Method for processing plant biomass

Abstract

Provided is a method for treating plant biomass, which can reduce the content of components such as potassium, sulfur, chlorine, sodium, silicon, and magnesium extremely efficiently compared to conventional techniques before using plant biomass as fuel, and can reduce adverse effects on combustion furnaces, chimneys, and the like during combustion. [Solution] The plant raw material is cut, crushed or pulverized into an easy-to-handle form, and then immersed in an immersion solution of electrolytic alkaline ionized water or an immersion solution of electrolytic alkaline ionized water diluted with water for 10 hours or more, and then dried. The immersion solution preferably has a pH of 9 or more, and the plant raw material is preferably a perennial plant of the genus Ricinus in the family Euphorbiaceae.

Description

[Technical field]

[0001] The present invention relates to a method for treating plant biomass that can reduce the contents of components such as potassium, sulfur, chlorine, sodium, silicon, and magnesium before using the plant biomass as fuel. [Background technology]

[0002] When attempting to obtain thermal energy and / or electrical energy by burning plant biomass (woody biomass, herbaceous biomass, etc.), a method is carried out in which the plant raw materials (trunks, bark, branches, etc.) are chipped in advance and stored, and then these are supplied to a combustion furnace for combustion. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent No. 5753959 Summary of the Invention [Problem to be solved by the invention]

[0004] Plant biomass contains elements such as potassium, sulfur, chlorine, sodium, silicon, and magnesium. If it is burned as is, problems arise in that clinker will adhere to and accumulate on the surfaces of the inner walls of combustion furnaces and chimneys, heat transfer tubes, etc., and this can lead to corrosion of metal parts.

[0005] Although Patent Document 1 discloses a method for removing components such as potassium from plant biomass, a method capable of reducing the content of these components more efficiently is desired.

[0006] The present invention seeks to solve the problems associated with the conventional technologies as described above, and aims to provide a method for treating plant biomass that can extremely efficiently reduce the content of components such as potassium, sulfur, chlorine, sodium, silicon, and magnesium before using the plant biomass as fuel. [Means for solving the problem]

[0007] The method for treating plant biomass according to the present invention is characterized in that the plant raw material is cut, crushed or pulverized, and then immersed in an immersion solution consisting of electrolytic alkaline ionized water or an immersion solution obtained by diluting electrolytic alkaline ionized water with water for 10 hours or more, and then dried. The immersion solution preferably has a pH of 9 or more, and the plant raw material is preferably a perennial plant of the genus Ricinus in the family Euphorbiaceae. Effect of the Invention

[0008] According to the method for processing plant biomass of the present invention, the content of potassium and other elements can be reduced extremely efficiently compared to conventional techniques, and adverse effects on combustion furnaces and the like during combustion can be effectively reduced. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] Hereinafter, an embodiment of the "method for treating plant biomass" according to the present invention will be described. The method for treating plant biomass according to the present invention is basically characterized in that collected or recovered plant material is cut, crushed, or pulverized into easy-to-handle sizes, immersed in electrolytic alkaline ionized water (immersion liquid) for a predetermined period of time, and then dried.

[0010] Plants that can be used as raw materials may be any of trees (coniferous trees such as cedar, cypress, and fir, deciduous broad-leaved trees such as oak, Japanese oak, sawtooth oak, and maple, and evergreen broad-leaved trees such as Quercus edulis) and herbaceous plants, and any of the parts thereof may be used, such as trunks, bark, branches, stems, leaves, flowers, seeds, and roots.

[0011] When using tree trunks, bark, and branches as raw materials, they are cut into appropriate sizes (e.g., lengths of about 10 to 500 mm) in advance. When using twigs, stems, leaves, etc., they are cut into chips (e.g., lengths of about 10 to 50 mm).

[0012] The soaking process is carried out by putting the raw material into a water tank containing electrolytic alkaline ionized water and maintaining most of the raw material (especially the cut surface) submerged under the water surface. During soaking, the electrolytic alkaline ionized water may be stirred as necessary. It is preferable to bundle the cut trunks and branches into easy-to-handle sizes and put them into the water tank. Small pieces such as chipped twigs, stems, and leaves can be put into the water tank while being contained in a net bag (mesh bag) of an appropriate size. In addition, for roots with soil attached, there is no need to remove the soil beforehand, and they can be put into the water with the soil still attached.

[0013] As the immersion liquid stored in the water tank, alkaline ionized water produced by electrolysis can basically be used without any problem. For example, electrolytic alkaline ionized water produced by the method of producing ionized water disclosed in Japanese Patent No. 2949322 (a method in which crystalline clay minerals are further dissolved in alkaline and acidic ionized water obtained by electrolyzing raw water in which crystalline clay minerals are dissolved, and each ionized water is supplied to a specific electrode side for electrolysis) can be used. In addition, as the immersion liquid, a stock solution of electrolytic alkaline ionized water (e.g., pH 12 or more) can be used, and a stock solution diluted with water (tap water, etc.) (e.g., pH 9 to 12) can also be used.

[0014] The immersion step is preferably carried out for 10 hours or more, and may be carried out multiple times with intervals therebetween.

[0015] After the soaking process is completed, the raw material is removed from the water tank and a drying process is carried out. The drying process can be carried out by natural drying (drying in the sun) or by using a dryer (especially a dryer that uses biomass fuel as a heat source).

[0016] After the drying step, the raw material that has not yet been chipped is chipped as necessary. For example, the raw material is put into a crusher and crushed to a size of about 10 to 50 mm. Alternatively, the raw material may be crushed to a particle size of about 1 mm using a crusher (hammer mill, etc.). The chips obtained by crushing or pulverization may be further subjected to a drying step.

[0017] By carrying out the method for treating plant biomass according to this embodiment, it is possible to reduce the content of components such as potassium extremely efficiently, as compared with the conventional technique (immersion in tap water, etc.). Such an effect has been confirmed by experiments carried out by the inventors of the present invention. The results of the experiments carried out by the inventors of the present invention will be described below as examples. EXAMPLES

[0018] An experiment was conducted in which samples obtained by harvesting and cutting grass planted in Miyazaki Prefecture were immersed in various soaking solutions, and the amount of potassium and sulfur dissolved in the soaking solutions and the pH of the soaking solutions were measured over time. In this experiment, castor beans (perennial plants of the genus Ricinus, Euphorbiaceae) (registered variety: Yamatodama) leaves, stems, and roots were each cut into pieces 10 to 30 mm in size to prepare samples.

[0019] As the liquids for immersing the samples, 6 L each of tap water (comparative example), electrolytic alkaline ionized water stock solution (pH 12 or higher) (present invention 1), and electrolytic alkaline ionized water stock solution diluted 10 times with tap water (pH 9) (present invention 2) were prepared. 1 L each of these three types of immersion liquids were placed in 6 containers (total of 18). Then, 50 g of the sample was placed in each of the 18 containers. The samples were distributed so that the composition ratio of leaves, stems, and roots was approximately the same.

[0020] Thirty minutes after the samples were poured into the containers, one container each containing the Comparative Example, the Invention 1, and the Invention 2 were selected from the 18 containers, the samples were removed from the containers, and the amounts of potassium and sulfur in the immersion liquid and the pH of the immersion liquid were measured. The same measurement was also carried out 1 hour, 2 hours, 5 hours, 10 hours, and 24 hours after the samples were poured into the containers. The results are shown in the following table.

[0021] [Table 1]

[0022] As shown in the above table, in invention 1 (undiluted electrolytic alkaline ionized water, pH 12 or higher), the amount of potassium eluted was about twice that of the comparative example (tap water), and when immersed for 10 hours or more, an amount of sulfur eluted that exceeded that of the comparative example. Also, in invention 2 (10-fold diluted electrolytic alkaline ionized water, pH 9), an amount of potassium and sulfur eluted that exceeded that of the comparative example.

[0023] These experimental results confirmed that by immersing castor beans (perennial plants of the genus Ricinus in the family Euphorbiaceae) in electrolyzed alkaline ionized water, it is possible to dissolve components such as potassium and sulfur (reduce the content in castor beans) much more efficiently than with conventional techniques (immersion in tap water, etc.).

[0024] In the above experiment, castor beans were used as the subject of application, but it is presumed that the same effect can be expected when the present invention is applied to other plant materials. Also, in the above experiment, electrolytic alkaline ionized water produced by the ionized water production method disclosed in Japanese Patent No. 2949322 was used as the electrolytic alkaline ionized water, but it is presumed that the same effect can be expected when electrolytic alkaline ionized water produced by other methods is used.

[0025] Also, even if electrolytic alkaline ionized water diluted with water is used as the immersion liquid, it is expected that a certain degree of effect can be expected as long as the pH is 9 or higher.

[0026] In addition, although the above experiment only measured the amount of eluted potassium and sulfur, it is presumed that other contained components, such as chlorine, sodium, silicon, magnesium, etc., can also be eluted in a similar manner and their contents reduced, which is believed to reduce the adverse effects on combustion furnaces, chimneys, etc. during combustion.

Claims

1. A method for treating plant biomass, comprising cutting, crushing or pulverizing a plant raw material, immersing the plant raw material in an immersion solution consisting of electrolytic alkaline ionized water or an immersion solution obtained by diluting electrolytic alkaline ionized water with water for 10 hours or more, and then drying the plant raw material.

2. 2. The method for treating plant biomass according to claim 1, wherein the soaking liquid has a pH of 9 or higher.

3. 3. The method for treating plant biomass according to claim 1 or 2, wherein a perennial plant of the genus Ricinus in the family Euphorbiaceae is used as the plant raw material.

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