KR-20260062753-A - Multipurpose fertilizer biochar and method of preparing the same

Abstract

The present invention relates to a multi-purpose fertilizer biochar and a method for manufacturing the same, which can prevent soil acidification and the separation of chitosan as well as carbon sequestration, soil improvement, and heavy metal adsorption capabilities by pyrolyzing wood chips at a temperature of 350°C or higher and then surface modifying them with chitosan.

Inventors

• 김성호
• 우영준

Assignees

• 한국바이오차 농업회사법인 주식회사

Dates

Publication Date

20260507

Application Date

20241029

Claims (4)

1. Step of drying wood chips of a predetermined size; A step of producing biochar by pyrolyzing the dried wood chips at 350 to 600°C in an oxygen-free atmosphere; and A method for manufacturing a multi-purpose fertilizer biochar comprising the step of surface modification by adding the biochar to a chitosan solution.
2. A method for manufacturing a multi-purpose fertilizer biochar according to claim 1, wherein the surface modification step comprises mixing 100 to 200 parts by weight of a chitosan solution with 100 parts by weight of the biochar, and wherein the chitosan solution is prepared by mixing 0.1 to 2% w/v chitosan with 0.1 to 5% (v/v) acetic acid solution.
3. A method for manufacturing a multi-purpose fertilizer biochar according to claim 1, characterized in that the manufacturing method comprises the step of immersing the biochar produced in the biochar manufacturing step in a 1-10% sodium carbonate solution for 1 hour to 24 hours.
4. A multi-purpose fertilizer biochar produced by the method of any one of claims 1 to 3, wherein the biochar is surface-modified with chitosan and has a pH of 6.5 or higher.

Description

Multipurpose fertilizer biochar and method of preparing the same The present invention relates to a multi-purpose fertilizer biochar and a method for manufacturing the same, and more specifically, to a multi-purpose fertilizer biochar and a method for manufacturing the same that can prevent soil acidification and separation of chitosan, as well as carbon sequestration, soil improvement, and heavy metal adsorption capabilities, by pyrolyzing wood chips at a temperature of 350°C or higher and then surface modifying them with chitosan. Generally, amidst concerns over global warming and the depletion of fossil resources, biomass, which is the next most abundant energy source after coal and oil, is attracting attention as a new energy source. Biomass is a 'renewable' organic resource produced from inorganic water and carbon dioxide through photosynthesis utilizing solar energy. Furthermore, because the carbon dioxide released when biomass is burned is the same as the carbon dioxide absorbed into the atmosphere through photosynthesis during the growth process of organisms, biomass possesses 'carbon neutral' characteristics that do not increase the concentration of carbon dioxide in the atmosphere during its life cycle. Therefore, if energy or products derived from fossil resources are replaced with biomass, the emission of greenhouse gases (carbon dioxide) that cause global warming can be significantly reduced, and because of its low sulfur content, it can also be used to reduce SO2 emissions when co-fired with high-sulfur coal. In this regard, the IPCC (Intergovernmental Panel on Climate Change) recognized the technology of incorporating biochar into soil as a carbon sequestration technology in 2019 and published guidelines for calculating it. Since carbon converted into biochar is chemically very stable and can be stored in the soil for a long time without being decomposed by microorganisms, biochar can consequently serve as a medium for carbon sequestration. Furthermore, biochar is also utilized as a soil conditioner due to its properties of increasing soil fertility and adsorbing heavy metals, organic pollutants, and herbicides. Generally, soil conditioners must be equipped with appropriate permeability, water retention, and nutrient retention capacity to support plants and ensure a smooth supply of nutrients and water. Recently, there has been active development of soil conditioners and biochar fertilizers using biochar. Korean Patent Publication No. 10-2023-0138122 discloses a potting soil composition comprising biochar, natural minerals, vermiculite, perlite, and moisture-removed coffee by-products. In addition, Korean registered patent No. 10-2451530 discloses a soil conditioner and an organic fertilizer comprising a powder composition and additives comprising biochar, peat moss, coco peat, composted fallen leaves, natural minerals, vermiculite, perlite, and coffee by-products from which moisture has been removed. The aforementioned registered patents enhance soil improvement performance by mixing natural minerals or various types of biomass with biochar. However, the aforementioned published patents mix large amounts of various additives to improve the performance of soil conditioners (e.g., pH increase, heavy metal adsorption performance). In particular, Korean Registered Patent No. 10-2451530 contains less than 20% by weight of biochar, while the additive content accounts for more than 80%. Furthermore, the aforementioned registered patents do not contain any content regarding the improvement of the performance of the biochar itself. Figure 1 is an example of a biochar production system usable in the present invention. Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings. However, the scope of the present invention is not limited to the description of the embodiments or drawings below. That is, the terms used in this specification are used merely to describe specific embodiments and are not intended to limit the present invention. Singular expressions include plural expressions unless the context clearly indicates otherwise. Furthermore, terms such as "comprising" or "having" described in this specification are intended to indicate the existence of the features, numbers, steps, actions, components, parts, or combinations thereof described in the specification, and should be understood as not precluding the existence or addition of one or more other features, numbers, steps, actions, components, parts, or combinations thereof. The method for manufacturing biochar fertilizer according to the present invention includes a drying step, a pyrolysis step, and a surface modification step. The above drying step and pyrolysis step may use known pyrolysis devices, carbonization devices, or torrefaction devices. For example, FIG. 1 is a pyrolysis device disclosed in the applicant's registered patent No. 10-204107 as an example of a biochar production system u