TWI684566B - Method for preparing biomass carbon and method for preparing soil improver and biomass fuel using this method - Google Patents

Abstract

A method for preparing biomass carbon, including providing a biomass material; providing a plasma gas containing carbon dioxide, so that the plasma gas generates a carbon dioxide plasma at 300 to 500° C. and 1 atmosphere pressure, wherein the carbon dioxide accounts for the The volume percentage of plasma gas is 1 v/v% to 10 v/v %; and the biomass material is subjected to a thermal cracking reaction under the action of the carbon dioxide plasma for 15 to 60 seconds to form biomass carbon. The method for preparing biomass carbon of the present invention can effectively improve the processing efficiency of utilizing biomass materials, and can be applied to the use of soil improvement and biomass fuel.

Description

Biomass carbon preparation method and method for preparing soil improver and biomass Fuel method

The invention relates to a method for preparing biomass carbon, in particular to a method for preparing biomass carbon by using carbon dioxide plasma to treat biomass materials.

Biochar is a solid product obtained by heating and decomposing organic substances in an oxygen-deficient or low-oxygen environment, and has a porous structure. Therefore, biochar has excellent adsorption, not only can adsorb carbon dioxide and other greenhouses Gas can also improve the phenomenon of soil acidification and enhance the soil's ability to retain water. In addition, biomass carbon is an alkaline solid product left by the thermal decomposition of organic substances, so biomass carbon can also be used for soil modification. Biomass carbon can generally be produced by roasting reaction of organic wastes in the environment. For example, crop wastes such as coconut husks, waste rice husks, rice straws, peels, and pits can be used to convert organic wastes from crops. Using roasting method, the biomass carbon with utilization value is made again. In recent years, due to the widespread use of biomass carbon in environmental protection and agriculture, the production method of biomass carbon has also attracted public attention.

The traditional production method of biomass carbon is usually a method of roasting. The biomass raw materials, for example, the aforementioned organic wastes are placed in a closed and oxygen-deficient reaction furnace, and then the roasting reaction is performed at 200 to 500°C. In this roasting reaction process, the water content of the biomass raw material can be reduced, and solid biomass carbon can be produced and can be used as biomass fuel. gas. However, the traditional roasting reaction requires a long processing time, for example, 1 to 2 hours, so the yield is not easy to increase, and the roasting process requires a lot of heat energy.

Therefore, the industry generally needs a fast and energy-saving roasting process to improve the production efficiency of biomass carbon. .

According to the above description, the object of the present invention is to provide a method for preparing biomass carbon, which includes the following steps: providing a biomass material; providing a plasma gas containing carbon dioxide, such that the plasma gas is at 300°C to 500°C and 1 A carbon dioxide plasma is generated under atmospheric pressure, wherein the volume percentage of the carbon dioxide in the plasma gas is 1 v/v% to 10 v/v %; and the biomass material is subjected to thermal cracking reaction under the action of the carbon dioxide plasma 15 to 60 seconds to form primary carbon.

According to an embodiment of the present invention, wherein the plasma gas further includes one of helium or nitrogen.

According to an embodiment of the present invention, the method for generating the carbon dioxide plasma includes passing the plasma gas into a plasma torch system of a plasma heat treatment device to generate a carbon dioxide plasma torch.

According to an embodiment of the present invention, wherein the plasma heat treatment equipment is heated to 300° C. and the volume percentage of the carbon dioxide gas is 5 v/v %.

According to an embodiment of the present invention, wherein the thermal cracking reaction time is 30 seconds.

According to an embodiment of the present invention, it further comprises passing a steam to make the steam and a gas generated by thermal cracking of the biomass material undergo a thermal gasification cracking reaction.

According to an embodiment of the present invention, wherein the biomass material includes construction wood waste and peel waste.

According to an embodiment of the present invention, it further includes the step of crushing the biomass material first.

In addition, the present invention further provides a method for preparing a soil improver using the aforementioned biomass carbon preparation method, further comprising carbon dioxide in a volume percentage of plasma gas of 5 v/v %, and making the plasma gas at 300 ℃ and 1 atmosphere The carbon dioxide plasma is generated under the conditions; the biomass material is subjected to a thermal cracking reaction under the action of the carbon dioxide plasma for 30 seconds to form biomass carbon; and the biomass carbon is used as a soil improver.

Furthermore, the present invention provides a method for preparing biomass fuel using the aforementioned biomass carbon preparation method, further comprising carbon dioxide in a volume percentage of plasma gas of 5 v/v %, and making the plasma gas at 300 ℃ and 1 The carbon dioxide plasma is generated under atmospheric pressure; the biomass material is subjected to a thermal cracking reaction under the action of the carbon dioxide plasma for 30 seconds to form biomass carbon; and the biomass carbon is used as a biomass fuel.

In summary, the method for preparing biomass carbon of the present invention can effectively improve the processing efficiency of utilizing biomass materials, and can be applied to the use of soil improvement and biomass fuel.

100‧‧‧Plasma heat treatment equipment

10‧‧‧Plasma gas supply system

11‧‧‧He cylinder

12‧‧‧Carbon dioxide gas cylinder

20‧‧‧Power supply and cooling system

21‧‧‧Flow controller

22‧‧‧Temperature monitoring system

30‧‧‧Reactor

31‧‧‧Plasma Torch System

32‧‧‧Take the plate

33‧‧‧Exhaust flow meter

40‧‧‧Exhaust equipment

50‧‧‧ Distilled water equipment

1 is a flow chart of a method for preparing biomass carbon according to a preferred embodiment of the present invention; FIG. 2 is a schematic diagram of a plasma heat treatment apparatus according to a preferred embodiment of the present invention; Comparison chart of biomass carbon yield and calorific value of the method under different CO ₂ concentrations; FIG. 4 is an approximate analysis chart of biomass carbon composition under different CO ₂ concentrations of the biomass carbon preparation method of a preferred embodiment of the present invention; 5 is a comparison chart of biomass carbon yield and calorific value at different calcination times of the biomass carbon preparation method of the preferred embodiment of the present invention; and FIG. 6 is a calcination of the biomass carbon preparation method of the preferred embodiment of the invention at different calcinations Approximate analysis chart of biomass carbon composition under time.

In order to explain the present invention more clearly, a preferred embodiment is described in detail below with reference to the drawings. 1 and 2, FIG. 1 is a flowchart of a method for preparing biomass carbon according to a preferred embodiment of the present invention, and FIG. 2 is a plasma heat treatment device used in the method for preparing biomass carbon according to a preferred embodiment of the present invention. The method for preparing biomass carbon of the present invention includes the following steps:

Step S1: Provide a biomass material. In this embodiment, a biomass material 200 is placed in a plasma heat treatment apparatus 100. This biomass material 200 contains organic substances derived from organisms, such as wood and wood chips from construction industry waste, or agricultural wastes such as rice husks, rice straw, bagasse, or kitchen waste peels, pomace, etc. Or industrial organic waste such as waste paper. In this embodiment, the wood chips used for construction are crushed as the source of biomass material.

Step S2: providing a plasma gas containing carbon dioxide, so that the plasma gas generates a carbon dioxide plasma at 300°C to 500°C, wherein the volume percentage of carbon dioxide in the plasma gas is 1 v/v% to 10 v/v %. In this embodiment, the plasma gas containing carbon dioxide and helium is passed into a plasma heat treatment device 100, wherein the volume percentage of carbon dioxide in the overall plasma gas is 1 v/v% to 10 v/v%, The pressure in the plasma heat treatment apparatus 100 is 1 to 2 atm, and a voltage of 85 to 150 volts is provided to start the plasma heat treatment apparatus 100, and the temperature of the plasma heat treatment apparatus 100 is heated to 300°C to 500°C to generate carbon dioxide plasma .

Step S3: The biomass material is subjected to thermal cracking reaction under the action of carbon dioxide plasma for 15 to 60 seconds to form a biomass carbon. In this embodiment, the carbon dioxide plasma is passed through the plasma torch system (detailed below) included in the plasma heat treatment apparatus 100 into the reaction furnace (detailed below) in which the biomass material is placed, so that the carbon dioxide plasma and The biomass material undergoes a thermal cracking reaction for 15 to 60 seconds to generate biomass carbon.

The plasma heat treatment apparatus 100 may be a hot plasma, a cold plasma, a high frequency plasma, a flare plasma, a microwave plasma, a non-transmission plasma, or a transmission plasma. In this embodiment, the plasma heat treatment equipment 100 is a type of flare plasma, which includes a plasma gas supply system 10, a power supply and cooling system 20, a reactor 30, an exhaust device 40 and a distilled water device 50 , Its function will be described as follows: The plasma gas supply system 10 includes a helium gas bottle 11 and a carbon dioxide gas bottle 12 for supplying helium gas with a purity of 99.99% and carbon dioxide gas with a purity of 99.99% to the reaction furnace 30, respectively. The power supply and cooling system 20 is used to supply the voltage and current required by the reaction furnace 30 to generate plasma, and to provide cooling for the return line.

Among them, the power supply and cooling system 20 further includes a flow controller 21 and a temperature monitoring system 22, wherein the flow controller 21 is used to control the flow rate of the plasma gas flowing into the reactor 30 from the plasma gas supply system 10, and That is, it is used to control the gas flow of helium and carbon dioxide flowing into the reaction furnace 30; the temperature monitoring system 22 is used to monitor the temperature inside the reaction furnace 30. Although in this embodiment, the flow controller 21 and the temperature monitoring system 22 are provided in the power supply and cooling system 20, but in In other embodiments, the power supply and the cooling system 20 may be independently installed separately.

The reaction furnace 30 includes a plasma torch system 31, a receiving plate 32 and an exhaust gas flow meter 33 for performing the plasma thermal cracking reaction. The aforementioned plasma gas supply system 10 passes the supplied helium and carbon dioxide gas into the plasma torch system 31, so that the plasma gas can form a high-temperature carbon dioxide plasma torch by the voltage and heat energy supplied by the power supply system 20. And introduced into the reaction furnace 30. Biomass material 200, such as wood chips, is placed in the receiving tray 32 and undergoes a thermal cracking (roasting) reaction through a carbon dioxide plasma torch to form biomass carbon on the receiving tray 32. In addition, the exhaust gas flowmeter 33 is used to monitor the gas discharged from the reactor. The extraction equipment 40 is used to extract the reaction furnace 30. The distilled water device 50 is used to provide steam to the reaction furnace, and to provide the water vapor required for the recombination reaction after the biomass material is thermally cracked. Although the distilled water device 50 is provided in this embodiment to provide the water vapor required for the recombination reaction, in other embodiments, the distilled water device 50 may not be provided.

Several examples are provided below to illustrate the preparation method of the biomass carbon of the present invention.

In the following examples, the weight of the biomass material is 20 grams. The source is obtained from the purchased construction wood, such as pine material, and crushed to produce powder particles with a particle size of about 2 mm. Several examples are the roasting experiments of biomass materials under different gas concentrations, reaction temperatures and reaction times.

Example one

This example uses the method for preparing biomass carbon of the present invention to perform different CO ₂ concentrations (including volume percentages of 0 v/v%, 5 v/v%, and 10) at 300°C and 1 atmosphere of biomass carbon under the same conditions v/v%) roasting experiment, and control the contact time of the biomass material and the plasma torch to be fixed at 30sec, and then the biomass carbon yield and calorific value of each experimental group are listed in Figure 3. It can be seen from FIG. 3 that the biomass material of this example is at 300 ℃ and the reaction time is 30sec. When the concentration of CO ₂ is higher, the yield of the obtained product (that is, the yield of biomass carbon) will decrease. The unit calorific value (HHV, unit kcal/kg) will increase accordingly. In addition, please refer to Fig. 4, which shows an approximate analysis of the composition of the biomass carbon obtained by the aforementioned experimental groups. It can be seen from FIG. 4 that the higher the CO ₂ concentration, the higher the proportion of combustible components contained in the obtained product. According to the experimental results of this example, the decrease in product yield shows that carbon dioxide plasma can cause a rapid thermal cracking reaction on the surface of the biomass material and quickly remove impurities on the surface of the biomass material; an increase in the unit calorific value shows that the thermal cracking reaction can be removed The moisture on the surface of the biomass material increases the proportion of combustible components. Therefore, it is confirmed that carbon dioxide plasma is beneficial to the rapid processing of surface processing that is difficult for general organic waste to decompose, such as surface coating, epoxy resin waterproof layer, etc., to achieve the purpose of purifying biomass. The roasting treatment rate of the preparation method of the biomass carbon of the present invention is much higher than that of the traditional roasting treatment technology, which can effectively improve the processing efficiency of utilizing the biomass material. The biomass carbon product prepared according to the biomass carbon preparation method of the present invention can be applied to the use of biomass fuel, and can also be used as a soil improver, and the present invention is not limited thereto.

Example 2

This example uses the present invention to prepare the biomass carbon of the present invention under conditions of 300°C, 1 atm, and CO ₂ concentration fixed at a volume percentage of 5 v/v% for different times (15sec, 30sec, 45sec, and 60sec) calcination experiment, and then the biomass carbon yield and calorific value of each experimental group are listed in Figure 5. It can be seen from FIG. 5 that the biomass material of this example is under the conditions of 300° C. and the CO ₂ concentration is fixed at a volume percentage of 5 v/v%. When the biomass material is in contact with the carbon dioxide plasma flame for a longer time, the product produced The rate (i.e. the yield of biomass carbon) will decrease, and its unit heating value (HHV, unit kcal/kg) will increase accordingly. In addition, please refer to Fig. 6, which shows an approximate analysis of the composition of the biomass carbon obtained by the aforementioned experimental groups. It can be seen from FIG. 6 that as the reaction time increases, the proportion of combustible components contained in the obtained product is higher.

According to the experimental results of this example, when the reaction time is 30sec, the yield of biomass carbon is 83.77%, and its calorific value is 4664.71kcal/kg, and when the reaction time is 45sec, the yield of biomass carbon decreases to 66.68%. The experimental results show that when the reaction time is 30sec, the surface of the biomass material can be moderately roasted, and the surface impurities have been removed. When the reaction time is extended to 45sec, it will cause excessive components due to thermal cracking reaction. Decomposition reduces the yield of biomass carbon. Since biomass carbon is mainly used for the application of soil improvers, the surface structure characteristics of biomass carbon are mainly used. Therefore, when the method for preparing biomass carbon of the present invention is used for the preparation of soil improvers, the preferred reaction time is 30sec .

In addition, please refer to Table 3, which shows the results of analysis of the benefits and energy consumption of biomass carbon preparation using different roasting equipment. It can be seen from Table 3 that the biomass carbon roasting method of the present invention has the lowest energy-consuming output benefit under the same roasting conditions. This result confirms that the method of using carbon dioxide plasma roasting has the fastest reaction efficiency and high roasting efficiency. The biomass carbon output (output rate) per unit time can be increased by about 12.28 times compared with the traditional high-temperature roaster . In addition, please refer to Table 4, which shows the analysis results of the component elements of the biomass carbon obtained in the previous groups of experiments. It can be seen from the table that the oxygen/carbon ratio (O/C) of the biomass carbon prepared by the method for preparing biomass carbon of the present invention is much higher than that of the biomass carbon of the traditional roasting method, showing that the present invention The roasting efficiency of the qualitative carbon preparation method is higher than the traditional roasting method.

The above is only the preferred and feasible embodiments of the present invention, and any equivalent changes in applying the description of the present invention and the scope of patent application should be included in the patent scope of the present invention.

Claims (9)

A method for preparing biomass carbon, comprising: providing a biomass material; providing a plasma gas containing carbon dioxide, so that the plasma gas generates a carbon dioxide plasma at 300°C to 500°C and 1 atmosphere pressure, wherein the carbon dioxide accounts for The volume percentage of the plasma gas is 1 v/v% to 10 v/v%; and the biomass material is subjected to a thermal cracking reaction under the action of the carbon dioxide plasma for 30 seconds to form biomass carbon. The method for preparing biomass carbon according to claim 1, wherein the plasma gas further includes one of helium or nitrogen. The method for preparing biomass carbon according to claim 2, wherein the method for generating the carbon dioxide plasma includes passing the plasma gas into a plasma torch system of a plasma heat treatment device to generate a carbon dioxide plasma torch. The method for preparing biomass carbon according to claim 3, wherein the plasma heat treatment equipment is heated to 300°C and the volume percentage of the carbon dioxide gas is 5 v/v %. The method for preparing biomass carbon according to claim 2, further comprising: passing a steam to cause the steam to undergo a thermal gasification cracking reaction with a gas generated by thermal cracking of the biomass material. The method for preparing biomass carbon according to claim 1, wherein the biomass material includes construction wood waste and peel waste. The method for preparing biomass carbon according to claim 6 further includes the step of crushing the biomass material. A method for preparing a soil improver by using the method according to claim 1, further comprising: The volume percentage of the carbon dioxide to the plasma gas is 5 v/v %, and the plasma gas is generated at 300° C. and 1 atm to produce the carbon dioxide plasma; the biomass material is heated under the action of the carbon dioxide plasma Cracking reaction for 30 seconds to form the biomass carbon; and using the biomass carbon as a soil improver. A method for preparing biomass fuel using the method according to claim 1, further comprising: the volume percentage of the carbon dioxide to the plasma gas is 5 v/v %, and the plasma gas is generated at 300°C and 1 atmosphere pressure The carbon dioxide plasma; subjecting the biomass material to thermal cracking reaction under the action of the carbon dioxide plasma for 30 seconds to form the biomass carbon; and using the biomass carbon as a biomass fuel.

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