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: introducing first tail gas into an outer boiler used for secondary carbonization treatment and activation treatment, and then igniting and combusting to obtain combustion tail gas; purifying the combustion tail gas and the second tail gas to obtain purified gas; the purified gas and methane are introduced into first reaction equipment for a catalytic reaction, and first reaction gas containing H2 and CO is generated; purifying the activated tail gas to obtain second reaction gas; the first reaction gas and the second reaction gas are introduced into second reaction equipment for a catalytic reaction, and first synthesis gas containing H2 and CO2 is generated; recovering CO2 in the first synthesis gas to generate third reaction gas; and introducing the third reaction gas into third reaction equipment for catalytic reaction to generate second 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 object, according to one 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 the first tail gas produced by the primary carbonization treatment, the second tail gas produced by the secondary carbonization treatment and the third tail gas produced by the activation treatment. The adhesive used for the green body subjected to the secondary carbonization treatment is a polymer adhesive, and the activator used for the activation treatment is water vapor. The method for utilizing the tail gas includes the steps of:

[0011] The first tail gas is passed into an external boiler used for secondary carbonization treatment and activation treatment, and then ignited and burned to obtain combustion tail gas;

[0012] Purifying a first mixed gas consisting of the combustion exhaust gas and the second exhaust gas to obtain purified gas;

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

[0014] Purifying the activated tail gas to obtain a second reaction gas;

[0015] The second mixed gas consisting of the first reaction gas and the second reaction gas is introduced into a second reaction device loaded with a catalyst for catalytic reaction to generate a mixture containing H 2 and CO 2 The first synthesis gas;

[0016] Recovering CO from the first synthesis gas 2 , generating a third reaction gas;

[0017] The third reaction gas is introduced into a third reaction device loaded with a catalyst for catalytic reaction to generate a second synthesis gas containing methanol.

[0018] As a further improvement of the above-mentioned method for utilizing tail gas produced by bamboo activated carbon: the purification treatment of the first mixed gas includes condensation treatment, deacidification treatment, dust removal treatment and adsorption treatment performed in sequence; the purification treatment of the activated tail gas includes condensation treatment, dust removal treatment, adsorption treatment and deacidification treatment performed in sequence.

[0019] As a further improvement of the above-mentioned method for utilizing tail gas produced by bamboo activated carbon: the adsorption treatment adopts activated carbon adsorption; the first mixed gas is deacidified by dry deacidification; and the activated tail gas is deacidified by wet deacidification.

[0020] As a further improvement of the above-mentioned bamboo activated carbon production tail gas utilization method: the water vapor volume fraction content in the purified 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 The water vapor volume fraction in the second reaction gas is 30-40%, COD content ≤5ppm, volatile organic matter content ≤3ppm, acid gas content ≤2ppm, particulate matter content ≤20mg / Nm 3 .

[0021] As a further improvement of the above-mentioned method for utilizing tail gas produced by bamboo activated carbon, the method further comprises: recovering CO from the first synthesis gas; 2 The product is refluxed to the first reaction device to react with methane.

[0022] As a further improvement of the above-mentioned method for utilizing tail gas produced by bamboo activated carbon: using CO 2 Selective separation membrane to recover CO from the first syngas 2 .

[0023] As a further improvement of the above-mentioned method for utilizing tail gas produced by bamboo activated carbon: the catalyst in the first reaction device is a perovskite-type nickel-based composite catalyst. Preferably, the preparation method of the perovskite-type nickel-based composite catalyst comprises the following steps:

[0024] 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;

[0025] 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);

[0026] 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.

[0027] 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 is a Cu-Zr catalyst. Preferably, the preparation method of the Cu-Zr catalyst comprises the following steps:

[0028] An aqueous solution including urea and a soluble zirconium salt is prepared, the aqueous solution is hydrothermally treated, and the generated first solid is collected, washed and dried; more preferably, the soluble zirconium salt is zirconium nitrate, and the molar ratio of urea to zirconium ions in the aqueous solution is 1.8 to 2.2; the hydrothermal reaction temperature is 140 to 160° C., and the hydrothermal reaction time is 18 to 30 hours;

[0029] The first solid is calcined to obtain a zirconium precursor; more preferably, the calcination temperature of the first solid is 230 to 270° C., and the calcination time is 3 to 5 hours;

[0030] The zirconium precursor and the copper salt are ground and mixed, and then dispersed in deionized water to form a dispersion, an alkali solution is added to the dispersion under water bath conditions, and the generated second solid is collected, washed and dried; more preferably, the copper salt is copper nitrate, and the molar ratio of copper ions to zirconium ions is 0.1-0.15; the water bath temperature is 50-70° C., sodium hydroxide is used as the alkali solution, and after stirring for 1-3 hours under water bath conditions, sodium hydroxide is used to adjust the pH of the dispersion to 9;

[0031] The second solid is calcined to obtain a Cu-Zr catalyst. Further preferably, the second solid is calcined at a temperature of 350 to 450° C. for 3 to 5 hours.

[0032] As a further improvement of the above-mentioned method for utilizing tail gas produced by bamboo activated carbon: the catalyst in the third 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: using a coprecipitation method to prepare Fe by reacting a soluble trivalent iron salt, a soluble divalent iron salt and ammonia water. 3 O 4 core; using a hydrothermal method, a soluble cerium salt and urea react in Fe 3 O 4 Core surface loaded with CeO 2 Inner layer: using chemical reduction method, soluble copper salt, soluble zinc salt and sodium borohydride react on CeO 2 A Cu-Zn alloy intermediate layer is deposited on the surface of the inner layer; ZrO is loaded on the surface of the Cu-Zn alloy intermediate layer by reacting n-butoxide zirconium, water and ethanol using a sol-gel method. 2 Outer layer: Using the impregnation method, the graphene quantum dot solution is impregnated in ZrO 2 The outer surface is loaded with graphene quantum dots; after loading the graphene quantum dots, calcination and reduction treatment are performed: the calcination atmosphere is air, the temperature is 400-500°C, and the duration is 3-5 hours; the reduction atmosphere is N 2 and H 2 The mixture has a temperature of 300-400°C and a duration of 1-3 hours.

[0033] A system for utilizing tail gas produced by bamboo activated carbon, wherein the tail gas produced includes a first tail gas produced by a primary carbonization treatment, a second tail gas produced by a secondary carbonization treatment, and a third tail gas produced by an activation treatment, wherein the adhesive used for the green body subjected to the secondary carbonization treatment is a polymer adhesive, and the activating agent used for the activation treatment is water vapor, and the utilization system includes: an electric gas heating unit, wherein the electric gas heating unit includes an ignition device and an external boiler for providing heat for the secondary carbonization treatment and the activation treatment, wherein the first tail gas flows into the external boiler and is ignited and burned by the ignition device to generate combustion tail gas; a first purification unit, including a first condensing 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 a first mixed gas composed of the combustion tail gas and the second tail gas; the first purification unit outputs purified gas after treating the first mixed gas; a first reaction device, wherein a catalyst filler structure is provided in the first reaction device, and the purified gas and methane are catalytically reacted in the first reaction device to generate a gas containing H 2 and CO; the air inlet of the first reaction device is connected to the air outlet of the first adsorption device and the methane conveying device; the second purification unit comprises a second condensing device, a second dust removal device, a second adsorption device and a second deacidification device which sequentially perform condensation treatment, dust removal treatment, adsorption treatment and deacidification treatment on the activated tail gas; the second purification unit outputs a second reaction gas after treating the activated tail gas; the second reaction device is provided with a catalyst packing structure, and a second mixed gas composed of the first reaction gas and the second reaction gas is catalyzed by the catalyst in the second reaction device to generate a second mixed gas containing H 2 and CO 2 The first synthesis gas; the gas inlet of the second reaction device is connected to the gas outlet of the first reaction device and the second deacidification device; the separation device adopts CO 2 Selective separation membrane to recover CO from the first syngas 2 , outputting the third reaction gas; the air inlet of the separation device is connected to the air outlet of the second separation device; a third reaction device, wherein a catalyst packing structure is arranged in the third reaction device, and the third reaction gas generates a synthesis gas containing methanol after a catalytic reaction in the reaction device; the air inlet of the third reaction device is connected to the air outlet of the separation device.

[0034] 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.

[0035] As a further improvement of the above-mentioned bamboo activated carbon production tail gas utilization system: the first deacidification equipment is a dry deacidification tower; the second deacidification equipment is a spray tower.

[0036] As a further improvement of the above-mentioned bamboo activated carbon production tail gas utilization system: the first adsorption device and the second adsorption device are 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 the following steps: 2 Reflux to the reflux pipeline in the first reaction device.

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

[0042] A method for producing bamboo activated carbon, comprising performing a primary carbonization treatment, a secondary carbonization treatment and an activation treatment on a bamboo raw material, and also comprising utilizing the production tail gas using the above-mentioned method for utilizing the production tail gas of bamboo activated carbon, wherein the production tail gas comprises a first tail gas generated by the primary carbonization treatment, a second tail gas generated by the secondary carbonization treatment and a third tail gas generated by the activation treatment;

[0043] The primary carbonization treatment comprises the following steps:

[0044] 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;

[0045] Continue to raise the temperature to 300-400°C and keep it warm for 0.5-1.5 hours;

[0046] Continue to raise the temperature to 500-600°C, keep it at that temperature for 0.5-1.5 hours, then cool it with the furnace to obtain the primary carbonized material;

[0047] The second carbonization treatment comprises the steps of:

[0048] The primary carbonized material and the polymer adhesive are granulated into a green body, the green body is placed in a carbonization furnace, and the furnace temperature is raised from room temperature to 500-600°C under an inert atmosphere, and kept at this temperature for 0.5-1.5 hours, and the secondary carbonized material is obtained by cooling the furnace;

[0049] The activation treatment is as follows: putting the secondary 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.

[0050] The bamboo activated carbon production system includes a first carbonization furnace for primary carbonization of bamboo raw materials, a second carbonization furnace for secondary carbonization and an activation furnace for activation. The adhesive used for the secondary carbonized body is a polymer adhesive, and the activator used for the activation is water vapor. The system also includes a utilization system for the exhaust gas produced by the above-mentioned bamboo activated carbon. The exhaust gas includes a first exhaust gas generated by the primary carbonization, a second exhaust gas generated by the secondary carbonization and a third exhaust gas generated by the activation.

[0051] The present invention has the following advantages:

[0052] (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), a higher purity liquid methanol 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 economic benefits.

[0053] (2) By igniting and burning the first tail gas, on the one hand, the heat generated by the combustion is used to heat the secondary carbonization and activation treatments, reducing energy consumption; on the other hand, most of the organic matter will be burned and converted into CO that can react with methane. 2 , greatly reducing the difficulty of handling organic matter.

[0054] (3) The combustion exhaust gas and the second exhaust gas have similar compositions. After the first mixed gas composed of them is purified, the CO 2 Reaction with methane (reaction equation: CO 2 +2CH 4 →2CO+H 2 ), a large amount of CO in the purified gas obtained after purifying the first mixed gas 2 Converted into CO and H for methanol production 2 In this way, the reaction gas compatible with the activated exhaust gas after purification is obtained, which can significantly improve the reaction efficiency of the subsequent catalytic reaction.

[0055] (4) According to the particularity of the first mixed gas (composed of combustion exhaust gas and second exhaust gas) and the activated exhaust gas, the first mixed gas and the activated exhaust gas are pretreated respectively, so that water vapor, organic vapor, volatile organic matter, acidic gas and particulate impurities are efficiently removed. The catalytic reaction thereafter helps to improve the activity of the catalyst and the efficiency of the catalytic reaction, and reduce the problems of catalyst poisoning and equipment clogging and wear.

[0056] (5) First, use CO 2 +2CH 4 →2CO+H 2 Increase H 2 content, and then through CO+H 2 O→CO 2 +H 2 Further improve H 2 The content of CO and H in the final third reaction gas is 2 The content is suitable, no or a small amount of H is added 2 Methanol synthesis reaction can be carried out, effectively reducing H 2 Replenishment, saving costs.

[0057] 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

[0058] 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:

[0059] 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.

[0060] 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.

[0061] Figure 3 is the XRD pattern of Cu-Zr catalyst.

[0062] The relevant marks in the above drawings are:

[0063] 110 - electric and gas heating unit, 120 - first purification unit, 130 - first reaction equipment, 140 - second purification unit, 150 - second reaction equipment, 160 - separation equipment, 170 - third reaction equipment, 180 - third condensation equipment, 190 - distillation equipment. DETAILED DESCRIPTION

[0064] 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:

[0065] 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.

[0066] 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.

[0067] 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.

[0068] The embodiment of the method for producing bamboo activated carbon of the present invention comprises the steps of:

[0069] Drying treatment: Put the fresh bamboo raw materials into an oven and dry them at 100℃ for 48 hours.

[0070] 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.

[0071] Secondary carbonization treatment: grind the primary carbonized material to a particle size of 325 mesh, and then use molasses as a binder and water as an auxiliary agent. According to the mass ratio of molasses to primary carbonized material of 0.5, 30 mL of auxiliary agent is added to every 100 g of primary carbonized material, and granulate into a green body in a kneader. Put the green body into a carbonization furnace, and in an inert atmosphere, raise the furnace temperature from room temperature to 550°C, keep it warm for 1 hour, and cool it with the furnace to obtain the secondary carbonized material.

[0072] Activation treatment: put the secondary 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.

[0073] The method for utilizing the tail gas produced by bamboo activated carbon of the present invention is used to utilize the tail gas produced by the above-mentioned bamboo activated carbon production method, wherein the tail gas comprises a first tail gas produced by a primary carbonization treatment, a second tail gas produced by a secondary carbonization treatment, and a third tail gas produced by an activation treatment. The first embodiment thereof comprises the following steps:

[0074] The first tail gas is introduced into an external boiler used for secondary carbonization treatment and activation treatment, and then ignited and burned to obtain combustion tail gas.

[0075] The first mixed gas consisting of the combustion tail gas and the second tail gas is purified to obtain purified gas; the purification treatment is a condensation treatment, a deacidification treatment, a dust removal treatment and an adsorption treatment performed in sequence, wherein the water vapor, organic vapor and low-boiling acidic gas in the production tail gas can be removed by the condensation treatment; the deacidification treatment adopts dry deacidification, thereby, the acidic gas remaining in the first mixed gas can be removed by the deacidification treatment and a relatively dry low-acid gas can be obtained, thereby avoiding the introduction of more water vapor by the wet deacidification to affect the catalytic reaction of the catalyst in the first reaction device; the dust removal treatment is preferably a filtration dust removal, and the dust removal is set after the deacidification treatment, which can not only remove the particulate impurities in the first mixed gas, but also remove the deacidification agent used in the deacidification treatment. The volatile organic matter in the first mixed gas can be adsorbed by the adsorption treatment, and preferably activated carbon is used as the adsorbent. Thus, the particulate impurities, volatile organic matter and residual acidic gas in the first mixed gas can be removed by purification treatment, and the volume fraction of water vapor in the obtained purified 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 .

[0076] The purified gas and methane are introduced into a first reaction device loaded with a catalyst for catalytic reaction to generate H 2 and CO as the first reaction gas.

[0077] The activated tail gas is purified to obtain a second reaction gas; the purification treatment is a condensation treatment, a dust removal treatment, an adsorption treatment and a deacidification treatment performed in sequence, wherein the water vapor, organic vapor and low-boiling acidic gas in the production tail gas can be removed by the condensation treatment. The dust removal treatment is preferably a filtration dust removal. The volatile organic matter in the production tail gas can be adsorbed by the adsorption treatment, and activated carbon is preferably used as an adsorbent. The acid gas remaining in the production tail gas can be removed by the deacidification treatment. The deacidification treatment preferably uses a spray tower for wet deacidification, which can not only effectively deacidify, but also increase the humidity of the reaction gas, making it more suitable for the catalytic reaction in the second reaction equipment. Thus, the first mixed gas and the activated tail gas after deacidification are adsorbed by activated carbon, and the water vapor volume fraction content in the obtained second reaction gas is 30-40%, the COD content is ≤5ppm, the volatile organic content is ≤3ppm, the acid gas content is ≤2ppm, and the particulate matter content is ≤20mg / Nm 3 .

[0078] The second mixed gas consisting of the first reaction gas and the second reaction gas is introduced into a second reaction device loaded with a catalyst for catalytic reaction to generate a mixture containing H 2 and CO 2 The first synthesis gas.

[0079] Using CO 2 Selective separation membrane to recover CO from the first syngas 2 , generating the third reaction gas. A CO 2 Concentration detection device, when the purified gas contains CO 2 When the content is low, the CO recovered by the separation equipment 2 The purified gas is refluxed to the first reaction device through the reflux pipeline. 2 When the content is sufficient to react with methane, the CO recovered by the separation equipment 2 Simply drain.

[0080] The third reaction gas is passed into a third reaction device loaded with a catalyst for catalytic reaction to generate a second synthesis gas containing methanol. 2 When the volume is slightly higher than twice the volume of CO, it is helpful for the methanol synthesis reaction. Therefore, in order to adjust the H 2 The volume ratio of CO is (2.05-2.1):1. A CO concentration detection device and a H concentration detection device for detecting the third reaction gas are provided at the gas inlet end of the third reaction device. 2 concentration detection device, and then introduce H into the third reaction device according to demand. 2 .

[0081] 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 first carbonization furnace for primary carbonization of bamboo raw materials, a second carbonization furnace for secondary carbonization, an activation furnace for activation after carbonization, and a utilization system for production tail gas, the production tail gas includes the first tail gas generated by the primary carbonization, the second tail gas generated by the secondary carbonization, and the third tail gas generated by the activation. The utilization system includes an electric gas heating unit 110, a first purification unit 120, a first reaction device 130, a second purification unit 140, a second reaction device 150, a separation device 160, and a third reaction device 170.

[0082] The electric gas heating unit 110 includes an ignition device and an external boiler for providing heat for the secondary carbonization process and the activation process. After the first tail gas flows into the external boiler, it is ignited and burned by the ignition device to generate combustion tail gas.

[0083] The first purification unit 120 includes 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 a first mixed gas consisting of combustion exhaust gas and second exhaust gas; the first purification unit 120 processes the first mixed gas and outputs purified gas.

[0084] The first reaction device 130 is provided with a catalyst packing structure, and the purified gas and methane are catalytically reacted in the first reaction device 130 to generate H 2 and the first reaction gas of CO; the gas inlet of the first reaction device 130 is connected to the gas outlet of the first adsorption device and the methane delivery device.

[0085] The second purification unit 140 includes a second condensing device, a second dust removal device, a second adsorption device and a second deacidification device for sequentially performing condensation treatment, dust removal treatment, adsorption treatment and deacidification treatment on the activated tail gas; the second purification unit 140 outputs a second reaction gas after treating the activated tail gas.

[0086] The second reaction device 150 is provided with a catalyst packing structure. The second mixed gas consisting of the first reaction gas and the second reaction gas is catalytically reacted in the second reaction device 150 to generate a gas containing H 2 and CO 2 the gas inlet of the second reaction device 150 is connected to the gas outlet of the first reaction device 130 and the second deacidification device.

[0087] The separation device 160 uses CO 2 Selective separation membrane to recover CO from the first syngas 2, output the third reaction gas, the gas inlet of the separation device 160 is connected to the gas outlet of the second reaction device 150, the gas outlet of the separation device 160 is connected to the gas inlet of the third reaction device 170, the CO 2 The selective separation membrane is any one of a polyetherimide membrane, a polyamide membrane, and a carbon membrane. 2 Concentration detection device, when the purified gas contains CO 2 When the content is low, the CO recovered by the separation device 160 2 The purified gas flows back to the first reaction device 130 through the reflux pipeline. 2 When the content is sufficient to react with methane, the CO recovered by the separation device 160 2 Simply drain.

[0088] The third reaction device 170 is provided with a catalyst packing structure, and the third reaction gas generates a synthesis gas containing methanol after a catalytic reaction in the reaction device; the air inlet of the third reaction device 170 is connected to the air outlet of the separation device 160.

[0089] The first dust removal device and the second dust removal device are filters using porous metal filter elements. The first deacidification device is a dry deacidification tower; the second deacidification device is a spray tower. The first adsorption device and the second adsorption device are provided with an activated carbon filler structure.

[0090] 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 180 and a distillation device 190. The third condensing device 180 condenses the second synthesis gas and outputs liquid methanol; the gas inlet of the third condensing device 180 is connected to the gas outlet of the third reaction device 170. The distillation device 190 distills the liquid methanol and outputs high-purity methanol; the liquid inlet of the distillation device 190 is connected to the liquid outlet of the third condensing device 180.

[0091] The catalyst in the first reaction device 130 is a perovskite-type nickel-based composite catalyst, and an embodiment of a preparation method thereof includes the following steps:

[0092] 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 performed at 80°C for 2 hours; after collecting, washing and drying the solid, calcining at 600°C in air for 3-5 hours to obtain CeO 2 -ZrO 2 Carrier;

[0093] 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;

[0094] 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.

[0095] The perovskite-type nickel-based composite catalyst is used to purify gas (the volume fraction of one embodiment is: 5.41% CO, 75.24% CO 2 1.49% H 2 , 2.31% water vapor, the balance is N 2 ) and methane for catalysis, the volume ratio of purified 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%.

[0096] The catalyst in the second reaction device 150 is a Cu-Zr catalyst, and an embodiment of a preparation method thereof includes the following steps:

[0097] Dissolving zirconium nitrate and urea in 150 mL of deionized water to form an aqueous solution, wherein the molar ratio of urea to zirconium ions in the aqueous solution is 2, and the zirconium ion concentration is 0.2 mol / L; subjecting the aqueous solution to a hydrothermal treatment at a hydrothermal reaction temperature of 150° C. for 24 hours, and collecting, washing and drying the generated first solid;

[0098] calcining the first solid at a temperature of 250° C. for 4 hours to obtain a zirconium precursor;

[0099] The zirconium precursor and copper nitrate are ground and mixed, and the molar ratio of copper ions to zirconium ions (calculated according to zirconium nitrate) is 0.12; then the ground mixture is dispersed in 200 mL of deionized water to form a dispersion, and stirred for 2 hours in a water bath at a water bath temperature of 60° C., and sodium hydroxide is slowly added to the dispersion in a water bath until the pH of the dispersion reaches 9, and the generated second solid is collected, washed and dried;

[0100] The second solid was calcined at a temperature of 400° C. for 4 hours to obtain a Cu-Zr catalyst.

[0101] Figure 3 is the XRD pattern of Cu-Zr catalyst. Figure 3 As shown, the Cu-Zr catalyst has a good crystal structure, and its XRD pattern has CuO x and ZrO 2 The characteristic peaks of Cu in the preparation process are not embedded into the zirconium precursor (ZrO 2 ), but CuOx is uniformly attached to ZrO 2 The surface produces a better catalytic effect through the interaction between the two.

[0102] By N 2 The zirconium precursor (ZrO 2 ) has a specific surface area of ​​37.35 m 2 / g, with a total pore volume of 0.22cm 3 / g, the average pore size is 23.6nm, and the specific surface area of ​​the Cu-Zr catalyst is 56.48m 2 / g, with a total pore volume of 0.30 cm 3 / g, the average pore size is 21.8nm, it can be seen that when CuO is loaded x After that, the specific surface area of ​​the Cu-Zr catalyst increased significantly, which plays a decisive role in the adsorption and activation of the gas.

[0103] The volume fractions were divided into 15% CO, 40% H 2 、35%N 2 , 10% CO 2 The mixed gas was mixed with water vapor and catalyzed by Cu-Zr catalyst at 180-300℃. The results showed that the CO conversion rate increased sharply at first and then gradually tended to be gentle with the increase of catalytic temperature. The corresponding CO conversion rates at 180℃, 210℃, 240℃, 270℃ and 300℃ were 62%, 79%, 85%, 86% and 87%, respectively.

[0104] The Cu-Zr catalyst is used to treat the second mixed gas (the volume fraction of one embodiment is: 31.62% CO, 1.25% CO 2 、27.65%H 2 , 33.54% water vapor, the balance is N 2 ) for catalysis, the reaction temperature was 270°C, the reaction pressure was 5MPa, and the space velocity was 5000h -1 , the CO conversion rate is 83%.

[0105] The catalyst in the third reaction device 170 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 an embodiment of the preparation method thereof comprises the following steps:

[0106] Preparation of Fe by coprecipitation 3 O 4 Core: FeCl 3 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.

[0107] 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 2Inner layer, get CeO 2 @Fe 3 O 4 .

[0108] 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 4 The 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 .

[0109] 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 .

[0110] 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 .

[0111] 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.

[0112] Reduction treatment: The precursor is heated in N 2 and H 2 The catalyst was reduced at 350 °C for 2 hours in a mixed atmosphere of .

[0113] The multilayered catalyst is used to react the third reaction gas (the volume fraction of one embodiment is: 28.56% CO, 10.36% CO 2 52.24% H 2 , 2.28% water vapor, the balance is N 2 ) for catalysis, the third reaction gas and the supplementary H 2 The volume ratio is (20.05-20.5):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 0.6-1.2 kg methanol / (L catalyst·h). It is estimated that 6.98 tons of methanol can be produced as a by-product for every ton of bamboo activated carbon produced, and the purity of liquid methanol is above 95%.

[0114] The wet deacidification refers to spraying a liquid absorbent for deacidification; the dry deacidification refers to spraying a solid absorbent for deacidification.

[0115] 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 a first tail gas produced by a primary carbonization treatment, a second tail gas produced by a secondary carbonization treatment, and a third tail gas produced by an activation treatment, wherein the adhesive used for the green body subjected to the secondary carbonization treatment is a polymer adhesive, and the activator used for the activation treatment is water vapor, and the method is characterized in that: The method of use includes the following steps: The first tail gas is passed into an external boiler used for secondary carbonization treatment and activation treatment, and then ignited and burned to obtain combustion tail gas; Purifying a first mixed gas consisting of the combustion exhaust gas and the second exhaust gas to obtain purified gas; Passing the purified gas and methane into a first reaction device loaded with a catalyst for catalytic reaction to generate a first reaction gas containing H2 and CO; Purifying the activated tail gas to obtain a second reaction gas; Passing a second mixed gas consisting of the first reaction gas and the second reaction gas into a second reaction device loaded with a catalyst for catalytic reaction to generate a first synthesis gas containing H2 and CO2; Recovering CO2 from the first synthesis gas to generate a third reaction gas; The third reaction gas is introduced into a third reaction device loaded with a catalyst for catalytic reaction to generate a second synthesis gas containing methanol.

2. The method for utilizing tail gas produced by bamboo activated carbon production as claimed in claim 1, characterized in that: The purification treatment of the first mixed gas includes condensation treatment, deacidification treatment, dust removal treatment and adsorption treatment in sequence; the purification treatment of the activated tail gas includes condensation treatment, dust removal treatment, adsorption treatment and deacidification treatment in sequence.

3. The method for utilizing tail gas produced by bamboo activated carbon production as claimed in claim 2, characterized in that: The adsorption treatment adopts activated carbon adsorption; the first mixed gas is deacidified by dry deacidification; and the activated tail gas is deacidified by wet deacidification.

4. The method for utilizing tail gas produced by bamboo activated carbon according to claim 1, characterized in that: The volume fraction of water vapor in the purified gas is 2-5%, COD content ≤5ppm, volatile organic matter content ≤3ppm, acid gas content ≤2ppm, particulate matter content ≤20mg / Nm 3 The water vapor volume fraction in the second reaction gas is 30-40%, 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 recirculating CO2 recovered from the first synthesis gas to the first reaction device to react with methane.

6. The method for utilizing tail gas produced by bamboo activated carbon production as claimed in claim 1, characterized in that: A CO2 selective separation membrane is used to recover CO2 in the first synthesis gas.

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 first reaction device is a perovskite-type nickel-based composite catalyst.

8. 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 is a Cu-Zr catalyst.

9. The method for utilizing tail gas produced by bamboo activated carbon production as claimed in claim 1, characterized in that: The catalyst in the third 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.

10. A method for producing bamboo activated carbon, comprising subjecting bamboo raw materials to primary carbonization treatment, secondary carbonization treatment and activation treatment, characterized in that: The method also includes utilizing the production tail gas of bamboo activated carbon according to any one of claims 1 to 9, wherein the production tail gas includes a first tail gas generated by a primary carbonization treatment, a second tail gas generated by a secondary carbonization treatment, and a third tail gas generated by an activation treatment; The primary carbonization treatment comprises the following steps: 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 it at that temperature for 0.5-1.5 hours, then cool it with the furnace to obtain the primary carbonized material; The second carbonization treatment comprises the steps of: The primary carbonized material and the polymer adhesive are granulated into a green body, the green body is placed in a carbonization furnace, and the furnace temperature is raised from room temperature to 500-600°C under an inert atmosphere, and kept at this temperature for 0.5-1.5 hours, and the secondary carbonized material is obtained by cooling the furnace; The activation treatment is as follows: putting the secondary 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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