A method and device for improving the yield of carbon materials

Abstract

The present invention discloses a device for improving the yield of carbon materials, which includes a first reaction device, a first condenser connection, a second reaction device, and a second condenser; the first reaction device includes a first reactor and a first heating device, and the top of the first reactor is hermetically connected to the first condenser; the second reaction device includes a second reactor and a second heating device, and the inner tube of the first condenser is hermetically connected to the second reactor; the top of the second reactor is hermetically connected to the second condenser; the top of the inner tube of the second condenser is respectively provided with a first protective gas inlet and an exhaust port. The present invention also discloses a method for preparing carbon materials by slow pyrolysis using this device. The device of the present invention can enable bio-oil with a relatively low boiling point to in-situ polymerize on the surface of biomass char, greatly improving the yield and carbon content of biomass carbon materials. The device is simple, easy and safe to operate, suitable for large-scale production, and capable of being applied industrially.

Description

Technical Field

[0001] The present invention relates to the technical field of biomass pyrolysis, and particularly to a method and a device for improving the yield of carbon materials. Background Art

[0002] Biomass is currently the only sustainable carbon resource. China has a huge biomass energy reserve with great development potential, but the current utilization rate is still very low. Therefore, realizing the conversion of biomass pyrolysis into high-yield carbon materials is of great significance for improving the utilization rate of biomass. Biomass contains rich cellulose, hemicellulose, lignin and other aromatic high-molecular polymers. The pyrolysis process of biomass can be divided into three stages: the volatilization of free water, the evolution of volatile components (bio-oil and gas), and deep pyrolysis. The process is relatively complex and can be regarded as a process of continuous breaking and recombination of chemical bonds in biomass. Taking lignin as an example, in the initial stage of pyrolysis, the functional groups on the side chains of the aromatic rings in lignin break, generating aliphatic substances, which are collected after cooling (i.e., bio-oil). As the pyrolysis intensifies (temperature rises), the relatively stable benzene rings also break, so that the macromolecular structure degrades into small molecules and further recombines. Macroscopically, biomass such as lignin can form a structure with a spherical or hemispherical micro-morphology and a large number of pores on the surface after pyrolysis.

[0003] People can obtain carbon materials in the natural form of biomass precursors through this pyrolysis process. Its application fields are relatively wide, and it can be used in electrocatalysis, batteries, industrial catalysis and other fields. It can also be used to fertilize the land to increase yields and can reduce carbon emissions by 21%, and can be used as activated carbon to adsorb precious metals or antibiotics, etc. Therefore, preparing biochar can not only turn waste into treasure but also reduce human carbon emissions. The pyrolysis of biomass is divided into fast pyrolysis and slow pyrolysis according to the heating rate. Slow pyrolysis takes a long time and the char residue rate is not high. In industry, the carbon yield prepared by slow pyrolysis does not exceed 30% because the liquids (bio-oil) and gases with lower boiling points generated during the pyrolysis process cannot be completely fixed in the solid biochar; while fast pyrolysis takes less time but has a lower carbon yield, and the general coke yield is about 20% because the volatile components generated by pyrolysis do not react sufficiently with the biomass coke. The existing technical means limit the improvement of the yield of carbon materials and also prevent people from making full use of all the carbon elements in biomass. The existing biochar is generally obtained as a by-product of bio-oil preparation. Improving the yield of biochar can not only expand the application of biochar but also reduce carbon emissions. Therefore, a device for improving the carbon material yield is needed to prepare biochar by using this device to improve the carbon material yield. Summary of the Invention

[0004] In view of the above-mentioned prior art, the object of the present invention is to provide a method and a device for improving the yield of carbon materials. The device of the present invention can enable bio-oil with a relatively low boiling point to in-situ polymerize on the surface of biomass char, greatly improving the yield and carbon content of biomass carbon materials, and the operation is safe and simple, being suitable for industrial application.

[0005] To achieve the above object, the present invention adopts the following technical solutions:

[0006] In the first aspect of the present invention, there is provided a device for improving the yield of carbon materials, including a first reaction device, the first reaction device is connected to a first condenser, a second reaction device is provided above the first condenser, and the second reaction device is connected to a second condenser; the first reaction device includes a first reactor, a first heating device is provided outside the first reactor, and the top of the first reactor is hermetically connected to the first condenser; the second reaction device includes a second reactor, a second heating device is provided outside the second reactor, and the inner tube of the first condenser is hermetically connected to the second reactor; the top of the second reactor is hermetically connected to the second condenser; a first protective gas inlet and an exhaust port are respectively provided at the top of the inner tube of the second condenser.

[0007] Preferably, heat-insulating cotton is filled between the first reactor and the first heating device; heat-insulating cotton is filled between the second reactor and the second heating device.

[0008] Preferably, a second protective gas inlet is provided between the inner tube of the first condenser and the second reactor.

[0009] Preferably, a first coolant outlet is provided at the upper part of the first condenser, and a first coolant inlet is provided at the lower part; a second coolant outlet is provided at the upper part of the second condenser, and a second coolant inlet is provided at the lower part.

[0010] Preferably, the inner tube of the first condenser and the inner tube of the second condenser are connected by at least one gas conduit.

[0011] Preferably, first ball valves and second ball valves are respectively provided at both ends of the gas conduit. The first ball valve and the second ball valve have two functions: 1. The first ball valve and the second ball valve can be adjusted according to the reaction situation or reaction degree, and can be fully opened, fully closed or partially opened to control the flow rate of the reflux substance. 2. When the reaction starts to heat up, both the first ball valve and the second ball valve are closed to prevent the volatile components from flowing through the gas conduit. When the volatile components rise to the second condenser (i.e., when droplets appear in the second condenser), both the first ball valve and the second ball valve are opened.

[0012] Preferably, the gas conduit is a metal tube. The metal tube is easy to bend and change its shape. The shape of the metal tube can be adjusted according to the reflux situation of the gas.

[0013] The top of the first reactor is hermetically connected to the first condenser tube, and the top of the second reactor is hermetically connected to the second condenser tube. The hermetic connection can be achieved through a sealing device (such as a sealing plug, etc.) or a sealing treatment (such as winding PTFE tape, high-temperature tape, etc.).

[0014] In the second aspect of the present invention, there is provided the use of the above device in increasing the yield of carbon materials.

[0015] In the third aspect of the present invention, there is provided a method for increasing the yield of carbon materials by the above device, comprising the following steps:

[0016] (1) Wash the raw materials with distilled water, break them into pieces and sieve them after drying.

[0017] (2) Put the sieved raw materials from step (1) into the first reactor, introduce the protective gas into the first protective gas inlet and the second protective gas inlet. After 30 minutes, seal the first protective gas inlet and the second protective gas inlet, introduce the coolant into the first condenser tube and the second condenser tube, turn on the first heating device and the second heating device. The heating temperature of the first heating device is 200 - 600 °C, and the temperature of the second heating device is 100 - 450 °C, and keep warm for 0 - 10 h.

[0018] (3) After the first reaction device and the second reaction device are cooled to room temperature, dry the product, weigh it, and calculate the solid yield.

[0019] Preferably, the raw materials are selected from at least one of bark, tree trunk, leaves, grass, nut shell, fruit peel, apple stem, bamboo pole, rice straw, seaweed, livestock manure, industrial resin, plastic bottle, coal, sludge.

[0020] Preferably, the protective gas is selected from one of nitrogen, argon, helium, carbon dioxide.

[0021] Preferably, the coolant is selected from cooling water, cooling oil, cooling solvent or cooling air.

[0022] Preferably, the heating rate of the first heating device and the second heating device is 1 - 20 °C / min.

[0023] Advantages of the present invention:

[0024] (1) The device of the present invention can in-situ polymerize the bio-oil with a relatively low boiling point on the surface of the biomass char, greatly increasing the yield and carbon content of the biomass carbon material.

[0025] (2) The biochar prepared by the method of the present invention has a high carbon content, high calorific value when used as barbecue charcoal, and strong adsorption capacity when used as activated carbon; when applied to various fields, the quality of the carbon materials is higher than that of the carbon materials prepared by the prior art.

[0026] (3) The device of the present invention is simple, easy and safe to operate, suitable for large-scale production, and can be applied industrially. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 It is a schematic structural diagram of the device for increasing the yield of carbon materials of the present invention;

[0028] Wherein: 1. The first reaction device, 2. The first condenser, 3. The second reaction device, 4. The second condenser, 5. The first protective gas inlet, 6. The gas conduit, 61. The first ball valve, 62. The second ball valve, 11. The first reactor, 12. The first heating device, 13. The heat insulation cotton, 21. The first coolant inlet, 22. The first coolant outlet, 23. The inner tube of the first condenser, 31. The second reactor, 32. The second heating device, 41. The second coolant inlet, 42. The second coolant outlet, 43. The inner tube of the second condenser, 44. The exhaust port, 51. The second protective gas inlet. DETAILED DESCRIPTION OF THE INVENTION

[0029] It should be noted that the following detailed description is exemplary and is intended to provide further explanation of the present application. Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by those of ordinary skill in the technical field to which this application belongs.

[0030] As introduced in the background art section, biomass pyrolysis generally produces three products: bio-oil, gas and biochar. Bio-oil can be further processed into fuel, gas can be used for heating, and biochar has the widest application. Biochar with a high carbon content can be used as a raw material for graphene, activated carbon, etc. after treatment. However, the bio-oil prepared by the prior art is very unstable, and a series of reactions will occur after collection, making it unable to be used as fuel. Therefore, the development of bio-oil is greatly limited at present. Biochar has stable properties and is suitable for wide application. However, no matter whether the fast pyrolysis or slow pyrolysis method is adopted, the yield of the prepared biochar is low and the carbon content is not high.

[0031] Based on this, the object of the present invention is to provide a device for improving the yield of carbon materials. It includes a first reaction device 1, the first reaction device 1 is connected to a first condenser 2, the first condenser 2 is connected to a second reaction device 3, and the second reaction device 3 is connected to a second condenser 4; the first reaction device 1 includes a first reactor 11, a first heating device 12 is provided outside the first reactor 11, and the top of the first reactor 11 is hermetically connected to the first condenser 2; the second reaction device 3 includes a second reactor 31, a second heating device 32 is provided outside the second reactor 31, and the inner tube 23 of the first condenser is hermetically connected to the second reactor 31; the top of the second reactor 31 is hermetically connected to the second condenser 4; a first protective gas inlet 5 and an exhaust port 44 are respectively provided at the top of the inner tube 43 of the second condenser.

[0032] Heat insulating cotton 13 is filled between the first reactor 11 and the first heating device 12; heat insulating cotton 13 is filled between the second reactor 31 and the second heating device 32. A second protective gas inlet 51 is provided between the inner tube 23 of the first condenser and the second reactor 31. A first coolant outlet 22 is provided at the upper part of the first condenser 2, and a first coolant inlet 21 is provided at the lower part; a second coolant outlet 42 is provided at the upper part of the second condenser 4, and a second coolant inlet 41 is provided at the lower part. The inner tube 23 of the first condenser is connected to the inner tube 43 of the second condenser through at least one gas conduit 6. First ball valves 61 and second ball valves 62 are respectively provided at both ends of the gas conduit. The gas conduit 6 is a metal tube.

[0033] When preparing carbon materials using the device of the present invention, after heating starts, a cracking reaction first occurs in the first reactor 11. A small amount of steam that rushes into the first condenser 2 condenses into droplets at the lower end of the first condenser 2. These droplets are mainly colorless and transparent, and then slowly flow back into the first reactor 11. At lower temperatures, mainly free water volatilizes, without involving the reaction of carbon-containing organic compounds, and the free water flowing back into the first reactor 11 will not further polymerize with the raw materials. As the temperature continues to rise to 300 °C, a large amount of steam rushes into the first condenser 2 and flows down in a stream. These refluxed liquids are transparent light yellow. The uncondensed gas volatiles enter the second reactor 31, where the temperature of the second reactor 31 is set at 100 - 450 °C. As the temperature rises, the raw materials start to crack, and the functional groups on the side chains of the aromatic rings of lignin in the raw materials break, generating aliphatic substances, which are condensed and refluxed into the first reactor 11 and polymerize with the cracked raw materials. Among them, the refluxed aliphatic substances are mainly aldehydes, hydroxyaldehydes, and low-carbon acids. The solids in the first reactor 11 contain chemicals with aromatic structures, such as phenols, aldehydes containing benzene rings, etc. The reactions that occur between the refluxed substances and them mainly include aldol condensation or polymerization reactions initiated by electrophilic addition (such as aldehydes with low-carbon chains and phenols). In addition, the volatiles that have not been condensed in time enter the second reactor 31 and continue to undergo polymerization reactions. The generated product flows back to the first reactor 11. In the second reactor 31, the volatiles that have not had time to react continue to undergo polymerization reactions. Small molecules with low boiling points polymerize into macromolecules with high boiling points and flow back to the first reactor 11. The second reactor 31 has two functions: (1) allowing the substances that have not flowed back into the first reactor 11 to continue to react in the second reactor 31; (2) if a too long condenser is used, some polymerized macromolecular products will cool on the inner wall of the inner tube 43 of the second condenser and cannot flow back into the first reactor 11. Adding the second reactor 31 between the condensers also enables the high-boiling polymerized macromolecular products to flow back into the first reactor 11 smoothly through heating, facilitating collection. As the reaction temperature continues to rise, the cracking intensifies, and a large amount of steam rushes into the first condenser 2 and the second condenser 4, and there is a yellow-brown liquid reflux. As the temperature rises, the relatively stable benzene rings also break, so that the macromolecular structure degrades into small molecules and further undergoes polymerization reactions, and finally the obtained carbon materials have very high yields and carbon contents.

[0034] In order to enable those skilled in the art to more clearly understand the technical solutions of the present application, the technical solutions of the present application will be described in detail below in conjunction with specific embodiments.

[0035] The test materials used in the embodiments of the present invention are all conventional test materials in the art and can be obtained through commercial channels.

[0036] Example 1

[0037] After washing the poplar wood with distilled water, it was dried at 100 °C for 12 h. After cooling to room temperature, it was broken and screened to obtain particles with a mesh size of 80 - 100. 4.0 g of the screened particles were weighed and placed into the first reactor. Cooling water was passed through the first condenser and the second condenser. Carbon dioxide was introduced through the first protective gas inlet and the second protective gas inlet. After 30 min, the process was stopped. The first reactor and the second reactor were heated to 450 °C at a rate of 20 °C / min and kept at this temperature for 2 h before stopping the heating. After the first reactor and the second reactor were cooled to room temperature, the product was dried at 100 °C for 12 h, weighed, and the solid yield was calculated to be 62.7%.

[0038] Example 2

[0039] After washing the poplar wood with distilled water, it was dried at 100 °C for 12 h. After cooling to room temperature, it was broken and screened to obtain particles with a mesh size of 80 - 100. 4.0 g of the screened particles were weighed and placed into the first reactor. Cooling water was passed through the first condenser and the second condenser. Carbon dioxide was introduced through the first protective gas inlet and the second protective gas inlet. After 30 min, the process was stopped. The first reactor and the second reactor were heated to 450 °C at a rate of 2 °C / min and kept at this temperature for 2 h before stopping the heating. After the first reactor and the second reactor were cooled to room temperature, the product was dried at 100 °C for 12 h, weighed, and the solid yield was calculated to be 63.6%.

[0040] Example 3

[0041] After washing the poplar wood with distilled water, it was dried at 100 °C for 12 h. After cooling to room temperature, it was broken and screened to obtain particles with a mesh size of 80 - 100. 4.0 g of the screened particles were weighed and placed into the first reactor. Cooling water was passed through the first condenser and the second condenser. Carbon dioxide was introduced through the first protective gas inlet and the second protective gas inlet. After 30 min, the process was stopped. The first reactor and the second reactor were heated to 450 °C at a rate of 5 °C / min and kept at this temperature for 2 h before stopping the heating. After the first reactor and the second reactor were cooled to room temperature, the product was dried at 100 °C for 12 h, weighed, and the solid yield was calculated to be 61.0%.

[0042] Example 4

[0043] After washing the poplar wood with distilled water, it was dried at 100 °C for 12 h. After cooling to room temperature, it was broken and screened to obtain particles with a mesh size of 80 - 100. 4.0 g of the screened particles were weighed and placed into the first reactor. Cooling water was passed through the first condenser and the second condenser. Carbon dioxide was introduced through the first protective gas inlet and the second protective gas inlet. After 30 min, the process was stopped. The first reactor and the second reactor were heated to 450 °C at a rate of 1 °C / min and kept at this temperature for 2 h before stopping the heating. After the first reactor and the second reactor were cooled to room temperature, the product was dried at 100 °C for 12 h, weighed, and the solid yield was calculated to be 68.3%.

[0044] Example 5

[0045] After washing the poplar wood with distilled water, it was dried at 100 °C for 12 h. After cooling to room temperature, it was broken and screened to obtain particles with a mesh size of 80 - 100. 4.0 g of the screened particles were weighed and placed into the first reactor. Cooling water was passed through the first condenser and the second condenser. Argon was introduced through the first protective gas inlet and the second protective gas inlet. After 30 min, it was stopped. The first reactor and the second reactor were heated to 450 °C at a rate of 1 °C / min and held at this temperature for 2 h before stopping the heating. After the first reactor and the second reactor were cooled to room temperature, the product was dried at 100 °C for 12 h, weighed, and the solid yield was calculated to be 65.9%.

[0046] Example 6

[0047] After washing the poplar wood with distilled water, it was dried at 100 °C for 12 h. After cooling to room temperature, it was broken and screened to obtain particles with a mesh size of 80 - 100. 4.0 g of the screened particles were weighed and placed into the first reactor. Cooling water was passed through the first condenser and the second condenser. Helium was introduced through the first protective gas inlet and the second protective gas inlet. After 30 min, it was stopped. The first reactor and the second reactor were heated to 450 °C at a rate of 1 °C / min and held at this temperature for 2 h before stopping the heating. After the first reactor and the second reactor were cooled to room temperature, the product was dried at 100 °C for 12 h, weighed, and the solid yield was calculated to be 64.6%.

[0048] Example 7

[0049] After washing the poplar wood with distilled water, it was dried at 100 °C for 12 h. After cooling to room temperature, it was broken and screened to obtain particles with a mesh size of 80 - 100. 4.0 g of the screened particles were weighed and placed into the first reactor. Cooling water was passed through the first condenser and the second condenser. Nitrogen was introduced through the first protective gas inlet and the second protective gas inlet. After 30 min, it was stopped. The first reactor and the second reactor were heated to 450 °C at a rate of 1 °C / min and held at this temperature for 2 h before stopping the heating. After the first reactor and the second reactor were cooled to room temperature, the product was dried at 100 °C for 12 h, weighed, and the solid yield was calculated to be 65.1%.

[0050] Example 8

[0051] After washing the poplar wood with distilled water, it was dried at 100 °C for 12 h. After cooling to room temperature, it was broken and screened to obtain particles with a mesh size of 80 - 100. 4.0 g of the screened particles were weighed and placed into the first reactor. Air was passed through the condenser, and carbon dioxide was introduced into the reactor. After 30 min, it was sealed and heated to 450 °C at a rate of 1 °C / min and held at this temperature for 2 h. After the first reactor and the second reactor were cooled to room temperature, the product was dried at 100 °C for 12 h, weighed, and the solid yield was calculated to be 56.4%.

[0052] Example 9

[0053] The pig manure was dried at 100 °C for 12 h, cooled to room temperature, broken up, and sieved to obtain particles with a mesh size of 80 - 100. 4.0 g of the sieved particles were weighed and placed into the first reactor. Cooling water was passed through the first condenser and the second condenser. Carbon dioxide was introduced through the first protective gas inlet and the second protective gas inlet. After 30 min, the process was stopped. The first reactor and the second reactor were heated to 450 °C at a rate of 1 °C / min, and the heating was stopped after maintaining the temperature for 2 h. After the first reactor and the second reactor were cooled to room temperature, the product was dried at 100 °C for 12 h, weighed, and the solid yield was calculated to be 61.2%.

[0054] Example 10

[0055] The Hawaiian fruit peels were washed with distilled water, dried at 100 °C for 12 h, cooled to room temperature, broken up, and sieved to obtain particles with a mesh size of 80 - 100. 4.0 g of the sieved particles were weighed and placed into the first reactor. Cooling water was passed through the first condenser and the second condenser. Carbon dioxide was introduced through the first protective gas inlet and the second protective gas inlet. After 30 min, the process was stopped. The first reactor and the second reactor were heated to 450 °C at a rate of 1 °C / min, and the heating was stopped after maintaining the temperature for 2 h. After the first reactor and the second reactor were cooled to room temperature, the product was dried at 100 °C for 12 h, weighed, and the solid yield was calculated to be 62.9%.

[0056] Example 11

[0057] The seaweed was washed with distilled water, dried at 100 °C for 12 h, cooled to room temperature, broken up, and sieved to obtain particles with a mesh size of 80 - 100. 4.0 g of the sieved particles were weighed and placed into the first reactor. Cooling water was passed through the first condenser and the second condenser. Carbon dioxide was introduced through the first protective gas inlet and the second protective gas inlet. After 30 min, the process was stopped. The first reactor and the second reactor were heated to 450 °C at a rate of 1 °C / min, and the heating was stopped after maintaining the temperature for 2 h. After the first reactor and the second reactor were cooled to room temperature, the product was dried at 100 °C for 12 h, weighed, and the solid yield was calculated to be 55.4%.

[0058] Example 12

[0059] The coal was washed with distilled water, dried at 100 °C for 12 h, cooled to room temperature, broken up, and sieved to obtain particles with a mesh size of 80 - 100. 4.0 g of the sieved particles were weighed and placed into the first reactor. Cooling water was passed through the first condenser and the second condenser. Carbon dioxide was introduced through the first protective gas inlet and the second protective gas inlet. After 30 min, the process was stopped. The first reactor and the second reactor were heated to 450 °C at a rate of 1 °C / min, and the heating was stopped after maintaining the temperature for 2 h. After the first reactor and the second reactor were cooled to room temperature, the product was dried at 100 °C for 12 h, weighed, and the solid yield was calculated to be 51.5%.

[0060] Example 13

[0061] After washing the plastic bottles with distilled water, cut them into small pieces, cool to room temperature, then break them up and sieve to obtain particles with a mesh size of 80 - 100. Weigh 4.0 g of the sieved particles and put them into the first reactor. Pass cooling water through the first condenser and the second condenser, and pass carbon dioxide into the first protective gas inlet and the second protective gas inlet. Stop after 30 min. Heat the first reactor and the second reactor at a rate of 1 °C / min to 450 °C, keep the temperature for 6 h, and then stop heating. After the first reactor and the second reactor cool to room temperature, dry the product at 100 °C for 12 h, weigh it, and calculate that the solid yield is 33.4%.

[0062] Example 14

[0063] Dry the sludge at 100 °C for 12 h, cool to room temperature, then break it up and sieve to obtain particles with a mesh size of 80 - 100. Weigh 4.0 g of the sieved particles and put them into the first reactor. Pass cooling water through the first condenser and the second condenser, and pass carbon dioxide into the first protective gas inlet and the second protective gas inlet. Stop after 30 min. Heat the first reactor and the second reactor at a rate of 1 °C / min to 450 °C, keep the temperature for 2 h, and then stop heating. After the first reactor and the second reactor cool to room temperature, dry the product at 100 °C for 12 h, weigh it, and calculate that the solid yield is 30.2%.

[0064] Example 15

[0065] After washing the coconut shells with distilled water, dry them at 100 °C for 12 h, cool to room temperature, then break them up and sieve to obtain particles with a mesh size of 80 - 100. Weigh 4.0 g of the sieved particles and put them into the first reactor. Pass cooling water through the first condenser and the second condenser, and pass carbon dioxide into the first protective gas inlet and the second protective gas inlet. Stop after 30 min. Heat the first reactor and the second reactor at a rate of 1 °C / min to 450 °C, keep the temperature for 2 h, and then stop heating. After the first reactor and the second reactor cool to room temperature, dry the product at 100 °C for 12 h, weigh it, and calculate that the solid yield is 61.2%.

[0066] Comparative Example 1

[0067] After washing the poplar wood with distilled water, dry it at 100 °C for 12 h, cool to room temperature, then break it up and sieve to obtain particles with a mesh size of 80 - 100. Weigh 4.0 g of the sieved particles and put them into the reaction device. The reaction device uses the first reaction device in Example 1. Pass carbon dioxide for 30 min and then stop. Heat it to 450 °C at a rate of 20 °C / min and keep the temperature for 2 h. After the first reactor cools to room temperature, dry the product at 100 °C for 12 h, weigh it, and calculate that the solid yield is 34.5%.

[0068] Comparative Example 2

[0069] After washing the poplar wood with distilled water, it was dried at 100 °C for 12 h. After cooling to room temperature, it was broken and screened to obtain particles with a mesh size of 80 - 100. 4.0 g of the screened particles were placed into the device of Example 1 without the second reaction device. After introducing carbon dioxide for 30 min, the introduction was stopped, and the temperature was raised to 450 °C at a rate of 20 °C / min and held for 2 h. After the first reactor cooled to room temperature, the product was dried at 100 °C for 12 h, weighed, and the solid yield was calculated to be 39.8%.

[0070] Comparative Example 3

[0071] After washing the coconut shell with distilled water, it was dried at 100 °C for 12 h. After cooling to room temperature, it was broken and screened to obtain particles with a mesh size of 80 - 100. 4.0 g of the screened particles were placed into the reaction device, and the first reaction device in Example 1 was used. After introducing carbon dioxide for 30 min, the introduction was stopped, and the temperature was raised to 450 °C at a rate of 1 °C / min and held for 2 h. After the first reactor cooled to room temperature, the product was dried at 100 °C for 12 h, weighed, and the solid yield was calculated to be 31.9%.

[0072] Comparative Example 4

[0073] After washing the coconut shell with distilled water, it was dried at 100 °C for 12 h. After cooling to room temperature, it was broken and screened to obtain particles with a mesh size of 80 - 100. 4.0 g of the screened particles were placed into the device of Example 1 without the second reaction device. After introducing carbon dioxide for 30 min, the introduction was stopped, and the temperature was raised to 450 °C at a rate of 1 °C / min and held for 2 h. After the first reactor cooled to room temperature, the product was dried at 100 °C for 12 h, weighed, and the solid yield was calculated to be 41.0%.

[0074] Test Example 1

[0075] 0.6 g of the biochar prepared in Example 1 and Comparative Examples 1 - 2 were respectively taken, and the contents of C, H, O, and N were tested using an elemental analyzer (model: EuroEA3000). The ash content was detected in accordance with GB / T 36057 - 2018, and the calorific value was calculated using formula (1). The results are shown in Table 1.

[0076] Formula (1):

[0077] Calorific value = 0.3419 * C% + 1.1783 * H% + 0.1005 * S% - 0.1034 * O% - 0.015 * N% - 0.0211 * Ash content%

[0078] Table 1

[0079]

[0080] As can be seen from Table 1, the combustion value of the biochar prepared in Example 1 is much higher than that of Comparative Examples 1-2, indicating that the method of the present invention can improve the combustion value of carbon materials, and the carbon materials prepared in Example 1 can be widely used in the field of barbecue or providing combustion energy. At the same time, it can be seen from Table 1 that the carbon content of the biochar prepared in Example 1 is higher than that of Comparative Examples 1-2, indicating that the biochar prepared by the method of the present invention has a high carbon content and can improve the quality of carbon materials.

[0081] Test Example 2

[0082] The biochar prepared in Example 15 and Comparative Examples 3 to 4 was used as activated carbon to measure its adsorption performance.

[0083] (1) Specific surface area

[0084] The size of the specific surface area reflects the richness of the activated carbon pores and is also an important parameter for measuring its adsorption performance. The biochar prepared in Example 15 and Comparative Examples 3 to 4 was subjected to CO 2 Activated carbons (respectively referred to as Example 15, Comparative Example 3 and Comparative Example 4) were prepared by activation (the activation conditions were the same). The specific surface areas of the activated carbons in Example 15, Comparative Example 3 and Comparative Example 4 were measured using an SSA-6000 pore size specific surface area analyzer (Biotech). The results are shown in Table 2.

[0085] Table 2

[0086] Project 15 groups of Examples 3 groups of Comparative Examples 4 groups of Comparative Examples <![CDATA[Specific surface area (m 2 / g)]]> 988.2 544.1 570.9

[0087] As shown in Table 2, the specific surface area of ​​Example 15 is nearly twice as large as that of Comparative Examples 3 to 4, indicating that the pore structure of the activated carbon of Example 15 is more developed than that of Comparative Examples 3 to 4. This indicates that the carbon material prepared by the device and method of the present invention has a more developed pore structure and is more suitable for making activated carbon.

[0088] (2) Adsorption test

[0089] 50 mg of activated carbon from Example 15 and Comparative Examples 3-4 were added to 100 mL of a tetracycline solution with a mass concentration of 20 mg / L. After stirring at room temperature for 6 hours, the removal rate of tetracycline in the solution was tested. The results are shown in Table 3.

[0090] Table 3

[0091] Removal rate of tetracycline (%) 15 groups of Examples 92.5 3 groups of Comparative Examples 86.0 4 groups of Comparative Examples 88.9

[0092] As shown in Table 3, the activated carbon of Example 15 has the strongest adsorption capacity, which is higher than the activated carbon of Comparative Examples 3 to 4. This indicates that the carbon material prepared by the device and method of the present invention has a strong adsorption capacity and can be effectively used as activated carbon for adsorption treatment.

[0093] The above are only the preferred embodiments of the present application and are not intended to limit the present application. For those skilled in the art, various modifications and changes can be made to the present application. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included within the protection scope of the present application.

Claims

1. Application of a device for improving the carbon material yield in improving the carbon material yield, Characterized in that, The device for improving the carbon material yield includes a first reaction device, the first reaction device is connected to a first condenser, a second reaction device is provided above the first condenser, and the second reaction device is connected to a second condenser; the first reaction device includes a first reactor, a first heating device is provided outside the first reactor, and the top of the first reactor is hermetically connected to the first condenser; the second reaction device includes a second reactor, a second heating device is provided outside the second reactor, and the inner tube of the first condenser is hermetically connected to the second reactor; the top of the second reactor is hermetically connected to the second condenser; a first protective gas inlet and an exhaust port are respectively provided at the top of the inner tube of the second condenser; heat insulation cotton is filled between the first reactor and the first heating device; heat insulation cotton is filled between the second reactor and the second heating device; a second protective gas inlet is provided between the inner tube of the first condenser and the second reactor; a first coolant outlet is provided at the upper part of the first condenser, and a first coolant inlet is provided at the lower part; a second coolant outlet is provided at the upper part of the second condenser, and a second coolant inlet is provided at the lower part; the inner tubes of the first condenser and the second condenser are connected by at least one gas duct; first ball valves and second ball valves are respectively provided at both ends of the gas duct.

2. The application according to claim 1, Characterized in that, The method for the device for improving the carbon material yield to improve the carbon material yield includes the following steps: (1) Wash the raw materials with distilled water, dry them, break them up and sieve them. (2) Put the sieved raw materials from step (1) into the first reactor, introduce the protective gas into the first protective gas inlet and the second protective gas inlet, seal the first protective gas inlet and the second protective gas inlet after 30 minutes, pass the coolant through the first condenser and the second condenser, turn on the first heating device and the second heating device, the heating temperature of the first heating device is 200 - 600 °C, the temperature of the second heating device is 100 - 450 °C, and keep warm for 0 - 10 h; the heating rate of both the first heating device and the second heating device is 1~20 °C / min. (3) After the first reaction device and the second reaction device are cooled to room temperature, dry the product, weigh it, and calculate the solid yield.

3. The application according to claim 2, Characterized in that, The raw materials are selected from at least one of bark, tree trunk, leaves, grass, nut shell, fruit peel, bamboo pole, rice straw, seaweed, livestock manure, industrial resin, plastic bottle, coal, and sludge.

4. The application according to claim 2, Characterized in that, The protective gas is selected from one of nitrogen, argon, helium, and carbon dioxide.

5. The application according to claim 2, Characterized in that, The coolant is selected from cooling water, cooling oil or cooling air.

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