Utilization method of tail gas in production of bamboo activated carbon and production method of bamboo activated carbon

Abstract

The invention discloses a bamboo activated carbon production tail gas utilization method and a bamboo activated carbon production method.The utilization method comprises the following steps that production tail gas is subjected to condensation treatment, and condensate is obtained; carrying out solid-liquid separation treatment on the condensate to obtain permeate; performing extraction treatment on the permeate liquid by adopting an extraction agent to obtain a first extraction agent soluble liquid; carrying out reduced pressure distillation treatment on the first extractant soluble liquid to obtain distillate; performing extraction treatment on the distillate by adopting an extraction agent and water to obtain a second extraction agent soluble liquid; and carrying out reduced pressure distillation treatment on the second extractant soluble liquid to obtain the biomass oil. Through condensation treatment, solid-liquid separation treatment and two-stage extraction-distillation treatment, organic matter steam in carbonized tail gas is converted into biomass oil with a high calorific value (HHV), the overall additional value of bamboo activated carbon is increased, energy and chemical components of bamboo raw materials are utilized to the maximum extent, resource waste is reduced, and economic benefits of enterprises are increased.

Description

Technical Field

[0001] The present invention relates to the technical field of bamboo activated carbon production. Specifically, it relates to a method for utilizing the tail gas in bamboo activated carbon production and a method for producing bamboo activated carbon. Background Art

[0002] Biomass energy is the fourth largest energy source after coal, oil, and natural gas. Biomass energy is the energy carried by biomass, usually from firewood, straw, livestock manure, and municipal solid waste, etc. Modern technologies usually convert these biomasses into solid, liquid, or gaseous fuels for utilization. Bamboo energy is an important form of biomass energy, with the advantages of low pollution, wide distribution, large reserves, and renewability. China is the country with the richest bamboo resources in the world, possessing favorable conditions and environment for the development of bamboo energy.

[0003] Currently, an important use of bamboo resources in China is for the preparation of bamboo activated carbon. The preparation process mainly includes a carbonization process and an activation process. The carbonization process can be one or two times. Secondary carbonization usually means that the primary carbonized material obtained from the primary carbonization is ground, kneaded, and granulated into special shapes such as columns, honeycombs, spheres, etc., and then secondary carbonization is carried out to remove the binder used in granulation. In addition to a large amount of tail gas generated during the activation process, both the primary carbonization process and the secondary carbonization process will also generate relatively more tail gas, and the components of the tail gas generated by the two carbonization processes are significantly different.

[0004] In the tail gas generated by the primary carbonization, in addition to the protective gas and water vapor, the main components are CO, CO 2 generated by the pyrolysis of biomass components (such as lignin and hemicellulose, etc.), H 2 , volatile organic compounds (such as alkanes, alkenes, aldehydes, etc.), organic vapors (such as terpenes, tannic acid, methanol, etc.), acidic gases (such as formic acid, phenol, acetic acid, H 2 S, SO 2 , NH 3 , nitrogen oxides, etc.).

[0005] The tail gas generated by the secondary carbonization varies greatly depending on the type of binder. For example, the main components of the secondary carbonization tail gas with traditional asphalt or coal tar as the binder are protective gas, water vapor, CO, CO 2 , volatile organic compounds (such as benzene, toluene, xylene, methylphenol, ethylphenol, etc.) and acidic gases (such as phenol, formic acid, acetic acid, aldehydes, nitrogen oxides, etc.), which are highly toxic. When using polymer binders (such as starch, molasses, carboxymethyl cellulose, lignin, gelatin, chitosan, etc.), the content of volatile organic compounds and acidic gases in the secondary carbonization tail gas is significantly reduced, and the main components are protective gas, water vapor, CO and CO 2 .

[0006] During the activation process, the activator reacts with carbon elements, resulting in the erosion of pores and the formation of a large number of micropores. The main components of the resulting activation exhaust gas, in addition to the protective gas and the activator (such as water vapor, CO 2 , O 2 ), also contain H 2 , CO, a small amount of volatile organic compounds (such as CH 4 , C 2 H 4 , propylene), and acidic gases (such as phenol).

[0007] If the tail gases generated during the carbonization process and the activation process can be converted into clean energy, the utilization rate of bamboo resources can be significantly improved. Chinese invention patent CN116332128A discloses a system for preparing methanol by co-producing high-quality activated carbon from biomass and its preparation method. This method directly conducts a water-gas shift reaction on the tail gas generated during the activation process, and then conducts a CO hydrogenation reaction to finally obtain methanol. On the one hand, a large amount of tail gas generated during the carbonization process is not recycled. On the other hand, directly conducting a synthesis reaction on the activation tail gas is likely to cause catalyst poisoning and result in a low purity of methanol. Summary of the Invention

[0008] The technical problem to be solved by the present invention is to provide a simple and efficient method and system for utilizing the tail gas of bamboo activated carbon production that can convert the tail gas of bamboo activated carbon production into clean energy, as well as a production method and production system for bamboo activated carbon.

[0009] To achieve the above object, according to the first aspect of the present invention, a method and system for utilizing the tail gas of bamboo activated carbon production are provided, and the technical solution is as follows:

[0010] A method for utilizing the tail gas of bamboo activated carbon production, wherein the production tail gas at least includes the carbonization tail gas generated by carbonizing bamboo raw materials. The utilization method includes the following steps:

[0011] Conduct condensation treatment on the production tail gas to obtain condensate;

[0012] Conduct solid-liquid separation treatment on the condensate to obtain a permeate;

[0013] Use an extractant to conduct extraction treatment on the permeate to obtain a first extractant-soluble liquid;

[0014] Conduct vacuum distillation treatment on the first extractant-soluble liquid to obtain a distillate;

[0015] Use an extractant and water to conduct extraction treatment on the distillate to obtain a second extractant-soluble liquid;

[0016] Conduct vacuum distillation treatment on the second extractant-soluble liquid to obtain bio-oil.

[0017] As a further improvement to the method for utilizing the tail gas in the production of bamboo-based activated carbon described above: The condensation treatment is divided into two stages. First, condensation is carried out at 70 - 100 °C, and then condensation is carried out at 40 - 60 °C.

[0018] As a further improvement to the method for utilizing the tail gas in the production of bamboo-based activated carbon described above: The extractant is dichloromethane; the volume of the extractant is 1.5 - 2 times the volume of the permeate or the first bio-oil; the volume of water is 1 - 2 times the volume of the first bio-oil.

[0019] As a further improvement to the method for utilizing the tail gas in the production of bamboo-based activated carbon described above: Keep stirring, first add the extractant dropwise. After the addition of the extractant is completed, keep stirring for 10 - 20 minutes, then add water dropwise. After the addition of water is completed, continue stirring for 20 - 40 minutes, then seal and let stand for 24 - 72 hours, and finally obtain the second extractant-soluble liquid through phase separation.

[0020] As a further improvement to the method for utilizing the tail gas in the production of bamboo-based activated carbon described above: The vacuum distillation treatment is carried out at 30 - 35 °C and 15 - 18 kPa.

[0021] As a further improvement to the method for utilizing the tail gas in the production of bamboo-based activated carbon described above: It also includes atmospheric distillation of the bio-oil into a solid at 200 - 250 °C. The utilization method also includes crushing, grinding, and vacuum drying the solid, and then solid bio-oil is obtained.

[0022] As a further improvement to the method for utilizing the tail gas in the production of bamboo-based activated carbon described above: It also includes atmospheric distillation of the bio-oil into a concentrated liquid at 200 - 250 °C. The utilization method also includes hydrorefining treatment of the concentrated liquid, including the steps: preparing a reaction solution according to the mass ratio of bio-oil:methanol:catalyst of (15 - 25):(20 - 30):1, and carrying out hydrothermal reaction at 180 - 200 °C and 1 MPa hydrogen pressure for 2 - 4 h, and then refined bio-oil is obtained.

[0023] As a further improvement to the method for utilizing the tail gas in the production of bamboo-based activated carbon described above: An activated carbon-based Ni / BC catalyst is used, and its preparation method is: dispersing soluble nickel salt and activated carbon in ethanol, and stirring for 4 - 6 h; rotating and evaporating completely at 80 °C to remove the ethanol solvent, and then drying in a vacuum oven; calcining at 500 - 600 °C for 1 - 3 h under a reducing atmosphere, and then the activated carbon-based Ni / BC catalyst is obtained.

[0024] As a further improvement to the method for utilizing the tail gas in the production of bamboo-based activated carbon described above: When the bamboo raw material is subjected to segmented carbonization treatment, the production tail gas at least includes the segmented tail gas generated during carbonization treatment at 300 - 400 °C.

[0025] Utilization system for the tail gas in the production of bamboo-based activated carbon, comprising a carbonization furnace for carbonizing bamboo raw materials to obtain carbonization tail gas. The utilization system includes: a condensation device for condensing the production tail gas and outputting condensate; a solid-liquid separation device for performing solid-liquid separation on the condensate and outputting permeate; the liquid inlet of the solid-liquid separation device is connected to the liquid outlet of the condensation device; a primary extraction device for extracting the permeate and outputting a first extractant-soluble liquid; the liquid inlet of the primary extraction device is connected to the permeate outlet of the solid-liquid separation device; a primary distillation device for performing vacuum distillation on the first extractant-soluble liquid and outputting distillate; the liquid inlet of the primary distillation device is connected to the first extractant-soluble liquid outlet of the primary extraction device; a secondary extraction device for extracting the distillate and outputting a second extractant-soluble liquid; the liquid inlet of the secondary extraction device is connected to the distillate outlet of the primary distillation device; a secondary distillation device for performing vacuum distillation on the second extractant-soluble liquid and outputting bio-oil; the liquid inlet of the secondary distillation device is connected to the second extractant-soluble liquid outlet of the secondary extraction device.

[0026] As a further improvement of the above utilization system for the tail gas in the production of bamboo-based activated carbon: the solid-liquid separation device is a filtration device or a centrifugal separation device.

[0027] As a further improvement of the above utilization system for the tail gas in the production of bamboo-based activated carbon: it further includes a first conveying pipeline for inputting an extractant into the primary extraction device; it further includes a first reflux pipeline for returning the condensate obtained by distillation in the primary distillation device to the primary extraction device.

[0028] As a further improvement of the above utilization system for the tail gas in the production of bamboo-based activated carbon: it further includes a second conveying pipeline for inputting an extractant and a third conveying pipeline for inputting water into the secondary extraction device; it further includes a second reflux pipeline for returning the condensate obtained by distillation in the secondary distillation device to the primary extraction device.

[0029] As a further improvement of the above utilization system for the tail gas in the production of bamboo-based activated carbon: it further includes a tertiary distillation device for performing atmospheric distillation on the bio-oil; the liquid inlet of the tertiary distillation device is connected to the liquid outlet of the secondary distillation device.

[0030] As a further improvement of the above utilization system for the tail gas in the production of bamboo-based activated carbon: the tertiary distillation distills the bio-oil into a solid, and the utilization system further includes a crushing device, a powder grinding device, and a drying device for successively performing crushing, grinding, and vacuum drying on the solid.

[0031] As a further improvement of the utilization system for the tail gas in the production of bamboo-based activated carbon described above: the three-stage distillation distills the biomass oil into a concentrated liquid, and the utilization system further includes a hydrothermal reaction device for refining the concentrated liquid.

[0032] To achieve the above object, according to the second aspect of the present invention, there is provided a method and a production system for producing bamboo-based activated carbon, which adopt the method and the utilization system for the tail gas in the production of bamboo-based activated carbon described in the first aspect above. The technical solutions are as follows:

[0033] A method for producing bamboo-based activated carbon includes carbonizing bamboo raw materials, and further includes utilizing the tail gas in the production of bamboo-based activated carbon by using the method for utilizing the tail gas in the production of bamboo-based activated carbon described in the first aspect above. The production tail gas at least includes the carbonization tail gas generated by carbonizing the bamboo raw materials.

[0034] The carbonization treatment at least includes a primary carbonization treatment, which includes the steps of:

[0035] Put the dried bamboo raw materials into a carbonization furnace. Under an inert atmosphere, raise the furnace temperature from room temperature to 130 - 280 °C and keep it warm for 0.5 - 1.5 hours.

[0036] Continue to raise the temperature to 300 - 400 °C and keep it warm for 0.5 - 1.5 hours.

[0037] Continue to raise the temperature to 500 - 600 °C, keep it warm for 0.5 - 1.5 hours, and then cool it with the furnace to obtain the primary carbonized material. After the carbonization is completed, an activation treatment is carried out to obtain the bamboo-based activated carbon.

[0038] A preparation system for the tail gas in the production of bamboo-based activated carbon includes a carbonization furnace for carbonizing bamboo raw materials, and further includes utilizing the tail gas in the production of bamboo-based activated carbon by using the utilization system for the tail gas in the production of bamboo-based activated carbon described in the first aspect above. The production tail gas at least includes the carbonization tail gas generated by carbonizing the bamboo raw materials.

[0039] Biomass oil is an important resource and has uses such as fuel, chemical raw material, and energy storage. The present invention effectively utilizes the organic matter generated by the pyrolysis of the biomass component of bamboo raw materials during carbonization. By adopting simple and efficient purification means, through condensation treatment, solid-liquid separation treatment, and two-stage extraction-distillation treatment, the organic matter vapor in the carbonization tail gas is converted into biomass oil with a high calorific value (HHV), improving the overall added value of the bamboo-based activated carbon, maximizing the utilization of the energy and chemical components of the bamboo raw materials, reducing resource waste, and increasing the economic benefits of the enterprise.

[0040] The following further describes the embodiments of the invention provided in this specification in conjunction with the accompanying drawings and specific implementation manners. Some of the additional aspects and advantages of the embodiments of the invention provided in this specification will be given in the following description, some will become apparent from the following description, or will be understood through the practice of the embodiments of the invention provided in this specification. Brief Description of the Drawings

[0041] The accompanying drawings that form a part of the embodiments of the invention provided in this specification are used to assist in understanding the embodiments of the invention provided in this specification. The content provided in the accompanying drawings and the related descriptions in the embodiments of the invention provided in this specification can be used to explain the embodiments of the invention provided in this specification, but do not constitute an improper limitation on the embodiments of the invention provided in this specification. In the accompanying drawings:

[0042] Figure 1 It is a schematic structural diagram of the first embodiment of the bamboo charcoal production system and the utilization system of the bamboo charcoal production tail gas.

[0043] Figure 2 It is a schematic structural diagram of the second embodiment of the bamboo charcoal production system and the utilization system of the bamboo charcoal production tail gas.

[0044] Figure 3 It is an XRD pattern of the Cu-Zr catalyst.

[0045] The relevant markings in the above-mentioned accompanying drawings are as follows:

[0046] 210 - Condensing equipment, 220 - Solid-liquid separation equipment, 230 - Primary extraction equipment, 240 - Primary distillation equipment, 250 - Secondary extraction equipment, 260 - Secondary distillation equipment, 270 - Tertiary distillation equipment. Detailed Description of the Invention

[0047] The following clearly and completely describes the embodiments of the invention provided in this specification in conjunction with the accompanying drawings. Those of ordinary skill in the art will be able to implement the embodiments of the invention provided in this specification based on these descriptions. Before describing the embodiments of the invention provided in this specification in conjunction with the accompanying drawings, it is particularly noted that:

[0048] In the embodiments of the invention provided in this specification, the technical solutions and technical features provided in each part including the following descriptions can be combined with each other without conflict.

[0049] In addition, the embodiments of the invention provided in this specification involved in the following description are usually only a partial embodiment rather than all embodiments of the embodiments of the invention provided in this specification. Therefore, based on the embodiments of the invention provided in this specification, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the scope of protection of the embodiments of the invention provided in this specification.

[0050] Regarding the terms and units in the embodiments of the invention provided in this specification: The terms "comprising", "including", "having" and any variations thereof in the specification, claims and relevant parts of the embodiments of the invention provided in this specification are intended to cover non-exclusive inclusion. In addition, other relevant terms and units in the embodiments of the invention provided in this specification can be reasonably interpreted based on the relevant content of the embodiments of the invention provided in this specification.

[0051] The first embodiment of the production method of bamboo-based activated carbon of the present invention includes the steps:

[0052] Drying treatment: Put the fresh bamboo raw materials into an oven and dry them at 100°C for 48 hours.

[0053] Primary carbonization treatment: Put the dried bamboo raw materials into a carbonization furnace. Under an inert atmosphere, raise the furnace temperature from room temperature to 200°C and keep it warm for 1 hour; continue to raise the temperature to 350°C and keep it warm for 1 hour; continue to raise the temperature to 550°C, keep it warm for 1 hour and then cool it with the furnace to obtain carbonized materials.

[0054] Activation treatment: Put the carbonized materials into an activation furnace. Under an inert atmosphere, use water vapor as the activator. The volume of liquid water introduced per 100 g of the green body per hour is 40 mL. Keep it warm at 1000°C for 3 hours and then cool it with the furnace to obtain bamboo-based activated carbon.

[0055] Compared with the first embodiment, the difference of the second embodiment of the production method of bamboo-based activated carbon of the present invention is that it further includes a secondary carbonization treatment: Grind the primary carbonized materials to a particle size of 325 mesh, then use molasses as the binder and water as the auxiliary agent. According to the mass ratio of molasses to the primary carbonized materials being 0.5 and adding 30 mL of the auxiliary agent per 100 g of the primary carbonized materials, granulate them into green bodies in a kneader. Put the green bodies into a carbonization furnace. Under an inert atmosphere, raise the furnace temperature from room temperature to 550°C, keep it warm for 1 hour, and cool it with the furnace to obtain secondary carbonized materials. Then carry out activation treatment on the secondary carbonized materials to obtain bamboo-based activated carbon.

[0056] The method for utilizing the tail gas in the production of bamboo-based activated carbon is used to utilize the production tail gas generated by the bamboo-based activated carbon production method described in the above first embodiment or second embodiment. The production tail gas at least includes the segmented tail gas generated by carbonization treatment at 300-400°C. For example, the production tail gas may only include the segmented tail gas generated by carbonization treatment at 300-400°C, or may include all the primary carbonization tail gas, and may further include secondary carbonization tail gas and / or activation tail gas.

[0057] The first embodiment of the method for utilizing the tail gas in the production of bamboo-based activated carbon includes the following steps:

[0058] Conduct condensation treatment on the production tail gas to obtain condensate; preferably, the condensation treatment is divided into two stages. First, conduct condensation at 85°C, and then conduct condensation at 50°C. In this way, as much organic vapor as possible can be condensed.

[0059] Conduct solid-liquid separation treatment on the condensate to obtain the permeate; the solid-liquid separation treatment is filtration treatment or centrifugal separation treatment. Thus, particulate impurities captured by droplets during the condensation process can be removed.

[0060] Use an extractant to conduct extraction treatment on the permeate to obtain a first extractant-soluble liquid.

[0061] Conduct vacuum distillation treatment on the first extractant-soluble liquid at 35°C and 16 kPa to obtain a distillate; through vacuum distillation treatment, the extractant can be evaporated and condensed. The condensate obtained from the vacuum distillation treatment can be repeatedly used for extraction treatment of the permeate, which can improve the utilization rate of the extractant.

[0062] Use an extractant and water to conduct extraction treatment on the distillate to obtain a second extractant-soluble liquid; preferably, during specific implementation, keep stirring, first dropwise add the extractant. After the extractant is added dropwise, keep stirring for 15 minutes, then dropwise add water. After the water is added dropwise, continue stirring for 30 minutes, then seal and let stand for 48 hours, and finally obtain the second extractant-soluble liquid through phase separation.

[0063] Conduct vacuum distillation treatment on the second extractant-soluble liquid at 35°C and 16 kPa, and biomass oil is obtained. Through vacuum distillation treatment, the extractant can be evaporated and condensed. The condensate obtained from the vacuum distillation treatment can be repeatedly used for extraction treatment of the permeate, which can improve the utilization rate of the extractant.

[0064] The extractant is dichloromethane; preferably, the volume of the extractant is 2 times the volume of the permeate or the first biomass oil; the volume of water is 1.5 times the volume of the first biomass oil.

[0065] The second embodiment of the utilization method of the tail gas in bamboo-based activated carbon production is as follows: on the basis of the first embodiment, it further includes distilling the biomass oil into a solid under normal pressure at 200-250 °C (preferably 235 °C). The utilization method further includes crushing, grinding and vacuum drying the solid to obtain solid biomass oil.

[0066] The third embodiment of the utilization method of the tail gas in bamboo-based activated carbon production is as follows: on the basis of the first embodiment, it further includes distilling the biomass oil into a concentrated liquid under normal pressure at 200-250 °C (preferably 235 °C). The utilization method further includes hydrorefining the concentrated liquid, including the steps of: preparing a reaction solution according to the mass ratio of biomass oil: methanol: catalyst of 20:25:1, and performing hydrothermal reaction at 190 °C and 1 MPa hydrogen pressure for 3 h to obtain refined biomass oil.

[0067] Using an activated carbon-based Ni / BC catalyst, its preparation method is as follows: disperse 0.5 g of nickel nitrate and 1 g of activated carbon in ethanol and stir for 5 h; rotate and evaporate completely at 80 °C to remove the ethanol solvent and then dry in a vacuum oven; use 20% H 2 -Ar as the reducing atmosphere and calcine at 550 °C for 2 h to obtain the activated carbon-based Ni / BC catalyst.

[0068] Figure 1 It is a schematic structural diagram of the first embodiment of the bamboo-based activated carbon production system and the utilization system of the tail gas in bamboo-based activated carbon production. As Figure 1 shown, the bamboo-based activated carbon production system includes a carbonization furnace (one or two) for carbonizing bamboo raw materials to obtain carbonization tail gas and a utilization system for the production tail gas. The production tail gas at least includes the segmented tail gas generated by carbonization treatment at 300-400 °C. For example, the production tail gas can only include the segmented tail gas generated by carbonization treatment at 300-400 °C, or can include all the primary carbonization tail gas, and can further include secondary carbonization tail gas and activation tail gas.

[0069] The first embodiment of the utilization system of the tail gas in bamboo-based activated carbon production includes a condensation device 210, a solid-liquid separation device 220, a primary extraction device 230, a primary distillation device 240, a secondary extraction device 250 and a secondary distillation device 260.

[0070] The condensation device 210 is used for condensing the production tail gas and outputting condensate. The solid-liquid separation device 220 is used for performing solid-liquid separation on the condensate and outputting permeate. The liquid inlet of the solid-liquid separation device 220 is connected to the liquid outlet of the condensation device 210. The solid-liquid separation device 220 is a filtration device or a centrifugal separation device. The primary extraction device 230 is used for extracting the permeate and outputting a first extractant-soluble liquid. The liquid inlet of the primary extraction device 230 is connected to the permeate outlet of the solid-liquid separation device 220. The primary distillation device 240 is used for performing vacuum distillation on the first extractant-soluble liquid and outputting distillate. The liquid inlet of the primary distillation device 240 is connected to the first extractant-soluble liquid outlet of the primary extraction device 230. The secondary extraction device 250 is used for extracting the distillate and outputting a second extractant-soluble liquid. The liquid inlet of the secondary extraction device 250 is connected to the distillate outlet of the primary distillation device 240. The secondary distillation device 260 is used for performing vacuum distillation on the second extractant-soluble liquid and outputting bio-oil. The liquid inlet of the secondary distillation device 260 is connected to the second extractant-soluble liquid outlet of the secondary extraction device 250.

[0071] The utilization system further includes a first conveying pipeline for inputting an extractant into the primary extraction device 230, a first reflux pipeline for returning the condensate obtained by distillation in the primary distillation device 240 to the primary extraction device 230, a second conveying pipeline for inputting an extractant into the secondary extraction device 250, a third conveying pipeline for inputting water into the secondary extraction device 250, and a second reflux pipeline for returning the condensate obtained by distillation in the secondary distillation device 260 to the primary extraction device 230.

[0072] After testing, the obtained bio-oil contains 51.13% O, 40.04% C, 7.71% H, and 1.12% N.

[0073] Figure 2 It is a schematic structural diagram of the second embodiment of the bamboo charcoal production system and the utilization system of the bamboo charcoal production tail gas. As Figure 2 shown, compared with the first embodiment, the utilization system of the second embodiment further includes a tertiary distillation device 270 for performing atmospheric distillation on the bio-oil; the liquid inlet of the tertiary distillation device 270 is connected to the liquid outlet of the secondary distillation device 260.

[0074] When the tertiary distillation device 270 distills the bio-oil into a solid, the utilization system further includes a crushing device, a milling device, and a drying device for successively crushing, grinding, and vacuum-drying the solid. Thus, the obtained solid bio-oil is more convenient for storage, transportation, and use.

[0075] When the three-stage distillation device 270 distills the biomass oil into a concentrated liquid, the utilization system further includes a hydrothermal reaction device for refining the concentrated liquid. Thus, through hydrofining, the C / O and H / O ratios can be further increased, and the HHV value can be further improved.

[0076] After the three-stage distillation device 270 performs atmospheric distillation treatment, the C content of the biomass oil continuously increases from 40.04% to 59.87%, the O content continuously decreases from 51.13% to 31.95%, the H content decreases from 7.71% to 6.35%, and the N content remains basically unchanged. It can be seen that during the atmospheric distillation treatment, the C / O and H / O ratios increase, resulting in a significant improvement in the HHV value.

[0077] After the carbonization tail gas is condensed, the non-condensable gas still contains CO, H 2 , CO 2 and other resources. In order to deeply recover the valuable resources in the production tail gas, the utilization method of the bamboo activated carbon production tail gas of the present invention further utilizes the non-condensable gas. On the basis of the third embodiment, its fourth embodiment further includes the steps of:

[0078] For the non-condensable gas after the production tail gas is condensed, it is purified to remove volatile organic compounds, acidic gases and particulate impurities in the non-condensable gas. The purification treatment includes sequentially performing dust removal treatment, adsorption treatment and deacidification treatment on the production tail gas. Among them, the dust removal treatment is preferably filtration dust removal. Through the adsorption treatment, volatile organic compounds in the production tail gas can be adsorbed, and activated carbon is preferably used as the adsorbent. Through the deacidification treatment, the residual acidic gases in the production tail gas can be removed. The deacidification treatment preferably uses a spray tower for wet deacidification, and the deacidification is carried out through a circulating liquid absorbent. Thus, the volume fraction content of water vapor in the production tail gas obtained after purification treatment is 15-25%, the COD content ≤ 5 ppm, the volatile organic compound content ≤ 3 ppm, the acidic gas content ≤ 2 ppm, and the particulate content ≤ 20 mg / Nm 3 .

[0079] Use a CO 2 selective separation membrane to remove CO 2 from the production tail gas, and then pass the production tail gas into a reaction device containing a Cu-Zr catalyst, and carry out a catalytic reaction at 240-300 °C to generate syngas containing H 2 . Use a CO 2 selective separation membrane to remove CO 2 from the syngas.

[0080] Among them, the preparation method of the Cu-Zr catalyst includes the following steps:

[0081] Dissolve zirconium nitrate and urea in 150 mL of deionized water to form an aqueous solution. The molar ratio of urea to zirconium ions in the aqueous solution is 2, and the concentration of zirconium ions is 0.2 mol / L. Hydrothermally treat the aqueous solution at a hydrothermal reaction temperature of 150 °C for 24 hours. Collect, wash, and dry the resulting first solid.

[0082] Calcine the first solid at a calcination temperature of 250 °C for 4 hours to obtain a zirconium precursor.

[0083] Grind and mix the zirconium precursor and copper nitrate. The molar ratio of copper ions to zirconium ions (calculated based on zirconium nitrate) is 0.12. Then disperse the ground mixture in 200 mL of deionized water to form a dispersion. Stir the dispersion for 2 hours under a water bath condition with a water bath temperature of 60 °C. Continue to slowly add sodium hydroxide to the dispersion under the water bath condition until the pH of the dispersion is 9. Collect, wash, and dry the resulting second solid.

[0084] Calcine the second solid at a calcination temperature of 400 °C for 4 hours to obtain the Cu-Zr catalyst.

[0085] Figure 3 is the XRD pattern of the Cu-Zr catalyst. As Figure 3 shown, the Cu-Zr catalyst has a good crystal form, and its XRD pattern has characteristic peaks of CuO x and ZrO 2 , indicating that during the preparation process, Cu did not embed into the zirconium precursor (ZrO 2 ), but uniformly adhered to the surface of ZrO 2 as CuOx. Through the interaction between the two, a good catalytic effect is produced.

[0086] The specific surface area of the zirconium precursor (ZrO 2 ) is 37.35 m 2 ² / g, the total pore volume is 0.22 cm 2 ³ / g, and the average pore diameter is 23.6 nm obtained by N 3 ₂ adsorption-desorption experiments and the BET (Brunauer-Emmett-Teller) method. The specific surface area of the Cu-Zr catalyst is 56.48 m 2 ² / g, the total pore volume is 0.30 cm 3 ³ / g, and the average pore diameter is 21.8 nm. It can be seen that after loading CuO x , the specific surface area of the Cu-Zr catalyst has increased significantly, which plays a decisive role in the adsorption and activation of gases.

[0087] A gas mixture with a volume fraction composition of 15% CO, 40% H 2 ₂, 35% N2 、 A mixture of 10% CO 2 and water vapor is mixed and catalyzed at 180 - 300 °C using a Cu - Zr catalyst. The results show that the CO conversion rate first increases sharply and then gradually levels off as the catalytic temperature rises. The corresponding CO conversion rates at 180 °C, 210 °C, 240 °C, 270 °C, and 300 °C are 62%, 79%, 85%, 86%, and 87% respectively.

[0088] This Cu - Zr catalyst is used for the reaction gas to remove CO 2 (One example data is: 21.54% CO, 3.14% CO 2 、 23.55% H 2 、 22.35% water vapor, and the balance is N 2 ). The catalytic reaction is carried out at a reaction temperature of 270 °C, a reaction pressure of 5 MPa, and a space velocity of 5000 h -1 , and the CO conversion rate is 81%.

[0089] Different from the fourth embodiment, the fifth embodiment of the utilization method of the tail gas from bamboo - based activated carbon production is as follows:

[0090] The second tail gas and the third tail gas are condensed to obtain the second non - condensable gas.

[0091] The mixed gas composed of the first non - condensable gas obtained by condensing the first tail gas and the second non - condensable gas is purified to obtain the reaction gas; the purification treatment includes successively performing deacidification treatment, dust removal treatment, and adsorption treatment on the mixed gas; among them, the deacidification treatment adopts dry deacidification, that is, spraying a solid absorbent for deacidification. Thus, through the deacidification treatment, the residual acidic gas in the mixed gas can be removed and a relatively dry low - acid gas can be obtained, avoiding the influence of a large amount of water vapor introduced by wet deacidification on the methanol synthesis reaction; the dust removal treatment is preferably filtration dust removal. Setting dust removal after the deacidification treatment can not only remove the particulate impurities carried by the mixed gas, but also remove the deacidifying agent used in the deacidification treatment. Through the adsorption treatment, the volatile organic compounds in the mixed gas can be adsorbed, and activated carbon is preferably used as the adsorbent. Thus, through the purification treatment, particulate impurities, volatile organic compounds, and residual acidic gases can be removed. The reaction gas obtained after the mixed gas is purified is mainly composed of CO 2 、 CO and, the volume fraction of water vapor is 2 - 5%, the COD content ≤ 5 ppm, the volatile organic compound content ≤ 3 ppm, the acidic gas content ≤ 2 ppm, and the particulate content ≤ 20 mg / Nm 3 .

[0092] Use a CO 2 selective separation membrane to remove CO 2 from the reaction gas, and then mix the reaction gas and H2 It is introduced into a reaction device loaded with a multi-layer structured catalyst for catalytic reaction to generate syngas containing methanol.

[0093] The core of the multi-layer structured catalyst is Fe 3 O 4 , the inner layer is CeO 2 , the middle layer is a Cu-Zn alloy, the outer layer is ZrO 2 , and the surface layer is graphene quantum dots. Its preparation method includes the following steps:

[0094] Preparation of the Fe 3 O 4 core by co-precipitation method: Using FeCl 3 ·6H 2 O, FeCl 2 ·4H 2 O and ammonia water as raw materials, under nitrogen protection, mixing equal volumes of Fe 3+ solution and Fe 2+ solution. The molar ratio of Fe 3+ to Fe 2+ is 2:1; heating the mixed solution to 80 °C, adding ammonia water to the mixed solution until the pH is 10 - 11 at a stirring speed of 500 rpm; continuing the reaction for 30 minutes and then performing magnetic separation. The collected solid is washed 3 times with deionized water and ethanol, and dried in vacuum at 60 °C for 12 hours to obtain the Fe 3 O 4 core.

[0095] Preparation of the CeO 2 inner layer by hydrothermal method: Dissolving Ce(NO 3 ) 3 ·6H 2 O and urea in water, with the concentration of Ce 3+ being 0.05 M and the urea concentration being 0.5 M; dispersing 1 g of Fe 3 O 4 core in 150 mL of the above solution, transferring it to a hydrothermal reaction kettle, and reacting at 180 °C for 12 hours; after cooling to room temperature, performing centrifugal separation. The collected solid is washed 3 times with water and ethanol, dried at 60 °C for 12 hours, and then calcined at 350 °C for 2 hours to coat the surface of the Fe 3 O 4 core with CeO 2 inner layer to obtain CeO 2 @Fe 3 O 4 .

[0096] Preparation of the Cu-Zn alloy middle layer by chemical reduction method: Using Cu(NO 3 ) 2 ·3H2 O, Zn(NO 3 ) 2 ·6H 2 O is dissolved in water, the concentration of Cu 2+ is 0.1 M, and the concentration of Zn 2+ is 0.05 M; 0.8 g of CeO 2 @Fe 3 O 4 is dispersed in 100 mL of the above solution and sonicated for 30 minutes; stirred in an ice bath and slowly added dropwise with a NaBH 4 solution (concentration 0.2 M) until a precipitate forms; then stirred at room temperature for 2 hours and centrifuged. The collected solid is washed 3 times with water and ethanol and dried in vacuo at 50 °C for 8 hours, i.e., a Cu-Zn alloy interlayer is deposited on the inner surface of CeO 2 to obtain Cu-Zn@CeO 2 @Fe 3 O 4 .

[0097] Preparation of the ZrO 2 outer layer by the sol-gel method: Zr(OC 4 H 9 ) 4 is dissolved in ethanol, and the concentration of Zr(OC 4 H 9 ) 4 is 0.1 M; a small amount of water (water / Zr molar ratio = 2) and 0.6 g of Cu-Zn@CeO 2 @Fe 3 O 4 are added to 100 mL of the above solution and stirred at room temperature for 4 hours; then refluxed at 60 °C for 2 hours and centrifuged, dried at 80 °C for 12 hours, and then calcined at 450 °C for 3 hours, i.e., a ZrO 2 outer layer is coated on the surface of the Cu-Zn alloy interlayer to obtain ZrO 2 @Cu-Zn@CeO 2 @Fe 3 O 4 .

[0098] Preparation of graphene quantum dots (GQDs) by the impregnation method: Prepare an aqueous GQDs solution with a concentration of 1 mg / mL; then disperse 0.5 g of ZrO 2 @Cu-Zn@CeO 2 @Fe 3 O 4 in 100 mL of the aqueous GQDs solution; sonicate for 30 minutes, then stir at room temperature for 4 hours and centrifuged, dried in vacuo at 50 °C for 12 hours, i.e., on ZrO 2The outer surface is loaded with graphene quantum dots to obtain GQDs@ZrO 2 @Cu-Zn@CeO 2 @Fe 3 O 4 .

[0099] Calcination treatment: In air, GQDs@ZrO 2 @Cu-Zn@CeO 2 @Fe 3 O 4 is calcined at 450 °C for 4 hours to obtain a precursor.

[0100] Reduction treatment: In a mixed gas atmosphere of N 2 and H 2 (the volume fraction of H 2 is 10%), the precursor is reduced at 350 °C for 2 hours to obtain the catalyst.

[0101] Using this multi-layer structure catalyst to catalyze the reaction gas for removing CO 2 (data of one embodiment are: 25.41% CO, 3.05% CO 2 , 26.21% H 2 , 2.45% water vapor, and the balance is N 2 ), the volume ratio of the reaction gas to the supplemented H 2 is (7.05 - 7.5):1, the reaction temperature is 240 °C (any temperature from 220 to 300 °C is acceptable), the reaction pressure is 4 MPa (any pressure from 3 to 10 MPa is acceptable), the space velocity is 6000 h -1 (any space velocity from 3000 to 10000 h -1 is acceptable), and the space-time yield is 0.2 - 0.6 kg methanol / (L catalyst·h), and the purity of liquid methanol is above 95%.

[0102] Different from the fifth embodiment, the sixth embodiment of the utilization method of the tail gas from bamboo charcoal activated carbon production is as follows:

[0103] For the non-condensable gas after condensing the carbonization tail gas, it is successively subjected to deacidification treatment, dust removal treatment and adsorption treatment to obtain the first reaction gas and the adsorption-saturated liquid; among them, the deacidification treatment adopts dry deacidification, that is, spraying a solid absorbent for deacidification. Thus, through the deacidification treatment, the residual acidic gas in the carbonization tail gas can be removed and relatively dry low-acid gas can be obtained, avoiding the influence of introducing more water vapor by wet deacidification on the methanol synthesis reaction; the dust removal treatment is preferably filtration dust removal. Setting dust removal after the deacidification treatment can not only remove the particulate impurities carried by the carbonization tail gas, but also remove the deacidifying agent used in the deacidification treatment. The adsorption treatment uses alcohol as the adsorbent, which can adsorb the volatile organic compounds in the carbonization tail gas and form the first reaction gas and the adsorption-saturated liquid.

[0104] The adsorbed saturated liquid is subjected to combustion treatment to obtain combustion tail gas; since the adsorbed saturated liquid mainly contains volatile organic compounds, therefore, the combustion treatment can not only prevent environmental pollution caused by emissions, but also generate more CO 2 for reacting with methane.

[0105] The combustion tail gas and methane are introduced into a first reaction device loaded with a catalyst for catalytic reaction, and the reaction generates a second reaction gas containing H 2 and CO.

[0106] The activation tail gas is successively subjected to condensation treatment, deacidification treatment, dust removal treatment and adsorption treatment to obtain a third reaction gas; since the volatile organic compounds in the activation tail gas are relatively few, the adsorption treatment here can be carried out by using activated carbon for adsorption.

[0107] The mixed gas composed of the first reaction gas, the second reaction gas and the third reaction gas and H 2 are introduced into a second reaction device loaded with a catalyst (the above-mentioned multi-layer structure catalyst) for catalytic reaction to generate synthesis gas containing methanol; wherein, the volume fraction of water vapor in the mixed gas is 2-5%, the COD content ≤ 5 ppm, the volatile organic compound content ≤ 3 ppm, the acidic gas content ≤ 2 ppm, and the particulate matter content ≤ 20 mg / Nm 3 .

[0108] The catalyst in the first reaction device is a perovskite-type nickel-based composite catalyst. Dissolve soluble cerium salt and zirconium salt in deionized water, and the molar ratio of cerium ions to zirconium ions is 1; under stirring, add ammonia water to the solution until the pH is 9-10; then continue stirring for 2 h and age at 80 °C for 2 hours; after collecting, washing and drying the solid, calcine in air at 600 °C for 4 hours to obtain CeO 2 -ZrO 2 support;

[0109] Weigh soluble lanthanum salt, soluble strontium salt, soluble nickel salt, soluble ferric salt and soluble ruthenium salt according to the molar ratio of La, Sr, Ni, Fe, Ru of 0.8:0.2:0.7:0.2:0.1 and dissolve them in deionized water; according to the molar ratio of metal ions to citric acid of 1:1.5, add an appropriate amount of citric acid to the solution; stir and evaporate at 80 °C until a gel is formed; dry the gel at 120 °C for 12 hours to obtain a perovskite precursor;

[0110] Weigh the perovskite precursor and CeO 2 -ZrO 2The carrier was dispersed in a small amount of ethanol and mixed evenly. After stirring and evaporating the ethanol at 80 °C, it was first dried at 110 °C and then calcined in air at 900 °C for 6 hours to form a perovskite structure. Finally, it was reduced at 700 °C for 2 hours in a mixed atmosphere of H 2 and Ar, and a perovskite-type nickel-based composite catalyst was obtained.

[0111] Using this perovskite-type nickel-based composite catalyst to catalyze combustion tail gas (the volume fraction composition of one embodiment is: 5.68% CO, 74.32% CO 2 , 1.54% H 2 , 2.14% water vapor, and the balance is N 2 ) and methane. The volume ratio of combustion tail gas to methane is (1.05 - 1.5):1, the reaction temperature is 700 °C, the reaction pressure is 0.1 MPa, and the space velocity is 20000 h -1 , and the average CO 2 conversion rate is 81%.

[0112] Using the above multi-layer structure catalyst to catalyze the mixed gas (data of one embodiment is: 39.65% CO, 2.56% CO 2 , 38.56% H 2 , 2.68% water vapor, and the balance is N 2 ). The volume ratio of the mixed gas to the supplemented H 2 is (2.05 - 2.5):1, the reaction temperature is 240 °C (any temperature from 220 to 300 °C is acceptable), the reaction pressure is 4 MPa (any pressure from 3 to 10 MPa is acceptable), the space velocity is 6000 h -1 (any space velocity from 3000 to 10000 h -1 is acceptable), the space-time yield is 0.4 - 0.9 kg methanol / (L catalyst·h), and the purity of liquid methanol is above 95%.

[0113] The above has described the relevant content of the embodiments of the invention provided in this specification. Those of ordinary skill in the art will be able to implement the embodiments of the invention provided in this specification based on these descriptions. Based on the above content of the embodiments of the invention provided in this specification, all other preferred embodiments and examples obtained by those of ordinary skill in the art without creative efforts shall fall within the scope of protection of the embodiments of the invention provided in this specification.

Claims

1. A method for utilizing tail gas produced by bamboo activated carbon, wherein the tail gas produced includes carbonized tail gas generated by carbonizing bamboo raw materials, and the method is characterized in that: The exploitation method includes the following steps: Condensing the production tail gas to obtain condensate; Performing solid-liquid separation on the condensate to obtain a permeate; The permeate is subjected to extraction treatment using an extractant to obtain a first extractant-soluble liquid; The first extractant soluble liquid is subjected to reduced pressure distillation to obtain a distillate; The distillate is subjected to extraction treatment using an extractant and water to obtain a second extractant-soluble liquid; The second extractant soluble liquid is subjected to reduced pressure distillation to obtain biomass oil.

2. The method for utilizing tail gas produced by bamboo activated carbon according to claim 1, characterized in that: The condensation process is divided into two stages, firstly condensation is carried out at 70-100°C, and then condensation is carried out at 40-60°C.

3. The method for utilizing tail gas produced by bamboo activated carbon production as claimed in claim 1, characterized in that: The extractant is dichloromethane; the volume of the extractant is 1.5 to 2 times the volume of the permeate or the first biomass oil; the volume of water is 1 to 2 times the volume of the first biomass oil.

4. The method for utilizing tail gas produced by bamboo activated carbon production as claimed in claim 1, characterized in that: Keep stirring, first add the extractant dropwise, keep stirring for 10 to 20 minutes after the extractant is added, then add water dropwise, continue stirring for 20 to 40 minutes after the water is added, then seal and let stand for 24 to 72 hours, and finally obtain the second extractant soluble liquid by phase separation.

5. The method for utilizing tail gas produced by bamboo activated carbon production as claimed in claim 1, characterized in that: The reduced pressure distillation treatment is carried out at 30 to 35° C. and 15 to 18 kPa.

6. The method for utilizing tail gas produced by bamboo activated carbon production as claimed in claim 1, characterized in that: The method also includes distilling the biomass oil into solid at 200-250° C. under normal pressure. The utilization method also includes crushing, grinding and vacuum drying the solid to obtain solid biomass oil.

7. The method for utilizing tail gas produced by bamboo activated carbon production as claimed in claim 1, characterized in that: The method also includes distilling the biomass oil at 200-250°C under normal pressure into a concentrated liquid. The utilization method also includes performing a hydrogenation refining treatment on the concentrated liquid, including the steps of preparing a reaction liquid according to a mass ratio of biomass oil: methanol: catalyst of (15-25): (20-30): 1, and performing a hydrothermal reaction at 180-200°C and 1MPa hydrogen pressure for 2-4h to obtain refined biomass oil.

8. The method for utilizing tail gas produced by bamboo activated carbon production as claimed in claim 7, characterized in that: An activated carbon-based Ni / BC catalyst is used, and its preparation method is as follows: dispersing soluble nickel salt and activated carbon in ethanol, stirring for 4 to 6 hours; rotary evaporating at 80°C to completely remove the ethanol solvent and then drying in a vacuum oven; calcining at 500 to 600°C for 1 to 3 hours under a reducing atmosphere to obtain an activated carbon-based Ni / BC catalyst.

9. The method for utilizing tail gas produced by bamboo activated carbon production as claimed in claim 1, characterized in that: When the bamboo raw material is subjected to a segmented carbonization treatment, the produced tail gas at least includes segmented tail gas generated by the carbonization treatment at 300-400°C.

10. A method for producing bamboo activated carbon, comprising carbonizing bamboo raw materials, characterized in that: The method further comprises utilizing the production tail gas of bamboo activated carbon according to any one of claims 1 to 9, wherein the production tail gas at least comprises carbonized tail gas generated by carbonizing bamboo raw materials; The carbonization treatment includes at least one carbonization treatment, including the steps of: Put the dried bamboo raw material into the carbonization furnace, and raise the furnace temperature from room temperature to 130-280°C in an inert atmosphere, and keep it warm for 0.5-1.5 hours; Continue to raise the temperature to 300-400°C and keep it warm for 0.5-1.5 hours; Continue to raise the temperature to 500-600°C, keep warm for 0.5-1.5 hours, and then cool with the furnace to obtain the primary carbonized material; after the carbonization is completed, activate the material to obtain bamboo activated carbon.

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