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

Abstract

The utility model discloses a bamboo activated carbon production tail gas utilization system and a bamboo activated carbon production system. The utilization system comprises: a condensing device for condensing the production tail gas and outputting a condensate; the solid-liquid separation equipment is used for carrying out solid-liquid separation treatment on the condensate and outputting permeate liquid; a liquid inlet of the solid-liquid separation equipment is connected with a liquid outlet of the condensing equipment; the membrane separation equipment is used for carrying out membrane separation treatment on the permeate liquid and outputting oily liquid; a membrane adopted by the membrane separation equipment is a nanofiltration membrane; a liquid inlet of the membrane separation equipment is connected with a liquid outlet of the solid-liquid separation equipment; the extraction equipment is used for carrying out extraction treatment on the oily liquid and outputting an extracting agent soluble liquid; a liquid inlet of the extraction equipment is connected with an oily liquid outlet of the membrane separation equipment; and the primary distillation equipment is used for performing reduced pressure distillation treatment on the extractant soluble liquid and outputting biomass oil.

Description

TECHNICAL FIELD

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

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

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

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

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

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

[0007] If the tail gas generated during the carbonization process and the activation process can be converted into clean energy, the utilization rate of bamboo resources can be significantly improved. Chinese invention patent CN116332128A discloses a system for preparing methanol and high-quality activated carbon from biomass and a preparation method thereof. In this method, the tail gas generated during the activation process is directly subjected to a water-gas shift reaction, followed by a CO hydrogenation reaction, and finally methanol is obtained. On the one hand, a large amount of tail gas generated during the carbonization process is not recycled and utilized, and on the other hand, directly synthesizing the activation tail gas can easily cause catalyst poisoning and result in low purity of methanol. SUMMARY

[0008] The technical problem to be solved by the present application is to provide a simple and efficient method and system for utilizing the tail gas generated during the production of bamboo activated carbon, and a production method and system for bamboo activated carbon.

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

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

[0011] Condensing the production tail gas to obtain a condensate;

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

[0013] Performing membrane separation treatment on the permeate using a nanofiltration membrane to obtain an oily liquid;

[0014] Performing extraction treatment on the oily liquid using an extractant to obtain an extractant-soluble liquid;

[0015] Performing vacuum distillation treatment on the extractant-soluble liquid to obtain a biomass oil.

[0016] As a further improvement of the above-mentioned method for utilizing the tail gas generated during the production of bamboo activated carbon, the condensation treatment is divided into two stages, first condensation is performed at 70-100℃, and then condensation is performed at 40-60℃.

[0017] As a further improvement of the method for utilizing the tail gas produced in the production of bamboo activated carbon, the transudate is subjected to vacuum filtration treatment, the vacuum degree is 50-200mmHg, the temperature is 35-45℃, and the pore size of the nanofiltration membrane is 1-10nm.

[0018] As a further improvement of the method for utilizing the tail gas produced in the production of bamboo activated carbon, the extractant is ethanol and / or acetone, and the volume of the extractant is 1.5-2 times the volume of the condensed liquid.

[0019] As a further improvement of the method for utilizing the tail gas produced in the production of bamboo activated carbon, the vacuum distillation treatment is carried out at 45-55℃ and 15-18kPa, and the condensed liquid obtained from the vacuum distillation treatment is repeatedly used for the extraction treatment of the oily liquid.

[0020] As a further improvement of the method for utilizing the tail gas produced in the production of bamboo activated carbon, the biomass oil is subjected to atmospheric distillation into solid at 200-250℃, and the utilization method further comprises crushing, grinding and vacuum drying treatment of the solid, so as to obtain solid biomass oil.

[0021] As a further improvement of the method for utilizing the tail gas produced in the production of bamboo activated carbon, the biomass oil is subjected to atmospheric distillation into concentrated liquid at 200-250℃, and the utilization method further comprises hydrofining treatment of the concentrated liquid, which comprises the following steps: preparing a reaction liquid according to the mass ratio of biomass oil:methanol: catalyst as (15-25):(20-30):1, and subjecting to hydrothermal reaction at 180-200℃ and 1MPa hydrogen pressure for 2-4h, so as to obtain refined biomass oil.

[0022] As a further improvement of the method for utilizing the tail gas produced in the production of bamboo activated carbon, the activated carbon-based Ni / BC catalyst is used, and the preparation method comprises the following steps: dispersing soluble nickel salt and activated carbon in ethanol, stirring for 4-6h, completely removing the ethanol solvent by rotary evaporation at 80℃, and then drying in a vacuum oven, and calcining at 500-600℃ for 1-3h in a reducing atmosphere, so as to obtain the activated carbon-based Ni / BC catalyst.

[0023] As a further improvement of the method for utilizing the tail gas produced in the production of bamboo activated carbon, when the bamboo raw material is subjected to segmented carbonization treatment, the production tail gas at least comprises the segmented tail gas generated by carbonization treatment at 300-400℃.

[0024] The utilization system of the tail gas produced by the bamboo activated carbon production includes a carbonization furnace for carbonizing the bamboo raw material to obtain carbonization tail gas, and the utilization system includes: a condensing device for condensing the production tail gas and outputting a condensate; a solid-liquid separation device for solid-liquid separation treatment of the condensate and outputting a permeate; the liquid inlet of the solid-liquid separation device is connected with the liquid outlet of the condensing device; a membrane separation device for membrane separation treatment of the permeate and outputting an oily liquid; the membrane separation device adopts a nanofiltration membrane; the liquid inlet of the membrane separation device is connected with the liquid outlet of the solid-liquid separation device; an extraction device for extraction treatment of the oily liquid and outputting an extractant-soluble liquid; the liquid inlet of the extraction device is connected with the oily liquid outlet of the membrane separation device; a primary distillation device for vacuum distillation treatment of the extractant-soluble liquid and outputting a biomass oil; the liquid inlet of the primary distillation device is connected with the extractant-soluble liquid outlet of the extraction device.

[0025] As a further improvement of the above-mentioned utilization system of the tail gas produced by the bamboo activated carbon production: the solid-liquid separation device is a filtering device or a centrifugal separation device.

[0026] As a further improvement of the above-mentioned utilization system of the tail gas produced by the bamboo activated carbon production: the membrane separation device is a vacuum filtration device adopting a nanofiltration membrane.

[0027] As a further improvement of the above-mentioned utilization system of the tail gas produced by the bamboo activated carbon production: further including a conveying pipeline for inputting an extractant into the extraction device; further including a reflux pipeline for refluxing the condensate obtained by the distillation of the primary distillation device to the extraction device.

[0028] As a further improvement of the above-mentioned utilization system of the tail gas produced by the bamboo activated carbon production: further including a secondary distillation device for atmospheric distillation treatment of the biomass oil; the liquid inlet of the secondary distillation device is connected with the liquid outlet of the primary distillation device.

[0029] As a further improvement of the above-mentioned utilization system of the tail gas produced by the bamboo activated carbon production: the secondary distillation device distills the biomass oil into a solid, and the utilization system further includes a crushing device, a grinding device and a drying device for crushing, grinding and vacuum drying treatment of the solid.

[0030] As a further improvement of the above-mentioned utilization system of the tail gas produced by the bamboo activated carbon production: the secondary distillation device distills the biomass oil into a concentrated liquid, and the utilization system further includes a hydrothermal reaction device for refining treatment of the concentrated liquid.

[0031] In order to achieve the above-mentioned purpose, according to the second aspect of the present application, the bamboo activated carbon production method and production system using the utilization method and utilization system of the bamboo activated carbon production tail gas of the first aspect are provided, and the technical scheme is as follows:

[0032] The production method of the bamboo activated carbon comprises carbonization treatment on the bamboo raw material, and further comprises utilization of the production tail gas by using the utilization method of the bamboo activated carbon production tail gas of the first aspect, wherein the production tail gas at least comprises carbonization tail gas generated by the carbonization treatment on the bamboo raw material;

[0033] The carbonization treatment at least comprises one-time carbonization treatment, comprising the following steps:

[0034] The dried bamboo raw material is placed in a carbonization furnace, and the furnace temperature is increased from room temperature to 130-280 DEG C under an inert atmosphere, and the temperature is maintained for 0.5-1.5 hours;

[0035] The temperature is continuously increased to 300-400 DEG C, and the temperature is maintained for 0.5-1.5 hours;

[0036] The temperature is continuously increased to 500-600 DEG C, and the temperature is maintained for 0.5-1.5 hours, and then the furnace is cooled to obtain one-time carbonization material; after the carbonization is completed, the activation treatment is carried out to obtain the bamboo activated carbon.

[0037] The production system of the bamboo activated carbon comprises a carbonization furnace for carbonization treatment on the bamboo raw material, and further comprises a utilization system of the bamboo activated carbon production tail gas for utilization of the production tail gas, wherein the production tail gas at least comprises carbonization tail gas generated by the carbonization treatment on the bamboo raw material.

[0038] The biomass oil is an important resource, which has the purposes of fuel, chemical raw material, energy storage and the like. The present application effectively utilizes the organic matter generated by pyrolysis of the biomass component of the bamboo raw material in the carbonization process, adopts simple and efficient purification means, converts the organic matter steam in the carbonization tail gas into biomass oil with high heat value (HHV) through condensation treatment, solid-liquid separation treatment, membrane separation treatment, extraction treatment and distillation treatment, improves the overall added value of the bamboo activated carbon, maximally utilizes the energy and chemical components of the bamboo raw material, reduces resource waste, and increases enterprise economic benefits.

[0039] The embodiments of the application provided in the present specification will be further described in combination with the drawings and specific embodiments. Additional aspects and advantages of the embodiments of the application provided in the present specification will be partially given in the following description, partially become obvious from the following description, or be understood by the practice of the embodiments of the application provided in the present specification. BRIEF DESCRIPTION OF DRAWINGS

[0040] The accompanying drawings, which form a part of this specification, are included to provide a further understanding of the embodiments of the application described herein and are incorporated in and constitute a part of this specification, illustrate embodiments of the application and serve to explain the related work described herein. In the drawings:

[0041] Figure 1 Structure schematic diagram of a first embodiment of a bamboo activated carbon production system and a utilization system of tail gas produced in the bamboo activated carbon production.

[0042] Figure 2 Structure schematic diagram of a second embodiment of a bamboo activated carbon production system and a utilization system of tail gas produced in the bamboo activated carbon production.

[0043] Figure 3 XRD pattern of Cu-Zr catalyst.

[0044] The relevant signs in the above-mentioned drawings are as follows:

[0045] 210 - condensing equipment, 220 - solid-liquid separation equipment, 230 - membrane separation equipment, 240 - extraction equipment, 250 - first-stage distillation equipment, 260 - second-stage distillation equipment. DETAILED DESCRIPTION

[0046] The embodiments of the application provided by the present specification will be described in detail below with reference to the drawings. Those skilled in the art can implement the embodiments of the application provided by the present specification based on these descriptions. Before the embodiments of the application provided by the present specification are described in conjunction with the drawings, it should be particularly pointed out that:

[0047] The technical solutions and technical features provided in each part of the embodiments of the application provided by the present specification, including the following descriptions, can be combined with each other without conflict.

[0048] In addition, the embodiments of the application provided by the present specification involved in the following descriptions are generally only a part of the embodiments of the application provided by the present specification rather than all the embodiments, and therefore, all other embodiments obtained by those skilled in the art based on the embodiments of the application provided by the present specification without creative labor should belong to the protection scope of the embodiments of the application provided by the present specification.

[0049] Terms and units in the embodiments of the application provided in the specification: the terms "include", "contain", "have" and any variants thereof in the specification and the claims and related parts of the embodiments of the application provided in the specification are intended to cover non-exclusive inclusion. In addition, other related terms and units in the embodiments of the application provided in the specification can be reasonably interpreted based on the related content of the embodiments of the application provided in the specification.

[0050] The first embodiment of the bamboo active carbon production method of the utility model is including steps of:

[0051] Drying treatment: put the fresh bamboo raw material into the oven and dry for 48 hours at 100 DEG C.

[0052] Primary carbonization treatment: put the dried bamboo raw material into the carbonization furnace, under inert atmosphere, the furnace temperature is raised from room temperature to 200 DEG C, and the temperature is kept for 1 hour, then the temperature is raised to 350 DEG C, and the temperature is kept for 1 hour, then the temperature is raised to 550 DEG C, and the temperature is kept for 1 hour, and then the furnace is cooled to obtain carbonized material.

[0053] Activation treatment: put the carbonized material into the activation furnace, under inert atmosphere, use water vapor as the activator, the volume of liquid water per 100g blank body is 40ml per hour, keep the temperature at 1000 DEG C for 3 hours, and then cool the furnace to obtain bamboo active carbon.

[0054] Compared with the first embodiment, the second embodiment of the bamboo active carbon production method of the utility model has the difference that: it further includes secondary carbonization treatment: the primary carbonized material is ground to a particle size of 325 mesh, then molasses is used as the adhesive, water is used as the auxiliary agent, the mass ratio of molasses to primary carbonized material is 0.5, and 30ml of auxiliary agent is added for every 100g of primary carbonized material, the blank body is granulated in the kneader, the blank body is put into the carbonization furnace, under inert atmosphere, the furnace temperature is raised from room temperature to 550 DEG C, and the temperature is kept for 1 hour, and then the furnace is cooled to obtain secondary carbonized material. Then the secondary carbonized material is activated to obtain bamboo active carbon.

[0055] The bamboo active carbon production tail gas utilization method of the utility model is used for utilizing the production tail gas generated by the bamboo active carbon production method of the first embodiment or the second embodiment, and the production tail gas at least includes the segmented tail gas generated by carbonization treatment at 300-400 DEG C, for example, the production tail gas can only include the segmented tail gas generated by carbonization treatment at 300-400 DEG C, or it can include all primary carbonization tail gas, and it can further include secondary carbonization tail gas and / or activation tail gas.

[0056] The first embodiment of the bamboo active carbon production tail gas utilization method is including the following steps:

[0057] The production tail gas is condensed to obtain a condensed material; preferably, the condensation is divided into two stages, first condensation at 85°C and then condensation at 50°C, so that as much organic vapor as possible is condensed.

[0058] The condensed material is subjected to solid-liquid separation to obtain a permeate; the solid-liquid separation is filtration or centrifugal separation, so that particulate impurities captured by liquid droplets during condensation can be removed.

[0059] The permeate is subjected to membrane separation using a nanofiltration membrane to obtain an oily liquid; preferably, the membrane separation is vacuum filtration of the permeate at a vacuum degree of 100 mmHg and a temperature of 40°C, and the nanofiltration membrane has a pore size of 5 nm. Thus, water can pass through the nanofiltration membrane, while most of the organic matter is effectively retained, so that most of the organic matter is enriched in the oily liquid.

[0060] The oily liquid is subjected to extraction using an extractant to obtain an extractant-soluble liquid; preferably, the extractant is ethanol and / or acetone; the volume of the extractant is 2 times the volume of the condensed liquid.

[0061] The extractant-soluble liquid is subjected to vacuum distillation at 50°C and 16 kPa to obtain a biomass oil. Through vacuum distillation, the extractant can be evaporated and condensed, and the condensed material obtained by vacuum distillation can be repeatedly used for extraction of the oily liquid, so that the utilization rate of the extractant can be improved.

[0062] The second embodiment of the method for utilizing the bamboo-based activated carbon production tail gas is based on the first embodiment, and further includes subjecting the biomass oil to atmospheric distillation at 200-250°C (preferably 235°C) to obtain a solid, and the method further includes subjecting the solid to crushing, grinding, and vacuum drying, thereby obtaining a solid biomass oil.

[0063] The third embodiment of the method for utilizing the bamboo-based activated carbon production tail gas is based on the first embodiment, and further includes subjecting the biomass oil to atmospheric distillation at 200-250°C (preferably 235°C) to obtain a concentrated liquid, and the method further includes subjecting the concentrated liquid to hydrofining treatment, including the steps of: preparing a reaction liquid according to a mass ratio of biomass oil:methanol: catalyst of 20:25:1, and subjecting the reaction liquid to hydrothermal reaction at 190°C and 1 MPa hydrogen pressure for 3 h, thereby obtaining a refined biomass oil.

[0064] The activated carbon-based Ni / BC catalyst is prepared by dispersing 0.5 g of nickel nitrate and 1 g of activated carbon in ethanol and stirring for 5 h, completely removing the ethanol solvent by rotary evaporation at 80°C, and then drying in a vacuum oven, using 20% H2-Ar as a reducing atmosphere, and calcining at 550°C for 2 h.

[0065] Figure 1 This is a schematic diagram of the first embodiment of a bamboo activated carbon production system and a system for utilizing the exhaust gas from bamboo activated carbon production. Figure 1 As shown, the bamboo activated carbon production system includes one or two carbonization furnaces for carbonizing bamboo raw materials to obtain carbonization tail gas, and a system for utilizing the production tail gas. The production tail gas includes at least the segmented tail gas generated by carbonization treatment at 300-400°C. For example, the production tail gas may only include the segmented tail gas generated by carbonization treatment at 300-400°C, or it may include all the primary carbonization tail gas, and may further include secondary carbonization tail gas and activation tail gas.

[0066] The first embodiment of the system for utilizing the exhaust gas from bamboo activated carbon production includes a condensation device 210, a solid-liquid separation device 220, a membrane separation device 230, an extraction device 240, and a primary distillation device 250.

[0067] The condenser 210 is used to condense the production exhaust gas and output the condensate. The solid-liquid separation device 220 is used to separate the condensate into solid and liquid components and output the permeate. The inlet of the solid-liquid separation device 220 is connected to the outlet of the condenser 210. The solid-liquid separation device 220 is a filtration device or a centrifugal separator. The membrane separation device 230 is used to separate the permeate into an oily liquid. The membrane separation device 230 is a vacuum filtration device using a nanofiltration membrane. The inlet of the membrane separation device 230 is connected to the outlet of the solid-liquid separation device 220. The extraction device 240 is used to extract the oily liquid and output an extractant-soluble liquid. The inlet of the extraction device 240 is connected to the oily liquid outlet of the membrane separation device 230. The primary distillation device 250 is used to perform vacuum distillation on the extractant-soluble liquid and output biomass oil. The inlet of the primary distillation device 250 is connected to the extractant-soluble liquid outlet of the extraction device 240.

[0068] The system also includes a delivery pipe for feeding the extractant into the extraction device 240 and a reflux pipe for returning the condensate obtained from the first-stage distillation device 250 to the extraction device 240.

[0069] Tests showed that the obtained biomass oil contained 53.57% O, 37.65% C, 7.61% H and 1.17% N.

[0070] Figure 2 This is a schematic diagram of a second embodiment of a bamboo activated carbon production system and a system for utilizing the exhaust gas from bamboo activated carbon production. Figure 2Compared with the first embodiment, the utilization system of the second embodiment further comprises a secondary distillation device 260 for performing atmospheric distillation treatment on the biomass oil; the liquid inlet of the secondary distillation device 260 is connected with the liquid outlet of the primary distillation device 250.

[0071] When the secondary distillation device 260 distills the biomass oil into solid, the utilization system further comprises a crushing device, a grinding device and a drying device for performing crushing, grinding and vacuum drying treatment on the solid in sequence. Thus, the obtained solid biomass oil is more convenient to store, transport and use.

[0072] When the secondary distillation device 260 distills the biomass oil into concentrated liquid, the utilization system further comprises a hydrothermal reaction device for performing refining treatment on the concentrated liquid. Thus, by means of hydrorefining, the C / O and H / O ratio values can be further improved, and the HHV value can be further improved.

[0073] After the atmospheric distillation treatment by the secondary distillation device 260, the C content of the biomass oil continuously increases from 37.65% to 57.74%, the O content continuously decreases from 53.57% to 34.72%, the H content decreases from 7.61% to 6.05%, and the N content is basically unchanged. It can be seen that, by means of the atmospheric distillation treatment, the C / O and H / O ratio values are increased, so that the HHV value is obviously improved.

[0074] After the condensation treatment of the carbonization tail gas, the non-condensable gas still contains resources such as CO, H2 and CO2. In order to deeply recover the valuable resources of the production tail gas, the utilization method of the bamboo activated carbon production tail gas further utilizes the non-condensable gas, and on the basis of the third embodiment, the fourth embodiment further comprises the following steps:

[0075] For the non-condensable gas after the condensation treatment of the production tail gas, purification treatment is performed to remove volatile organic matter, acidic gas and particulate impurities in the non-condensable gas. The purification treatment comprises dust removal treatment, adsorption treatment and deacidification treatment in sequence. The dust removal treatment is preferably filtration dust removal. The adsorption treatment can adsorb volatile organic matter in the production tail gas, and preferably uses activated carbon as the adsorbent. The deacidification treatment can remove residual acidic gas in the production tail gas, and the deacidification treatment preferably uses a spray tower to perform wet deacidification by means of a circulating liquid absorbent. Thus, the production tail gas obtained after the purification treatment has a water vapor volume fraction content of 15-25%, a COD content of ≤5 ppm, a volatile organic matter content of ≤3 ppm, an acidic gas content of ≤2 ppm, and a particulate matter content of ≤20 mg / Nm 3 .

[0076] The CO2 selective separation membrane is used to remove CO2 in the production tail gas, and then the production tail gas is introduced into a reaction device containing the Cu-Zr catalyst to generate synthesis gas containing H2 by catalytic reaction at 240-300°C, and the CO2 selective separation membrane is used to remove CO2 in the synthesis gas.

[0077] The preparation method of the Cu-Zr catalyst comprises the following steps:

[0078] Zirconium nitrate and urea are dissolved in 150 mL of deionized water to form an aqueous solution, the molar ratio of urea to zirconium ions in the aqueous solution is 2, and the concentration of zirconium ions is 0.2 mol / L; the aqueous solution is subjected to hydrothermal treatment, the hydrothermal reaction temperature is 150°C, the hydrothermal reaction time is 24 hours, and the generated first solid is collected, washed and dried;

[0079] The first solid is subjected to calcination treatment, the calcination temperature is 250°C, the calcination time is 4 hours, and the zirconium precursor is obtained;

[0080] The zirconium precursor and copper nitrate are ground and mixed, 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, stirring is carried out under the condition of a water bath temperature of 60°C for 2 hours, sodium hydroxide is continuously added dropwise into the dispersion under the condition of a water bath until the pH of the dispersion is 9, and the generated second solid is collected, washed and dried;

[0081] The second solid is subjected to calcination treatment, the calcination temperature is 400°C, the calcination time is 4 hours, and the Cu-Zr catalyst is obtained.

[0082] Figure 3 The XRD pattern of the Cu-Zr catalyst is shown in FIG. 1. Figure 3 As shown in FIG. 1, the Cu-Zr catalyst has a good crystal form, and the XRD pattern thereof has characteristic peaks of CuO x and ZrO2, which indicates that Cu is not embedded into the zirconium precursor (ZrO2) during the preparation process, but is uniformly attached to the surface of ZrO2, and through the interaction between the two, a better catalytic effect is generated.

[0083] The specific surface area of the zirconium precursor (ZrO2) is 37.35 m 2 / g, the total pore volume is 0.22 cm 3 / g, and the average pore size is 23.6 nm, and the specific surface area of the Cu-Zr catalyst is 56.48 m 2 / g, the total pore volume is 0.30 cm 3 / g, and the average pore size is 21.8 nm, so it can be seen that CuOx After that, the specific surface area of the Cu-Zr catalyst increases obviously, which plays a decisive role in the adsorption and activation of the gas.

[0084] The mixed gas with a volume fraction of 15% CO, 40% H2, 35% N2 and 10% CO2 is mixed with water vapor, and the Cu-Zr catalyst is used for catalysis at 180-300°C. The results show that the CO conversion rate increases sharply at first and then gradually tends to be flat with the increase of the catalysis temperature. The CO conversion rates at 180°C, 210°C, 240°C, 270°C and 300°C are 62%, 79%, 85%, 86% and 87% respectively.

[0085] The Cu-Zr catalyst is used for catalysis of the reaction gas (one embodiment data: 21.54% CO, 3.14% CO2, 23.55% H2, 22.35% water vapor, and the rest is N2) for removing CO2. The reaction temperature is 270°C, the reaction pressure is 5MPa, the space velocity is 5000h-1, and the CO conversion rate is 81%. -1

[0086] Different from the fourth embodiment, the fifth embodiment of the method for utilizing the tail gas produced by the bamboo activated carbon is:

[0087] The second tail gas and the third tail gas are subjected to condensation treatment to obtain second non-condensable gas.

[0088] The mixed gas composed of the first non-condensable gas obtained by condensation treatment of the first tail gas and the second non-condensable gas is subjected to purification treatment to obtain reaction gas. The purification treatment includes acid removal treatment, dust removal treatment and adsorption treatment in sequence. The acid removal treatment is dry acid removal, that is, spraying solid absorbent for acid removal, so that the acid removal treatment can remove the residual acid gas in the mixed gas and obtain low-acid gas with relatively low moisture content, avoiding the influence of the introduction of a large amount of water vapor by wet acid removal on the methanol synthesis reaction. The dust removal treatment is preferably filtration dust removal, and the dust removal is arranged after the acid removal treatment, so that not only the particulate impurities in the mixed gas can be removed, but also the acid removal agent used in the acid removal treatment can be removed. The adsorption treatment can adsorb volatile organic compounds in the mixed gas, and the activated carbon is preferably used as the adsorbent. Therefore, the purification treatment can remove particulate impurities, volatile organic compounds and residual acid gas, and the reaction gas obtained after the purification treatment of the mixed gas is mainly composed of CO2, CO and H2, the volume fraction of water vapor is 2-5%, the COD content is ≤5ppm, the volatile organic compound content is ≤3ppm, the acid gas content is ≤2ppm, and the particulate matter content is ≤20mg / Nm 3 .

[0089] ​The CO2 selective separation membrane is used to remove CO2 in the reaction gas, and then the reaction gas and H2 are introduced into a reaction device loaded with a multi-layer structure catalyst to perform a catalytic reaction, thereby generating a synthesis gas containing methanol.

[0090] The core of the multi-layer structure catalyst is Fe3O4, the inner layer is CeO2, the intermediate layer is Cu-Zn alloy, the outer layer is ZrO2, and the surface layer is a graphene quantum dot. The preparation method comprises the following steps:

[0091] The Fe3O4 core is prepared by a coprecipitation method: equal volumes of FeCl3·6H2O, FeCl2·4H2O and ammonia are used as raw materials, and the mixture is heated to 80°C under nitrogen protection, and ammonia is added to the mixture at a stirring speed of 500 rpm until the pH is 10-11; after 30 minutes of continuous reaction, magnetic separation is performed, and the collected solid is washed with deionized water and ethanol for 3 times, and vacuum dried at 60°C for 12 hours, thereby obtaining the Fe3O4 core. 3+ The Fe 2+ solution is mixed, and the molar ratio of Fe 3+ and Fe 2+ is 2:1; the mixed solution is heated to 80°C, ammonia is added to the mixed solution at a stirring speed of 500 rpm until the pH is 10-11; after 30 minutes of continuous reaction, magnetic separation is performed, and the collected solid is washed with deionized water and ethanol for 3 times, and vacuum dried at 60°C for 12 hours, thereby obtaining the Fe3O4 core.

[0092] The CeO2 inner layer is prepared by a hydrothermal method: Ce(NO3)3·6H2O and urea are dissolved in water, the concentration of Ce 3+ is 0.05M, and the concentration of urea is 0.5M; 1g of the Fe3O4 core is dispersed in 150mL of the above solution, transferred to a hydrothermal reaction kettle, and reacted at 180°C for 12 hours; after cooling to room temperature, centrifugal separation is performed, the collected solid is washed with water and ethanol for 3 times, dried at 60°C for 12 hours, and then calcined at 350°C for 2 hours, thereby coating the CeO2 inner layer on the surface of the Fe3O4 core to obtain CeO2@Fe3O4.

[0093] The Cu-Zn alloy intermediate layer is prepared by a chemical reduction method: Cu(NO3)2·3H2O and Zn(NO3)2·6H2O are dissolved in water, the concentration of Cu 2+ is 0.1M, and the concentration of Zn 2+ is 0.05M; 0.8g of the CeO2@Fe3O4 is dispersed in 100mL of the above solution, ultrasonically treated for 30 minutes; in an ice bath, NaBH4 solution (concentration of 0.2M) is slowly added dropwise until a precipitate is formed; then after stirring at room temperature for 2 hours, centrifugal separation is performed, the collected solid is washed with water and ethanol for 3 times, and vacuum dried at 50°C for 8 hours, thereby depositing the Cu-Zn alloy intermediate layer on the surface of the CeO2 inner layer to obtain Cu-Zn@CeO2@Fe3O4.

[0094] Preparation of ZrO2 outer layer by sol-gel method: Zr(OC4H9)4 is dissolved in ethanol, and the concentration of Zr(OC4H9)4 is 0.1 M; a small amount of water (water / Zr molar ratio = 2) and 0.6 g of Cu-Zn@CeO2@Fe3O4 are added to 100 mL of the above solution, and stirring is performed at room temperature for 4 hours; then centrifugal separation is performed after refluxing at 60°C for 2 hours, drying at 80°C for 12 hours, and calcining at 450°C for 3 hours, so that the ZrO2 outer layer is coated on the surface of the Cu-Zn alloy intermediate layer, and ZrO2@Cu-Zn@CeO2@Fe3O4 is obtained.

[0095] Preparation of graphene quantum dots (GQDs) by impregnation method: a GQDs aqueous solution with a concentration of 1 mg / mL is prepared; then 0.5 g of ZrO2@Cu-Zn@CeO2@Fe3O4 is dispersed in 100 mL of the GQDs aqueous solution; ultrasonic treatment is performed for 30 minutes, and then centrifugal separation is performed after stirring at room temperature for 4 hours, and vacuum drying at 50°C for 12 hours, so that the graphene quantum dots are loaded on the surface of the ZrO2 outer layer, and GQDs@ZrO2@Cu-Zn@CeO2@Fe3O4 is obtained.

[0096] Calcination treatment: GQDs@ZrO2@Cu-Zn@CeO2@Fe3O4 is calcined at 450°C for 4 hours in air, and a precursor is obtained.

[0097] Reduction treatment: the precursor is reduced at 350°C for 2 hours in a mixed gas atmosphere of N2 and H2 (the volume fraction of H2 is 10%), and a catalyst is obtained.

[0098] The multi-layer structure catalyst is used to catalyze the removal of CO2 reaction gas (one embodiment data: 25.41% CO, 3.05% CO2, 26.21% H2, 2.45% water vapor, and the balance is N2), the volume ratio of the reaction gas to the supplemented H2 is (4.05-4.5):1, the reaction temperature is 240°C (220-300°C can be used), the reaction pressure is 4 MPa (3-10 MPa can be used), the space velocity is 6000 h-1 (3000-10000 h-1 can be used), and the space time yield of liquid methanol is 0.2-0.6 kg methanol / (L catalyst·h), and the purity of liquid methanol is more than 95%. -1 (3000-10000 h -1

[0099] Different from the fifth embodiment, the sixth embodiment of the method for utilizing the tail gas produced in the production of bamboo activated carbon is as follows:

[0100] ​The non-condensable gas after the condensation treatment of the carbonization tail gas is sequentially subjected to deacidification treatment, dust removal treatment and adsorption treatment to obtain first reaction gas and adsorption saturated liquid; wherein the deacidification treatment adopts dry deacidification, that is, spraying solid absorbent for deacidification, so that the residual acid gas in the carbonization tail gas can be removed by the deacidification treatment and relatively dry low-acid gas can be obtained, avoiding the influence of the introduction of more water vapor by wet deacidification on the methanol synthesis reaction; the dust removal treatment is preferably filtration dust removal, which is arranged after the deacidification treatment, and can not only remove the particulate impurities carried by the carbonization tail gas, but also remove the deacidifying agent used in the deacidification treatment. The adsorption treatment uses alcohol as the adsorbent, which can adsorb volatile organic compounds in the carbonization tail gas and form first reaction gas and adsorption saturated liquid.

[0101] The adsorption saturated liquid is subjected to combustion treatment to obtain combustion tail gas; since the adsorption saturated liquid mainly contains volatile organic compounds, the combustion treatment of the adsorption saturated liquid can not only prevent environmental pollution caused by emission, but also generate more CO2 for reaction with methane.

[0102] The combustion tail gas and methane are introduced into the first reaction equipment loaded with a catalyst for catalytic reaction, and a second reaction gas containing H2 and CO is generated by the reaction.

[0103] The activated tail gas is sequentially subjected to condensation treatment, deacidification treatment, dust removal treatment and adsorption treatment to obtain third reaction gas; the volatile organic compounds in the activated tail gas are relatively less, so the adsorption treatment here uses activated carbon for adsorption.

[0104] The mixed gas composed of the first reaction gas, the second reaction gas and the third reaction gas and H2 are introduced into the second reaction equipment loaded with a catalyst (the above-mentioned multi-layer structure catalyst) for catalytic reaction to generate synthesis gas containing methanol; wherein the volume fraction content of water vapor in the mixed gas is 2-5%, the COD content is ≤5 ppm, the volatile organic compound content is ≤3 ppm, the acid gas content is ≤2 ppm, and the particulate matter content is ≤20 mg / Nm 3 .

[0105] The catalyst in the first reaction equipment is a perovskite type nickel-based composite catalyst, soluble cerium salt and zirconium salt are dissolved in deionized water, and the molar ratio of cerium ions to zirconium ions is 1; under the action of stirring, ammonia water is added dropwise into the solution until the pH is 9-10; then continue stirring for 2 h, and aging at 80°C for 2 hours; after collecting, washing and drying the solid, it is calcined in air at 600°C for 4 hours to obtain a CeO2-ZrO2 carrier;

[0106] The soluble lanthanum salt, the soluble strontium salt, the soluble nickel salt, the soluble ferric salt and the soluble ruthenium salt are weighed according to the molar ratio of La, Sr, Ni, Fe, Ru being 0.8:0.2:0.7:0.2:0.1 and dissolved in deionized water; the solution is added with an appropriate amount of citric acid according to the molar ratio of metal ions to citric acid being 1:1.5; the solution is stirred and evaporated at 80°C until a gel is formed; the gel is dried at 120°C for 12 hours to obtain the perovskite precursor;

[0107] The perovskite precursor and the CeO2-ZrO2 carrier are weighed according to the loading of the perovskite precursor being 20%, uniformly mixed by dispersing in a small amount of ethanol; after the ethanol is stirred and evaporated at 80°C, the perovskite structure is formed by first drying at 110°C and then calcining in air at 900°C for 6 hours, and finally reducing in a mixed atmosphere of H2 and Ar at 700°C for 2 hours to obtain the perovskite-type nickel-based composite catalyst.

[0108] The perovskite-type nickel-based composite catalyst is used to catalyze the combustion tail gas (the volume percentage of one embodiment is: 5.68% CO, 74.32% CO2, 1.54% H2, 2.14% water vapor, and the balance is N2) and methane, the volume ratio of the combustion tail gas to methane is (1.05-1.5):1, the reaction temperature is 700°C, the reaction pressure is 0.1 MPa, the space velocity is 20000h -1 -1, and the CO2 conversion rate is 81%.

[0109] The multi-layer structure catalyst is used to catalyze the mixed gas (the data of one embodiment is: 39.65% CO, 2.56% CO2, 38.56% H2, 2.68% water vapor, and the balance is N2), the volume ratio of the mixed gas to the supplemented H2 is (2.05-2.5):1, the reaction temperature is 240°C (220-300°C are all available), the reaction pressure is 4 MPa (3-10 MPa are all available), the space velocity is 6000h -1 (3000-10000h -1 are all available), and the space-time yield of liquid methanol is 0.4-0.9 kg methanol / (L catalyst·h), and the purity of liquid methanol is above 95%.

[0110] The above describes the related content of the embodiments of the invention provided in the specification. Those skilled in the art can implement the embodiments of the invention provided in the specification based on the descriptions. Based on the above content of the embodiments of the invention provided in the specification, all other preferred modes and embodiments obtained by those skilled in the art without creative labor should belong to the protection scope of the embodiments of the invention provided in the specification.

Claims

1. A system for utilizing exhaust gas from bamboo activated carbon production, comprising a carbonization furnace for carbonizing bamboo raw materials to obtain carbonization exhaust gas, characterized in that: The system includes: A condensation device (210) is used to condense the production exhaust gas and output the condensate; A solid-liquid separation device (220) is used to perform solid-liquid separation treatment on condensate and output permeate; the inlet of the solid-liquid separation device (220) is connected to the outlet of the condensation device (210); A membrane separation device (230) is used to perform membrane separation treatment on the permeate and output an oily liquid; the membrane used in the membrane separation device (230) is a nanofiltration membrane; the inlet of the membrane separation device (230) is connected to the outlet of the solid-liquid separation device (220); An extraction device (240) is used to extract an oily liquid and output an extractant-soluble liquid; the inlet of the extraction device (240) is connected to the oily liquid outlet of the membrane separation device (230); A primary distillation apparatus (250) is used to perform vacuum distillation on extractant-soluble liquid and output biomass oil; the inlet of the primary distillation apparatus (250) is connected to the extractant-soluble liquid outlet of the extraction apparatus (240).

2. The system for utilizing tail gas from bamboo activated carbon production as described in claim 1, characterized in that: The solid-liquid separation device (220) is a filtration device or a centrifugal separation device.

3. The system for utilizing tail gas from bamboo activated carbon production as described in claim 1, characterized in that: The membrane separation device (230) is a vacuum filtration device using nanofiltration membranes.

4. The system for utilizing tail gas from bamboo activated carbon production as described in claim 1, characterized in that: It also includes a delivery pipe for feeding extractant into the extraction apparatus (240); and a reflux pipe for returning the condensate obtained from distillation in the primary distillation apparatus (250) to the extraction apparatus (240).

5. The system for utilizing tail gas from bamboo activated carbon production as described in claim 1, characterized in that: It also includes a secondary distillation apparatus (260) for atmospheric distillation of biomass oil; the inlet of the secondary distillation apparatus (260) is connected to the outlet of the primary distillation apparatus (250).

6. The system for utilizing tail gas from bamboo activated carbon production as described in claim 5, characterized in that: The secondary distillation equipment (260) distills biomass oil into solids. The system also includes a pulverizing device, a grinding device, and a drying device for sequentially crushing, grinding, and vacuum drying the solids.

7. The system for utilizing exhaust gas from bamboo activated carbon production as described in claim 5, characterized in that: The secondary distillation equipment (260) distills biomass oil into a concentrated liquid, and the system also includes a hydrothermal reaction device for refining the concentrated liquid.

8. A bamboo-based activated carbon production system, comprising a carbonization furnace for carbonizing bamboo raw materials, characterized in that: It also includes utilizing the production exhaust gas using a system for utilizing the bamboo activated carbon production exhaust gas as described in any one of claims 1-7, wherein the production exhaust gas includes at least the carbonized exhaust gas generated from the carbonization treatment of bamboo raw materials.

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