of a method of obtaining a central part of a log with a circle having a predetermined diameter as a cross section from the center of the inscribed circle of the log, it is a cross-sectional view schematically showing that a log cut with the inscribed circle as a cross section is cut into a plurality of boards by a sawing machine to cut out the central part of the log. [Figure 4] It is a flowchart showing the essential oil extraction method according to the present invention in the order of steps together with the manufacturing process of plywood.

Best Mode for Carrying Out the Invention

[0020] The essential oil extraction method according to the present invention will be described in detail below with reference to FIGS. 2 to 4.

[0021] (Inner inscribed circle setting step) Prepare logs of coniferous trees such as cypress and cedar, or broad-leaved trees such as eucalyptus and camphor tree. The tree species of the logs is not limited as long as essential oil can be extracted. The logs are, for example, 160 to 500 mm in tree diameter and 2000 to 2150 mm in length.

[0022] As shown in FIG. 1, since the cross-section 2 of the log 1 is not a perfect circle but has an irregular cross-sectional shape, an inner inscribed circle 3 inscribed in this cross-section 2 is set. This setting can be easily calculated by a computer based on the data obtained by measuring the cross-sectional shape of the log 1, and is, for example, carried out as a preparation step when cutting veneer from the log using a rotary lathe.

[0023] (Log center part preparation step) A log center part 6 having a cross-section of all or part of the range of a concentric circle 5 having a diameter of 30 to 60 mm with respect to the inner inscribed circle 3 of the log 1 set as described above is obtained.

[0024] An example of the log center part 6 is the core left after continuously obtaining veneer with a rotary lathe. The veneer cutting by a rotary lathe is well-known. As shown in FIG. 2, after analyzing the cross-section of the log 1 with a computer or the like to set the inner inscribed circle 3 and its center 4, while rotating around the center 4 of the inner inscribed circle 3, the cutting edge 8 is pressed against the log surface for cutting. At the beginning of cutting, the portion 7 outside the inner inscribed circle 3 is gradually cut along the cutting line 10, and the log 1a with a substantially circular cross-section cut so that the inner inscribed circle 3 becomes the cross-section is further cut, and a veneer 9 with a predetermined thickness is continuously manufactured in the manner of peeling.

[0025] When veneer sheets 9 are continuously obtained using a rotary lathe in this manner, a long, cylindrical core remains at the end. From the standpoint of yield, it is preferable to continue producing veneer sheets 9 until the diameter of the core becomes as small as possible. On the other hand, as the diameter of the log 1a decreases, the warping of the resulting veneer sheets 9 increases, reducing their value as veneer sheets 9. Therefore, generally, the diameter of the core remaining at the end is about 50-60 mm (the length is the same as the log, 2000-2150 mm). Consequently, this core can be suitably used as the central part 6 of the log.

[0026] Alternatively, as shown in Figure 3, the log 1 may be repeatedly cut along the cutting line 10 using a sawmill equipped with a band saw or circular saw, or a composite sawmill combining a band saw and a circular saw, to cut out multiple planks, and the central part having a cross-section that falls within the range of concentric circles 5 with a diameter of 30 to 60 mm relative to the inscribed circle 3 may be used as the log center 6. In this case, the cross-section of the log center 6 obtained is not necessarily limited to the square or rectangle shown in Figure 3, but can have any cross-sectional shape as long as it falls within the above range.

[0027] (Grinding process) The central part of the log 6 prepared in the above log central part preparation step is crushed using a crushing means to obtain crushed material. The crushing means is not limited to those that can crush the central part of the log 6, and known cutting machines or crushers such as chippers, shredders, cutter mills (shear-type crushers), and flakers can be used. As an example, by feeding a large number of central parts of the log 6 together into a chipper and crushing them into chips, roughly rectangular flat chipped material (average length 25-40 mm, average width 25-40 mm, average thickness 3-5 mm) can be obtained. By further crushing this chipped material with a shredder, roughly rectangular flat chipped material with an average length of 20-35 mm, an average width of 3-20 mm, and an average thickness of 3-5 mm can be obtained. Alternatively, by feeding multiple logs (6) together into a chipper and crushing them into chips, a roughly rectangular, flat material (average length 25-40 mm, average width 25-40 mm, average thickness 3-5 mm) can be obtained. This chipped material can then be further compressed and cut in a cutter mill (shear-type crusher) to crush it while grinding, resulting in a long, thin, elongated crushed material with an average length of 10-30 mm, an average width of 3-10 mm, and an average thickness of 1-2 mm. Alternatively, by crushing multiple logs (6) together in a flaker, a roughly rectangular, thin, crushed material with an average length of 50-60 mm, an average width of 50-60 mm, and an average thickness of 1-1.5 mm can be obtained.

[0028] (Distillation process) The pulverized material obtained in the above grinding process is distilled to obtain a liquid distillate (essential oil and water). The processing method in the distillation process is not particularly limited and can be carried out using commonly used distillation equipment. For example, the pulverized material can be heated by steam distillation using heated steam or by hot water distillation by heating and boiling it in water, and the gas produced at that time can be cooled with a cooling device to obtain a distillate consisting of essential oil and water.

[0029] (separation process) The distillate obtained in the above distillation process is separated into essential oil and water. The processing method in the separation process is not particularly limited as long as it can separate the distillate into essential oil and water. For example, by letting the distillate stand for a certain period of time or by performing treatments such as redistillation, the essential oil layer and the water layer can be separated, and the essential oil layer can be recovered from that state. In addition, the water in the distillate is aromatic hydrosol (aroma water) containing trace amounts of essential oil components, so it can be recovered and used in fragrances, cosmetics, etc. If the essential oil and water are automatically separated and recovered during the above distillation process, the separation process can be omitted.

[0030] (Water removal process) The essential oil separated and recovered in the above separation process still contains a small amount of water (about 1% of the essential oil), so a water removal process is carried out to remove this water and obtain a high-purity essential oil. The water removal process is not particularly limited as long as it can remove the small amount of water dispersed in the recovered essential oil. For example, by cooling the essential oil to a temperature below the freezing point of water (0 degrees Celsius) and higher than the freezing point of the essential oil components, only the small amount of water contained in the essential oil can be frozen, and the frozen water (ice) can be removed by filtering it in this state. The amount of water contained in the essential oil can also be reduced by repeating the distillation process multiple times in the above distillation process, or by letting the distillate stand for a long time in the above separation process, but the above freezing treatment allows for efficient removal of water in a short time. It should be noted that the freezing point of essential oils is difficult to determine definitively due to factors such as tree species, growing environment, and extraction method, as well as the complex mixture of various components with different freezing points, such as α-pinene and limonene. However, it is generally in the range of -20 to -70 degrees Celsius. Therefore, cooling to a temperature between 0 and -20 degrees Celsius will bring the temperature above the freezing point of almost all essential oils, even those with varying freezing points, thus allowing for an appropriate water removal process.

[0031] The essential oils obtained as described above can be used in various applications (fragrances, cosmetics, antibacterial agents, insect repellents, deodorizers, detergents, aromatherapy, etc.) to exert effects such as stress relief, vitality restoration, improvement of depression, antibacterial properties, insect repellent properties, and deodorizing properties, similar to conventional techniques.

[0032] (Reuse process) The pulverized material remaining after essential oil extraction can be reused either as a standalone material or mixed with other materials in the manufacture of wood fiberboards such as MDF and wood-based boards such as particleboard.

[0033] The present invention will be specifically described below with reference to examples.

[0034] (Inscribed circle setting process) In this example, a cypress log from Shizuoka Prefecture (240 mm in diameter, 2100 mm in length) was used, and based on the data obtained by measuring the cross-sectional shape 2 of this cypress log 1, a computer was used to set an inscribed circle 3 with a diameter of 215 mm and its center 4 (Figure 1).

[0035] (Log center preparation process) After rotating this cypress log in a rotary lathe and cutting the surface with a cutting blade 8 to create veneers 9, many long cylindrical cores (50 mm in diameter, 2100 mm in length) remained, which were prepared as the central parts of the logs 6 (Figure 2). The veneers were cut under the following conditions. • Rotary race: Rotation speed 145 m / s • Cutting blade: Length 2200mm, tip thickness 0.5~16mm • Solid wood: 1.85mm thick

[0036] (Grinding process) After cutting the veneers, the remaining cores (center of the log 6) were put into a chipper in large quantities and crushed into chips to form roughly square, flat pieces (average length 25-40 mm, average width 25-40 mm, average thickness 3-5 mm). These chips were then further compressed and cut and ground using a cutter mill (shear-type crusher) to obtain 36 kg of elongated, thin cypress wood chips with an average length of 20 mm, an average width of 5 mm, and an average thickness of 1.5 mm.

[0037] (Distillation process) The cypress pulverized material obtained in the above grinding process was distilled using a steam distillation apparatus, the discharged steam was collected, cooled in a cooling apparatus, and the distilled water containing cypress essential oil was recovered in a recovery apparatus.

[0038] (separation process) In the distillation process described above, the cypress essential oil-containing distilled water was gradually recovered and left to stand in the recovery apparatus. Due to the difference in specific gravity between the cypress essential oil and water, the upper layer was separated into cypress essential oil and the lower layer into aromatic distilled water. By distilling and separating 36 kg of elongated, thin cypress pulverized material obtained in the grinding process, 450 mL of cypress essential oil and 60 L of aromatic distilled water were obtained.

[0039] (Water removal process) The cypress essential oil separated in the above separation process was cooled to a temperature below the freezing point of water but higher than the freezing point of the cypress essential oil (for example, -18 to -20 degrees Celsius). This froze the water scattered as small bubbles in the cypress essential oil, and the oil was then filtered through a filter (mesh size 126-3) to remove the frozen water (ice), thereby obtaining a high-purity cypress essential oil. Since the dimensions of the removed ice were 0.5 to 2 mm, it was confirmed that by using a filter with a mesh size that allows ice of this size to pass through, it is possible to remove the ice and extract an essential oil with reduced water content and higher purity.

[0040] In the above embodiment, the core of the cypress log, which remains after cutting the log into veneers using a rotary lathe, was used as the core of the log, and essential oil was extracted from this core. In order to demonstrate the advantages of using the core as the material for essential oil extraction, the essential oil recovery rate (amount of essential oil extracted per unit weight of raw material) was tested when the essential oil was extracted under different conditions. Unless otherwise specified, each process was carried out under the same conditions as described in the embodiment.

[0041] First, in addition to the cypress used in the example, we also conducted a comparative test on the essential oil recovery rate when essential oil was extracted from the peeled heartwood of Japanese cedar (Sugi), and obtained the results shown in Table 1. From these results, it was confirmed that cypress yielded a better essential oil recovery rate than Japanese cedar as a raw wood species.

[0042] [Table 1]

[0043] Next, we conducted a comparative test of essential oil recovery rates when extracting essential oil from different parts of the cypress log, and obtained the results shown in Table 2. From these results, it was confirmed that using the peeled heartwood yielded the best essential oil recovery rate.

[0044] [Table 2]

[0045] Next, we conducted comparative tests on the essential oil recovery rate when extracting essential oil from crushed material obtained by crushing the core of cypress logs, varying the shape and dimensions of the material. The results are shown in Table 3. From these results, we found that the essential oil recovery rate was best when using elongated, thin plate-shaped crushed material obtained by crushing roughly square, flat chip-shaped crushed material with a chipper, and then further compressing, cutting, and grinding it with a cutter mill (shear-type crusher). The best results were obtained using elongated, thin plate-shaped crushed material with an average length of 20 mm, an average width of 5 mm, and an average thickness of 1.5 mm. Based on these results, we further extracted essential oil from crushed material of various dimensions. When essential oil was extracted from elongated, thin plate-shaped crushed material with an average length of 10-30 mm, an average width of 3-10 mm, and an average thickness of 1-2 mm, the essential oil recovery rate was approximately 1% or more, confirming that essential oil can be extracted efficiently.

[0046] [Table 3]

[0047] The reason why the essential oil recovery rate is good when using elongated, thin, plate-shaped pulverized material obtained by further compressing, cutting, and grinding chip-shaped pulverized material obtained by cutting with a chipper is that it has a shape and dimensions that make it easy to extract essential oils, and in the process of further compressing, cutting, and grinding the chip-shaped pulverized material with a cutter mill (shear-type pulverizer), the essential oil is extracted and moves to the surface of the elongated, thin, plate-shaped pulverized material, where it is in a state that is easy to extract, and further cutting the chip-shaped pulverized material obtained by cutting with a chipper (which has a relatively smooth surface) The elongated, thin, plate-like pulverized material obtained by compressing, cutting, and grinding in a termiller (shear-type pulverizer) forms numerous microscopic irregularities on its surface. This increases the surface area of ​​each elongated, thin, plate-like pulverized material that comes into contact with water vapor. Furthermore, water vapor can spread through the voids formed between the irregular surfaces of the elongated, thin, plate-like pulverized material. Additionally, the previously tightly packed wood fibers separate, creating voids that allow water vapor to penetrate not only the surface but also the interior of the woody material. This is presumed to improve the efficiency of recovering cypress essential oil-containing distilled water during the distillation process.

[0048] Although the present invention has been described in detail above with reference to examples and test examples, the present invention can be implemented in a wide variety of ways by modifying or changing it within the scope of the invention as defined by the claims. [Explanation of symbols]

[0049] 1 Log 2 Cross-section of a log 3. Inscribed circle 4. Center of the inscribed circle 5. Outer diameter circle of the center of the log 6 Log center 7 Cutting blade 8 solid wood 10 cutting line

Claims

1. This is an essential oil extraction method characterized by comprising: an inscribed circle setting step of measuring the cross-sectional shape of a log and setting the inscribed circle of the cross-section; a log center preparation step of cutting the log to obtain a log center whose cross-section is all or part of a range of concentric circles with a diameter of 30 to 60 mm with respect to the inscribed circle set in the setting step; a crushing step of crushing the log center to obtain crushed material; a distillation step of distilling the crushed material to obtain a distillate; and a separation step of separating the distillate into essential oil and aromatic distilled water.

2. The essential oil extraction method according to claim 1, further comprising a water removal step for removing water contained in the essential oil obtained in the separation step.

3. The essential oil extraction method according to claim 2, characterized in that the water removal step comprises a step of cooling the essential oil obtained in the separation step to a temperature below the freezing point of water and higher than the freezing point of the essential oil components, and then removing the frozen water.

4. The essential oil extraction method according to claim 1, characterized in that the pulverized material obtained by the pulverization step is an elongated, thin, plate-shaped pulverized material having dimensions of an average length of 10 to 30 mm, an average width of 3 to 10 mm, and an average thickness of 1 to 2 mm.

5. An essential oil obtained after the separation step in the essential oil extraction method according to any one of claims 1 to 4.

6. Aromatic distilled water obtained after the separation step in the essential oil extraction method according to any one of claims 1 to 4.

7. An essential oil extracted from the central part of a log, with a cross-section encompassing all or part of a concentric circle with a diameter of 30 to 60 mm relative to the inscribed circle of the log.

8. Aromatic distilled water extracted from the central part of a log, with a cross-section encompassing all or part of a concentric circle with a diameter of 30 to 60 mm relative to the inscribed circle of the log.

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