KR20230123308A - Method for determining engineered biochar manufacturing conditions according to types of biomass to improve yield and adsorption performance of manufactured engineered biochar - Google Patents

Abstract

The present invention is a method for determining functional biochar manufacturing conditions according to the type of biomass to improve the yield and adsorption performance of functional biochar produced: (a) biomass used as a raw material is subjected to nitrogen and carbon dioxide atmosphere Conducting thermogravimetric analysis, respectively; (b) comparing the thermogravimetric analysis result in a nitrogen atmosphere with the thermogravimetric analysis result in a carbon dioxide atmosphere; (c) deriving a temperature at which weight loss due to carbon dioxide is obtained from a comparison result of a thermogravimetric analysis result in a nitrogen atmosphere and a thermogravimetric analysis result in a carbon dioxide atmosphere; and (d) determining, as the thermal decomposition temperature of the biomass, a temperature lower than the temperature at which c is reduced by carbon dioxide.

Description

Method for determining functional biochar manufacturing conditions according to the type of biomass to improve the yield and adsorption performance of manufactured functional biochar ENGINEERED BIOCHAR}

The present invention relates to a method for determining production conditions for functional biochar according to the type of biomass to improve the yield and adsorption performance of the functional biochar produced.

Fossil fuels have been used as the main energy source in modern society because they have high energy density and can be produced in large quantities.

Fossil fuel consumption increased 1.5 times from 8,050 Mtoe (million ton of oil equivalent) in 2000 to 11,739 Mtoe in 2018.

The increasing use of fossil fuels has increased the concentration of carbon dioxide in the atmosphere, exceeding the amount of carbon currently acceptable in nature. As a result, serious social and environmental problems such as global warming have been caused.

In order to solve the problem of global warming, countries and companies around the world are declaring carbon neutrality or carrying out activities such as the RE100 (Renewable Energy 100) campaign.

In order to technically solve the problem of global warming, research on carbon capture & storage (CCS) technology or carbon capture & utilization (CCU) technology, which can prevent carbon accumulation in the atmosphere, is being conducted. It is becoming.

However, CCS technology or CCU technology is pointed out as a limitation of field application in that it requires a lot of cost, and accordingly, an economical and effective method to solve global warming is required.

Interest in biochar is increasing as a way to replace CCS technology or CCU technology.

Biochar is produced by pyrolyzing biomass under anoxic conditions using an inert gas (nitrogen, argon, etc.).

During the pyrolysis process, biomass is carbonized, and the biochar thus produced has high physicochemical stability.

That is, biochar has high resistance to biodegradation, and can fix and store carbon for a long period of time in a natural environment.

In this respect, biochar has the advantage of being usable as a strategic alternative material for carbon capture and storage (CCS).

Biomass used in the manufacture of biochar is a composite composed of hemicellulose, cellulose, lignin, etc., and there are various types such as, for example, lignocellulosic biomass (wood sawdust, etc.), microalgae, and livestock manure.

Even in the same type of biomass, the composition of hemicellulose, cellulose, lignin, etc. constituting the biomass may vary depending on the growth environment of the organism that is the parent of the biomass.

In this way, when the composition of hemicellulose, cellulose, lignin, etc. constituting biomass is different, manufacturing conditions for producing biochar, in particular, appropriate thermal decomposition temperature may be different.

Therefore, there is a need for a method capable of determining manufacturing conditions (eg, pyrolysis temperature) of biomass suitable for manufacturing biochar before manufacturing biochar.

Republic of Korea Patent No. 10-2203466

One object of the present invention is to provide a method for determining biomass production conditions to improve the yield and pore performance of functional biochar in a method for producing functional biochar using biomass.

Meanwhile, other unspecified objects of the present invention will be additionally considered within the scope that can be easily inferred from the following detailed description and effects thereof.

In order to solve the problems described above, the following solutions are proposed.

The method for determining the production conditions for functional biochar according to an embodiment of the present invention is to improve the yield and adsorption performance of the functional biochar to be produced. Conducting thermogravimetric analysis, respectively; (b) comparing the thermogravimetric analysis result in a nitrogen atmosphere with the thermogravimetric analysis result in a carbon dioxide atmosphere; (c) deriving a temperature at which weight loss due to carbon dioxide is obtained from a comparison result of a thermogravimetric analysis result in a nitrogen atmosphere and a thermogravimetric analysis result in a carbon dioxide atmosphere; and (d) determining, as the thermal decomposition temperature of the biomass, a temperature lower than the temperature at which the reduction in C by carbon dioxide occurs.

In one embodiment, it may be characterized in that the temperature at which the reduction of ?c by carbon dioxide occurs in step (d) is the temperature at which the Boudouard reaction starts.

In one embodiment, the thermal decomposition temperature may be characterized in that it indicates a temperature 10 to 40 degrees lower than the temperature at which the middle ?c reduction by carbon dioxide appears.

A method for producing functional biochar according to another embodiment of the present invention includes the steps of (a) preparing a first biomass and a second biomass identical to each other; (b) determining a thermal decomposition temperature for producing functional biochar using the first biomass to improve the yield and adsorption performance of the functional biochar produced; and (c) preparing a functional biochar by thermally decomposing the second biomass in a carbon dioxide atmosphere and at the determined thermal decomposition temperature.

In another embodiment, step (b) may include (a) thermogravimetric analysis of the first biomass in a nitrogen atmosphere and a carbon dioxide atmosphere, respectively; (b) comparing the thermogravimetric analysis result in a nitrogen atmosphere with the thermogravimetric analysis result in a carbon dioxide atmosphere; (c) deriving a temperature at which weight loss due to carbon dioxide is obtained from a comparison result of a thermogravimetric analysis result in a nitrogen atmosphere and a thermogravimetric analysis result in a carbon dioxide atmosphere; and (d) determining, as the thermal decomposition temperature of the second biomass, a temperature lower than the temperature at which the reduction in C by carbon dioxide occurs.

In another embodiment, in step (d), the temperature at which the reduction of ?c by carbon dioxide occurs may be a temperature at which a Boudouard reaction starts.

In another embodiment, the thermal decomposition temperature may be characterized in that it indicates a temperature 10 to 40 degrees lower than the temperature at which the middle ?c reduction by carbon dioxide occurs.

A method for determining functional biochar manufacturing conditions according to the type of biomass to improve the yield and adsorption performance of functional biochar produced according to an embodiment of the present invention is to change the biomass used as a raw material in a nitrogen atmosphere and a carbon dioxide atmosphere The thermogravimetric analysis was performed in each, and the thermogravimetric analysis result in a nitrogen atmosphere and the thermogravimetric analysis result in a carbon dioxide atmosphere were compared to derive the temperature at which the weight loss due to carbon dioxide appeared, and the temperature at which the weight loss due to carbon dioxide appeared. The slightly lower temperature is determined as the pyrolysis temperature of the biomass in question.

The surface area of the functional biochar can be improved while maintaining the yield of the functional biochar produced by thermally decomposing the biomass in the pyrolysis temperature and carbon dioxide atmosphere of the biomass determined in the above step at a high level.

It is added that even if the effects are not explicitly mentioned here, the effects described in the following specification expected by the technical features of the present invention and their provisional effects are treated as described in the specification of the present invention.

1 is a schematic flow chart of a method for manufacturing functional biochar according to an embodiment of the present invention.
2 is a schematic flowchart showing in detail the step of determining the manufacturing conditions for biochar in the method for manufacturing functional biochar according to an embodiment of the present invention.
3 is a graph showing the results of thermogravimetric analysis of biomass (pine sawdust) in a nitrogen atmosphere and a carbon dioxide atmosphere, respectively.
Figure 4 shows the thermogravimetric curve of biomass (pine sawdust) maintained isothermally for 1 hour after reaching (a) 700 ° C and (b) 800 ° C through temperature elevation (10 ° C / min) in a nitrogen atmosphere and a carbon dioxide atmosphere. it did
5 (a) and 5 (b) are the results of isothermal nitrogen adsorption/desorption analysis according to the BET method to confirm the surface characteristics of biochar produced at 700 ° C and 800 ° C.
6 is the result of the carbon dioxide adsorption experiment to evaluate the applicability to the environmental field according to the surface modification of biochar using carbon dioxide. This is the result.
7 shows the results of thermogravimetric analysis of biomass (lignocellulosic biomass (12 species), microalgae (3 species), and livestock manure (3 species)) in a nitrogen atmosphere and a carbon dioxide atmosphere, respectively. .
It is revealed that the accompanying drawings are illustrated as references for understanding the technical idea of the present invention, and thereby the scope of the present invention is not limited thereto.

Hereinafter, with reference to the drawings, look at the configuration of the present invention guided by various embodiments of the present invention and the effects resulting from the configuration. In the description of the present invention, if it is determined that a related known function may unnecessarily obscure the subject matter of the present invention as an obvious matter to those skilled in the art, the detailed description thereof will be omitted.

Biochar is a porous material and can be used in various environmental fields such as soil conditioners, adsorbents, and catalysts.

Biochar is produced by thermal decomposition of biomass such as wood sawdust, seaweed and livestock manure in an inert gas atmosphere (nitrogen, argon, etc.).

The surface properties of biochar are affected by pyrolysis operating conditions such as temperature, heating rate, and reaction medium.

In order to manufacture functional biochar with improved surface properties of biochar, various studies on physical and chemical activation methods are being conducted.

In order to manufacture biochar using biomass, thermal decomposition must be performed at a very high temperature.

In particular, when thermal decomposition is performed in a carbon dioxide atmosphere, the pore structure of biochar can be developed, but there is a problem in that the yield of biochar is significantly reduced.

Therefore, it is very important to determine the thermal decomposition conditions that can develop the pore structure of biochar and at the same time increase the yield of biochar.

However, there are many types of biomass used as a raw material for manufacturing biochar, and different types of biomass have different compositions of hemicellulose, cellulose, and lignin, which constitute biomass, and because of the different composition, the pore structure of biochar The thermal decomposition conditions that can simultaneously increase the development of biomass and increase the yield are different for each biomass.

Even in the same biomass, the composition of hemicellulose, cellulose, lignin, etc. constituting the biomass may be different depending on the growth environment of the organism that is the parent of the biomass.

Therefore, in order to simultaneously increase the development of the pore structure of biochar and the increase in yield, it is necessary to check the thermal decomposition conditions whenever the raw material is changed.

However, deriving optimal pyrolysis conditions by pyrolysis of biomass by pyrolysis temperature and checking yield and pores is wasteful of unnecessary time and cost.

Accordingly, the present invention proposes a method capable of deriving appropriate thermal decomposition conditions of biomass in order to simultaneously increase the development of the pore structure of biochar and the increase in yield.

1 is a schematic flow chart of a method for manufacturing functional biochar (M100) according to an embodiment of the present invention, and FIG. 2 is a biochar manufacturing condition determination step in the method for manufacturing functional biochar according to an embodiment of the present invention. It is a schematic flowchart showing in more detail.

The method for manufacturing functional biochar (M100) according to an embodiment of the present invention includes preparing a first biomass and a second biomass that are identical to each other (S10), and improving the yield and adsorption performance of the functional biochar produced. The step of determining the thermal decomposition temperature for producing functional biochar using the first biomass (S20), and the step of thermally decomposing the second biomass in a carbon dioxide atmosphere and the determined thermal decomposition temperature to produce functional biochar (S30) include

The step of preparing the first biomass and the second biomass (S10) is performed by selecting raw materials to be used as the first biomass and second biomass, and drying and grinding the selected raw materials.

Next, a step (S20) of determining a pyrolysis temperature for producing functional biochar using the first biomass is performed. In this step, the pyrolysis temperatures of the first biomass and the second biomass that can simultaneously achieve high yield and high adsorption performance of the functional biochar produced are derived.

In the step of determining the pyrolysis temperature for producing functional biochar using the first biomass (S20), the biomass (eg, the first biomass) to be used as a raw material is subjected to thermogravimetry in a nitrogen atmosphere and a carbon dioxide atmosphere, respectively. Analyzing (S21), comparing the thermogravimetric analysis result in a nitrogen atmosphere with the thermogravimetric analysis result in a carbon dioxide atmosphere (S22), comparing the thermogravimetric analysis result in a nitrogen atmosphere with the thermogravimetric analysis result in a carbon dioxide atmosphere Deriving the temperature at which weight loss by carbon dioxide appears from the comparison result (S23) and determining a temperature lower than the temperature at which weight loss by carbon dioxide appears as the pyrolysis temperature of the biomass (S24) do.

Thermogravimetric analysis of the biomass (for example, the first biomass) to be used as a raw material in a nitrogen atmosphere and a carbon dioxide atmosphere, respectively (S21) is performed by raising the temperature of the biomass to a certain temperature in a nitrogen atmosphere and a carbon dioxide atmosphere (for example, , 1 ~ 10 ℃/min) to raise the temperature to 900 ℃.

By performing thermogravimetric analysis, the residual mass of the biomass can be measured as the temperature increases, thereby confirming the composition of the biomass.

After performing thermogravimetric analysis, comparing the thermogravimetric analysis result in nitrogen atmosphere with the thermogravimetric analysis result in carbon dioxide atmosphere (S22), and the thermogravimetric analysis result in nitrogen atmosphere and the thermogravimetric analysis result in carbon dioxide atmosphere A step (S23) of deriving the temperature at which weight loss by carbon dioxide appears from the comparison result of is performed.

Comparing the results of thermogravimetric analysis in a nitrogen atmosphere with the results of thermogravimetric analysis in a carbon dioxide atmosphere show similar tendencies up to a certain temperature.

However, in a nitrogen atmosphere, the thermogravimetric curve is maintained at a high temperature, but in a carbon dioxide atmosphere, the thermogravimetric curve tends to decrease again at a high temperature.

That is, unlike nitrogen, carbon dioxide causes weight loss in the thermogravimetric analysis result.

The temperature at which the trend of the thermogravimetric curve in the nitrogen atmosphere and the trend of the thermogravimetric curve in the carbon dioxide atmosphere are different is the temperature at which the Boudouard reaction starts. will decrease

The Buda reaction thermodynamically starts around 710 degrees. However, the starting temperature of the Buddha reaction depends on the composition and content of inorganic substances such as alkali metals/earth metals and transition metals as well as the crystallinity and aromaticity of organic substances according to the composition of hemicellulose, cellulose, and lignin constituting biomass. may vary.

After determining the temperature at which the trend of the thermogravimetric curve in the nitrogen atmosphere and the trend of the thermogravimetric curve in the carbon dioxide atmosphere are different, a temperature lower than the temperature at which the mid-c reduction by carbon dioxide appears is determined by biomass (eg, the second A step (S24) of determining the pyrolysis temperature of the biomass) is performed.

The thermal decomposition temperature may be determined at a temperature 10 to 30 degrees lower than the temperature at which the reduction of C by carbon dioxide occurs, preferably 15 to 25 degrees.

After determining the pyrolysis temperature using the first biomass, a step (S30) of preparing a functional biochar by pyrolysis of the second biomass in a carbon dioxide atmosphere and the determined pyrolysis temperature is performed.

After introducing the second biomass into the pyrolysis chamber, injecting carbon dioxide to create a carbon dioxide atmosphere, isothermal pyrolysis is performed for 30 minutes to 2 hours at the pyrolysis temperature determined using the first biomass to prepare a functional biochar.

Example

Pine sawdust was prepared as biomass. The prepared pine sawdust was dried and pulverized and divided into first biomass and second biomass, respectively.

Thermogravimetric analysis was performed on the first biomass in a nitrogen atmosphere and a carbon dioxide atmosphere. Thermogravimetric analysis was performed in a nitrogen atmosphere and a carbon dioxide atmosphere, and the weight loss according to the temperature was measured by raising the temperature to 900 ℃ at 10 ℃ / min. The thermogravimetric analysis results are shown in FIG. 3 .

As shown in FIG. 3, it was possible to determine the composition of the raw material by measuring the residual mass of biomass (pine sawdust) according to the temperature increase through thermogravimetric analysis. In the case of pine sawdust, it can be confirmed that the thermal weight reduction by the Boudouard reaction occurs distinctly in a carbon dioxide atmosphere at 720 ° C. On the other hand, at temperatures before 720 °C, the same weight loss tendency was shown in nitrogen and carbon dioxide atmospheres. That is, at a temperature before 720 ° C, the reaction between carbon dioxide and biochar was not made.

The temperature at which the weight loss by carbon dioxide of the pine sawdust used in this experiment was determined to be 720 ° C, and accordingly, the thermal decomposition temperature for producing functional biochar using pine sawdust was determined to be 700 ° C, which is 20 ° C lower than 720 ° C. .

In order to confirm that the functional biochar produced when pyrolysis is performed at the determined pyrolysis temperature has a high yield and a developed pore structure, biochar was heated at 700 ° C, which is the determined pyrolysis temperature, and 800 ° C, which is higher than the temperature at which weight loss by carbon dioxide appears. was manufactured. The gas atmosphere was performed in a nitrogen atmosphere and a carbon dioxide atmosphere, respectively. The results are shown in FIG. 4 .

After thermal decomposition at 700 °C for 1 hour in a nitrogen atmosphere and a carbon dioxide atmosphere, the remaining biocar amounts were 19.7 wt.% and 18.8 wt.%, respectively, almost the same.

The production yields of biochar produced by thermal decomposition at 800 °C for 1 hour in a nitrogen atmosphere and a carbon dioxide atmosphere were 19.5 wt.% and 4.9 wt.%, respectively.

At 800 ° C, the carbon dioxide atmosphere showed a weight loss of 14.6 wt.% compared to the nitrogen atmosphere, which is due to the effect of carbon dioxide.

5 (a) and 5 (b) are the results of isothermal nitrogen adsorption/desorption analysis according to the BET method to confirm the surface characteristics of biochar produced at 700 ° C and 800 ° C.

Referring to FIG. 5, the nitrogen adsorption/desorption isotherm curves of biochar made at 700 ° C and 800 ° C correspond to type I of the pore type classification method defined by the International Union of Pure and Applied Chemistry (IUPAC), which is mainly due to the biochar produced. It means that it has micropores (≤2 nm).

In particular, it can be seen that there are more micropores in biochar by looking at a higher amount of nitrogen adsorption at a relative pressure (P/P ₀ ) of 0 under carbon dioxide conditions.

The specific surface area of biochar prepared in a carbon dioxide atmosphere and 700 ° C was increased by about 1.3 times compared to the nitrogen condition, and the increase in the specific surface area by carbon dioxide is a result of the gaseous reaction between carbon dioxide and volatile compounds.

Considering that volatile compounds generated in the biochar production process contribute to the formation of the surface of biochar, the pyrolysis process at 700°C and carbon dioxide causes a gas-phase reaction between volatile compounds and carbon dioxide to decompose volatile compounds, It can be seen that the specific surface area was increased by affecting the formation of the tea surface.

The specific surface area of biochar prepared at 800 ° C increased by about 1.7 times under carbon dioxide conditions compared to nitrogen conditions, which is a result of the Boudouard reaction.

Comparing the surface characteristics of biochar produced at 700℃ and 800℃, it can be seen that the total pore volume increased under nitrogen versus carbon dioxide conditions, while the average pore diameter decreased. It can be seen that the specific surface area increased due to the development of micropores on the surface.

However, as described above, the yield of biochar produced at 800 ° C and a carbon dioxide atmosphere is about 13.9 wt% lower than the yield of biochar produced at 700 ° C and a carbon dioxide atmosphere.

6 is the result of the carbon dioxide adsorption experiment to evaluate the applicability to the environmental field according to the surface modification of biochar using carbon dioxide. This is the result.

Referring to FIG. 6, as a result of analysis of carbon dioxide adsorption by condition, more carbon dioxide was adsorbed in the biochar made under nitrogen versus carbon dioxide conditions, and the carbon dioxide adsorption capacity of the biochar increased as the pyrolysis temperature increased under the carbon dioxide condition.

The carbon dioxide adsorption capacity showed a similar trend to the specific surface area of biochar, and it was confirmed that the change in the surface properties of biochar by carbon dioxide contributed to the improvement of the carbon dioxide adsorption capacity.

To evaluate the biochar manufacturing process, Table 1 shows the results per unit weight of biomass (pine sawdust) converted by considering the biochar production yield of the specific surface area and carbon dioxide adsorption amount of the produced biochar.

Feedstock Biochar
production
condition Yield,
[wt.%] per unit gram of biochar per unit gram of feedstock specific surface area,
[m ² /g _biochar ] CO ₂ absorption capacity,
[mmol/g _biochar ] specific surface area,
[m ² /g _feedstock ] CO ₂ absorption capacity,
[mmol/g _feedstock ] Pine sawdust at 700℃
for 1 hour
in N ₂ 19.7 424.3 1.48 83.5 0.29 Pine sawdust at 700℃for 1h
in CO ₂ 18.8 548.8 1.61 103.2 0.3 Pine sawdust at 800℃for 1h
in N ₂ 19.5 440.4 1.51 85.8 0.29 Pine sawdust at 800℃
for 1 hour
in CO ₂ 4.9 737.2 1.81 36.1 0.09

Comprehensively evaluating the produced biochar with reference to Table 1, it can be confirmed that the specific surface area increases and the adsorption capacity of carbon dioxide improves as the temperature increases under the carbon dioxide condition.

However, when looking at the amount of biochar produced per unit weight of biomass (pine sawdust), it can be seen that the amount of biochar produced under carbon dioxide conditions decreases compared to nitrogen conditions. It can be seen that it is significantly reduced to 1/4 level compared to the car.

If the yield decreases, the amount of energy and biomass input to produce the same amount of biochar increases, which is disadvantageous in securing price competitiveness of the produced biochar.

Therefore, considering the yield of produced biochar, the specific surface area and carbon dioxide adsorption amount of biochar produced in relation to the amount of biomass input were converted.

As a result, the biochar made at 700 ° C, which was derived by determining the temperature lower than 720 ° C, which is the temperature for weight loss by carbon dioxide, as the pyrolysis temperature, showed the highest specific surface area and carbon dioxide adsorption per unit weight of biomass (pine sawdust) introduced. Confirmed.

This is a 2.9-fold increase in specific surface area and a 3.3-fold increase in carbon dioxide adsorption capacity compared to biochar produced in a carbon dioxide atmosphere at 800 °C.

Referring to FIG. 7, the results of thermogravimetric analysis performed in a nitrogen and carbon dioxide atmosphere for various biomass (lignocellulosic biomass, microalgae, livestock manure, etc.) along with pine sawdust are shown, and the Buda reaction start temperature is confirmed. By doing so, it is possible to determine the temperature for producing functional biochar using carbon dioxide.

Feedstock Temperature exhibiting
Boudouard reaction, [?C] 1. Lignocellulosic Biomass Pine sawdust 720 Oak wood 670 Rice straw 740 Dead leaves 670 Galic stem 660 Maize residue 700 Grass 670 Moss 670 Peatmoss 700 Cellulose - Xylan - Lignin 720 2. Microalgae Microcystis aeruginosa 820 Chlorella vulgaris 840 Arthrospira platensis 780 3. Animal Manure Cattle manure 700 Swine manure 745 Chicken manure 710

Referring to Table 2, it can be confirmed that the Buddha reaction start temperature is different for each biomass, and it can be confirmed that the Buddha reaction start temperature cannot be specified for some biomass. That is, by using the present invention, an appropriate pyrolysis temperature of each biomass can be derived without trial and error.

The protection scope of the present invention is not limited to the description and expression of the embodiments explicitly described above. In addition, it is added once again that the scope of protection of the present invention cannot be limited due to obvious changes or substitutions in the technical field to which the present invention belongs.

Claims (7)

As a method for determining functional biochar manufacturing conditions according to the type of biomass to improve the yield and adsorption performance of the functional biochar produced:
(a) thermogravimetric analysis of biomass to be used as a raw material in a nitrogen atmosphere and a carbon dioxide atmosphere, respectively;
(b) comparing the thermogravimetric analysis result in a nitrogen atmosphere with the thermogravimetric analysis result in a carbon dioxide atmosphere;
(c) deriving a temperature at which weight loss due to carbon dioxide is obtained from a comparison result of a thermogravimetric analysis result in a nitrogen atmosphere and a thermogravimetric analysis result in a carbon dioxide atmosphere; and
(d) determining a temperature lower than the temperature at which the reduction of C by carbon dioxide appears as the thermal decomposition temperature of the biomass; characterized in that it comprises,
A method for determining conditions for producing functional biochar.
According to claim 1,
Characterized in that, in step (d), the temperature at which the reduction of carbon dioxide by carbon dioxide occurs is the temperature at which the Boudouard reaction starts.
A method for determining conditions for producing functional biochar.
According to claim 1,
The thermal decomposition temperature is characterized in that it indicates a temperature 10 to 40 degrees lower than the temperature at which the reduction of carbon dioxide by carbon dioxide occurs.
A method for determining conditions for producing functional biochar.
As a method for producing functional biochar using biomass:
(a) preparing a first biomass and a second biomass identical to each other;
(b) determining a thermal decomposition temperature for producing functional biochar using the first biomass to improve the yield and adsorption performance of the functional biochar produced; and
(c) preparing a functional biochar by thermally decomposing the second biomass in a carbon dioxide atmosphere and the determined thermal decomposition temperature; a method for producing functional biochar, comprising:
According to claim 4,
In step (b),
(a) thermogravimetric analysis of the first biomass in a nitrogen atmosphere and a carbon dioxide atmosphere, respectively;
(b) comparing the thermogravimetric analysis result in a nitrogen atmosphere with the thermogravimetric analysis result in a carbon dioxide atmosphere;
(c) deriving a temperature at which weight loss due to carbon dioxide is obtained from a comparison result of a thermogravimetric analysis result in a nitrogen atmosphere and a thermogravimetric analysis result in a carbon dioxide atmosphere; and
(d) determining a temperature lower than the temperature at which the reduction of C by carbon dioxide appears as the thermal decomposition temperature of the second biomass; characterized in that it comprises,
Manufacturing method of functional biochar
According to claim 5,
Characterized in that, in step (d), the temperature at which the reduction of carbon dioxide by carbon dioxide occurs is the temperature at which the Boudouard reaction starts.
Manufacturing method of functional biochar.
According to claim 5,
The thermal decomposition temperature is characterized in that it indicates a temperature 10 to 40 degrees lower than the temperature at which the reduction of carbon dioxide by carbon dioxide occurs.
Manufacturing method of functional biochar.