Vegetable oil solvent extraction system

Abstract

To eliminate, in a batch process more effective at vegetable oil extraction in a smaller production volume, a risk of exposure to a solvent such as hexane included in a raw material after extraction if a person takes out the raw material from an extractor, at which heating of the raw material is required for separating the solvent being a toxic substance, and also to reduce an increase of a cost of equipment or a possibility of trouble such as jamming of the raw material, when machinery with a larger number of movable parts is used to move the raw material to another container.SOLUTION: A raw material is put in a container mountable to an extractor. The container is heated by an electromagnetic induction coil or a heating wire after making a vegetable oil be extracted. Through heating the container with the raw material therein, a solvent can be separated within the same extractor.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to the solvent extraction of vegetable oils. [Background technology]

[0002] Along with the social trend toward moving away from fossil fuels, the use of vegetable oil as machinery fuel is expanding. It is also possible to use vegetable oil as fuel for agricultural machinery such as tractors, and it is thought that if farmers and rural areas can produce their own vegetable oil from rice bran, rapeseed, etc., sustainable agriculture that does not rely on external fuels can be realized.

[0003] There are two methods for extracting vegetable oil: pressing and solvent extraction. Solvent extraction is more efficient at extracting lipids from plants than pressing, and is the method most commonly used for vegetable oil extraction today. Summary of the Invention [Problem to be solved by the invention]

[0004] Currently, in the solvent extraction of vegetable oils, rotary extractors and the like are used to enable continuous processing and efficient vegetable oil extraction. However, while such continuous processing systems are efficient on a large scale, they are inefficient when used on a small scale with a small annual production volume, such as on farms or in rural areas, resulting in overcapacity.

[0005] Batch processing is more efficient for vegetable oil extraction when annual production volumes are small. However, the residue left after vegetable oil extraction contains solvents such as hexane, and the raw material must be heated to separate the solvent. Removing the residue manually from the extractor could expose the person to harmful solvents, which requires additional labor. While mechanical transfer of the residue to a solvent separation device is also an option, it involves many moving parts, increases equipment costs, and increases the risk of problems such as residue jamming. [Means for solving the problem]

[0006] As shown in Figures 1 and 3, the system of the present invention provides the functions necessary for solvent extraction and the functions necessary for solvent separation in the same extractor (1).

[0007] The raw materials used to extract vegetable oil are placed in a separate container (called the "raw material container") that can be removed from the extractor, and the vegetable oil extraction (4b) and solvent separation (4c) processes are completed while the raw materials remain in the raw material container (2). This prevents the raw materials and extraction residue from coming into contact with other parts of the extraction system, minimizing problems such as the raw materials and extraction residue getting caught. In addition, because the raw material container (2) can be removed, it can be washed completely. By separating the raw material container (2), the only manual work required is to take the raw material container in and out before and after the extraction process and to start the system, making it possible for non-experts such as farmers to operate the system.

[0008] The raw material container (2) has a mesh (2b) at the bottom, which allows liquids and gases to flow downwards.

[0009] The raw material container (2) is made of metal that is heated by electromagnetic induction, and by placing the raw material container (2) together with the raw material container (2) in the extraction container, the raw material container (2) is heated by the electromagnetic induction coil (1f) built into the extraction container, and the raw material is heated by the heat conduction, and the solvent mixed in the raw material is evaporated.

[0010] As a method for heating the raw material to evaporate the solvent mixed in the raw material, in addition to heating with an electromagnetic induction coil (1f), heating with an electric heating wire is also possible. In this case, the electric heating wire and the raw material container need to be in close contact with each other so that heat is efficiently conducted from the electric heating wire to the raw material container. To achieve this, it is preferable to design the raw material container so that it will be in close contact with the inner wall of the extractor due to thermal expansion of the heated raw material container during the solvent separation process.

[0011] The entire system shown in Figure 3 is a closed system when the lid of the extractor is closed. Because the inside of the extractor becomes positive pressure due to evaporation of the solvent, the lid (1a) is designed to be able to seal the extractor so that gases and the like inside the extractor (1) do not leak.

[0012] In solvent separation, the extraction residue is heated for a long period of time to completely remove the solvent. To improve thermal efficiency, it is preferable to use a heat insulating material on the outer wall of the extractor. [Effects of the Invention]

[0013] According to the present invention, vegetable oil extraction (4b) and solvent separation (4c) can be performed in the same extractor (1), eliminating the need to move the extraction residue containing the solvent between the vegetable oil extraction (4b) and solvent separation (4c) steps, thereby reducing the labor and equipment required.

[0014] Eliminating the need to move solvent-laden pulp minimizes the risk of worker exposure to toxic solvents.

[0015] By eliminating the need to move the extraction residue mixed with the solvent, problems such as the extraction residue getting caught in the machinery are eliminated, minimizing the risk of performing vegetable oil extraction (4b) and solvent separation (4c) unmanned, and reducing labor costs.

[0016] The introduction of the raw material container (2) makes it possible for even non-specialized farmers to operate the system. Specifically, farmers place the raw material in the raw material container and place it inside the extraction vessel. They simply operate the solvent extraction system and remove the raw material container from the extraction vessel when the entire process is complete.

[0017] This invention makes it possible to introduce solvent extraction systems on a small scale, such as at farms or in rural villages, allowing farmers to bring their own raw materials to the extraction system and take the vegetable oil home. Large-scale extraction systems require the costs of collecting raw materials from farmers, transporting them to a factory with an extraction system, and delivering the refined vegetable oil back to the farm. This also allows farmers and rural villages to contribute to national food security. [Brief explanation of the drawings]

[0018] [Figure 1]1A and 1B are perspective and cross-sectional views of the body of the extractor of the present invention; [Figure 2] FIG. [Figure 3] 1 is a block diagram of a solvent extraction system of the present invention. [Figure 4] 1 is a process of one embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0019] One embodiment of the present invention will be described below with reference to Fig. 4. This embodiment is broadly comprised of four steps: raw material placement (4a), vegetable oil extraction (4b), solvent separation (4c), and extraction residue removal (4d).

[0020] Before the process is performed, valves 1, 2, and 3 are closed, the gas-liquid pump, liquid pump 1, liquid pump 2, and compressor are stopped, and the heating functions of the electromagnetic induction coil (1f) and the evaporator heating wire, etc. are also stopped.

[0021] In the raw material setting (4a) step, raw materials such as pressed rapeseed or bran from which vegetable oil is to be extracted are placed in the raw material container (2), the top surface is flattened, and the raw material container (2) is placed inside the extractor (1) by opening the lid (1a). Once it is confirmed that the lid (1a) is completely closed, the raw material setting (4a) step is completed and the process moves on to the next step.

[0022] In the vegetable oil extraction (4b), valves 1, 2, and 3 are opened. Next, the liquid pump is operated, and the solvent is introduced into the extractor (1) via the solvent inlet pipe (1b). Inside the extractor, the solvent is sprayed from the nozzle (1d) to impregnate the raw material. The solvent dissolves the fats and oils in the raw material and falls through the mesh (1e). The fallen solvent is sent to the evaporator via the solvent outlet pipe (1c) by a gas-liquid pump. In the evaporator, the solvent is heated to a temperature above its boiling point using an electric heating wire or other device, evaporating the solvent and separating the vegetable oil as a liquid. The gaseous solvent is cooled in the condenser by cooling water delivered by the liquid pump, liquefied, and stored in the solvent tank. The vegetable oil is extracted by continuously repeating the process from the introduction of the solvent into the extractor (1) to this point. When no additional vegetable oil is produced, the vegetable oil extraction (4b) process ends and the next step begins.

[0023] In solvent separation (4c), the heating function of the evaporator's heating wire and other components is stopped, and the compressor is operated. Electricity is applied to the electromagnetic induction coil (1f), which heats the raw material container (2) by electromagnetic induction. The raw material (1e) is heated by heat conduction from the heated raw material container (2), exceeding the boiling point of the solvent mixed with the raw material, causing the solvent to evaporate. The liquid passes through valve 1 and the evaporator and is sent to the condenser. The solvent is liquefied in the condenser, passes through valve 2, and is stored in the solvent tank. The evaporated solvent, and any unliquefied gas, which is mainly air, is sent to the extractor via the compressor's check valve. When the solvent returns to its initial amount, the gas-liquid pump and compressor are stopped, valves 1, 2, and 3 are closed, and the process proceeds to the next step.

[0024] In the extraction dregs removal step (4d), after confirming that the temperature and pressure inside the extractor have dropped to a safe level, the lid (1a) is opened and the raw material container (2) containing the remaining extraction dregs is removed. Once removed, the lid is closed, completing the entire process.

[0025] Examples of raw materials that can be used in the system of the present invention include rice bran and pressed rapeseed cake. Rice bran can be made from rice milling. Rapeseed is cultivated by utilizing part of the cultivated land. In particular, in warm regions, rapeseed can be grown as a double crop with paddy rice, making it possible to produce rapeseed without reducing the area planted with paddy rice. Furthermore, since the extracted cake can be used as feed or compost material, an extraction system that can be installed in rural areas will contribute to resource circulation on a rural level.

[0026] In one example of a farmer's use in a rural area, a farmer could bring rice bran to an oil refinery equipped with the system of the present invention in the afternoon, place the rice bran or rapeseed pressed cake in the raw material container (2), install the system in the extraction system, place a container for the vegetable oil in the vegetable oil outlet, start the extraction system, and the system would operate automatically, extract the vegetable oil and separate the solvent from the extracted cake. The farmer would then remove the raw material container the next morning, collect the extracted cake as feed or compost, wash the raw material container, and take the vegetable oil home. This allows more than 12 hours for vegetable oil extraction (4b) and solvent separation (4c), providing ample time for vegetable oil extraction (4b), solvent separation (4c), and subsequent system cooling. Furthermore, this allows for ample time to minimize the scale of the facility and reduce costs.

[0027] An example of the structure of the extractor (1) is described below. The extractor (1) is cylindrical with a conical bottom. It is equipped with a lid (1a), and a raw material container (2) containing raw materials can be placed inside. A mechanism is provided to apply pressure to the lid (1a) when closing it to prevent any gaps between the extractor (1) and the lid (1a) and secure it in place. To minimize heat loss during the solvent separation (4c) process, the extractor (1) may be covered with insulating material. As shown in the cross-sectional view (1b) of Figure 1, the inside of the extractor (1) has a nozzle (1d) at the top connected to the solvent inlet pipe (1b). The nozzle (1d) has multiple holes to ensure that the solvent is evenly distributed over the raw materials. An electromagnetic induction coil (1f) is located within the side wall of the extractor (1), at the same height as the raw material container (2). The bottom of the extractor (1) is conical, tapering downward, and a solvent outlet pipe (1c) is connected to the bottom.

[0028] An example of the structure of the raw material container (2) will be described. The raw material container (2) is cylindrical, with an open top and a mesh (2b) at the bottom. Raw materials from which vegetable oil is extracted, such as pressed rapeseed meal or rice bran, can be placed inside from the top. The cylindrical outer frame (2a) of the container is made of metal, which is heated by electromagnetic waves from the electromagnetic induction coil (1f).

[0029] Examples of raw materials used in the present invention include rapeseed and rice bran. In the case of rapeseed, the pressed pomace may be used. To accommodate any raw material, it is preferable to use a mesh (2b) of the raw material container (2) with a sufficiently fine mesh. Furthermore, positive pressure from a compressor is applied from above the raw material, and negative pressure from a gas-liquid pump is applied from below the mesh, allowing the solvent to pass through even a fine mesh.

[0030] An example of a solvent that can be used in the present invention is normal hexane. The boiling point of normal hexane is 68.7°C. In the vegetable oil extraction (4b) step, it is possible to evaporate only the solvent in an evaporator without evaporating the vegetable oil dissolved in the solvent. In the solvent separation (4c) step, it is possible to evaporate only the solvent without evaporating the water mixed in the extraction residue from the extractor. [Explanation of symbols]

[0031] 1 extractor 1A Perspective view of the extractor 1B Cross-sectional view of extractor 1a Lid 1b Solvent injection pipe 1c Solvent discharge pipe 1d nozzle 1e raw materials 1f Electromagnetic induction coil 2 Raw material container 2A Perspective view of the raw material container with the raw material inlet facing up 2B Perspective view of raw material container with mesh facing up 2a outer frame 2b net 3 System configuration diagram 4 Extraction process 4a Raw material installation 4b Vegetable oil extraction 4c Solvent Separation 4d. Extraction of the lees

Claims

1. A vegetable oil solvent extraction system that uses electromagnetic induction to heat the raw material container and separate the solvent.

2. A vegetable oil solvent extraction system that uses an electric heating wire to heat the raw material container and separate the solvent.

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