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

Abstract

The invention belongs to the technical field of bamboo activated carbon production, and discloses a utilization method of bamboo activated carbon production tail gas and a bamboo activated carbon production method. The utilization method comprises the following steps: sequentially carrying out condensation treatment, deacidification treatment, dust removal treatment and adsorption treatment on carbonized tail gas to obtain first reaction gas and adsorption saturated liquid; carrying out combustion treatment on the adsorption saturated liquid to obtain combustion tail gas; the combustion tail gas and methane are introduced into first reaction equipment loaded with a catalyst for a catalytic reaction, and second reaction gas containing H2 and CO is generated through the reaction; sequentially carrying out condensation treatment, deacidification treatment, dust removal treatment and adsorption treatment on the activated tail gas to obtain third reaction gas; and introducing a mixed gas composed of the first reaction gas, the second reaction gas and the third reaction gas into a second reaction device loaded with a catalyst, and carrying out a catalytic reaction to generate a synthesis gas containing methanol. The method is simple and efficient, and can convert the bamboo activated carbon production tail gas into clean energy.

Description

Technical Field

[0001] The invention relates to the technical field of bamboo activated carbon production, and in particular to a method for utilizing tail gas produced from 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 energy based on biomass, usually from firewood, straw, livestock manure and urban garbage. Modern technology usually converts these biomass into solid, liquid or gaseous fuels for use. Bamboo energy is an important form of biomass energy, with the advantages of low pollution, wide distribution, large reserves and renewable. my country is the country with the richest bamboo resources in the world and has favorable conditions and environment for the development of bamboo energy.

[0003] At present, an important use of bamboo resources in my country is to prepare bamboo activated carbon. The preparation process mainly includes carbonization process and activation process. The carbonization process can be one or two times. Secondary carbonization usually refers to grinding, kneading, and granulating the primary carbonized material obtained by the first carbonization into special shapes such as columns, honeycombs, and spheres, and then performing secondary carbonization to remove the adhesive used for granulation. In addition to the activation process, which will produce a large amount of exhaust gas, the primary carbonization process and the secondary carbonization will also produce a lot of exhaust gas, and the exhaust gas components produced by the two carbonizations are significantly different.

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

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

[0006] During the activation process, the activator reacts with the carbon element, causing pore erosion to generate a large number of micropores. The main components of the activated exhaust gas obtained are the protective gas, the activator (such as water vapor, CO 2 , O 2 ), it also contains H 2 , CO, a small amount of volatile organic compounds (such as CH 4 , C 2 H 4 , propylene), 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 from biomass and co-producing high-quality activated carbon and its preparation method. This method directly performs a water-gas change reaction on the tail gas generated during the activation process, and then performs 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 performing a synthesis reaction on the activated 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 bamboo activated carbon production tail gas, which can convert bamboo activated carbon production tail gas into clean energy, as well as a bamboo activated carbon production method and system.

[0009] In order to achieve the above-mentioned object, according to the first aspect of the present invention, a method and system for utilizing tail gas produced by bamboo activated carbon are provided, and the technical scheme is as follows:

[0010] The method for utilizing tail gas produced by bamboo activated carbon includes carbonized tail gas produced by carbonizing bamboo raw materials and activated tail gas produced by activation treatment after carbonization, and the activating agent used in the activation treatment is water vapor. The method for utilizing the tail gas 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 a first reaction gas and adsorption saturated liquid;

[0012] The adsorbed saturated liquid is combusted to obtain combustion tail gas;

[0013] The combustion tail gas and methane are introduced into a first reaction device loaded with a catalyst for catalytic reaction to generate H 2 and a second reaction gas of CO;

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

[0015] A mixed gas consisting of the first reaction gas, the second reaction gas and the third reaction gas is introduced into a second reaction device loaded with a catalyst for catalytic reaction to generate a synthesis gas containing methanol.

[0016] As a further improvement to the above-mentioned method for utilizing tail gas from bamboo activated carbon production: alcohol is used to adsorb the carbonized tail gas after dust removal.

[0017] As a further improvement to the above-mentioned method for utilizing tail gas produced by bamboo activated carbon: activated carbon is used to adsorb the activated tail gas after dust removal treatment.

[0018] As a further improvement of the above-mentioned bamboo activated carbon production tail gas utilization method: 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 acid gas content is ≤2ppm, and the particulate matter content is ≤20mg / Nm 3 .

[0019] As a further improvement of the above-mentioned method for utilizing tail gas produced by bamboo activated carbon, it further comprises introducing H 2 .

[0020] As a further improvement of the above-mentioned method for utilizing tail gas produced by bamboo activated carbon: it also includes purifying the condensate obtained after condensing the carbonized tail gas to obtain biomass oil.

[0021] As a further improvement of the above-mentioned method for utilizing tail gas produced by 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 soluble cerium salt and zirconium salt in deionized water; add ammonia water to the solution under stirring until the pH is 9-10; then continue stirring for 2 hours and age at 70-90°C for 2 hours; collect, wash and dry the solid, and then calcine in air to obtain CeO 2 -ZrO 2 carrier; further preferably, the molar ratio of cerium ions to zirconium ions is 1; the calcination temperature is 500 to 700° C., and the calcination time is 3 to 5 hours;

[0023] According to the molar ratio of La, Sr, Ni, Fe and Ru being 0.8:0.2:0.7:0.2:0.1, soluble lanthanum salt, soluble strontium salt, soluble nickel salt, soluble trivalent iron salt and soluble ruthenium salt are weighed and dissolved in deionized water; an appropriate amount of citric acid is added to the solution; stirring and evaporating at 70-90° C. until a gel is formed; drying the gel at 110-130° C. for 12 hours to obtain a perovskite precursor; more preferably, the molar ratio of metal ions to citric acid is 1:(1.4-1.6);

[0024] The perovskite precursor and CeO 2 -ZrO 2 The carrier is dispersed in a small amount of ethanol and mixed uniformly; after stirring at 70-90°C to evaporate the ethanol, it is first dried at 100-120°C, then calcined in air to form a perovskite structure, and finally reduced in a reducing atmosphere to obtain a perovskite-type nickel-based composite catalyst. Further preferably, the perovskite precursor and CeO are weighed according to the loading amount of the perovskite precursor being 15-25%. 2 -ZrO 2 Carrier; the calcination temperature is 800-1000°C, and the calcination time is 4-8 hours; the reduction temperature is 600-800°C, and the reduction time is 1-3 hours.

[0025] As a further improvement of the above-mentioned method for utilizing tail gas produced by bamboo activated carbon: the catalyst in the second reaction device has a multi-layer structure, the core of which is Fe 3 O 4 , the inner layer is CeO 2 , the middle layer is Cu-Zn alloy, the outer layer is ZrO 2 , the surface layer is graphene quantum dots. Preferably, the preparation method of the multilayer catalyst comprises the following steps:

[0026] The Fe2O3 was prepared by the coprecipitation method through the reaction of soluble ferric salt, soluble ferrous salt and ammonia water. 3 O 4 core;

[0027] The hydrothermal method was used to react soluble cerium salt with urea in Fe 3 O 4 Core surface loaded with CeO 2 Inner layer;

[0028] The chemical reduction method is to react soluble copper salt, soluble zinc salt and sodium borohydride on CeO 2 A Cu-Zn alloy intermediate layer is deposited on the surface of the inner layer;

[0029] ZrO was loaded on the surface of Cu-Zn alloy interlayer by reaction of n-butoxide zirconium, water and ethanol using sol-gel method. 2Outer layer;

[0030] The impregnation method was used to impregnate the graphene quantum dot solution in ZrO 2 The outer surface is loaded with graphene quantum dots.

[0031] As a further improvement of the above-mentioned method for utilizing tail gas produced by bamboo activated carbon, the method further includes calcining and reducing the graphene quantum dots after loading them: the calcining atmosphere is air, the temperature is 400-500°C, and the duration is 3-5 hours; the reducing atmosphere is N 2 and H 2 The mixture has a temperature of 300-400°C and a duration of 1-3 hours.

[0032] A system 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 activated tail gas generated by activation treatment after carbonization, wherein the activating agent used in the activation treatment is water vapor, and 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 that sequentially perform condensation treatment, deacidification treatment, dust removal treatment and adsorption treatment on the carbonized tail gas; the first purification unit outputs a first reaction gas and adsorption saturated liquid after treating the carbonized tail gas; a combustion device, wherein the combustion device is used to perform combustion treatment on the adsorption saturated liquid and output combustion tail gas; the air inlet of the combustion device is connected to the liquid outlet of the first adsorption device; a first reaction device, wherein a catalyst filler structure is provided in the first reaction device, and the combustion tail gas and methane react in the first reaction device to generate a catalyst containing H 2 and a second reaction gas of CO; the air inlet of the first reaction equipment is connected to the air outlet of the combustion equipment and the air outlet of the methane conveying equipment; the second purification unit comprises a second condensing equipment, a second deacidification equipment, a second dust removal equipment and a second adsorption equipment which sequentially perform condensation treatment, deacidification treatment, dust removal treatment and adsorption treatment on the activated tail gas; the second purification unit outputs a third reaction gas after treating the activated tail gas; the second reaction equipment, the second reaction equipment is provided with a catalyst filling structure, and the mixed gas composed of the first reaction gas, the second reaction gas and the third reaction gas is catalyzed in the second reaction equipment to generate a synthesis gas containing methanol; the air inlet of the second reaction equipment is connected to the air outlets of the first adsorption equipment, the first reaction equipment and the second adsorption equipment.

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

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

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

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

[0037] As a further improvement of the above-mentioned bamboo activated carbon production tail gas utilization system, it also includes inputting H 2 Hydrogen delivery equipment.

[0038] As a further improvement of the above-mentioned bamboo activated carbon production tail gas utilization system: it also includes:

[0039] a third condensing device, which condenses the synthesis gas and outputs liquid methanol; an air inlet of the third condensing device is connected to an air outlet of the second reaction device;

[0040] A distillation device is provided, wherein the distillation device performs distillation treatment on liquid methanol to output high-purity methanol; a liquid inlet of the distillation device is connected to a liquid outlet of the third condensing device.

[0041] As a further improvement of the above-mentioned bamboo activated carbon production tail gas utilization system: it also includes a fourth condensing device for condensing the second reaction gas, and the gas outlet of the fourth condensing device is connected to the gas inlet of the second reaction device.

[0042] In order to achieve the above object, according to the second aspect of the present invention, a bamboo activated carbon production method and production system using the bamboo activated carbon production tail gas utilization method and utilization system described in the first aspect are provided, and the technical scheme is as follows:

[0043] A method for producing bamboo activated carbon, comprising carbonizing and activating bamboo raw materials, and further comprising utilizing the production tail gas of bamboo activated carbon according to the first aspect, wherein the production tail gas comprises carbonized tail gas generated by carbonization treatment and activated tail gas generated by activation treatment;

[0044] The carbonization process comprises the steps of:

[0045] 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;

[0046] Continue to raise the temperature to 300-400°C and keep it warm for 0.5-1.5 hours;

[0047] 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 carbonized material;

[0048] The activation treatment is as follows: putting the carbonized material into an activation furnace, in an inert atmosphere, using water vapor as an activating agent, keeping the temperature at 800-1100° C. for 2-4 hours, and then cooling with the furnace to obtain bamboo activated carbon.

[0049] The bamboo activated carbon production system includes a carbonization furnace for carbonizing bamboo raw materials and an activation furnace for activating bamboo raw materials after carbonization, wherein the activating agent used in the activation treatment is water vapor. The system also includes a utilization system for bamboo activated carbon production tail gas as described in the first aspect, wherein the production tail gas includes the carbonization tail gas generated by carbonizing bamboo raw materials and the activation tail gas generated by activating bamboo raw materials after carbonization.

[0050] The present invention has the following advantages:

[0051] (1) Effectively utilize the tail gas generated during the carbonization and activation process of bamboo raw materials through CO and H 2 The catalytic reaction converts the tail gas into synthesis gas including methanol (reaction equation: CO+2H 2 →CH 3 OH), and further through simple treatment (such as distillation), liquid methanol with higher purity can be obtained, which not only reduces the pollution of tail gas emissions to the environment, but also has a wide range of uses. Methanol is an important chemical raw material and fuel. For example, it can be used as a raw material for the production of formaldehyde, acetic acid, dimethyl ether, and biodiesel. It can also be used as a fuel or fuel additive. Methanol can be sold to increase the economic benefits of the enterprise.

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

[0053] (3) Through CO 2 Reaction with methane (reaction equation: CO 2 +2CH 4 →2CO+H 2 ), a large amount of CO in the purified carbonized tail gas 2 Converted into CO and H for methanol production 2 , which can significantly improve the production efficiency of methanol and further improve the utilization rate of tail gas.

[0054] The following is a further description of the embodiments of the invention provided in this specification in conjunction with the accompanying drawings and specific implementation methods. Additional aspects and advantages of the embodiments of the invention provided in this specification will be partially given in the following description, and partially 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

[0055] The drawings that constitute part of the embodiments of the inventions provided in this specification are used to assist in understanding the embodiments of the inventions provided in this specification. The contents provided in the drawings and the related descriptions in the embodiments of the inventions provided in this specification can be used to explain the embodiments of the inventions provided in this specification, but do not constitute improper limitations on the embodiments of the inventions provided in this specification. In the drawings:

[0056] Figure 1 It is a structural schematic diagram of a first embodiment of a bamboo activated carbon production system and a bamboo activated carbon production tail gas utilization system.

[0057] Figure 2 It is a structural schematic diagram of a second embodiment of a bamboo activated carbon production system and a bamboo activated carbon production tail gas utilization system.

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

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

[0060] The following is a clear and complete description of the embodiments of the inventions provided in this specification in conjunction with the accompanying drawings. A person of ordinary skill in the art will be able to implement the embodiments of the inventions provided in this specification based on these descriptions. Before describing the embodiments of the inventions provided in this specification in conjunction with the accompanying drawings, it should be particularly noted that:

[0061] The technical solutions and technical features provided in each part of the embodiments of the invention provided in this specification, including the following description, may be combined with each other if there is no conflict.

[0062] In addition, the embodiments of the inventions provided in this specification involved in the following descriptions are generally only a partial embodiment of the embodiments of the inventions provided in this specification rather than all the embodiments. Therefore, based on the embodiments of the inventions provided in this specification, all other embodiments obtained by ordinary technicians in this field without making any creative work should fall within the scope of protection of the embodiments of the inventions provided in this specification.

[0063] Regarding the terms and units in the embodiments of the inventions provided in this specification: The terms "including", "comprising", "having" and any variations thereof in the descriptions and claims of the embodiments of the inventions provided in this specification and in the related parts are intended to cover non-exclusive inclusions. In addition, other relevant terms and units in the embodiments of the inventions provided in this specification can be reasonably interpreted based on the relevant contents of the embodiments of the inventions provided in this specification.

[0064] The first embodiment of the method for producing bamboo activated carbon of the present invention comprises the following steps:

[0065] Drying treatment: Put the fresh bamboo raw materials into an oven and dry them at 100℃ for 48 hours.

[0066] Primary carbonization treatment: put the dried bamboo raw material into the carbonization furnace, and 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 and keep it warm for 1 hour, then cool it with the furnace to obtain the carbonized material.

[0067] Activation treatment: put the carbonized material into an activation furnace under an inert atmosphere, use water vapor as an activating agent, and introduce 40 mL of liquid water per 100 g of the green body per hour. After keeping warm at 1000°C for 3 hours, cool it with the furnace to obtain bamboo activated carbon.

[0068] Compared with the first embodiment, the second embodiment of the method for producing bamboo activated carbon of the present invention has the following differences: it also includes a secondary carbonization treatment: the primary carbonized material is ground to a particle size of 325 meshes, and then molasses is used as a binder and water is used as an auxiliary agent, and molasses is used as a binder and water is used as an auxiliary agent. The mass ratio of molasses to the primary carbonized material is 0.5, and 30 mL of auxiliary agent is added to each 100 g of the primary carbonized material. The green body is granulated in a kneader, and the green body is placed in a carbonization furnace. In an inert atmosphere, the furnace temperature is raised from room temperature to 550° C., and the temperature is kept for 1 hour. The secondary carbonized material is cooled with the furnace to obtain the secondary carbonized material. Then, the secondary carbonized material is activated to obtain bamboo activated carbon.

[0069] In the carbonization tail gas, H 2 The output is less than that of CO. Usually, the volume fraction of CO is about 10-30%, and the volume fraction of H 2 The volume fraction of CO is about 1.5-8%.2 The volume fraction of carbon is about 10-25%. However, during the activation process, water vapor reacts with carbon to generate H 2 and CO, which can further react with water vapor to produce CO 2 and H 2 Therefore, in the activated tail gas, CO 2 and H 2 is the main component, and the CO content is relatively small. Therefore, using carbonized tail gas together with activated tail gas can reduce the CO and H 2 The difference in production of CO and H 2 More suitable for the reaction to produce methanol.

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

[0071] The first embodiment of the method for utilizing tail gas produced by bamboo activated carbon 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 the first reaction gas and adsorption saturated liquid; wherein, the deacidification treatment adopts dry deacidification, that is, spraying solid absorbent for deacidification, thereby, the acid gas remaining in the carbonization tail gas can be removed by deacidification treatment and a relatively dry low-acid gas can be obtained, avoiding the introduction of more water vapor by wet deacidification to affect the methanol synthesis reaction; the dust removal treatment is preferably filtration dust removal, and dust removal is set after the deacidification treatment, which can not only remove the particulate impurities brought by the carbonization tail gas, but also remove the deacidification agent used in the deacidification treatment. The adsorption treatment adopts alcohol as an adsorbent, which can adsorb volatile organic matter in the carbonization tail gas and form the first reaction gas and adsorption saturated liquid.

[0073] The adsorbed saturated liquid is burned to obtain combustion tail gas; since the adsorbed saturated liquid mainly contains volatile organic compounds, its combustion can not only prevent the emission from causing environmental pollution, but also generate more CO 2 For reaction with methane.

[0074] The combustion tail gas and methane are introduced into a first reaction device loaded with a catalyst for catalytic reaction to generate H 2 and a second reaction gas of CO.

[0075] The activated tail gas is sequentially subjected to condensation treatment, deacidification treatment, dust removal treatment and adsorption treatment to obtain a third reaction gas; the volatile organic matter in the activated tail gas is relatively small, so the adsorption treatment here can be performed using activated carbon.

[0076] The mixed gas consisting of the first reaction gas, the second reaction gas and the third reaction gas is introduced into a second reaction device loaded with a catalyst for catalytic reaction to generate a synthesis gas containing methanol; wherein the water vapor volume fraction in the mixed gas is 2-5%, the COD content is ≤5ppm, the volatile organic matter 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 tail gas produced by bamboo activated carbon is as follows: based on the first embodiment, the method further comprises introducing H into the second reaction device. 2 .

[0078] Figure 1 The structure diagram of the first embodiment of the bamboo activated carbon production system and the bamboo activated carbon production tail gas utilization system. Figure 1 As shown, the bamboo activated carbon production system includes a carbonization furnace (1 or 2) for carbonizing the bamboo raw materials, an activation furnace for activating the bamboo raw materials after carbonization, and a production exhaust gas utilization system, wherein the production exhaust gas includes the carbonization exhaust gas discharged from 1 or 2 carbonization furnaces and the activation exhaust gas discharged from the activation furnace.

[0079] The first embodiment of the utilization system of tail gas produced by bamboo activated carbon includes 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 includes a first condensation device, a first deacidification device, a first dust removal device and a first adsorption device for sequentially performing condensation treatment, deacidification treatment, dust removal treatment and adsorption treatment on the carbonized tail gas; the first purification unit 210 outputs a first reaction gas and an adsorbed saturated liquid after treating the carbonized tail gas.

[0081] The combustion device 220 is used to burn the adsorbed saturated liquid and output combustion exhaust gas, and the air inlet of the combustion device 220 is connected to 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 a catalyst containing H 2 and a second reaction gas of CO; the air inlet of the first reaction device 230 is connected to the air outlet of the combustion device 220 and the air outlet of the methane delivery device.

[0083] The second purification unit 240 includes a second condensing device, a second deacidification device, a second dust removal device and a second adsorption device for sequentially performing 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.

[0084] The second reaction device 250 is provided with a catalyst packing structure, and the mixed gas consisting of the first reaction gas, the second reaction gas and the third reaction gas and H 2 In the second reaction device 250, synthesis gas containing methanol is generated after catalytic reaction; the air inlet of the second reaction device 250 is connected to the first adsorption device, the first reaction device 230, the air outlet of the second adsorption device and the hydrogen delivery device.

[0085] The first dust removal device and the second dust removal device are filters using porous metal filter elements. The first deacidification device and the second deacidification device are dry deacidification towers. The first adsorption device is an alcohol spray tower. The second adsorption device is provided with an activated carbon filler structure.

[0086] H 2 A volume fraction slightly higher than twice the volume fraction of CO will be beneficial to the methanol synthesis reaction. Therefore, in the reaction gas treated by the adsorption equipment, by adding H 2 , which can promote the synthesis reaction towards the production of methanol.

[0087] Figure 2 The structure diagram of the second embodiment of the bamboo activated carbon production system and the bamboo activated carbon production tail gas utilization system. Figure 2 As shown, compared with the first embodiment, the utilization system of the second embodiment further includes a third condensing device 260, a distillation device 270 and a fourth condensing device 280. The third condensing device 260 performs condensation treatment on the synthesis gas and outputs liquid methanol, and the air inlet of the third condensing device 260 is connected to the air outlet of the second reaction device 250. The distillation device 270 performs distillation treatment on the liquid methanol and outputs high-purity methanol; the liquid inlet of the distillation device 270 is connected to the liquid outlet of the third condensing device 260. The fourth condensing device 280 is used to condense the second reaction gas, and the air outlet of the fourth condensing device 280 is connected to the air inlet of the second reaction device 250.

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

[0089] Soluble cerium salt and zirconium salt are dissolved in deionized water, and the molar ratio of cerium ion to zirconium ion is 1; ammonia water is added dropwise to the solution under stirring until the pH value is 9-10; stirring is continued for 2 hours, and aging is carried out at 80°C for 2 hours; after collecting, washing and drying the solid, calcining at 600°C in air for 4 hours to obtain CeO 2 -ZrO 2 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, soluble lanthanum salt, soluble strontium salt, soluble nickel salt, soluble trivalent iron salt, and soluble ruthenium salt are weighed and dissolved in deionized water; according to the molar ratio of metal ions to citric acid being 1:1.5, an appropriate amount of citric acid is added to the solution; stirring and evaporating at 80° C. until a gel is formed; and drying the gel at 120° C. for 12 hours to obtain a perovskite precursor;

[0091] According to the loading amount of perovskite precursor being 20%, the perovskite precursor and CeO 2 -ZrO 2 The carrier was dispersed in a small amount of ethanol and mixed uniformly; after stirring at 80°C to evaporate the ethanol, it was first dried at 110°C, then calcined at 900°C in air for 6 hours to form a perovskite structure, and finally heated in H 2 The catalyst was reduced at 700°C for 2 hours in a mixed atmosphere of N,N, and Ar to obtain a perovskite-type nickel-based composite catalyst.

[0092] The perovskite-type nickel-based composite catalyst is used to treat the combustion tail gas (the volume fraction of one embodiment is: 5.68% CO, 74.32% CO 2 1.54% H 2 , 2.14% water vapor, the balance is N 2 ) and methane for catalysis, the volume ratio of combustion exhaust gas to methane is (1.05-1.5):1, the reaction temperature is 700°C, the reaction pressure is 0.1MPa, and the space velocity is 20000h -1 , CO 2 The conversion rate averaged 81%.

[0093] The catalyst in the second reaction device 250 has a multi-layer structure, the core of which is Fe 3 O 4 , the inner layer is CeO 2 , the middle layer is Cu-Zn alloy, the outer layer is ZrO 2 , the surface layer is graphene quantum dots, and the preparation method thereof comprises the following steps:

[0094] Preparation of Fe by coprecipitation 3 O 4 Core: FeCl3 6H 2 O, FeCl 2 ·4H 2 O and ammonia water as raw materials, under nitrogen protection, an equal volume of Fe 3+ Solution and Fe 2+ Solution mixing, Fe 3+ and Fe 2+ The molar ratio of the mixture was 2:1; the mixture was heated to 80°C, and ammonia water was added to the mixture at a stirring speed of 500 rpm until the pH value was 10-11; the reaction was continued for 30 minutes and then magnetic separation was performed, and the collected solid was washed with deionized water and ethanol for 3 times, and vacuum dried at 60°C for 12 hours to obtain Fe 3 O 4 core.

[0095] Preparation of CeO by hydrothermal method 2 Inner layer: Ce(NO 3 ) 3 6H 2 O and urea dissolved in water, Ce 3+ The concentration of Fe is 0.05M, the concentration of urea is 0.5M; 1g Fe 3 O 4 The core was dispersed in 150 mL of the above solution, transferred to a hydrothermal reactor, and reacted at 180 ° C for 12 hours; after cooling to room temperature, centrifuged, the collected solid was washed with water and ethanol three times, dried at 60 ° C for 12 hours, and then calcined at 350 ° C for 2 hours. 3 O 4 Core surface coated with CeO 2 Inner layer, get CeO 2 @Fe 3 O 4 .

[0096] Preparation of Cu-Zn alloy intermediate layer by chemical reduction method: Cu(NO 3 ) 2 ·3H 2 O、Zn(NO 3 ) 2 6H 2 O dissolves in water, Cu 2+ The concentration of Zn is 0.1M. 2+ The concentration of CeO is 0.05M; 0.8gCeO 2 @Fe 3 O 4 Disperse in 100 mL of the above solution, sonicate for 30 minutes; stir in an ice bath, and slowly drop NaBH 4The solution (concentration of 0.2 M) was stirred at room temperature for 2 hours and then centrifuged. The collected solid was washed with water and ethanol three times and dried under vacuum at 50 ° C for 8 hours. 2 A Cu-Zn alloy intermediate layer is deposited on the inner surface to obtain Cu-Zn@CeO 2 @Fe 3 O 4 .

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

[0098] Preparation of graphene quantum dots (GQDs) by impregnation method: prepare a GQDs aqueous solution with a concentration of 1 mg / mL; then add 0.5 g ZrO 2 @Cu-Zn@CeO 2 @Fe 3 O 4 Dispersed in 100 mL of GQDs aqueous solution; ultrasonically treated for 30 min, then stirred at room temperature for 4 h and centrifuged, and dried in vacuum at 50 °C for 12 h. 2 The outer surface is loaded with graphene quantum dots to obtain GQDs@ZrO 2 @Cu-Zn@CeO 2 @Fe 3 O 4 .

[0099] Calcination treatment: GQDs@ZrO 2 @Cu-Zn@CeO 2 @Fe 3 O 4 The precursor was obtained by calcining at 450°C for 4 hours.

[0100] Restore processing: In N 2 and H 2 Mixed gas atmosphere (H 2 The precursor was reduced at 350° C. for 2 hours to obtain a catalyst.

[0101] The prepared catalyst has a multilayer structure and each structural layer has excellent performance, among which Fe 3 O 4 The core facilitates magnetic separation and recovery of the catalyst, CeO 2 The inner layer can provide high oxygen storage capacity and oxygen vacancies to promote the reaction, and the Cu-Zn alloy middle layer provides the main catalytic active sites. 2 The outer layer can enhance the stability and anti-sintering ability of the catalyst, and the surface layer loaded with graphene quantum dots can enhance electron transfer and improve catalytic activity. Through the synergistic effect of each structural layer, the catalyst has a higher catalytic activity and can promote the conversion of CO and H at a lower temperature. 2 The reaction can improve the efficiency of the catalytic reaction. 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 frequency of catalyst renewal, thereby saving long-term operating costs. The effective conversion of bamboo activated carbon production tail gas through catalytic reaction technology is an innovative green chemical process, which is in line with the global trend of promoting green production and reducing carbon emissions, and has a significant promotion effect on the development and application of bamboo resources.

[0102] The double-layered catalyst is used to treat the mixed gas (data of one embodiment: 39.65% CO, 2.56% CO 2 38.56% H 2 , 2.68% water vapor, the balance is N 2 ) for catalysis, the mixed gas and the supplementary H 2 The volume ratio is (2.05-2.5):1, the reaction temperature is 240°C (220-300°C), the reaction pressure is 4MPa (3-10MPa), and the space velocity is 6000h -1 (3000~10000h -1 The space-time yield is 0.4-0.9 kg methanol / (L catalyst·h), and the purity of liquid methanol is above 95%.

[0103] The condensate obtained after the carbonization tail gas is condensed contains a large amount of organic matter, which can be condensed into bio-oil with high calorific value. In order to deeply recover the valuable resources of the production tail gas, the method for utilizing the tail gas produced by bamboo activated carbon of the present invention further utilizes the condensate recovered by the condensation equipment. On the basis of the second embodiment, the third embodiment further includes the steps of:

[0104] The condensate obtained by condensing the carbonized tail gas is subjected to solid-liquid separation treatment to obtain a permeate; the solid-liquid separation treatment is a filtration treatment or a centrifugal separation treatment, thereby removing particulate impurities captured by the droplets during the condensation process.

[0105] The permeate is subjected to membrane separation treatment using a nanofiltration membrane to obtain an oily liquid; preferably, the membrane separation treatment is a vacuum 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. Thus, the nanofiltration membrane can allow water to pass through, while 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 with an extractant to obtain an extractant-soluble liquid; preferably, the extractant is ethanol and / or acetone; and the volume of the extractant is twice the volume of the condensate.

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

[0108] Different from the third embodiment, the fourth embodiment of the method for utilizing tail gas produced by bamboo activated carbon is as follows:

[0109] The condensate obtained by condensing the carbonized tail gas is subjected to solid-liquid separation treatment to obtain a permeate; the solid-liquid separation treatment is a filtration treatment or a centrifugal separation treatment, thereby removing particulate impurities captured by the droplets during the condensation process.

[0110] The permeate is subjected to extraction treatment by using an extractant to obtain a first extractant-soluble liquid.

[0111] The first extractant soluble liquid is subjected to reduced pressure distillation at 35°C and 16kPa to obtain a distillate; the extractant can be evaporated and condensed by the reduced pressure distillation, and the condensate obtained by the reduced pressure distillation is repeatedly used for extraction of the permeate, which can improve the utilization rate of the extractant.

[0112] The distillate is extracted with an extractant and water to obtain a second extractant-soluble liquid; preferably, in the 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, and then water is added dropwise, stirring is continued for 30 minutes after the addition of water is completed, and then the mixture is sealed and allowed 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 biomass oil. The vacuum distillation can evaporate and condense the extractant, and the condensate obtained by the vacuum distillation can be repeatedly used for extraction of the permeate, which can improve the utilization rate of the extractant.

[0114] The extractant is dichloromethane; preferably, the volume of the extractant is twice 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.

[0115] The second embodiment of the method for utilizing tail gas produced by bamboo activated carbon is as follows: based on the first embodiment, it also includes distilling the biomass oil into a solid at 200-250°C (preferably 235°C) under normal pressure, and the utilization method also includes crushing, grinding and vacuum drying the solid to obtain solid biomass oil.

[0116] In the third and fourth embodiments, the biomass oil can be further distilled at 200-250°C to form a solid or a concentrated liquid. For the solid, the solid is crushed, ground and vacuum dried to obtain solid biomass oil; for the concentrated liquid, the concentrated liquid is subjected to a hydrogenation refining treatment, including the steps of: preparing a reaction liquid according to a mass ratio of biomass oil: methanol: catalyst of 20:25:1, and hydrothermally reacting at 190°C and 1MPa hydrogen pressure for 3h to obtain refined biomass oil; using an activated carbon-based Ni / BC catalyst, the preparation method of which is: dispersing 0.5g nickel nitrate and 1g activated carbon in ethanol, stirring for 5h; rotary evaporation at 80°C to completely remove the ethanol solvent and then drying in a vacuum oven; heating at 20% H 2 -Ar was used as a reducing atmosphere and calcined at 550 °C for 2 h to obtain the activated carbon-based Ni / BC catalyst.

[0117] The above is a description of the relevant contents of the embodiments of the inventions provided in this specification. Based on these descriptions, a person of ordinary skill in the art will be able to implement the embodiments of the inventions provided in this specification. Based on the above contents of the embodiments of the inventions provided in this specification, all other preferred implementations and embodiments obtained by a person of ordinary skill in the art without making any creative work shall fall within the scope of protection of the embodiments of the inventions 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 produced by carbonizing bamboo raw materials and activated tail gas produced by activation treatment after carbonization, wherein the activating agent used in the activation treatment is water vapor, and the method is characterized in that: The method of use includes the following steps: The carbonization tail gas is sequentially subjected to condensation treatment, deacidification treatment, dust removal treatment and adsorption treatment to obtain a first reaction gas and adsorption saturated liquid; The adsorbed saturated liquid is combusted to obtain combustion tail gas; The combustion tail gas and methane are introduced into a first reaction device loaded with a catalyst for catalytic reaction to generate a second reaction gas containing H2 and CO; The activated tail gas is sequentially subjected to condensation treatment, deacidification treatment, dust removal treatment and adsorption treatment to obtain a third reaction gas; A mixed gas consisting of the first reaction gas, the second reaction gas and the third reaction gas is introduced into a second reaction device loaded with a catalyst for catalytic reaction to generate a synthesis gas containing methanol.

2. The method for utilizing tail gas produced by bamboo activated carbon according to claim 1, characterized in that: Alcohol is used to adsorb the carbonized exhaust gas after dust removal.

3. The method for utilizing tail gas produced by bamboo activated carbon production as claimed in claim 1, characterized in that: Activated carbon is used to adsorb the activated tail gas after dust removal.

4. The method for utilizing tail gas produced by bamboo activated carbon according to claim 1, characterized in that: The water vapor volume fraction in the mixed gas is 2-5%, COD content ≤5ppm, volatile organic matter content ≤3ppm, acid gas content ≤2ppm, particulate matter content ≤20mg / Nm 3 .

5. The method for utilizing tail gas produced by bamboo activated carbon production as claimed in claim 1, characterized in that: The method also includes introducing H2 into the second reaction device.

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 purifying the condensate obtained after condensing the carbonized tail gas to obtain biomass oil.

7. The method for utilizing tail gas produced by bamboo activated carbon production as claimed in claim 1, characterized in that: The catalyst in the second reaction device has a multi-layer structure, with a core of Fe3O4, an inner layer of CeO2, a middle layer of Cu-Zn alloy, an outer layer of ZrO2, and a surface layer of graphene quantum dots.

8. The method for utilizing tail gas produced by bamboo activated carbon production as claimed in claim 7, characterized in that: The preparation method of the multilayer catalyst comprises the following steps: The Fe3O4 core was prepared by the coprecipitation method through the reaction of soluble ferric salt, soluble ferrous salt and ammonia water; The inner layer of CeO2 was loaded on the surface of Fe3O4 core by the reaction of soluble cerium salt and urea using hydrothermal method; A Cu-Zn alloy intermediate layer is deposited on the surface of the CeO2 inner layer by chemical reduction method through the reaction of soluble copper salt, soluble zinc salt and sodium borohydride; The ZrO2 outer layer was loaded on the surface of the Cu-Zn alloy intermediate layer by the reaction of n-butoxide zirconium, water and ethanol using the sol-gel method; The graphene quantum dots are loaded on the surface of the outer layer of ZrO2 by impregnation with a graphene quantum dot solution.

9. The method for utilizing tail gas produced by bamboo activated carbon production as claimed in claim 7, characterized in that: It also includes calcination and reduction treatment after loading graphene quantum dots: The calcination treatment is carried out in an atmosphere of air, at a temperature of 400 to 500° C., for a period of 3 to 5 hours; The reduction treatment is carried out in an atmosphere of a mixture of N2 and H2 at a temperature of 300 to 400°C for 1 to 3 hours.

10. A method for producing bamboo activated carbon, comprising carbonizing and activating 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 comprises carbonized tail gas generated by carbonization treatment and activated tail gas generated by activation treatment; The carbonization process comprises 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 carbonized material; The activation treatment is as follows: putting the carbonized material into an activation furnace, in an inert atmosphere, using water vapor as an activating agent, keeping the temperature at 800-1100° C. for 2-4 hours, and then cooling with the furnace to obtain bamboo activated carbon.

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