JPH04265216A - Production of carbide of plant - Google Patents

Abstract

PURPOSE:To obtain a carbide of a plant having excellent strength and shape holding property in relatively short time with high yield. CONSTITUTION:The dried plant wrapped into a microsphere of heat resistant inorganic material is pre-oxidized by heating at 200-300 deg.C and is heated to carbonize under a flow of non-oxidizing atmosphere.

Description

Description: [0001] The present invention relates to a method for producing carbonized plant materials. [Prior art and its problems] As a conventional technology, branch charcoal, charcoal, etc. obtained by semi-drying trees and the like and then heating them in the air for 24 hours or more have been used as charcoal of plants for a long time. It was known. [0003] On the other hand, as a recent technique for producing carbonized plant materials, there is a method disclosed in Japanese Patent Application Laid-open No. 176199/1983, that is, a method in which dried flowers are heated and carbonized in a non-oxidizing atmosphere. ing. However, if the temperature is raised rapidly using this method, organic plants (
A problem arises in that dry flowers (dried flowers) undergo rapid and significant decomposition, resulting in lower molecular weight, and the strength of the carbide decreases. Further, in order to prevent this, the above method requires a long time (10 hours) for carbonization, and the carbonization yield is not high. In addition, a method of impregnating a thermosetting resin is used as a means for maintaining the shape of the carbide, but this method cannot be said to be sufficient. [Means for Solving the Problems] In view of the above-mentioned problems, the inventor of the present invention, as a result of extensive research, discovered that by subjecting dried plants to oxidation treatment (pre-oxidation) prior to carbonization treatment. We have discovered that it is possible to prevent the above-mentioned lower molecular weight, increase the strength of the resulting carbonized product, and shorten the carbonization time. Furthermore, we have found that the above-mentioned preoxidation or carbonization can be carried out by embedding dried plants in microspheres of heat-resistant inorganic material. It has been found that when the treatment is applied, uniform heating is possible and the shape retention of the plant is improved. [0005] That is, the present invention provides the following method for producing a carbonized plant. 1. Dried plants are embedded in microspheres made of heat-resistant inorganic material and pre-oxidized at 200 to 300°C, and then heated and carbonized under an air flow in a non-oxidizing atmosphere while the plants are embedded in the microspheres. A method for producing carbonized plant material, which is characterized by: 2. It is characterized by embedding dried plants in microspheres made of heat-resistant inorganic material, pre-oxidizing them at 200 to 300°C, then removing the microspheres, and then heating and carbonizing them in an air stream in a non-oxidizing atmosphere. A method for producing carbide from plants. 3. The method for producing a carbide according to item 1 or 2 above, wherein the microspheres of the heat-resistant inorganic material are silica gel. 4. The method for producing a carbide of a plant according to the above item 1 or 2, using either nitrogen gas, argon gas, or hydrogen gas as the non-oxidizing atmosphere airflow. The present invention will be explained in detail below. [0007] The plants targeted by the present invention are not particularly limited, and may include flowers, branches, leaves, fruits, or a combination of these as long as they are dried. [0008] First, the above-mentioned plant is placed in a heat-resistant glass container or the like, and then microspheres made of a heat-resistant inorganic material are filled in the container without any gaps to embed the plant. It is preferable to use silica gel as the microspheres of this heat-resistant inorganic material. The particle size of the microspheres is usually about 0.06 to 0.5 mm. Next, the dried plant is preoxidized prior to carbonization. Pre-oxidation is performed by oxidizing the above dried plants in the air to 200~
It may be heated at 300°C. If the heating temperature is lower than 200° C., oxidation takes time and sufficient oxidation cannot be achieved. If the heating temperature exceeds 300°C, carbonization will proceed excessively and the weight will decrease significantly, which is not preferable. Further, although the heating time and temperature increase rate are not constant depending on the size, type, etc. of the plant, the heating time is usually about 2 to 6 hours. Next, the air is replaced with nitrogen gas, argon gas, hydrogen gas, etc. to create a non-oxidizing atmosphere while maintaining the heating temperature in the preliminary oxidation. The replaced gas continues to flow in as an airflow. [0011] The temperature of the dried plant in the airflow gas is then raised to carbonize it. The carbonization temperature is not constant depending on the size, type, etc. of the plant, but is usually around 600°C, and may be raised to 600°C or higher if necessary. [0012] After the temperature has been raised, the heating is stopped and airflow gas is continued to flow until it is cooled, thereby obtaining the charcoal of the plant of the present invention as Ohana charcoal or the like. In this case, in order to enhance the shape retention of the plant during carbonization, depending on the size and type of the plant, the plant may be carbonized by being embedded in microspheres of heat-resistant inorganic material following preliminary oxidation. . [0013]According to the present invention, pre-oxidation prior to carbonization prevents the rapid and drastic decomposition of organic matter from plants, thereby producing carbonized materials with excellent strength at a relatively high carbonization yield. In addition, the carbonization time is significantly shortened, and excellent productivity can be achieved. Furthermore, since preliminary oxidation or carbonization is carried out by embedding it in microspheres of a heat-resistant inorganic material such as silica gel, it has excellent shape retention and can form a carbide without being limited by the thickness of the petal. be able to. On the other hand, it is possible to accurately control the temperature during oxidation and carbonization, and it is also possible to uniformly heat the plants. Furthermore, since the carbonization is carried out under an air flow, air will not enter the container and cause oxidation, and decomposition products will be discharged outside the container, allowing a clean carbide surface to be maintained. Examples [0016] Examples will be shown below to further clarify the features of the present invention. [Example 1] Dried rose flowers with branches and leaves are placed in a glass beaker, and silica gel for column chromatography is poured on top of the beaker, packed between the petals without any gaps, and then placed in a dryer at room temperature. Heat to 250℃ for 1 hour, and heat to 250℃.
The mixture was held at 0°C for 2 hours, and then heated to 300°C over 30 minutes for oxidation. After reaching 300°C, the silica gel was removed by cooling to room temperature, and the oxidized rose was placed in a quartz container.
The atmosphere was replaced with argon gas. After that, 300
The temperature was increased from 120°C to 800°C at a rate of 120°C/hr for heating and carbonization. As soon as the temperature reached 800°C, the charcoal was cooled to 200°C while continuing to flow argon gas and the carbide was taken out, resulting in shiny rose charcoal. The total time required for this entire process was approximately 7.7 hours. Table 1 shows the results of examining the carbonization yield and dimensional yield of the carbide. [0020]
Table 1
Carbonization yield
dimensional yield
(%)
(%)
rose 35
[Example 2] Two types of dried chrysanthemum flowers, one with elongated petals and one with slightly wide petals, are placed in a heat-resistant petri dish, and spherical silica gel for column chromatography is placed on top of the petals to separate the petals. Fill it so that there are no gaps. Next, put it in a dryer heated to 200℃ and dry it for 30 minutes.
The temperature is raised to 50°C and maintained at that temperature for 5 hours for oxidation. Next, after cooling once, the heat-resistant Petri dish was placed in a quartz container, argon gas was introduced to replace the atmosphere, and the mixture was heated and carbonized from 250°C to 600°C at a heating rate of 120°C/hr. As soon as the temperature reached ℃, the heating was stopped, and then the mixture was cooled to 200 ℃ while flowing argon gas, and the carbide was taken out, and a beautiful carbide chrysanthemum was obtained. The time required for this entire process is approximately 8.
It was 4 hours. Table 2 shows the results of examining the carbonization yield and dimensional yield of the carbide. [0024]

Claims (4)

[Claims] Claim 1: Dried plants are embedded in microspheres made of a heat-resistant inorganic material and subjected to preliminary oxidation treatment at 200 to 300°C, and then the plants are exposed to air flow in a non-oxidizing atmosphere while being embedded in the microspheres. A method for producing charred vegetable products, which is characterized by heating and carbonizing them under water. Claim 2: Dried plants are embedded in microspheres made of a heat-resistant inorganic material and subjected to preliminary oxidation treatment at 200 to 300°C.Then, after removing the microspheres, heating and A method for producing carbonized plant materials characterized by carbonization. 3. The method for producing a carbide according to claim 1 or 2, wherein the microspheres of the heat-resistant inorganic material are silica gel. 4. The method for producing a carbide of a plant according to claim 1 or 2, wherein any one of nitrogen gas, argon gas, or hydrogen gas is used as the non-oxidizing atmosphere air stream.