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

Abstract

The invention discloses a bamboo activated carbon production tail gas utilization method and a bamboo activated carbon production method.The utilization method comprises the following steps that first tail gas is subjected to condensation treatment, and first non-condensable gas and condensate are obtained; condensing the second tail gas and the third tail gas to obtain second non-condensable gas; carrying out purification treatment on a mixed gas formed by the first non-condensable gas and the second non-condensable gas to obtain a reaction gas; and introducing the reaction gas into reaction equipment loaded with a catalyst, and carrying out catalytic reaction to generate synthesis gas containing methanol. According to the invention, the tail gas can be converted into the synthesis gas containing methanol, and the liquid methanol with higher purity can be obtained through further simple treatment (such as rectification), so that not only is the pollution of tail gas emission to the environment reduced, but also the methanol has wide application, is an important chemical raw material and fuel, and can be sold to increase the economic benefits of enterprises.

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 following steps:

[0011] condensing the first tail gas to obtain a first non-condensable gas and a condensate;

[0012] condensing the second tail gas and the third tail gas to obtain a second non-condensable gas;

[0013] Purifying the mixed gas consisting of the first non-condensable gas and the second non-condensable gas to obtain a reaction gas;

[0014] The reaction gas is introduced into a reaction device loaded with a catalyst for catalytic reaction to generate synthesis gas containing methanol.

[0015] As a further improvement of the above-mentioned bamboo activated carbon production tail gas utilization method: the water vapor volume fraction content in the reaction gas obtained after purification treatment 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 .

[0016] As a further improvement of the above-mentioned method for utilizing tail gas produced by bamboo activated carbon: the purification treatment includes sequentially performing deacidification treatment, dust removal treatment and adsorption treatment on the mixed gas; the deacidification treatment adopts dry deacidification.

[0017] As a further improvement of the above-mentioned method for utilizing tail gas produced by bamboo activated carbon, it also includes using CO before the catalytic reaction. 2 Selective separation membrane to remove CO from production tail gas 2 .

[0018] As a further improvement of the above-mentioned method for utilizing tail gas produced by bamboo activated carbon, it also includes introducing H into the reaction equipment. 2 .

[0019] 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 by condensation treatment to obtain biomass oil.

[0020] As a further improvement of the above-mentioned method for utilizing tail gas produced by bamboo activated carbon: the catalyst 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.

[0021] As a further improvement of the above-mentioned method for utilizing tail gas produced by bamboo activated carbon: the preparation method of the catalyst comprises the following steps:

[0022] 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;

[0023] 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;

[0024] 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;

[0025] ZrO was loaded on the surface of Cu-Zn alloy interlayer by reaction of n-butoxide zirconium, water and ethanol using sol-gel method. 2 Outer layer;

[0026] The impregnation method was used to impregnate the graphene quantum dot solution in ZrO 2 The outer surface is loaded with graphene quantum dots.

[0027] 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.

[0028] The utilization system of 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 utilization system includes: a first condensation device, which condenses the first tail gas to obtain a first non-condensable gas and a condensate; a second condensation device, which condenses the second tail gas and the third tail gas to obtain a second non-condensable gas; a deacidification device, which condenses the mixed gas consisting of the first non-condensable gas and the second non-condensable gas. Deacidification treatment is performed to obtain low-acid gas; the air inlet of the deacidification equipment is connected to the air outlets of the first condensation equipment and the second condensation equipment; a dust removal equipment, the dust removal equipment performs dust removal treatment on the low-acid gas to obtain low-dust gas; the air inlet of the dust removal equipment is connected to the air outlet of the deacidification equipment; an adsorption equipment, the adsorption equipment performs adsorption treatment on the low-dust gas to obtain reaction gas; the air inlet of the adsorption equipment is connected to the air outlet of the dust removal equipment; a reaction equipment, the reaction equipment is provided with a catalyst filling structure, and the reaction gas is subjected to a catalytic reaction in the reaction equipment to obtain a synthesis gas containing methanol; the air inlet of the reaction equipment is connected to the air outlet of the adsorption equipment.

[0029] As a further improvement of the above-mentioned bamboo activated carbon production tail gas utilization system: the dust removal equipment is a filter using a porous metal filter element.

[0030] As a further improvement of the above-mentioned bamboo activated carbon production tail gas utilization system: the deacidification equipment is a dry deacidification tower.

[0031] As a further improvement of the above-mentioned bamboo activated carbon production tail gas utilization system: an activated carbon filler structure is provided in the adsorption device.

[0032] As a further improvement of the above-mentioned bamboo activated carbon production tail gas utilization system: it also includes removing CO in the reaction gas 2 A separation device, wherein the air inlet of the separation device is connected to the air outlet of the adsorption device, and the air outlet of the separation device is connected to the air inlet of the reaction device.

[0033] As a further improvement of the above-mentioned bamboo activated carbon production tail gas utilization system: the separation device is loaded with CO 2 Membrane separation equipment with selective separation membrane, the CO 2 The selective separation membrane is any one of a polyetherimide membrane, a polyamide membrane, and a carbon membrane.

[0034] 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.

[0035] As a further improvement of the above-mentioned bamboo activated carbon production tail gas utilization system: it also includes:

[0036] a third condensing device, wherein the fourth condensing device condenses the synthesis gas and outputs liquid methanol; the air inlet of the third condensing device is connected to the air outlet of the reaction device;

[0037] 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.

[0038] 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:

[0039] 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;

[0040] The primary carbonization treatment comprises the following steps:

[0041] 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;

[0042] Continue to raise the temperature to 300-400°C and keep it warm for 0.5-1.5 hours;

[0043] 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;

[0044] The second carbonization treatment comprises the steps of:

[0045] 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;

[0046] The activation treatment is as follows: putting the secondary carbonized material into an activation furnace, using water vapor as an activating agent under an inert atmosphere, keeping the temperature at 800-1100° C. for 2-4 hours, and then cooling the furnace to obtain bamboo activated carbon.

[0047] The bamboo activated carbon production system includes a first carbonization furnace for performing a primary carbonization treatment on bamboo raw materials, a second carbonization furnace for performing a secondary carbonization treatment, and an activation furnace for performing an activation treatment after carbonization. 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. The system also includes a utilization system for the exhaust gas produced by the above-mentioned bamboo activated carbon. The exhaust gas produced includes a first exhaust gas generated by the primary carbonization treatment, a second exhaust gas generated by the secondary carbonization treatment, and a third exhaust gas generated by the activation treatment.

[0048] The present invention has the following advantages:

[0049] (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.

[0050] (2) According to the particularity of the three types of tail gas, pretreatment is first performed and then mixed and purified, which can significantly improve the purification efficiency, so that water vapor, organic vapor, volatile organic matter, acidic gas and particulate impurities are efficiently removed. The subsequent catalytic reaction not only helps to improve the activity and efficiency of the catalyst, reduce catalyst poisoning and equipment clogging and wear problems, but also can significantly improve the purity of methanol. Among them, the condensate obtained after the primary carbonization tail gas (i.e., the first 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.

[0051] The embodiments of the invention provided in this specification are further described below 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

[0052] 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:

[0053] 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.

[0054] 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.

[0055] Figure 3 It is a structural schematic diagram of a third embodiment of a bamboo activated carbon production system and a bamboo activated carbon production tail gas utilization system.

[0056] The relevant marks in the above drawings are:

[0057] 210 - first condensation equipment, 220 - second condensation equipment, 230 - deacidification equipment, 240 - dust removal equipment, 250 - adsorption equipment, 260 - reaction equipment, 270 - third condensation equipment, 280 - distillation equipment, 290 - separation equipment. DETAILED DESCRIPTION

[0058] 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:

[0059] 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.

[0060] 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.

[0061] 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.

[0062] The embodiment of the method for producing bamboo activated carbon of the present invention comprises the steps of:

[0063] Drying treatment: Put the fresh bamboo raw materials into an oven and dry them at 100℃ for 48 hours.

[0064] 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.

[0065] 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.

[0066] 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.

[0067] 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 2and 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 the yield of CO and H 2 More suitable for the reaction to produce methanol.

[0068] The method for utilizing the production tail gas of bamboo activated carbon of the present invention is used to utilize the production tail gas generated by the above-mentioned bamboo activated carbon production method, and the production tail gas includes the first tail gas generated by the primary carbonization treatment, the second tail gas generated by the secondary carbonization treatment and the third tail gas generated by the activation treatment.

[0069] The first embodiment of the method for utilizing tail gas produced by bamboo activated carbon comprises the following steps:

[0070] The first tail gas is condensed to obtain the first non-condensable gas and condensate. The second tail gas and the third tail gas are condensed to obtain the second non-condensable gas. Through the condensation process, water vapor, organic vapor and some low-boiling acidic gases are mainly removed. Condensing the first tail gas alone can enrich the organic vapor in the first tail gas at a higher concentration, which is helpful for the recovery and preparation of biomass oil.

[0071] The mixed gas consisting of the first non-condensable gas and the second non-condensable gas is purified to obtain a reaction gas; the purification treatment includes sequentially performing deacidification, dust removal and adsorption treatment on the mixed gas; wherein, the deacidification adopts dry deacidification, that is, spraying a solid absorbent for deacidification, thereby, the acid gas remaining in the 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 wet deacidification and affecting the methanol synthesis reaction; the dust removal treatment is preferably filtering dust removal, and dust removal is provided after the deacidification treatment, which can not only remove the particulate impurities in the mixed gas itself, but also remove the deacidification agent used in the deacidification treatment. The volatile organic matter in the 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 acid gas can be removed by the purification treatment, and the reaction gas obtained after the mixed gas is purified is CO 2 , CO and , water vapor volume fraction is 2-5%, COD content ≤5ppm, volatile organic matter content ≤3ppm, acid gas content ≤2ppm, particulate matter content ≤20mg / Nm 3 .

[0072] The reaction gas is introduced into a reaction device loaded with a catalyst for catalytic reaction to generate synthesis gas containing methanol.

[0073] 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 reaction device. 2 .

[0074] The third embodiment of the method for utilizing tail gas produced by bamboo activated carbon is as follows: based on the second embodiment, the method further comprises using CO before the catalytic reaction. 2 Selective separation membrane to remove CO from production tail gas (reaction gas) 2 .

[0075] 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 performing a primary carbonization treatment on the bamboo raw material, a second carbonization furnace for a secondary carbonization treatment, an activation furnace for performing an activation treatment after the carbonization, and a production exhaust gas utilization system, wherein the production exhaust gas includes a first exhaust gas generated by the primary carbonization treatment, a second exhaust gas generated by the secondary carbonization treatment, and a third exhaust gas generated by the activation treatment.

[0076] The first embodiment of the utilization system of tail gas produced by bamboo activated carbon includes a first condensation device 210 , a second condensation device 220 , a deacidification device 230 , a dust removal device 240 , an adsorption device 250 and a reaction device 260 .

[0077] The first condensing device 210 performs condensation treatment on the first tail gas to obtain a first non-condensable gas and a condensate. The second condensing device 220 performs condensation treatment on the second tail gas and the third tail gas to obtain a second non-condensable gas. The deacidification device 230 performs deacidification treatment on the mixed gas consisting of the first non-condensable gas and the second non-condensable gas to obtain low-acid gas; the air inlet of the deacidification device 230 is connected to the air outlet of the first condensing device 210 and the second condensing device 220, and the deacidification device 230 is a dry deacidification tower. The dust removal device 240 performs dust removal treatment on the low-acid gas to obtain low-dust gas; the air inlet of the dust removal device 240 is connected to the air outlet of the deacidification device 230, and the dust removal device 240 is a filter using a porous metal filter element. The adsorption device 250 performs adsorption treatment on the low-dust gas to obtain a reaction gas; the air inlet of the adsorption device 250 is connected to the air outlet of the dust removal device 240, and the adsorption device 250 is provided with an activated carbon filler structure. The reaction device 260 is provided with a catalyst packing structure, and the reaction gas and H 2 After the catalytic reaction in the reaction device 260, a synthesis gas containing methanol is obtained. The gas inlet of the reaction device 260 is connected to the gas outlet of the adsorption device 250 and the hydrogen delivery device.

[0078] H 2A 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 device 250, by adding H 2 , which can promote the synthesis reaction towards the production of methanol.

[0079] 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 270 and a distillation device 280. The third condensing device 270 performs condensation treatment on the synthesis gas and outputs liquid methanol, and the gas inlet of the third condensing device 270 is connected to the gas outlet of the reaction device 260. The distillation device 280 performs distillation treatment on the liquid methanol and outputs high-purity methanol, and the liquid inlet of the distillation device 280 is connected to the liquid outlet of the third condensing device 270.

[0080] Figure 3 FIG. 1 is a schematic diagram of the structure of a third embodiment of a bamboo activated carbon production system and a bamboo activated carbon production tail gas utilization system. Figure 3 As shown, compared with the first embodiment, the third embodiment also includes removing CO from the reaction gas. 2 The separation device 290 has an air inlet connected to the air outlet of the adsorption device 250, and the air outlet of the separation device 290 is connected to the air inlet of the reaction device 260; the separation device 290 is loaded with CO 2 Membrane separation equipment with selective separation membrane, the CO 2 The selective separation membrane is any one of a polyetherimide membrane, a polyamide membrane, and a carbon membrane.

[0081] The right amount of CO 2 It helps maintain the activity of the catalyst, but too much will reduce the methanol selectivity. Therefore, part of the CO in the reaction gas is removed by the separation device 290. 2 , so that the CO in the treated reaction gas 2 The volume fraction is 2 to 8%, which can effectively promote the methanol synthesis reaction.

[0082] The catalyst in the reaction device has a multi-layer structure, with the core being 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:

[0083] 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.

[0084] 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 .

[0085] 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 .

[0086] 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 .

[0087] 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 .

[0088] 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.

[0089] 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.

[0090] 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.

[0091] The multi-layered catalyst is used to treat the reaction gas (data in one embodiment: 25.41% CO, 3.05% CO) after being treated by the separation device 290. 2 26.21% H 2 , 2.45% water vapor, the balance is N 2 ) for catalysis, the reaction gas and the supplementary H 2 The volume ratio is (4.05-4.5):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 0.2-0.6 kg methanol / (L catalyst·h), and the purity of liquid methanol is above 95%.

[0092] 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 production tail gas, the method for utilizing 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 third embodiment, the fourth embodiment further includes the steps of:

[0093] The condensate obtained by condensing the first 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.

[0094] 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.

[0095] 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.

[0096] 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.

[0097] Different from the fourth embodiment, the fifth embodiment of the method for utilizing tail gas produced by bamboo activated carbon is as follows:

[0098] The condensate obtained by condensing the first 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.

[0099] The permeate is subjected to extraction treatment by using an extractant to obtain a first extractant-soluble liquid.

[0100] 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.

[0101] 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.

[0102] 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.

[0103] 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.

[0104] 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.

[0105] In the fourth and fifth embodiments, the biomass oil can be further distilled at 200-250°C under normal pressure into 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.

[0106] 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 exploitation method includes the following steps: condensing the first tail gas to obtain a first non-condensable gas and a condensate; condensing the second tail gas and the third tail gas to obtain a second non-condensable gas; Purifying the mixed gas consisting of the first non-condensable gas and the second non-condensable gas to obtain a reaction gas; The reaction gas is introduced into a reaction device loaded with a catalyst for catalytic reaction to generate 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 volume fraction of water vapor in the reaction gas obtained after purification is 2-5%, COD content is ≤5ppm, volatile organic matter content is ≤3ppm, acid gas content is ≤2ppm, and particulate matter content is ≤20mg / Nm 3 .

3. The method for utilizing tail gas produced by bamboo activated carbon production as claimed in claim 2, characterized in that: The purification treatment includes sequentially performing deacidification treatment, dust removal treatment and adsorption treatment on the mixed gas; the deacidification treatment adopts dry deacidification.

4. The method for utilizing tail gas produced by bamboo activated carbon production as claimed in claim 1, characterized in that: It also includes using a CO2 selective separation membrane to remove CO2 from the production tail gas before the catalytic reaction.

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

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 by the condensation treatment 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 has a multi-layer structure, 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 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 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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