KR20240027909A - Preparing method for graphene like carbon by pyrolysis of biomass with hybrid metal salts and Treating method for wastewater contaminated with organic compound using granular adsorbent loaded with the same - Google Patents

Abstract

The present invention relates to a method for producing biomass-based pseudo-graphene using a hybrid metal salt modifier and a method for treating organic polluted wastewater using a granular medium carrying them. The method for producing a pseudo-graphene granular medium according to the present invention is a hybrid metal salt. By using a modifier to activate biomass, pseudo-graphene can be mass-produced economically. Meanwhile, according to the present invention, it is possible to mass-produce pseudo-graphene (high specific surface area, high sp ² /sp ³ carbon ratio, etc.) powder with properties very similar to those of graphene manufactured in a single layer form through graphite exfoliation in an environmentally friendly manner. do. In addition, according to the present invention, unlike the conventional pyrolysis manufacturing method, the problem of reducing the specific surface area due to the formation of multilayers due to agglomeration between sheets when manufacturing pseudo-graphene is effectively prevented, thereby maintaining excellent adsorption performance and It can be secured. Furthermore, when applied to remove organic contaminants in water, the pseudo-graphene granular medium according to the present invention has the advantage of being easy to recover and reusable after water treatment, unlike conventional powder types.

Description

Method for manufacturing biomass-based pseudo-graphene using a hybrid metal salt modifier and method for treating organic contaminated wastewater using a granular medium carrying them {Preparing method for graphene like carbon by pyrolysis of biomass with hybrid metal salts and Treatment method for wastewater contaminated with organic compound using granular adsorbent loaded with the same}

The present invention relates to a method for producing biomass-based pseudo-graphene using a hybrid metal salt modifier and a method for treating organic polluted wastewater using a granular medium carrying them.

Graphene has a hexagonal lattice-shaped connection extending in a two-dimensional direction due to sp ² hybridization of carbon. Graphene is a very thin, semi-metallic material with excellent mechanical and physical properties and is used in various fields such as electronics, optoelectronic devices, chemical sensors, and nanocomposites.

Meanwhile, graphene can be manufactured through various methods. Specifically, it can be manufactured by mechanical exfoliation from graphite, or by chemical vapor deposition (CVD) on the metal surface using methane, ethylene, or acetylene decomposition. It can be manufactured by, epitaxially grown on SiC, formed by a chemical graphitization reaction of graphene oxide, or carbonized by biomass.

The improved Hummer's method is one of the most widely used chemical synthesis methods for producing reduced graphene oxide (rGO), using sulfuric acid (H ₂ SO ₄ ) and potassium permanganate (KMnO ₄ ). , Graphite oxide is manufactured through oxidation using a large amount of strong oxidizing agents such as hydrogen peroxide (H ₂ O ₂ ) and sodium nitrate (NaNO ₃ ), and then exfoliated through ultrasonic treatment to produce graphene oxide. GO) is manufactured. This method has the advantage of being able to produce graphene oxide in large quantities, but when producing graphene oxide from graphite, a large number of strong acidic substances and oxidizing agents are required, which poses risks in the manufacturing process, is not economical or environmentally friendly, and requires ultrasonic treatment and centrifugation. Due to this, it has the limitation of taking a lot of time. Additionally, when producing reduced graphene oxide (rGO), an expensive reducing agent must be used.

Meanwhile, carbon that can be obtained from biomass such as plants can be obtained in a more nature-friendly way than graphite. In particular, cellulose is one of the components of biomass (cellulose, hemicellulose, lignin), is abundant in carbon, is easy to obtain, and is not subject to thermal decomposition. With a simple process, moisture is removed along with the dehydrogenation reaction and conversion to elemental carbon is possible. The mechanism by which cellulose is elementally carbonized is as shown in Equation 1 below.

(Table 1)

However, when pseudo-graphene is manufactured from lignocellulosic biomass containing cellulose, lignin, or both using existing pyrolysis manufacturing methods, multi-layers are created by aggregation of pseudo-graphene sheets, Because of this, there is a limit to reducing the specific surface area. In addition, pseudo-graphene manufactured in powder form with fine particles has the problem of difficulty in recovery when applied to water treatment. To overcome this, when coated on a specific medium, the specific surface area of graphene decreases, resulting in lower water treatment efficiency compared to powder. There is a falling problem.

The present invention was devised to solve the problems of the prior art described above, and utilizes a metal salt modifier, specifically a hybrid metal salt modifier, to economically produce large quantities of graphene-like from biomass containing cellulose, lignin, or both. In order to establish an optimized process for production, and to overcome the limitations of the manufactured powder particles, a pseudo-graphene granular medium manufactured in the form of a porous foam that is easy to separate/recover when applying water treatment and a method for manufacturing the same The purpose is to provide a method for adsorbing and removing organic pollutants in water using the same.

In addition, the technical problems to be solved by the present invention are not limited to the technical problems mentioned above, and other technical problems not mentioned will be clearly apparent to those skilled in the art from the description below. It will be understandable.

In this specification, a) adding a hybrid metal salts modifier to lignocellulosic biomass to chemically activate the biomass; b) producing graphene-like carbon by pyrolyzing the activated biomass in a temperature range of 700 to 900° C.; and c) mixing the produced pseudo-graphene with an organic binder material to produce a granular medium in the form of a porous foam.

The lignocellulosic biomass of step a may include one or more types selected from cellulose and lignin.

The hybrid metal salt modifier of step a may include iron chloride (FeCl ₃ ) and zinc chloride (ZnCl ₂ ).

The chemical activation in step a may be performed at a temperature ranging from 80 to 100° C. for 16 to 32 hours after mixing lignocellulosic biomass and a hybrid metal salt modifier.

The thermal decomposition in step b may be performed by carbonizing in a tubular ignition reactor for 0.5 to 1.5 hours under nitrogen ventilation at 200 mL/min.

In order to remove impurities inside and on the surface of the pseudo-graphene produced after carbonization in step b, the step of washing and drying using 15 to 20% hydrogen chloride (HCl) for more than 24 hours may be further included.

The organic binder material in step c may be 2% sodium alginate.

Step c may be performed by mixing and stirring pseudo-graphene and an organic binder material at a ratio of 0.5:99.5 parts by weight to 4:96 parts by weight.

After the mixing and stirring, the resulting mixture may be frozen at -20°C and then freeze-dried for 48 to 96 hours.

It may further include cross-linking the freeze-dried mixture in a 3% calcium chloride (CaCl ₂ ) solution to form a porous foam.

In addition, in the present specification, a pseudo-graphene granular medium manufactured according to the above method, wherein the porous foam-like graphene granular medium has a BET specific surface area of 700 m ² /g or more, is provided. to provide.

The pseudo-graphene granular medium is used to remove organic contaminants in water, and may have an adsorption performance of Rhodamine B water dye in the range of 140.36 to 633.86 mg/g.

The pseudo-graphene granular medium is used to remove organic contaminants in water, and may have an adsorption performance of Congo Red water dye in the range of 106.06 to 220.67 mg/g.

The pseudo-graphene granular medium is used to remove organic contaminants in water, and may have an adsorption performance of toluene in water in the range of 200 to 250 mg/g.

In addition, the present specification provides a method for adsorbing and removing organic pollutants in water by adding the pseudo-graphene granular medium into contaminated water to adsorb and remove organic pollutants in water.

The organic contaminant may be one or more hydrophobic organic contaminants selected from colorants, benzene, toluene, ethyl benzene, and xylene.

The method for manufacturing a pseudo-graphene granular medium according to the present invention utilizes a hybrid metal salt modifier to activate biomass, so that pseudo-graphene can be mass-produced economically.

Meanwhile, according to the present invention, it is possible to mass-produce pseudo-graphene (high specific surface area, high sp ² /sp ³ carbon ratio, etc.) powder with properties very similar to those of graphene manufactured in a single layer form through graphite exfoliation in an environmentally friendly manner. do. In addition, according to the present invention, unlike the conventional pyrolysis manufacturing method, the problem of reducing the specific surface area due to the formation of multilayers due to agglomeration between sheets when manufacturing pseudo-graphene is effectively prevented, thereby maintaining excellent adsorption performance and It can be secured.

Furthermore, when applied to remove organic contaminants in water, the pseudo-graphene granular medium according to the present invention has the advantage of being easy to recover and reusable after water treatment, unlike conventional powder types.

Figure 1 schematically shows the manufacturing process of a graphene-like granular medium according to an embodiment of the present invention.
Figure 2 is a conceptual diagram showing the mechanism and role of the hybrid metal salt modifier according to temperature change during thermal decomposition of lignocellulosic biomass containing cellulose, lignin, or both according to an embodiment of the present invention.
Figure 3 shows the results of FT-IR analysis of pseudo-graphene powder prepared from lignocellulosic biomass according to an embodiment of the present invention.
Figure 4 shows the results of Raman analysis of pseudo-graphene powder prepared from lignocellulosic biomass according to an embodiment of the present invention.
Figure 5 shows the results of XRD analysis of pseudo-graphene powder prepared from lignocellulosic biomass according to an embodiment of the present invention.
Figures 6 and 7 show the results of XPS analysis of pseudo-graphene powder prepared from lignocellulosic biomass according to an embodiment of the present invention.
Figure 8 schematically shows the process of manufacturing a pseudo-graphene granular medium in the form of a porous foam using pseudo-graphene powder and alginate according to an embodiment of the present invention.

Hereinafter, embodiments of the present invention will be described in detail with reference to the attached drawings. However, in explaining this description, descriptions of already known functions or configurations will be omitted to make the gist of this description clear.

Meanwhile, 'pseudo-graphene', a term used throughout the specification, drawings, and claims of the present invention, is a material obtained by thermally decomposing biomass such as cellulose, hemicellulose, and lignin, either alone or in a mixed state, and has a high specific surface area and single-layer structure. , high sp ² /sp ³ carbon ratio, etc., should be understood to mean a material with physicochemical properties very similar to those of graphene obtained by exfoliating graphite.

As described above, in the case of a series of processes for producing graphene oxide from existing graphite and producing reduced graphene oxide using a reducing agent, a large amount of acidic substances and oxidizing agents are required, which poses risks in the manufacturing process and reduces economic feasibility. , there was a problem that it was not eco-friendly. In addition, when the manufactured powder was directly applied to the water treatment process, there was a problem in that separation/recovery was not easy due to the limitations of the powder particles.

Accordingly, the present inventors used lignocellulosic biomass containing cellulose, lignin alone or both as a carbon source, and used a hybrid metal salt modifier containing iron chloride (FeCl ₃ ) and zinc chloride (ZnCl ₂ ) to chemically activate the biomass. By thermal decomposition in an ignition reactor, a powder-type pseudo-graph with a large specific surface area, less agglomeration, and a high sp ² /sp ³ carbon ratio is produced in an economical and rapid form compared to the reduced graphene oxide produced according to the prior art. Fins (graphene-like carbon, hereinafter referred to as 'GLC') can be manufactured, and furthermore, when mixed with an organic binder and manufactured into a porous foam form, it is advantageous for separation/recovery when applied to water treatment. was confirmed through experiment, and the present invention was completed.

Quasi-graphene granular medium and manufacturing method thereof

Specifically, the method for producing a graphene-like granular medium according to an embodiment of the present invention includes the steps of: a) adding a hybrid metal salt modifier to lignocellulosic biomass to chemically activate the biomass; b) producing pseudo-graphene by pyrolyzing the activated biomass at a temperature range of 700 to 900 °C; and c) mixing the produced pseudo-graphene with an organic binder material to prepare a granular medium in the form of a porous foam (see FIGS. 1 and 2).

First, the biomass is chemically activated by adding a hybrid metal salts modifier to the lignocellulosic biomass (step a). Next, pseudo-graphene is prepared by pyrolyzing the activated biomass at a temperature range of 700 to 900° C. (step b).

In the present invention, lignocellulosic biomass is used as a carbon source for producing pseudo-graphene, and may be a material that can be converted to elemental carbon through thermal decomposition and dehydrogenation reactions. Specifically, the lignocellulosic biomass according to an embodiment of the present invention may contain one or more types selected from cellulose and lignin, and in particular may contain both cellulose and lignin. there is.

Meanwhile, in the present invention, the hybrid metal salts modifier serves as a catalyst or template for producing high quality pseudo-graphene, and includes iron chloride (FeCl ₃ ) and zinc chloride (ZnCl ₂ ). It may include simultaneously. Specifically, the hybrid metal salt modifier may be a hybrid metal salt in which iron chloride (FeCl ₃ ) and zinc chloride (ZnCl ₂ ) are mixed in a weight ratio of 1:9 to 9:1. For example, when using a hybrid metal salt modifier in which iron chloride (FeCl ₃ ) and zinc chloride (ZnCl ₂ ) are mixed at a weight ratio of 2:1, iron ( The role of the Fe) metal as a template and the volatilization of the Zn (Zn) metal are optimized, making it possible to manufacture pseudo-graphene more smoothly.

Meanwhile, the activation step may be performed at a temperature ranging from 80 to 100° C. for 16 to 32 hours after mixing the lignocellulosic biomass and the hybrid metal salt modifier.

Meanwhile, in the above step, the hybrid metal salt modifier added based on 100 parts by weight of lignocellulosic biomass may be 50 to 500 parts by weight. Specifically, 300 parts by weight of the metal salt modifier may be mixed with 100 parts by weight of lignocellulosic biomass.

Meanwhile, graphene-like carbon is produced when activated biomass is pyrolyzed in a temperature range of 700 to 900 °C.

As a specific example, in steps a and b, explaining the role of the hybrid metal salt modifier, first, in the activation step (step a), iron chloride (FeCl _-3 ) is converted into amorphous FeOOH by lignocellulosic biomass, for example, cellulose. It is converted to and then reduced to ferric tetroxide (Fe ₃ O ₄ ) by the carbon of cellulose. Next, in the thermal decomposition process (step b), ferric tetroxide (Fe ₃ O ₄ ) meets carbon atoms decomposed from cellulose at a temperature of 700°C or higher and is reduced to Fe.

Meanwhile, during the activation step (step a), zinc chloride (ZnCl- ₂ ) reacts with moisture and oxygen-containing substances in the biomass and is converted to zinc oxide (ZnO), and at 500 to 700°C, zinc oxide (ZnO) is converted into biomass. It is converted into Zn metal through a reduction reaction with carbon in the mass, and in the subsequent thermal decomposition process (step b), Zn metal is volatilized and removed from the medium at a temperature of 700°C or higher.

Meanwhile, after going through the above series of processes, the carbon atoms leaked out of the biomass are aggregated on the surface of the Fe template to form a two-dimensional carbon layer. Afterwards, the Fe template is washed and removed using hydrogen chloride (HCl) to produce a pseudo-graphene sheet.

According to one embodiment of the present invention, the pyrolysis step may be performed by carbonizing in a tubular ignition reactor for 0.5 to 1.5 hours under 200 mL/min nitrogen aeration, and specifically, in a tubular ignition reactor under 200 mL/min nitrogen aeration. This can be accomplished by carbonizing in a reactor for 1 hour.

Next, to remove impurities inside and on the surface of the pseudo-graphene produced after the carbonization, an additional process of washing and drying for more than 24 hours using 15 to 20% hydrogen chloride (HCl) and distilled water may be performed, through which iron , zinc and other impurities can be removed from pseudo-graphene. In detail, it can be washed with 16 to 18% hydrogen chloride (HCl) for more than 24 hours and then washed with distilled water three additional times.

Next, the prepared pseudo-graphene is mixed with an organic binder material to prepare a granular medium in the form of a porous foam (step c).

Since the pseudo-graphene produced by the above method is in the form of powder, there is a risk of loss when applied as is to remove organic contaminants in water. To solve this problem, it is manufactured in the form of a porous foam at this stage. .

The organic binder material used in this step may be, for example, 2% sodium alginate. Specifically, the above step can be performed by mixing and stirring pseudo-graphene and an organic binder material at a ratio of 0.5:99.5 parts by weight to 2:98 parts by weight, and the mixture obtained after performing mixing and stirring as described above is placed in an appropriate mold ( It can be placed in a mold, frozen at -20°C, and then freeze-dried for 48 to 96 hours. Meanwhile, the freeze-drying process may be performed for 72 hours.

Additionally, the freeze-dried mixture can be manufactured into a porous foam form by cross-linking in a 3% calcium chloride (CaCl ₂ ) solution. The porous foam-like graphene granular medium manufactured through the above-described process effectively solves the loss problem that occurs when used in powder form during water treatment applications, and has the advantage of being reusable as it is easy to recover after water treatment.

The pseudo-graphene granular medium manufactured through the above method may have a porous foam form and may have a Brunauer-Emmett-Teller (BET) specific surface area of 700 m ² /g or more. In addition, the pseudo-graphene granular medium is used to remove organic contaminants in water, and has an underwater dye adsorption performance of Rhodamine B in the range of 140.36 to 633.86 mg/g, or in the range of 106.06 to 220.67 mg/g. Congo Red may have underwater dye adsorption performance or may have water toluene adsorption performance in the range of 200 to 250 mg/g, specifically, water toluene adsorption performance of 247.00 mg/g.

In addition, the pseudo-graphene granular medium is a polycyclic aromatic material, as well as a coloring material, one or more hydrophobic organic substances selected from benzene, toluene, ethyl benzene, and xylene. It exhibits excellent underwater adsorption performance for contaminants, etc.

Adsorption and removal method of underwater organic polluted wastewater

The method for adsorption and removal of organic contaminants in water according to an embodiment of the present invention can be performed by adding the pseudo-graphene granular medium into contaminated water, adsorbing and removing organic contaminants in water, and the organic contaminants are It may be one or more hydrophobic organic pollutants selected from colorants, benzene, toluene, ethyl benzene, and xylene.

Example

Since the present invention can be subject to various changes and can take various forms, specific embodiments will be illustrated and described in detail below. However, this is not intended to limit the present invention to a specific disclosed form, and should be understood to include all changes, equivalents, and substitutes included in the spirit and technical scope of the present invention.

Examples 1-1 to 1-3: Preparation of pseudo-graphene

Prepare 10.0 g of cellulose, and add iron chloride (FeCl ₃ ) to it. 30.0 g of hybrid metal salt modifier prepared by mixing 20.0 g and 10.0 g of zinc chloride (ZnCl ₂ ) was mixed and then activated at a temperature of 80 to 100° C. for 24 hours. Next, the activated cellulose was placed in a tubular ignition reactor, the temperature was raised at a rate of 5°C/min under conditions where the temperature range was maintained at 700 to 900°C under 200 mL/min nitrogen ventilation, and carbonized for 1 hour to produce pseudo-graphene. (GLC) was manufactured, and the gas generated during the process was collected with a cooler. Next, to remove iron, zinc and other impurities remaining inside and on the surface of the pseudo-graphene, it was washed with 16 to 18% HCl for 24 hours, washed again with distilled water three times, and dried in a dry oven (performed) Example 1-1).

Meanwhile, pseudo-graphene was manufactured in the same manner using lignin instead of cellulose (Example 1-2), and pseudo-graphene was also manufactured in the same manner as above using waste wood containing both cellulose and lignin (Example 1-2). Example 1-3).

Comparative Example 1: Activated carbon in powder form

Activated carbon in powder form (Samchully Carbotech Co., Ltd., passing through 200 mesh) was prepared.

Comparative Example 2: Activated carbon in granule form

Activated carbon in granule form (Hanil Activated Carbon Co., Ltd., 4*8 mesh pass) was prepared.

[Experiment 1: Analysis of physical and chemical properties]

FT-IR analysis

FT-IR analysis was performed to analyze the surface functional groups of the pseudo-graphene (GLC) powder prepared according to Example 1-1, and the results are shown in FIG. 3. Referring to Figure 3, in the case of pseudo-graphene (GLC) powder prepared according to Example 1-1, it was confirmed that there were almost no oxygen-containing functional groups other than C=C bending around 1600 cm ^-1 .

RAMAN analysis

RAMAN analysis was performed to measure sp ² and sp ³ hybrid carbon on the surface of the graphene-like (GLC) powder prepared according to Example 1-1, and the results are shown in FIG. 4. Referring to Figure 4, the ratio (I _D /I _G ) of I _D and I _G , which is the peak intensity of sp ³ and sp ² hybrid carbon, was obtained as 0.64, which was obtained by reducing graphene oxide (GO). When compared to the I _D /I _G (>1) value of graphene (rGO), it was confirmed that the proportion of carbon with sp ² hybridization was higher.

XRD analysis

XRD analysis was performed to confirm the crystallinity of the graphene-like (GLC) powder prepared according to Example 1-1, and the results are shown in FIG. 5. Specifically, in the case of pseudo-graphene (GLC) obtained according to Example 1-1, XRD analysis was performed to confirm the crystallinity of the pseudo-graphene (GLC) powder prepared according to Example 1, and the results are shown in It is shown in 5. Specifically, in the case of pseudo-graphene (GLC) obtained according to Example 1-1, a strong peak was shown at 2θ = 26.5 ^o . This corresponds to the typical 2θ = 26 ^o found in the (002) plane of graphite carbon, supporting the creation of carbon with sp ² hybridization.

XPS analysis

XPS analysis was performed to confirm the crystallinity of the graphene-like (GLC) powder prepared according to Example 1-1, and the results are shown in Figures 6 and 7. As shown in Figure 6, in the case of GLC obtained by thermal decomposition in the presence of a hybrid metal salt modifier, the carbon (C) / oxygen (O) atomic ratio is 18.68, which is larger than the C / O atomic ratio of the general reduced graph (rGO). Meanwhile, in the case of GLC obtained by thermal decomposition in the presence of a hybrid metal salt modifier as shown in Figure 7, the C=C carbon with sp ² hybridization showed a peak at 284.6 eV, the CC carbon with sp ³ hybridization showed a peak at 285.4 eV, and the CO carbon peaked at 286.2 eV. . When comparing the peak intensities, it can be seen that the prepared GLC has a relatively large amount of C=C carbons with sp ² hybridization.

Example 2: Preparation of porous foam using pseudo-graphene

After preparing pseudo-graphene (GLC) prepared according to Example 1-1, GLC was mixed in a 2% sodium alginate solution at a ratio of 0.5 - 2% and placed in a mold with a width and length of 1 cm each. Added and frozen below -20℃. The freeze-dried sample was immersed in 3% calcium chloride (CaCl ₂ ) solution for 72 hours to induce a cross-linking reaction, and a foam-type adsorbent was completed.

Brunauer-Emmett-Teller to measure the specific surface area of GLC (Example 1-1, Example 1-2, Example 1-3) prepared by hybrid metal salt modifier and foam-type adsorbent prepared by the above method. (BET) measurements were conducted and the results are shown in Table 1.

Materials BET surface area (m ² /g) Example 1-1 Graphene-like carbon (GLC)_Cellulose 1799-2069 Example 1-2 Graphene-like carbon (GLC)_lignin 1716-1787 Example 1-3 Graphene-like carbon (GLC)_Waste wood 1769-2073 Example 2 Alginate-GLC foam 700

Meanwhile, in order to confirm the adsorption performance of the above-prepared examples for the underwater coloring materials, an underwater dye adsorption test was performed using Rhodamine B and Congo Red, and the results of calculating the maximum adsorption amount are shown in Table 2 below.

Materials Rhodamine B (mg/g) Congo Red (mg/g) Example 1-1 Graphene-like carbon (GLC)-cellulose 572.81 220.67 Example 1-2 Graphene-like carbon (GLC)-lignin 140.36 106.06 Example 1-3 Graphene-like carbon (GLC)-waste wood 633.86 141.28 Comparative Example 1 Commercial Powdered Activated Carbon (PAC) 36.49 30.60

Meanwhile, to confirm the toluene removal performance of the powder or foam type adsorbent prepared according to the example, a batch adsorption experiment was conducted using artificially contaminated water, and the results of calculating the maximum adsorption amount are shown in the table below. Same as 3.

Materials Toluene adsorption capacity (mg/g) Comparative Example 1
(Powder activated carbon (PAC)) 447.21 Comparative Example 2 (Granular activated carbon (GAC)) 222.26 Example 1-1 (Graphene-like carbon (GLC)) 1641.99 Example 2
(GLC-alginate-foam) 247.00

Referring to the results in Tables 2 and 3, it was confirmed that the pseudo-graphene according to the examples exhibited excellent adsorption performance for chromatic materials compared to powder carbon, and that the pseudo-graphene powder (Example 1-1) and foam It was confirmed that the adsorption performance for toluene in water of the form (Example 2) was 1641.99 mg/g and 247.00 mg/g, respectively, showing excellent toluene adsorption performance compared to Comparative Examples 1 and 2 in the same form. Accordingly, it was confirmed that pseudo-graphene according to the present invention has high applicability as an adsorption material for removing hydrophobic organic contaminants.

Although specific embodiments of the present invention have been described and shown above, it is known in the art that the present invention is not limited to the described embodiments, and that various modifications and changes can be made without departing from the spirit and scope of the present invention. This is self-evident to those who have it. Accordingly, such modifications or variations should not be understood individually from the technical idea or viewpoint of the present invention, and the modified embodiments should be regarded as falling within the scope of the claims of the present invention.

Claims (16)

a) chemically activating the biomass by adding a hybrid metal salts modifier to the lignocellulosic biomass;
b) producing graphene-like carbon by pyrolyzing the activated biomass in a temperature range of 700 to 900° C.; and
c) mixing the prepared graphene with an organic binder material to produce a granular medium in the form of a porous foam.
According to claim 1,
A method for producing a pseudo-graphene granular medium, wherein the lignocellulosic biomass in step a includes at least one selected from cellulose and lignin.
According to claim 1,
The hybrid metal salt modifier of step a includes iron chloride (FeCl ₃ ) and zinc chloride (ZnCl ₂ ). A method for producing a pseudo-graphene granular medium.
According to claim 1,
The chemical activation in step a is performed at a temperature ranging from 80 to 100° C. for 16 to 32 hours after mixing lignocellulosic biomass and a hybrid metal salt modifier.
According to claim 1,
The thermal decomposition in step b is carried out by carbonizing in a tubular ignition reactor for 0.5 to 1.5 hours under 200 mL/min nitrogen ventilation.
According to claim 5,
Preparation of a pseudo-graphene granular medium further comprising the step of washing and drying for more than 24 hours using 15 to 20% hydrogen chloride (HCl) to remove impurities inside and on the surface of the pseudo-graphene produced after carbonization in step b. method.
According to claim 1,
A method of producing a pseudo-graphene granular medium, wherein the organic binder material in step c is 2% sodium alginate.
According to claim 1,
Step c is a method of producing a pseudo-graphene granular medium, which is performed by mixing and stirring pseudo-graphene and an organic binder material at a ratio of 0.5:99.5 parts by weight to 4:96 parts by weight.
According to claim 8,
After the mixing and stirring, the method for producing a pseudo-graphene granular medium further includes the step of freezing the obtained mixture at -20° C. and then freeze-drying for 48 to 96 hours.
According to clause 9,
A method for producing a pseudo-graphene granular medium, further comprising the step of cross-linking the freeze-dried mixture in a 3% calcium chloride (CaCl ₂ ) solution to form a porous foam.
A pseudo-graphene granular medium manufactured according to the method of claim 1,
A BET specific surface area of the porous foam-like graphene granular medium is 700 m ² /g or more.
According to claim 11,
The pseudo-graphene granular medium is used to remove organic contaminants in water,
A pseudo-graphene granular medium with an underwater dye adsorption performance of Rhodamine B in the range of 140.36 to 633.86 mg/g.
According to claim 11,
The pseudo-graphene granular medium is used to remove organic contaminants in water,
A pseudo-graphene granular medium having Congo Red underwater dye adsorption performance in the range of 106.06 to 220.67 mg/g.
According to claim 11,
The pseudo-graphene granular medium is used to remove organic contaminants in water,
A pseudo-graphene granular medium having toluene adsorption performance in water in the range of 200 to 250 mg/g.
A method for adsorption and removal of organic pollutants in water, wherein the pseudo-graphene granular medium of claim 11 is added to contaminated water to adsorb and remove organic pollutants in water.
According to claim 15,
A method of adsorbing and removing organic pollutants in water, wherein the organic pollutant is one or more hydrophobic organic pollutants selected from color substances, benzene, toluene, ethyl benzene, and xylene.