Utilization system for tail gas in bamboo activated carbon production and bamboo activated carbon production system

Abstract

The utility model discloses a bamboo activated carbon production tail gas utilization system and a bamboo activated carbon production system. The utilization system comprises a first purification unit, a second purification unit and a third purification unit, wherein the first purification unit treats carbonized tail gas and then outputs first reaction gas and adsorption saturated liquid; the combustion equipment is used for carrying out combustion treatment on the adsorption saturated liquid and outputting combustion tail gas; the first reaction equipment is internally provided with a catalyst filler structure, and combustion tail gas and methane react in the first reaction equipment to generate second reaction gas containing H2 and CO; the second purification unit is used for treating the activated tail gas and then outputting third reaction gas; the second reaction equipment is internally provided with a catalyst filler structure, and a mixed gas formed by the first reaction gas, the second reaction gas and the third reaction gas is subjected to a catalytic reaction through a catalyst in the second reaction equipment to generate synthesis gas containing methanol.

Description

TECHNICAL FIELD

[0001] The utility model relates to the technical field of bamboo quality activated carbon production, specifically, relate to the utilization system of bamboo quality activated carbon production tail gas and bamboo quality activated carbon production system. BACKGROUND

[0002] Biomass energy is the fourth largest energy after coal, oil and natural gas. Biomass energy is energy with biomass as carrier, usually from firewood, straw, livestock manure and municipal solid waste, etc. Modern technology usually converts these biomass into solid, liquid or gaseous fuel for use. Bamboo energy is an important form of biomass energy, with the advantages of low pollution, wide distribution, large reserves and renewable. China is the country with the most abundant bamboo resources in the world, and has favorable conditions and environment for developing bamboo energy.

[0003] At present, an important use of bamboo resources in China is to prepare bamboo activated carbon. The preparation process mainly includes carbonization process and activation process, and the carbonization process can be one or two times. Twice carbonization usually refers to grinding, kneading, granulating the once carbonized material into special shapes such as columnar, honeycomb and spherical, and then performing secondary carbonization to remove the adhesive used in granulation. In addition to the activation process which produces a large amount of tail gas, the once carbonization process and the twice carbonization also produce a lot of tail gas, and the composition of the tail gas produced by the two carbonizations is obviously different.

[0004] In addition to the protective gas and water vapor, the main components of the tail gas produced by the once carbonization are CO, CO2, H2, volatile organic compounds (such as alkanes, alkenes, aldehydes, etc.), organic vapor (such as terpenes, tannins, methanol, etc.), and acid gases (such as formic acid, phenol, acetic acid, H2S, SO2, NH3, nitrogen oxides, etc.).

[0005] The tail gas produced by twice carbonization is quite different depending on the type of adhesive. For example, the main components of the tail gas of traditional twice carbonization with pitch or coal tar as adhesive are protective gas, water vapor, CO, CO2, volatile organic compounds (such as benzene, toluene, xylene, methyl phenol, ethyl phenol, etc.) and acid gases (such as phenol, formic acid, acetic acid, aldehydes, nitrogen oxides, etc.), which have great toxicity. When using high molecular adhesive (such as starch, molasses, carboxymethyl cellulose, lignin, gelatin, chitosan, etc.), the content of volatile organic compounds and acid gases in the twice carbonization tail gas is significantly reduced, and the main components are protective gas, water vapor, CO and CO2.

[0006] During the activation process, the activator reacts with carbon elements, causing the erosion of the pore channels to generate a large number of micropores. In addition to the protective gas and the activator (such as water vapor, CO2, and O2), the resulting activation exhaust gas also contains H2, CO, a small amount of volatile organic compounds (such as CH4, C2H4, and propylene), and acidic gases (such as phenol).

[0007] If the tail gas 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 and high-quality activated carbon from biomass and a preparation method thereof. In this method, the tail gas generated during the activation process is directly subjected to a water-gas shift reaction, followed by a CO hydrogenation reaction, and finally methanol is obtained. On the one hand, a large amount of tail gas generated during the carbonization process is not recycled and utilized, and on the other hand, directly synthesizing the activation tail gas can easily cause catalyst poisoning and result in low purity of methanol. Practical new type content

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

[0009] To achieve the above-mentioned purpose, according to the first aspect of the present utility model, a method and system for utilizing the tail gas generated during the production of bamboo activated carbon are provided, and the technical solution is as follows:

[0010] The method for utilizing the tail gas generated during the production of bamboo activated carbon includes the carbonization tail gas generated by carbonizing the bamboo raw material and the activation tail gas generated by activating the carbonized bamboo. The activation agent used in the activation process is water vapor. The utilization method includes the following steps:

[0011] The carbonization tail gas is sequentially subjected to condensation treatment, deacidification treatment, dust removal treatment, and adsorption treatment to obtain first reaction gas and adsorption saturated liquid;

[0012] The adsorption saturated liquid is subjected to combustion treatment to obtain combustion tail gas;

[0013] The combustion tail gas and methane are introduced into the first reaction equipment loaded with a catalyst to perform a catalytic reaction, and the reaction generates second reaction gas containing H2 and CO;

[0014] The activation tail gas is sequentially subjected to condensation treatment, deacidification treatment, dust removal treatment, and adsorption treatment to obtain third reaction gas;

[0015] The mixed gas composed of the first reaction gas, the second reaction gas, and the third reaction gas is introduced into the second reaction equipment loaded with a catalyst to perform a catalytic reaction, and the reaction generates synthesis gas containing methanol.

[0016] As a further improvement of the method for utilizing the tail gas produced in the production of bamboo activated carbon, the carbonized tail gas after dust removal treatment is adsorbed by alcohol.

[0017] As a further improvement of the method for utilizing the tail gas produced in the production of bamboo activated carbon, the activated tail gas after dust removal treatment is adsorbed by activated carbon.

[0018] As a further improvement of the method for utilizing the tail gas produced in the production of bamboo activated carbon, the water vapor volume fraction content in the mixed gas is 2-5%, the COD content is ≤5ppm, the volatile organic matter content is ≤3ppm, the acidic gas content is ≤2ppm, and the particulate matter content is ≤20mg / Nm 3 .

[0019] As a further improvement of the method for utilizing the tail gas produced in the production of bamboo activated carbon, H2 is also introduced into the second reaction device.

[0020] As a further improvement of the method for utilizing the tail gas produced in the production of bamboo activated carbon, the condensate obtained after condensing the carbonized tail gas is purified to obtain biomass oil.

[0021] As a further improvement of the method for utilizing the tail gas produced in the production of bamboo activated carbon, the catalyst in the first reactor is a perovskite type nickel-based composite catalyst. Preferably, the preparation method of the perovskite type nickel-based composite catalyst comprises the following steps:

[0022] Dissolve the soluble cerium salt and zirconium salt in deionized water; under the action of stirring, add ammonia water dropwise to the solution until the pH is 9-10; then continue stirring for 2h, and age at 70-90℃ for 2 hours; after collecting, washing and drying the solid, carry out calcination treatment in air to obtain a CeO2-ZrO2 carrier; further preferably, the molar ratio of cerium ions and zirconium ions is 1; the calcination temperature is 500-700℃, and the calcination time is 3-5 hours;

[0023] Dissolve the soluble lanthanum salt, the soluble strontium salt, the soluble nickel salt, the soluble trivalent iron salt and the soluble ruthenium salt in deionized water according to the molar ratio of La, Sr, Ni, Fe and Ru as 0.8:0.2:0.7:0.2:0.1; add an appropriate amount of citric acid to the solution; evaporate under stirring at 70-90℃ until a gel is formed; dry the gel at 110-130℃ for 12 hours to obtain a perovskite precursor; further preferably, the molar ratio of metal ions to citric acid is 1:(1.4-1.6);

[0024] The perovskite precursor and the CeO2-ZrO2 carrier are uniformly mixed by being dispersed in a small amount of ethanol; after the ethanol is evaporated by stirring at 70-90 DEG C, the perovskite structure is formed by first drying at 100-120 DEG C and then calcining in air, and finally the perovskite type nickel-based composite catalyst is obtained by reduction treatment in a reducing atmosphere.

[0025] As a further improvement of the above-mentioned method for utilizing the tail gas produced in the production of bamboo-based activated carbon: the catalyst in the second reaction device has a multi-layer structure, the core is Fe3O4, the inner layer is CeO2, the middle layer is Cu-Zn alloy, the outer layer is ZrO2, and the surface layer is graphene quantum dots. Preferably, the preparation method of the multi-layer structure catalyst comprises the following steps:

[0026] The Fe3O4 core is prepared by a coprecipitation method through the reaction of a soluble ferric salt, a soluble ferrous salt and ammonia water;

[0027] The CeO2 inner layer is loaded on the surface of the Fe3O4 core by a hydrothermal method through the reaction of a soluble cerium salt and urea;

[0028] The Cu-Zn alloy middle layer is deposited on the surface of the CeO2 inner layer by a chemical reduction method through the reaction of a soluble copper salt, a soluble zinc salt and sodium borohydride;

[0029] The ZrO2 outer layer is loaded on the surface of the Cu-Zn alloy middle layer by a sol-gel method through the reaction of n-butoxy zirconium, water and ethanol;

[0030] The graphene quantum dots are loaded on the surface of the ZrO2 outer layer by an impregnation method through impregnating a graphene quantum dot solution.

[0031] As a further improvement of the above-mentioned method for utilizing the tail gas produced in the production of bamboo-based activated carbon: it further includes calcination treatment and reduction treatment after loading the graphene quantum dots: the atmosphere of the calcination treatment is air, the temperature is 400-500 DEG C, and the time is 3-5 hours; the atmosphere of the reduction treatment is a mixture of N2 and H2, the temperature is 300-400 DEG C, and the time is 1-3 hours.

[0032] The utilization system of the tail gas produced in the production of bamboo activated carbon, the tail gas includes carbonization tail gas produced by carbonization treatment of bamboo raw materials and activation tail gas produced by activation treatment after carbonization, the activation agent used in the activation treatment is water vapor, the utilization system includes: a first purification unit including a first condensing device, a first deacidification device, a first dust removal device and a first adsorption device which sequentially perform condensing treatment, deacidification treatment, dust removal treatment and adsorption treatment on the carbonization tail gas; the first purification unit outputs first reaction gas and adsorption saturated liquid after processing the carbonization tail gas; a combustion device, the combustion device is used for combustion treatment of the adsorption saturated liquid and outputs combustion tail gas; the gas inlet of the combustion device is connected with the liquid outlet of the first adsorption device; a first reaction device, the first reaction device is provided with a catalyst packing structure, the combustion tail gas and methane react in the first reaction device to generate second reaction gas containing H2 and CO; the gas inlet of the first reaction device is connected with the gas outlet of the combustion device and the gas outlet of a methane conveying device; a second purification unit including a second condensing device, a second deacidification device, a second dust removal device and a second adsorption device which sequentially perform condensing treatment, deacidification treatment, dust removal treatment and adsorption treatment on the activation tail gas; the second purification unit outputs third reaction gas after processing the activation tail gas; a second reaction device, the second reaction device is provided with a catalyst packing structure, mixed gas composed of the first reaction gas, the second reaction gas and the third reaction gas generates synthetic gas containing methanol after catalytic reaction in the second reaction device; the gas inlet of the second reaction device is connected with the gas outlets of the first adsorption device, the first reaction device and the second adsorption device.

[0033] As a further improvement of the above-mentioned utilization system of the tail gas produced in the production of bamboo activated carbon: the first dust removal device and the second dust removal device are filters adopting porous metal filter cores.

[0034] As a further improvement of the above-mentioned utilization system of the tail gas produced in the production of bamboo activated carbon: the first deacidification device and the second deacidification device are dry deacidification towers.

[0035] As a further improvement of the above-mentioned utilization system of the tail gas produced in the production of bamboo activated carbon: the first adsorption device is an alcohol spraying tower.

[0036] As a further improvement of the above-mentioned utilization system of the tail gas produced in the production of bamboo activated carbon: the second adsorption device is provided with an activated carbon packing structure.

[0037] As a further improvement of the above-mentioned utilization system of the tail gas produced in the production of bamboo activated carbon: further including a hydrogen conveying device for inputting H2 into the second reaction device.

[0038] As a further improvement of the above-mentioned utilization system of the tail gas produced in the production of bamboo activated carbon: further including:

[0039] A third condensing device condenses the synthesis gas and outputs liquid methanol; the gas inlet of the third condensing device is connected with the gas outlet of the second reaction device;

[0040] A rectifying device rectifies the liquid methanol and outputs high-purity methanol; the liquid inlet of the rectifying device is connected with the liquid outlet of the third condensing device.

[0041] As a further improvement of the above-mentioned utilization system of the tail gas produced in the production of bamboo activated carbon, the fourth condensing device condenses the second reaction gas, and the gas outlet of the fourth condensing device is connected with the gas inlet of the second reaction device.

[0042] In order to achieve the above-mentioned purpose, according to the second aspect of the present application, the bamboo activated carbon production method and production system using the utilization method and utilization system of the tail gas produced in the production of bamboo activated carbon are provided, and the technical scheme is as follows:

[0043] The bamboo activated carbon production method comprises carbonization treatment and activation treatment of bamboo raw materials, and further comprises the utilization of the production tail gas by the utilization method of the tail gas produced in the production of bamboo activated carbon, wherein the production tail gas comprises carbonization tail gas produced in the carbonization treatment and activation tail gas produced in the activation treatment.

[0044] The carbonization treatment comprises the following steps:

[0045] The dried bamboo raw materials are placed in the carbonization furnace, the furnace temperature is increased from room temperature to 130-280 DEG C under inert atmosphere, and the temperature is kept for 0.5-1.5 hours;

[0046] The temperature is continuously increased to 300-400 DEG C, and the temperature is kept for 0.5-1.5 hours;

[0047] The temperature is continuously increased to 500-600 DEG C, and the temperature is kept for 0.5-1.5 hours, and then the carbonization material is obtained by cooling the furnace;

[0048] The activation treatment is that the carbonization material is placed in the activation furnace, water vapor is used as the activation agent under inert atmosphere, the temperature is kept for 2-4 hours at 800-1100 DEG C, and then the bamboo activated carbon is obtained by cooling the furnace.

[0049] The bamboo activated carbon production system comprises a carbonization furnace for carbonization treatment of bamboo raw materials and an activation furnace for activation treatment after carbonization, the activation agent used in the activation treatment is water vapor, and further comprises the utilization system of the tail gas produced in the production of bamboo activated carbon, wherein the production tail gas comprises carbonization tail gas produced in the carbonization treatment of the bamboo raw materials and activation tail gas produced in the activation treatment after carbonization.

[0050] The present application has the following advantages:

[0051] (1) Effective use of tail gas generated in the carbonization process and the activation process of bamboo raw materials, the tail gas is converted into synthesis gas including methanol through the catalytic reaction of CO and H2 (reaction equation: CO + 2H2→ CH3OH), and further through simple processing (such as rectification), high-purity liquid methanol can be obtained, which not only reduces the environmental pollution caused by tail gas emission, but also has a wide range of uses. Methanol is an important chemical raw material and fuel, which can be used as raw material for the production of formaldehyde, acetic acid, dimethyl ether, and bio-diesel, and can also be used as fuel and fuel additive, and the methanol can be sold to increase the economic benefits of the enterprise.

[0052] (2) According to the particularity of the carbonization tail gas and the activation tail gas, the carbonization tail gas and the activation tail gas are pretreated respectively, so that the water vapor, organic vapor, volatile organic compounds, acidic gas and particulate matter impurities are removed efficiently, which helps to improve the activity of the catalyst and the catalytic reaction efficiency, reduces the catalyst poisoning and equipment blockage and wear problems, and can significantly improve the purity of methanol. Among them, the condensate obtained after condensation of the carbonization tail gas contains a large amount of organic matter, which can be condensed into bio-oil with high calorific value, further creating revenue for the enterprise.

[0053] (3) By the reaction of CO2 and methane (reaction equation: CO2 + 2CH4→ 2CO + H2), a large amount of CO2 in the purified carbonization tail gas is converted into CO and H2 for the preparation of methanol, which can significantly improve the production efficiency of methanol and further improve the utilization rate of tail gas.

[0054] The embodiments of the invention provided in the specification will be further described below in conjunction with the drawings and specific embodiments. Additional aspects and advantages of the embodiments of the invention provided in the specification will be partially given in the following description, partially become apparent from the following description, or be understood by the practice of the embodiments of the invention provided in the specification. BRIEF DESCRIPTION OF DRAWINGS

[0055] The drawings constituting part of the specification of the embodiments of the invention provided in the specification are used to assist the understanding of the embodiments of the invention provided in the specification, and the content provided in the drawings and its related description in the embodiments of the invention provided in the specification can be used to explain the embodiments of the invention provided in the specification, but do not constitute improper limitation on the embodiments of the invention provided in the specification. In the drawings:

[0056] Figure 1 Structure schematic diagram of the first embodiment of the bamboo-based activated carbon production system and the utilization system of the bamboo-based activated carbon production tail gas.

[0057] Figure 2Structure schematic view of a second embodiment of a bamboo active carbon production system and a bamboo active carbon production tail gas utilization system.

[0058] The relevant marks in the above-mentioned drawings are:

[0059] 210 - first purification unit, 220 - combustion device, 230 - first reaction device, 240 - second purification unit, 250 - second reaction device, 260 - third condensing device, 270 - rectifying device, 280 - fourth condensing device. DETAILED DESCRIPTION

[0060] The embodiments of the application provided in the specification will be described in detail below with reference to the drawings. Those skilled in the art can implement the embodiments of the application provided in the specification based on these descriptions. Before the embodiments of the application provided in the specification are described in conjunction with the drawings, it should be particularly pointed out that:

[0061] The technical solutions and technical features provided in each part of the embodiments of the application provided in the specification, including the following descriptions, can be combined with each other without conflict.

[0062] In addition, the embodiments of the application provided in the specification involved in the following descriptions are generally only a part of the embodiments of the application provided in the specification rather than all the embodiments, and therefore, all other embodiments obtained by those skilled in the art based on the embodiments of the application provided in the specification without creative labor should belong to the protection scope of the embodiments of the application provided in the specification.

[0063] Regarding the terms and units in the embodiments of the application provided in the specification: the terms "include", "contain", "have" and any variants thereof in the specification and claims of the embodiments of the application provided in the specification and relevant parts are intended to cover non-exclusive inclusion. In addition, other related terms and units in the embodiments of the application provided in the specification can be reasonably interpreted based on the relevant content of the embodiments of the application provided in the specification.

[0064] The first embodiment of the bamboo active carbon production method of the utility model is including steps of:

[0065] Drying treatment: put fresh bamboo raw materials into an oven and dry for 48 hours at 100 DEG C.

[0066] Primary carbonization treatment: the dried bamboo raw material is put into a carbonization furnace, under inert atmosphere, the furnace temperature is raised from room temperature to 200 DEG C, and kept for 1 hour, then raised to 350 DEG C, and kept for 1 hour, then raised to 550 DEG C, and kept for 1 hour, and then cooled down with the furnace to obtain carbonized material.

[0067] Activation treatment: the carbonized material is put into an activation furnace, under inert atmosphere, water vapor is used as activation agent, the volume of liquid water per 100g blank body per hour is 40mL, and kept for 3 hours at 1000 DEG C, and then cooled down with the furnace to obtain bamboo activated carbon.

[0068] Compared with the first embodiment, the second embodiment of the bamboo activated carbon production method has the difference that: it further comprises secondary carbonization treatment: the primary carbonized material is ground to a particle size of 325 mesh, then molasses is used as adhesive, water is used as auxiliary agent, and the primary carbonized material is granulated into blank body in a kneader according to the mass ratio of molasses to primary carbonized material of 0.5, and 30mL auxiliary agent is added for every 100g primary carbonized material, the blank body is put into a carbonization furnace, under inert atmosphere, the furnace temperature is raised from room temperature to 550 DEG C, and kept for 1 hour, and then cooled down with the furnace to obtain secondary carbonized material, and then the secondary carbonized material is activated to obtain bamboo activated carbon.

[0069] In the carbonization tail gas, the H2 yield is less than the CO yield, usually, the volume fraction of CO is about 10-30%, the volume fraction of H2 is about 1.5-8%, and the volume fraction of CO2 is about 10-25%. But in the activation process, water vapor reacts with carbon to generate H2 and CO, and CO can further react with water vapor to generate CO2 and H2, so in the activation tail gas, CO2 and H2 are the main components, and the content of CO is relatively small. Therefore, the carbonization tail gas and the activation tail gas are used together, which can reduce the yield difference of CO and H2, and make CO and H2 more suitable for reaction to generate methanol.

[0070] The utilization method of the bamboo activated carbon production tail gas is used for utilizing the production tail gas generated by the bamboo activated carbon production method in the first embodiment or the second embodiment, that is, the production tail gas includes carbonization tail gas generated by primary carbonization treatment or primary carbonization treatment and secondary carbonization treatment, and activation tail gas generated by activation treatment after carbonization.

[0071] The first embodiment of the utilization method of the bamboo activated carbon production tail gas comprises the following steps:

[0072] The carbonization tail gas is sequentially subjected to condensation treatment, deacidification treatment, dust removal treatment and adsorption treatment to obtain first reaction gas and adsorption saturated liquid; wherein the deacidification treatment adopts dry deacidification, that is, spraying solid absorbent for deacidification, so that the residual acid gas in the carbonization tail gas can be removed by the deacidification treatment and relatively dry low-acid gas can be obtained, thereby avoiding the influence of the introduction of a large amount of water vapor by wet deacidification on the methanol synthesis reaction; the dust removal treatment is preferably filtration dust removal, and the dust removal treatment is arranged after the deacidification treatment, so that not only the particulate impurities carried by the carbonization tail gas can be removed, but also the deacidifying agent used in the deacidification treatment can be removed. The adsorption treatment uses alcohol as the adsorbent, which can adsorb volatile organic compounds in the carbonization tail gas and form first reaction gas and adsorption saturated liquid.

[0073] The adsorption saturated liquid is subjected to combustion treatment to obtain combustion tail gas; since the adsorption saturated liquid mainly contains volatile organic compounds, the combustion treatment of the adsorption saturated liquid can not only prevent environmental pollution caused by emission, but also generate a large amount of CO2 for reaction with methane.

[0074] The combustion tail gas and methane are introduced into the first reaction equipment loaded with a catalyst to perform catalytic reaction, and a second reaction gas containing H2 and CO is generated by the reaction.

[0075] The activated tail gas is sequentially subjected to condensation treatment, deacidification treatment, dust removal treatment and adsorption treatment to obtain third reaction gas; the volatile organic compounds in the activated tail gas are relatively small, so that the adsorption treatment here uses activated carbon for adsorption.

[0076] The mixed gas composed of the first reaction gas, the second reaction gas and the third reaction gas is introduced into the second reaction equipment loaded with a catalyst to perform catalytic reaction, and a synthesis gas containing methanol is generated; wherein the volume fraction content of water vapor in the mixed gas is 2-5%, the COD content is ≤5ppm, the volatile organic compound content is ≤3ppm, the acid gas content is ≤2ppm, and the particulate matter content is ≤20mg / Nm 3 .

[0077] The second embodiment of the method for utilizing the bamboo activated carbon production tail gas is: on the basis of the first embodiment, further comprising introducing H2 into the second reaction equipment.

[0078] Figure 1 The first embodiment of the structure schematic diagram of the bamboo activated carbon production system and the utilization system of the bamboo activated carbon production tail gas is shown in FIG. 1. Figure 1 As shown in FIG. 1, the bamboo activated carbon production system includes a carbonization furnace (1 or 2) for carbonization treatment of bamboo raw materials, an activation furnace for activation treatment after carbonization, and a utilization system of production tail gas, wherein the production tail gas includes carbonization tail gas discharged by the carbonization furnace (1 or 2) and activated tail gas discharged by the activation furnace.

[0079] The first embodiment of the utilization system of the bamboo activated carbon production tail gas comprises a first purification unit 210, a combustion device 220, a first reaction device 230, a second purification unit 240, and a second reaction device 250.

[0080] The first purification unit 210 comprises a first condensing device, a first deacidification device, a first dust removal device, and a first adsorption device, which sequentially perform condensing treatment, deacidification treatment, dust removal treatment, and adsorption treatment on the carbonization tail gas; and the first purification unit 210 outputs first reaction gas and adsorption saturated liquid after processing the carbonization tail gas.

[0081] The combustion device 220 is used for performing combustion treatment on the adsorption saturated liquid and outputting combustion tail gas, and the gas inlet of the combustion device 220 is connected with the liquid outlet of the first adsorption device.

[0082] The first reaction device 230 is provided with a catalyst packing structure, and the combustion tail gas and methane react in the first reaction device 230 to generate second reaction gas containing H2 and CO; and the gas inlet of the first reaction device 230 is connected with the gas outlet of the combustion device 220 and the gas outlet of the methane conveying device.

[0083] The second purification unit 240 comprises a second condensing device, a second deacidification device, a second dust removal device, and a second adsorption device, which sequentially perform condensing treatment, deacidification treatment, dust removal treatment, and adsorption treatment on the activation tail gas; and the second purification unit 240 outputs third reaction gas after processing the activation tail gas.

[0084] The second reaction device 250 is provided with a catalyst packing structure, and the mixed gas composed of the first reaction gas, the second reaction gas, and the third reaction gas and H2 react in the second reaction device 250 to generate synthesis gas containing methanol after being catalyzed by the catalyst; and the gas inlet of the second reaction device 250 is connected with the gas outlets of the first adsorption device, the first reaction device 230, and the second adsorption device, and is connected with the hydrogen conveying device.

[0085] The first dust removal device and the second dust removal device are filters adopting porous metal filter cores. The first deacidification device and the second deacidification device are dry deacidification towers. The first adsorption device is an alcohol spraying tower. The second adsorption device is provided with an activated carbon packing structure.

[0086] The volume fraction of H2 is slightly higher than twice the volume fraction of CO, which will be beneficial to the methanol synthesis reaction, and therefore, by supplementing H2 in the reaction gas after being processed by the adsorption device, the synthesis reaction can be promoted to proceed in the direction of generating methanol.

[0087] Figure 2 The second embodiment of the utilization system of the bamboo activated carbon production tail gas is shown in the structure schematic view. Figure 2As shown, compared with the first embodiment, the utilization system of the second embodiment further comprises a third condensing device 260, a rectifying device 270 and a fourth condensing device 280. The third condensing device 260 is used for condensing the synthesis gas, and outputs liquid methanol. The gas inlet of the third condensing device 260 is connected with the gas outlet of the second reaction device 250. The rectifying device 270 is used for rectifying the liquid methanol, and outputs high-purity methanol. The liquid inlet of the rectifying device 270 is connected with the liquid outlet of the third condensing device 260. The fourth condensing device 280 is used for condensing the second reaction gas, and the gas outlet of the fourth condensing device 280 is connected with the gas inlet of the second reaction device 250.

[0088] The catalyst in the first reaction device 230 is a perovskite nickel-based composite catalyst, and the preparation method thereof comprises the following steps:

[0089] Dissolve soluble cerium salt and zirconium salt in deionized water, and the molar ratio of cerium ions to zirconium ions is 1. Under stirring, drop ammonia water into the solution until the pH is 9-10. Then continue stirring for 2 hours, and aging at 80℃ for 2 hours. After collecting, washing and drying the solid, calcine it in air at 600℃ for 4 hours to obtain a CeO2-ZrO2 carrier.

[0090] According to the molar ratio of La, Sr, Ni, Fe and Ru being 0.8:0.2:0.7:0.2:0.1, weigh soluble lanthanum salt, soluble strontium salt, soluble nickel salt, soluble trivalent iron salt and soluble ruthenium salt, and dissolve them in deionized water. According to the molar ratio of metal ions to citric acid being 1:1.5, add an appropriate amount of citric acid into the solution. Stir and evaporate at 80℃ until a gel is formed. Dry the gel at 120℃ for 12 hours to obtain a perovskite precursor.

[0091] According to the loading amount of the perovskite precursor being 20%, weigh the perovskite precursor and the CeO2-ZrO2 carrier, and uniformly mix them in a small amount of ethanol. After stirring and evaporating ethanol at 80℃, first dry at 110℃, then calcine in air at 900℃ for 6 hours to form a perovskite structure, and finally reduce in a mixed atmosphere of H2 and Ar at 700℃ for 2 hours to obtain a perovskite nickel-based composite catalyst.

[0092] Use the perovskite nickel-based composite catalyst to catalyze combustion tail gas (the volume percentage of one embodiment is: 5.68% CO, 74.32% CO2, 1.54% H2, 2.14% water vapor, and the balance is N2) and methane. The volume ratio of the combustion tail gas to methane is (1.05-1.5):1, the reaction temperature is 700℃, the reaction pressure is 0.1 MPa, the space velocity is 20000h-1, and the average CO2 conversion rate is 81%. -1 ​

[0093] The catalyst in the second reaction device 250 has a multi-layer structure, the core of which is Fe3O4, the inner layer is CeO2, the middle layer is Cu-Zn alloy, the outer layer is ZrO2, and the surface layer is graphene quantum dots, and the preparation method comprises the following steps:

[0094] Fe3O4 core prepared by coprecipitation method: FeCl3·6H2O, FeCl2·4H2O and ammonia are used as raw materials, and equal volume of Fe 3+ solution and Fe 2+ solution are mixed, and the molar ratio of Fe 3+ and Fe 2+ is 2:1; the mixed solution is heated to 80°C, ammonia is added to the mixed solution at a stirring speed of 500 rpm until the pH is 10-11; after continuing to react for 30 minutes, magnetic separation is carried out, the collected solid is washed with deionized water and ethanol for 3 times, and vacuum drying at 60°C for 12 hours, to obtain the Fe3O4 core.

[0095] CeO2 inner layer prepared by hydrothermal method: Ce(NO3)3·6H2O and urea are dissolved in water, the concentration of Ce 3+ is 0.05M, and the concentration of urea is 0.5M; 1g Fe3O4 core is dispersed in 150mL of the above solution, transferred to a hydrothermal reaction kettle, and reacted at 180°C for 12 hours; after cooling to room temperature, centrifugal separation is carried out, the collected solid is washed with water and ethanol for 3 times, dried at 60°C for 12 hours, and then calcined at 350°C for 2 hours, to coat the CeO2 inner layer on the surface of the Fe3O4 core, to obtain CeO2@Fe3O4.

[0096] Cu-Zn alloy middle layer prepared by chemical reduction method: Cu(NO3)2·3H2O and Zn(NO3)2·6H2O are dissolved in water, the concentration of Cu 2+ is 0.1M, and the concentration of Zn 2+ is 0.05M; 0.8g CeO2@Fe3O4 is dispersed in 100mL of the above solution, ultrasonic for 30 minutes; in an ice bath, NaBH4 solution (concentration of 0.2M) is slowly added dropwise until a precipitate is formed; then after stirring at room temperature for 2 hours, centrifugal separation is carried out, the collected solid is washed with water and ethanol for 3 times, and vacuum drying at 50°C for 8 hours, to deposit the Cu-Zn alloy middle layer on the surface of the CeO2 inner layer, to obtain Cu-Zn@CeO2@Fe3O4.

[0097] Preparation of ZrO2 outer layer by sol-gel method: Zr(OC4H9)4 is dissolved in ethanol, and the concentration of Zr(OC4H9)4 is 0.1 M; a small amount of water (water / Zr molar ratio = 2) and 0.6 g of Cu-Zn@CeO2@Fe3O4 are added to 100 mL of the above solution, and stirred at room temperature for 4 hours; then centrifugal separation is performed after refluxing at 60°C for 2 hours, drying at 80°C for 12 hours, and then calcining at 450°C for 3 hours, so as to coat ZrO2 outer layer on the surface of the Cu-Zn alloy intermediate layer, and obtain ZrO2@Cu-Zn@CeO2@Fe3O4.

[0098] Preparation of graphene quantum dots (GQDs) by impregnation method: prepare a GQDs aqueous solution with a concentration of 1 mg / mL; then disperse 0.5 g of ZrO2@Cu-Zn@CeO2@Fe3O4 in 100 mL of the GQDs aqueous solution; perform ultrasonic treatment for 30 minutes, then centrifugal separation after stirring at room temperature for 4 hours, and vacuum drying at 50°C for 12 hours, so as to load graphene quantum dots on the surface of the ZrO2 outer layer, and obtain GQDs@ZrO2@Cu-Zn@CeO2@Fe3O4.

[0099] Calcination treatment: GQDs@ZrO2@Cu-Zn@CeO2@Fe3O4 is calcined at 450°C for 4 hours in air, and a precursor is obtained.

[0100] Reduction treatment: the precursor is reduced at 350°C for 2 hours in a mixed gas atmosphere of N2 and H2 (the volume fraction of H2 is 10%), and a catalyst is obtained.

[0101] The prepared catalyst has a multi-layer structure and each structural layer has excellent performance. The Fe3O4 core facilitates magnetic separation and recovery of the catalyst, the CeO2 inner layer can provide high oxygen storage capacity and oxygen vacancies to promote the reaction, the Cu-Zn alloy intermediate layer provides the main catalytic active sites, the ZrO2 outer layer can enhance the stability and sintering resistance of the catalyst, and the graphene quantum dot surface layer can enhance electron transfer and improve catalytic activity. Through the synergistic effect of each structural layer, the catalyst has high catalytic activity, can promote the reaction of CO and H2 at a lower temperature, and improves the catalytic reaction efficiency. The preparation method adopted is simple, and the reaction activity and stability of the obtained catalyst are strong, which helps to improve the stability of the synthesis gas production process and reduce the updating frequency of the catalyst, thereby saving long-term operating costs. Through the catalytic reaction technology, the effective conversion of the tail gas produced in the production of bamboo activated carbon is realized, which is an innovative green chemical process, conforms to the global trend of promoting green production and reducing carbon emissions, and has a significant popularization effect on the development and application of bamboo resources.

[0102] The mixed gas (one example data: 39.65% CO, 2.56% CO2, 38.56% H2, 2.68% water vapor, and the balance is N2) is catalyzed by the catalyst with the pair of layers, the volume ratio of the mixed gas to the supplemented H2 is (2.05-2.5):1, the reaction temperature is 240°C (220-300°C is also available), the reaction pressure is 4 MPa (3-10 MPa is also available), and the space velocity is 6000h-1 (3000-10000h-1 is also available), and the space-time yield of the liquid methanol is 0.4-0.9 kg / (L of catalyst.h). -1 (3000-10000h -1 is also available), and the space-time yield of the liquid methanol is 0.4-0.9 kg / (L of catalyst.h).

[0103] The condensate obtained after condensation of the carbonization tail gas contains a large amount of organic matter, which can be condensed into bio-oil with high heat value. In order to deeply recover the valuable resources of the production tail gas, the utilization method of the bamboo-based activated carbon production tail gas further utilizes the condensate recovered by the condensation equipment. Based on the second embodiment, the third embodiment further includes the following steps:

[0104] The condensate obtained by condensing the carbonization tail gas is subjected to solid-liquid separation treatment to obtain a permeate. The solid-liquid separation treatment is filtration treatment or centrifugal separation treatment, so that the particulate impurities captured by liquid droplets in the condensation process can be removed.

[0105] The permeate is subjected to membrane separation treatment by using a nanofiltration membrane to obtain an oily liquid. Preferably, the membrane separation treatment is vacuum suction filtration treatment of the permeate, the vacuum degree is 100 mmHg, the temperature is 40°C, and the pore size of the nanofiltration membrane is 5 nm. By using the nanofiltration membrane, water can pass through, and most of the organic matter is effectively intercepted, so that most of the organic matter is enriched in the oily liquid.

[0106] The oily liquid is subjected to extraction treatment by using an extractant to obtain an extractant-soluble liquid. Preferably, the extractant is ethanol and / or acetone, and the volume of the extractant is 2 times the volume of the condensate.

[0107] The extractant-soluble liquid is subjected to vacuum distillation treatment at 50°C and 16 kPa to obtain bio-oil. By vacuum distillation treatment, the extractant can be evaporated and condensed, and the condensate obtained by vacuum distillation treatment can be repeatedly used for extraction treatment of the oily liquid, so that the utilization rate of the extractant can be improved.

[0108] Unlike the third embodiment, the fourth embodiment of the utilization method of the bamboo-based activated carbon production tail gas is as follows:

[0109] The condensate obtained by condensing the carbonization tail gas is subjected to solid-liquid separation treatment to obtain a permeate. The solid-liquid separation treatment is filtration treatment or centrifugal separation treatment, so that the particulate impurities captured by liquid droplets in the condensation process can be removed.

[0110] The extractant is used to extract the permeate liquid to obtain a first extractant-soluble liquid.

[0111] The first extractant-soluble liquid is subjected to vacuum distillation at 35°C and 16kPa to obtain a distillation liquid. The extractant can be evaporated and condensed by the vacuum distillation, and the condensate obtained by the vacuum distillation can be repeatedly used to extract the permeate liquid, thereby improving the utilization rate of the extractant.

[0112] The distillation liquid is subjected to extraction with the extractant and water to obtain a second extractant-soluble liquid. Preferably, in specific implementation, stirring is maintained, the extractant is first added dropwise, stirring is maintained for 15 minutes after the addition of the extractant is completed, then water is added dropwise, stirring is continued for 30 minutes after the addition of water is completed, then it is sealed and left to stand for 48 hours, and finally the second extractant-soluble liquid is obtained by phase separation.

[0113] The second extractant-soluble liquid is subjected to vacuum distillation at 35°C and 16kPa to obtain a biomass oil. The extractant can be evaporated and condensed by the vacuum distillation, and the condensate obtained by the vacuum distillation can be repeatedly used to extract the permeate liquid, thereby improving the utilization rate of the extractant.

[0114] The extractant is dichloromethane; preferably, the volume of the extractant is 2 times the volume of the permeate liquid or the first biomass oil; and the volume of the water is 1.5 times the volume of the first biomass oil.

[0115] The second embodiment of the utilization method of the tail gas produced in the production of bamboo activated carbon is that, on the basis of the first embodiment, the biomass oil is subjected to atmospheric distillation at 200-250°C (preferably 235°C) to obtain a solid, and the utilization method further includes crushing, grinding and vacuum drying the solid to obtain a solid biomass oil.

[0116] In the third and fourth embodiments, the biomass oil can be subjected to atmospheric distillation at 200-250°C to obtain a solid or a concentrated liquid. For the solid, crushing, grinding and vacuum drying are performed to obtain a solid biomass oil; for the concentrated liquid, hydrofining treatment is performed, including the steps of: preparing a reaction liquid according to a mass ratio of biomass oil:methanol: catalyst of 20:25:1, and subjecting to hydrothermal reaction at 190°C and 1MPa hydrogen pressure for 3h to obtain a refined biomass oil; using an activated carbon-based Ni / BC catalyst, the preparation method of which is: dispersing 0.5g of nickel nitrate and 1g of activated carbon in ethanol, stirring for 5h; after complete rotary evaporation of the ethanol solvent at 80°C, drying in a vacuum oven; using 20% H2-Ar as a reducing atmosphere, calcining at 550°C for 2h to obtain the activated carbon-based Ni / BC catalyst.

[0117] The above description is provided on the basis of the embodiments of the present application provided in the present specification. A person of ordinary skill in the art will be able to implement the embodiments of the present application provided in the present specification on the basis of the above description. Based on the above description of the embodiments of the present application provided in the present specification, all other preferred embodiments and examples obtained by a person of ordinary skill in the art without creative labor should belong to the scope of protection of the embodiments of the present application provided in the present specification.

Claims

1. A system for utilizing exhaust gas from bamboo activated carbon production, wherein the exhaust gas includes carbonization exhaust gas generated from carbonization of bamboo raw materials and activation exhaust gas generated from activation treatment after carbonization, wherein the activating agent used in the activation treatment is water vapor, characterized in that: The system includes: The first purification unit (210) includes a first condensing device, a first deacidifying device, a first dust removal device, and a first adsorption device that sequentially perform condensation treatment, deacidification treatment, dust removal treatment, and adsorption treatment on the carbonization tail gas; after processing the carbonization tail gas, the first purification unit (210) outputs a first reaction gas and an adsorbed saturated liquid. Combustion device (220) is used to combust saturated adsorbed liquid and output combustion exhaust gas; the inlet of the combustion device (220) is connected to the liquid outlet of the first adsorption device. The first reaction device (230) is equipped with a catalyst packing structure. The combustion exhaust gas and methane react in the first reaction device (230) to generate a second reaction gas containing H2 and CO. The inlet of the first reaction device (230) is connected to the outlet of the combustion device (220) and the outlet of the methane conveying device. The second purification unit (240) includes a second condensation device, a second deacidification device, a second dust removal device, and a second adsorption device that sequentially perform condensation treatment, deacidification treatment, dust removal treatment, and adsorption treatment on the activated tail gas; the second purification unit (240) outputs a third reaction gas after treating the activated tail gas; The second reaction device (250) is equipped with a catalyst packing structure. The mixture of the first reaction gas, the second reaction gas and the third reaction gas is catalyzed by the catalyst in the second reaction device (250) to generate synthesis gas containing methanol. The gas inlet of the second reaction device (250) is connected to the gas outlet of the first adsorption device, the first reaction device (230) and the second adsorption device.

2. The system for utilizing tail gas from bamboo activated carbon production as described in claim 1, characterized in that: The first dust removal device and the second dust removal device are filters using porous metal filter elements.

3. The system for utilizing tail gas from bamboo activated carbon production as described in claim 1, characterized in that: The first and second deacidification devices are dry deacidification towers.

4. The system for utilizing tail gas from bamboo activated carbon production as described in claim 1, characterized in that: The first adsorption device is an alcohol spray tower.

5. The system for utilizing tail gas from bamboo activated carbon production as described in claim 1, characterized in that: The second adsorption device is equipped with an activated carbon packing structure.

6. The system for utilizing tail gas from bamboo activated carbon production as described in claim 1, characterized in that: It also includes a hydrogen delivery device for introducing H2 into the second reaction device (250).

7. The system for utilizing exhaust gas from bamboo activated carbon production as described in claim 1, characterized in that: Also includes: The third condensing device (260) condenses the synthesis gas and outputs liquid methanol; the inlet of the third condensing device (260) is connected to the outlet of the second reaction device (250). A distillation apparatus (270) is used to distill liquid methanol to output high-purity methanol; the inlet of the distillation apparatus (270) is connected to the outlet of a third condenser (260).

8. The system for utilizing tail gas from bamboo activated carbon production as described in claim 1, characterized in that: It also includes a fourth condensation device (280) for condensing the second reaction gas, the outlet of which is connected to the inlet of the second reaction device (250).

9. A bamboo activated carbon production system, comprising a carbonization furnace for carbonizing bamboo raw materials and an activation furnace for activating the carbonized material, wherein the activating agent used in the activation treatment is steam, characterized in that: It also includes a system for utilizing the tail gas from the production of bamboo activated carbon as described in any one of claims 1-8, wherein the tail gas includes carbonization tail gas generated from carbonization of bamboo raw materials and activation tail gas generated from activation treatment after carbonization.

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