CN114029033A - Preparation method of pore diameter controllable carbon molecular sieve particle adsorbent - Google Patents
Preparation method of pore diameter controllable carbon molecular sieve particle adsorbent Download PDFInfo
- Publication number
- CN114029033A CN114029033A CN202111310411.7A CN202111310411A CN114029033A CN 114029033 A CN114029033 A CN 114029033A CN 202111310411 A CN202111310411 A CN 202111310411A CN 114029033 A CN114029033 A CN 114029033A
- Authority
- CN
- China
- Prior art keywords
- molecular sieve
- carbon molecular
- carbon
- temperature
- drying
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
Images
Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
- B01J20/00—Solid sorbent compositions or filter aid compositions; Sorbents for chromatography; Processes for preparing, regenerating or reactivating thereof
- B01J20/02—Solid sorbent compositions or filter aid compositions; Sorbents for chromatography; Processes for preparing, regenerating or reactivating thereof comprising inorganic material
- B01J20/20—Solid sorbent compositions or filter aid compositions; Sorbents for chromatography; Processes for preparing, regenerating or reactivating thereof comprising inorganic material comprising free carbon; comprising carbon obtained by carbonising processes
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
- B01J20/00—Solid sorbent compositions or filter aid compositions; Sorbents for chromatography; Processes for preparing, regenerating or reactivating thereof
- B01J20/02—Solid sorbent compositions or filter aid compositions; Sorbents for chromatography; Processes for preparing, regenerating or reactivating thereof comprising inorganic material
- B01J20/10—Solid sorbent compositions or filter aid compositions; Sorbents for chromatography; Processes for preparing, regenerating or reactivating thereof comprising inorganic material comprising silica or silicate
- B01J20/16—Alumino-silicates
- B01J20/18—Synthetic zeolitic molecular sieves
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
- B01J20/00—Solid sorbent compositions or filter aid compositions; Sorbents for chromatography; Processes for preparing, regenerating or reactivating thereof
- B01J20/28—Solid sorbent compositions or filter aid compositions; Sorbents for chromatography; Processes for preparing, regenerating or reactivating thereof characterised by their form or physical properties
- B01J20/28014—Solid sorbent compositions or filter aid compositions; Sorbents for chromatography; Processes for preparing, regenerating or reactivating thereof characterised by their form or physical properties characterised by their form
- B01J20/28016—Particle form
Landscapes
- Chemical & Material Sciences (AREA)
- Analytical Chemistry (AREA)
- Organic Chemistry (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Inorganic Chemistry (AREA)
- Carbon And Carbon Compounds (AREA)
- Solid-Sorbent Or Filter-Aiding Compositions (AREA)
Abstract
The invention provides a preparation method of a pore diameter controllable carbon molecular sieve particle adsorbent, which belongs to the technical field of porous adsorption materials, and the method comprises the steps of drying rice hulls, carbonizing the dried rice hulls under the condition of introducing reducing gas and pure oxygen to obtain rice hull carbon with high carbon content, treating the rice hull carbon with alkali to obtain slurry containing silicate/carbon, carrying out gel reaction on the slurry to obtain carbon molecular sieve gel, carrying out acid treatment, washing and low-temperature drying on the carbon molecular sieve gel, then carrying out granulation, drying and sizing, introducing reducing gas to carry out high-temperature activation under the atmosphere, cooling and discharging, screening and packaging to obtain the carbon molecular sieve particle adsorbent with high adsorption performance; the carbon molecular sieve produced by the invention belongs to a high-humidity water absorbent, a porous adsorbent and an organic gas adsorbent, has wide application field and has good industrial popularization significance.
Description
Technical Field
The invention belongs to the technical field of porous adsorption materials, and particularly relates to a preparation method of a pore diameter controllable carbon molecular sieve particle adsorbent.
Background
The information in this background section is only for enhancement of understanding of the general background of the disclosure and is not necessarily to be construed as an admission or any form of suggestion that this information forms the prior art that is already known to a person of ordinary skill in the art.
China is a big country of rice, the yield of the rice is more than two hundred million tons every year, the yield of the rice accounts for about one third of the total annual yield of the whole world, the rice is at the first position in the world, and the rice hull resource is rich. The chemical components of the dry basis of the rice hull are about 80 percent of organic matters and 20 percent of ash, the organic matters mainly comprise cellulose, lignin, hemicellulose and other organic matters, and the inorganic matters mainly comprise SiO2And minor amounts of alkali oxides, alkaline earth metals, iron and aluminum. The rice hulls can supply heat when being burnt, can be used as carbon sources to prepare porous adsorption materials such as active carbon, molecular sieves and the like, can be used as silicon sources to prepare silicides such as silicate, metasilicate, white carbon black and the like, can be hydrolyzed to produce liquid organic matters such as xylose, furfural, ethanol, biological oil and the like, and has wide comprehensive utilization field of rice hull resources.
The rice husk carbon or rice husk ash as pyrolysis products contains silicon dioxide and carbon content of 50-80% at different combustion pyrolysis temperatures and pyrolysis atmospheres: 20-50%, and the silicon dioxide in the pyrolysis product is in a gel state, is in a non-compact arrangement, is mutually cohered to form a porous structure, and has strong activity.
With the rapid development of economy, a large amount of industrial emission gas containing volatile organic compounds needs to be emitted according to new standards, and the treatment technical requirements are high. The methods applied to control the low-concentration treatment of organic gases mainly include a thermal destruction method, a biodegradation method, a catalytic combustion method and an adsorption method, wherein the adsorption method is mainly applied to the treatment of low-concentration high-flow volatile organic compounds. Researches show that the carbon molecular sieve containing the silicon-aluminum pairs has good adsorption performance. The carbon molecular sieve is a high-efficiency adsorption material, can be applied to adsorption treatment or recovery of organic gas, and particularly has obvious performance advantages in an environment with high humidity and low organic gas concentration after being activated and modified.
In the prior art of co-producing molecular sieves by rice hulls, rice hull ash is used as a raw material, so that a carbon molecular sieve with high carbon content and developed specific surface area is difficult to produce, and the application field is difficult to expand.
Disclosure of Invention
The invention aims to provide a preparation method of a pore diameter controllable carbon molecular sieve particle adsorbent, so as to solve the problems.
In order to solve the technical problems, the invention adopts the technical scheme that:
a method for preparing a pore size controllable carbon molecular sieve particle adsorbent comprises the following steps:
1) preparing rice husk charcoal: the rice hulls are collected, screened and dried at low temperature, then carbonized under reducing gas and pure oxygen, and the carbonized materials are cooled and deironized to obtain rice hull carbon;
2) preparing silicate/carbon slurry: mixing the rice hull carbon obtained in the step 1) with an alkali solution, grinding by a wet method, then feeding into a normal-pressure stirring reaction kettle, and introducing steam or hot water to control the temperature and the material concentration for reaction to obtain silicate/carbon slurry;
3) preparing carbon molecular sieve gel: uniformly mixing the silicate/carbon slurry obtained in the step 2) with an acid solution containing an aluminum source in proportion, controlling the reaction pH to 2.5-3.5, and then standing and aging to perform a gel reaction to obtain a carbon molecular sieve gel;
4) preparing raw powder of a carbon molecular sieve: adding the carbon molecular sieve gel obtained in the step 3) into a micro-acid solution for acid treatment and soaking, blowing compressed air for homogenization during the acid treatment, and filtering, washing with hot water and drying after the reaction is finished to obtain raw powder of the carbon molecular sieve;
5) preparing a carbon molecular sieve particle adsorbent: adding the raw powder of the carbon molecular sieve obtained in the step 4) into an organic binder solution and an inorganic binder for mixing and pugging, then carrying out molding granulation and low-temperature drying and shaping, conveying to an activation furnace filled with reducing gas, water vapor and carbonized tail gas for activation, and cooling and screening the activated material to obtain the carbon molecular sieve particle adsorbent.
Further, the low-temperature drying temperature in the step 1) is 100-160 ℃, and the moisture of the dried material is lower than 5%.
Further, in the step 1), the carbonization temperature is controlled to be 550-750 ℃, and the carbonization time is 60-180 min; the volume concentration of the reducing gas in the carbonization stage is 0.01-5% of the total atmosphere volume concentration, and the volume concentration of the pure oxygen in the total atmosphere volume concentration is 1-10%. The carbonized tail gas is fully combusted through the rotary spraying furnace to obtain high-temperature flue gas, the high-temperature flue gas is supplied to the activation furnace to be used as activated air supply, the rice husk carbon is cooled through a discharging device with a heat exchange tube to recover waste heat to obtain hot water or hot air, and cold water or fresh cold air can be arranged in a cavity of the heat exchange tube.
Further, the reducing gas is one or more of methane, ethane, propane, butane, natural gas and hydrogen, and the volume mass ratio of the consumption of the reducing gas to the raw materials is 150-200: 1 (m)3T); the pure oxygen is generated by an oxygen generator to obtain the purity of more than 90 percent.
Further, the alkali solution in the step 2) is 20-30% of sodium hydroxide solution or potassium hydroxide solution, and the alkali metal oxide M is contained in the solution2O; introducing steam or hot water, controlling the temperature to be 80-100 ℃, and reacting for 1-6 h; SiO of silicate in the silicate/carbon slurry2/M2The molar ratio of the O modulus is 2.5-3.5, and the concentration of the silicon dioxide is 15-25%.
Further, a drum-type rotary kettle is adopted in wet grinding in the step 2), the volume of ball grinding balls in the rotary kettle accounts for 20-50% of the volume of the rotary kettle, and the specification of the ball grinding balls is 5-15 mm; the wet grinding time is 5-10 min.
Further, in the step 3), the aluminum source is one of sodium aluminate, aluminum sulfate, aluminum chloride and aluminum nitrate, the aluminum source accounts for 0.5-5% of the mass concentration of the acid solution, the mass concentration of the acid solution is 20-35%, and the standing and aging time is more than 20 hours.
Wherein, the acid solution in the steps 3) and 4) is one of a sulfuric acid solution, a hydrochloric acid solution and a phosphoric acid solution.
Further, in the step 4), the acid concentration of the slightly acidic solution is 0.5-3.0%, and the acid treatment time is 1-6 h.
Further, in the step 4), the temperature of hot water for washing is 50-80 ℃, and the product is washed until the pH value is more than 4; drying at 100-160 deg.c to water content lower than 30%.
Further, the mass concentration of the organic binder solution in the step 5) is 0.05-5%; the organic binder is one or more of hydroxypropyl methylcellulose, carboxymethyl cellulose, methyl cellulose and polyvinyl alcohol, and the inorganic binder is one or two of attapulgite and diatomite;
the drying and shaping temperature is 80-160 ℃, and the moisture of the dried particles is within 10%;
drying and shaping are carried out in three specific sections, the first section drying temperature is 50-60 ℃, and the drying time is 2-6 hours; the second section drying temperature is 60-80 ℃, the drying time is 2-6 h, the third section drying temperature is 80-120 ℃, and the drying time is 2-6 h.
Preferably, the shaped pellets may be in the form of cylindrical, spherical, oval or irregular particles.
The activation temperature is 750-950 ℃, the activation time is 30-120 min, the activation atmosphere adopts fully-combusted high-temperature hot air of carbonization tail gas, and the reduction gas and the water vapor are introduced, and nitrogen can be introduced or not introduced to serve as a protective gas; the atmosphere concentration of the water vapor accounts for 20-60% of the total activated gas; the volume concentration of the reducing gas in the activation stage is 0.1-10% of the total atmosphere.
Preferably, the activated material is cooled by a discharger with a heat exchange tube to recover waste heat so as to obtain hot water or hot air, and cold water or fresh cold air can be filled in a cavity of the heat exchange tube. The activated tail gas is subjected to gradient recovery of waste heat to obtain hot water, hot air and steam which are reused for production.
The invention has the following advantages:
1. the invention promotes the carbonization of rice hulls and the thermal decomposition of volatile organic matters by regulating and controlling the reducing gas and the pure oxygen of the active carbon atmosphere concentration, reduces the supplement of fresh air, has high concentration of the beneficial carbonized atmosphere, can realize high-efficiency carbonization, has the carbonization yield of more than 40 percent, prevents the polymerization of silicon dioxide by high carbon content components, has low silicon dioxide lattice degree, promotes the extraction of silicon dioxide gel, has less supplementary air, can reduce the discharge of a large amount of ineffective air carrying heat, and reduces the energy consumption.
2. The invention introduces reducing gas capable of regulating and controlling the concentration of the activating atmosphere into the activating furnace, uses high-temperature flue gas from the combustion of the carbonization tail gas as the activating gas to supply heat, reduces fresh air, improves the concentration of the activating atmosphere, is favorable for further completely gasifying and pyrolyzing volatile organic matters in the carbon molecular sieve raw powder slurry, fully pyrolyzes an organic matter binder to enhance a particle framework, regulates the porosity and the pore size distribution in the high-temperature activating gas activation of the deposited carbon and silicon dioxide porous structures in the carbon molecular sieve raw powder, and has developed structures of micropores and mesopores.
3. The invention takes rice hulls as a silicon source and a carbon source, simultaneously skillfully adds an aluminum source, and forms a high-strength granular adsorbent by taking porous active silica as a framework, and simultaneously has a carbon molecular sieve with the carbon source, the silicon source and the aluminum source, a developed pore structure, excellent volatile organic gas adsorption and water absorption performances of the molecular sieve, wide application field and easy industrial popularization.
4. The comprehensive utilization rate of the rice hull resources is high, and the carbon source and the silicon source in the rice hulls are not wasted.
Drawings
FIG. 1 is a process flow diagram of the present invention.
Detailed Description
In order to make the objects, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the embodiments of the present invention, and it is obvious that the described embodiments are some embodiments of the present invention, but not all embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.
Referring to fig. 1, this embodiment provides a method for preparing an adsorbent of carbon molecular sieve particles with controllable pore size, which includes the following steps:
1) preparing rice husk charcoal: collecting rice hulls, screening the rice hulls by using a primary screen and a cyclone separator to remove sand and large-particle foreign matters, drying the rice hulls by using steam at a low temperature of 100-160 ℃ indirectly or hot air, and carbonizing the rice hulls for 60-180 min at a temperature of 550-750 ℃ under the condition of introducing a reducing gas atmosphere and pure oxygen with the purity of more than 90%, wherein the reducing gas accounts for 0.01-5% of the volume concentration of the total atmosphere in the carbonization stage, and the pure oxygen accounts for 1-10% of the volume concentration of the total atmosphere; then cooled to the temperature within 80 ℃ by a discharging device with a heat exchange tube, and then deironing is carried out by an iron remover to obtain the rice hull carbon.
The rice hull raw material is dried at low temperature to realize high-efficiency utilization because the moisture content is about 10 percent generally, and the dried hot air can be provided for carbonization to be used as air supplement. The method reduces the moisture in the rice hulls, is beneficial to improving the conversion efficiency and the conversion speed of converting the carbon-containing organic components into fixed carbon in the carbonization stage, and reduces the preheating time and the pre-decomposition time of pyrolysis.
The rice hull reduces carbon ablation under the atmosphere of reducing gas and pure oxygen with the purity of more than 90 percent, can improve the carbon yield, is favorable for improving the activity of silicon dioxide by the rice hull, and ensures that the silicon dioxide is easy to react with alkali solution to be converted into silicate. The carbonized tail gas is combustible with high heat value, and is supplied to an activation furnace for activation after being combusted, so that thick activation atmosphere can be provided, the pore structure of the carbon molecular sieve can be further promoted, and the pore diameter can be regulated and controlled through the activation atmosphere and the temperature. The pore volume and the pore diameter of the product are controlled by regulating and controlling the carbon activation atmosphere and the carbon activation temperature.
2) Preparing silicate/carbon slurry: mixing the rice husk carbon obtained in the step 1) with 20-30% alkali solution (containing alkali metal oxide M)2O), mixing, grinding for 5-10 min by a wet method through a rotary kettle with ball grinding balls (the volume of the ball grinding balls in the rotary kettle accounts for 20-50% of the volume of the rotary kettle, and the specification of the ball grinding balls is 5-15 mm), then feeding into a normal pressure stirring reaction kettle, introducing 0.3-0.8 MPa steam or 80-100 ℃ hot water, controlling the temperature to 80-100 ℃ and reacting for 1-6 h to obtain silicate/carbon slurry, wherein SiO of silicate in the silicate/carbon slurry2/M2The molar ratio of the O modulus is 2.5-3.5, and the concentration of the silicon dioxide is 15-25%.
The rice husk carbon and the alkali solution can play a role in mixing and grinding in a rotary kettle with ball milling balls, and can be fully soaked under the action of the ball milling balls, so that the time for extracting the active silicon dioxide is reduced, and the extraction rate is improved.
3) Preparing carbon molecular sieve gel: uniformly mixing the silicate/carbon slurry obtained in the step 2) with 20-35% acid solution (the mass concentration of the acid solution is 20-35%) containing 0.5-5% of aluminum source in a mixer, controlling the reaction pH to 2.5-3.5 by adjusting the proportion, and then standing and aging for more than 20 hours to perform gel reaction to obtain carbon molecular sieve gel;
the silicate in the silicate/carbon slurry is in a high free state, can quickly form silica gel with acid solutions such as sulfuric acid and the like, needs to control the temperature and pH value for controlling the reaction speed of the gel, enables the gel to be slowly formed, produces the silica gel with certain granularity, and enables the granularity to be uniform through further reaction time.
4) Preparing raw powder of a carbon molecular sieve: adding the carbon molecular sieve gel obtained in the step 3) into a 0.5-3% micro-acid solution for acid treatment and soaking, performing acid treatment for 1-6 h, blowing compressed air every 30min for 2min for homogenization, filtering acid when the acid is reached, performing countercurrent washing with hot water at 50-80 ℃, washing until the pH of the product is more than 4, and drying at 100-160 ℃ until the water content is within 30% to obtain the carbon molecular sieve raw powder.
The carbon molecular sieve gel is treated by acid solution and acid, so that inorganic salt in the gel can be quickly replaced, and finally, the inorganic salt is eluted by hot water washing and is dried and shaped at low temperature to form a porous structure.
5) Preparing a carbon molecular sieve particle adsorbent: adding 0.5-5% of organic binder solution and inorganic binder into the raw powder of the carbon molecular sieve obtained in the step 4), mixing and pugging until the raw powder reaches granulation viscosity, then granulating, drying and shaping at a low temperature of 80-160 ℃ until the moisture content is less than 10%, conveying to an activation furnace filled with 0.1-10% of reducing gas, 20-60% of water vapor and carbonized tail gas atmosphere, controlling the temperature to be 750-950 ℃ and activating for 30-120 min, cooling the obtained activated material by a discharging device with a heat exchange tube, screening and packaging to obtain the carbon molecular sieve particle adsorbent.
Preferably, the activated material is cooled by a discharger with a heat exchange tube to recover waste heat so as to obtain hot water or hot air, and cold water or fresh cold air can be filled in a cavity of the heat exchange tube. The activated tail gas is subjected to gradient recovery of waste heat to obtain hot water, hot air and steam which are reused for production.
The reducing gas is selected from methane, ethane, propane, butane, natural gas and hydrogenOne or more than one reducing gas, wherein the volume mass ratio of the consumption of the reducing gas to the raw materials is 150-200: 1 (m)3/t)。
The method is characterized in that reducing gas is introduced into an activation furnace, high-temperature flue gas from the combustion of carbonized tail gas is used as activation gas for supplying heat, fresh air is reduced, the concentration of the activation atmosphere is improved, the complete gasification and pyrolysis of volatile organic matters in the raw powder of the carbon molecular sieve are facilitated, an organic matter binder is fully pyrolyzed to enhance a particle framework, the porosity and pore size distribution of deposited carbon and a porous structure of silicon dioxide in the raw powder of the carbon molecular sieve can be regulated and controlled by the activation of the high-temperature activation gas, and the porous structure has a developed structure of micropores and mesopores. The activated tail gas is subjected to gradient recovery by waste heat to obtain steam, hot air and hot water which are reused for production.
Example 1
Collecting rice hulls, removing sand and large-particle foreign matters through primary screening and screening by a cyclone separator, drying the rice hulls through steam at low temperature of 160 ℃ or hot air indirectly, and then carbonizing the rice hulls at the temperature of 750 ℃ for 120min under the condition of introducing reducing gas atmosphere and pure oxygen with purity of more than 90%, wherein the reducing gas accounts for 3% of the volume concentration of the total atmosphere in the carbonization stage, and the pure oxygen accounts for 6% of the volume concentration of the total atmosphere; then cooling the rice husk to the temperature within 80 ℃ through a discharging device with a heat exchange tube, and removing iron through an iron remover to obtain rice husk carbon; mixing the obtained rice husk charcoal with 25% alkali solution (containing alkali metal oxide M)2O), mixing, wet grinding for 5min, feeding into a normal pressure stirring reaction kettle, introducing 0.5MPa steam, controlling the temperature to be 100 ℃ and reacting for 6h to obtain silicate/carbon slurry, wherein SiO of silicate in the silicate/carbon slurry is2/M2The molar ratio of the O modulus is 2.5-3.5, and the concentration of silicon dioxide is 20%; uniformly mixing the obtained silicate/carbon slurry and 20% acid solution containing 3% of aluminum source in a mixer, controlling the reaction pH to 2.5-3.5 by adjusting the proportion, and then standing and aging for 22h for gel reaction to obtain carbon molecular sieve gel; adding the obtained carbon molecular sieve gel into 1.5% micro-acid solution, performing acid treatment for 4 hr while homogenizing at 30min interval by blowing compressed air for 2min, filtering acid when the temperature is reached, and soaking at 80 deg.CWashing with hot water in a counter-current manner until the pH value of the product is greater than 4, and drying at 120 ℃ until the water content is within 30% to obtain carbon molecular sieve raw powder; adding a 3.5% organic binder solution and an inorganic binder into raw powder of the carbon molecular sieve, mixing and pugging until the raw powder reaches granulation viscosity, granulating, and drying in three stages, wherein the drying temperature of the first stage is 55 ℃, and the drying time is 6 hours; and drying at the second section for 4h at 70 ℃, drying at the third section for 2h at 100 ℃, drying and shaping at a low temperature until the moisture content is 7%, then conveying the dried material to an activation furnace filled with 10% of reducing gas, 40% of water vapor and carbonized tail gas, controlling the temperature to be 750 ℃ for activation for 90min, cooling the obtained activated material by a discharging device with a heat exchange tube, and screening and packaging to obtain the carbon molecular sieve particle adsorbent.
The reducing gas is methane, and the volume mass ratio of the consumption of the reducing gas to the raw materials is 150: 1 (m)3/t)。
Example 2
Collecting rice hulls, removing sand and large-particle foreign matters through primary screening and screening by a cyclone separator, drying the rice hulls through steam at low temperature of 100 ℃ or hot air indirectly, and then carbonizing the rice hulls at the temperature of 650 ℃ for 60min under the condition of introducing reducing gas atmosphere and pure oxygen with purity of more than 90%, wherein the reducing gas accounts for 5% of the volume concentration of the total atmosphere in the carbonization stage, and the pure oxygen accounts for 10% of the volume concentration of the total atmosphere; then cooling the rice husk to the temperature within 80 ℃ through a discharging device with a heat exchange tube, and removing iron through an iron remover to obtain rice husk carbon; mixing the obtained rice husk charcoal with 30% alkali solution (containing alkali metal oxide M)2O), mixing, grinding by a wet method for 8min, feeding into a normal pressure stirring reaction kettle, introducing 0.3MPa steam, controlling the temperature to be 90 ℃ and reacting for 4h to obtain silicate/carbon slurry, wherein SiO of silicate in the silicate/carbon slurry is2/M2The molar ratio of the O modulus is 2.5-3.5, and the concentration of silicon dioxide is 25%; uniformly mixing the obtained silicate/carbon slurry and 25% acid solution containing 0.5% of aluminum source in a mixer, controlling the reaction pH to 2.5-3.5 by adjusting the proportion, and then standing and aging for 24h for gel reaction to obtain carbon molecular sieve gel;adding the obtained carbon molecular sieve gel into a 0.5% micro-acid solution for acid treatment and soaking, performing acid treatment for 6 hours, blowing compressed air for 2 minutes every 30 minutes for homogenization, filtering acid when the acid is reached, performing countercurrent washing by using hot water at 50 ℃, washing until the pH of a product is more than 4, and drying at 160 ℃ until the water content is within 30% to obtain raw carbon molecular sieve powder; adding 5% organic binder solution and inorganic binder into the carbon molecular sieve raw powder, mixing and pugging until the carbon molecular sieve raw powder reaches granulation viscosity, granulating, and drying in three stages, wherein the first stage drying temperature is 60 ℃, and the drying time is 4 hours; and drying at the second section for 2h at 80 ℃, drying at the third section for 6h at 80 ℃, drying and shaping at a low temperature until the moisture content is 6%, then conveying the material to an activation furnace filled with 5% of reducing gas, 60% of water vapor and carbonized tail gas, controlling the temperature to be 850 ℃ for activation for 120min, cooling the obtained activated material by a discharging device with a heat exchange tube, and screening and packaging to obtain the carbon molecular sieve particle adsorbent.
The reducing gas is natural gas, and the volume mass ratio of the consumption of the reducing gas to the raw material is 180: 1 (m)3/t)。
Example 3
Collecting rice hulls, removing sand and large-particle foreign matters through primary screening and screening by a cyclone separator, drying the rice hulls through low-temperature steam at 130 ℃ indirectly or hot air, and carbonizing the rice hulls for 180min at the temperature of 550 ℃ under the condition of introducing reducing gas atmosphere and pure oxygen with the purity of more than 90 percent, wherein the reducing gas accounts for 0.3 percent of the volume concentration of the total atmosphere in the carbonization stage, and the pure oxygen accounts for 1 percent of the volume concentration of the total atmosphere; then cooling the rice husk to the temperature within 80 ℃ through a discharging device with a heat exchange tube, and removing iron through an iron remover to obtain rice husk carbon; mixing the obtained rice husk charcoal with 20% alkali solution (containing alkali metal oxide M)2O), mixing, wet grinding for 10min, feeding into a normal pressure stirring reaction kettle, introducing 90 ℃ hot water, controlling the temperature at 80 ℃ and reacting for 1h to obtain silicate/carbon slurry, wherein SiO of silicate in the silicate/carbon slurry is2/M2The molar ratio of the O modulus is 2.5-3.5, and the concentration of silicon dioxide is 15%; mixing the obtained silicate/carbon slurry with a slurry containing 5Uniformly mixing 35% acid solution of% aluminum source in a mixer, controlling the reaction pH to 2.5-3.5 by adjusting the proportion, and then standing and aging for 23h to perform gel reaction to obtain carbon molecular sieve gel; adding the obtained carbon molecular sieve gel into a 3% micro-acid solution for acid treatment and soaking, performing acid treatment for 1h, compressing air and blowing air every 30min for 2min for homogenization, filtering acid when the acid is reached, performing countercurrent washing by using hot water at 70 ℃, washing until the pH value of a product is more than 4, and drying at 100 ℃ until the water content is within 30% to obtain raw carbon molecular sieve powder; adding 0.5% organic binder solution and inorganic binder into the raw powder of the carbon molecular sieve, mixing and pugging until the raw powder reaches granulation viscosity, granulating, and drying in three stages, wherein the first stage drying temperature is 50 ℃, and the drying time is 2 hours; and drying at 60 ℃ for 6h in the second section, drying at 120 ℃ in the third section for 4h, drying and shaping at low temperature until the water content is 4%, then conveying the material to an activation furnace filled with 0.5% of reducing gas, 20% of water vapor and carbonized tail gas, controlling the temperature at 950 ℃ for activation for 30min, cooling the obtained activated material by a discharger with a heat exchange tube, screening and packaging to obtain the carbon molecular sieve particle adsorbent.
The reducing gas is ethane, and the volume mass ratio of the consumption of the reducing gas to the raw materials is 200: 1 (m)3/t)。
Example 4
Collecting rice hulls, removing sand and large-particle foreign matters through primary screening and screening by a cyclone separator, drying the rice hulls through steam at low temperature of 160 ℃ or hot air indirectly, and then carbonizing the rice hulls for 120min at the temperature of 750 ℃ under the condition of introducing reducing gas atmosphere and pure oxygen with purity of more than 90%, wherein the reducing gas accounts for 5% of the volume concentration of the total atmosphere in the carbonization stage, and the pure oxygen accounts for 10% of the volume concentration of the total atmosphere; then cooling the rice husk to the temperature within 80 ℃ through a discharging device with a heat exchange tube, and removing iron through an iron remover to obtain rice husk carbon; mixing the obtained rice husk charcoal with 25% alkali solution (containing alkali metal oxide M)2O), mixing by a rotary kettle with ball grinding balls (the volume of the ball grinding balls in the rotary kettle accounts for 50 percent of the volume of the rotary kettle, and the ball grinding balls have the specification of 5-15 mm), grinding by a wet method for 5min, then sending into a normal pressure stirring reaction kettle, introducing 0.5MPa steam, controlling the temperature and reacting for 6h at 100 ℃ to obtain silicate/carbon slurryWherein SiO of the silicate in the silicate/carbon slurry2/M2The molar ratio of the O modulus is 2.5-3.5, and the concentration of silicon dioxide is 20%; uniformly mixing the obtained silicate/carbon slurry and 20% acid solution containing 3% of aluminum source in a mixer, controlling the reaction pH to 2.5-3.5 by adjusting the proportion, and then standing and aging for 22h for gel reaction to obtain carbon molecular sieve gel; adding the obtained carbon molecular sieve gel into 1.5% micro-acid solution for acid treatment and soaking, performing acid treatment for 4h, blowing compressed air for 2min every 30min for homogenization, filtering acid when the acid is reached, performing countercurrent washing by using hot water at 80 ℃, washing until the pH of a product is more than 4, and drying at 120 ℃ until the water content is within 30% to obtain raw carbon molecular sieve powder; adding a 3.5% organic binder solution and an inorganic binder into raw powder of the carbon molecular sieve, mixing and pugging until the raw powder reaches granulation viscosity, granulating, and drying in three stages, wherein the drying temperature of the first stage is 55 ℃, and the drying time is 6 hours; and drying at the second section for 4h at 70 ℃, drying at the third section for 2h at 100 ℃, drying and shaping at a low temperature until the moisture content is 7%, then conveying the dried material to an activation furnace filled with 10% of reducing gas, 60% of water vapor and carbonized tail gas, controlling the temperature to be 750 ℃ for activation for 90min, cooling the obtained activated material by a discharging device with a heat exchange tube, and screening and packaging to obtain the carbon molecular sieve particle adsorbent.
The reducing gas is methane, and the volume mass ratio of the consumption of the reducing gas to the raw materials is 150: 1 (m)3/t)。
Example 5
Collecting rice hulls, removing sand and large-particle foreign matters through primary screening and screening by a cyclone separator, drying the rice hulls through steam at low temperature of 100 ℃ or hot air indirectly, and then carbonizing the rice hulls at the temperature of 750 ℃ for 60min under the condition of introducing reducing gas atmosphere and pure oxygen with purity of more than 90%, wherein the reducing gas accounts for 5% of the volume concentration of the total atmosphere in the carbonization stage, and the pure oxygen accounts for 10% of the volume concentration of the total atmosphere; then cooling the rice husk to the temperature within 80 ℃ through a discharging device with a heat exchange tube, and removing iron through an iron remover to obtain rice husk carbon; mixing the obtained rice husk charcoal with 30% alkali solution (containing alkali metal oxide M)2O) mixing, and passing through a rotary kettle with ball grinding balls (the volume of the ball grinding balls in the rotary kettle accounts for the rotary kettle20% of the volume and 5-15 mm of the specification of the ball-milling balls), wet grinding for 8min, sending into a normal-pressure stirring reaction kettle, introducing 95 ℃ hot water, controlling the temperature to 90 ℃ and reacting for 4h to obtain silicate/carbon slurry, wherein SiO of silicate in the silicate/carbon slurry2/M2The molar ratio of the O modulus is 2.5-3.5, and the concentration of silicon dioxide is 25%; uniformly mixing the obtained silicate/carbon slurry and 25% acid solution containing 0.5% of aluminum source in a mixer, controlling the reaction pH to 2.5-3.5 by adjusting the proportion, and then standing and aging for 24h for gel reaction to obtain carbon molecular sieve gel; adding the obtained carbon molecular sieve gel into a 0.5% micro-acid solution for acid treatment and soaking, performing acid treatment for 6 hours, blowing compressed air for 2 minutes every 30 minutes for homogenization, filtering acid when the acid is reached, performing countercurrent washing by using hot water at 50 ℃, washing until the pH of a product is more than 4, and drying at 160 ℃ until the water content is within 30% to obtain raw carbon molecular sieve powder; adding 5% organic binder solution and inorganic binder into the carbon molecular sieve raw powder, mixing and pugging until the carbon molecular sieve raw powder reaches granulation viscosity, granulating, and drying in three stages, wherein the first stage drying temperature is 60 ℃, and the drying time is 4 hours; and drying at the second section for 2h at 80 ℃, drying at the third section for 6h at 80 ℃, drying and shaping at a low temperature until the moisture content is 6%, then conveying the material to an activation furnace filled with 5% of reducing gas, 60% of water vapor and carbonized tail gas, controlling the temperature to be 950 ℃ for activation for 120min, cooling the obtained activated material by a discharger with a heat exchange tube, and screening and packaging to obtain the carbon molecular sieve particle adsorbent.
The reducing gas is natural gas, and the volume mass ratio of the consumption of the reducing gas to the raw material is 180: 1 (m)3/t)。
Product performance detection
The adsorption performance and micropore data of the carbon molecular sieve particles prepared in examples 1 to 5 and the commercially available carbon molecular sieve particles (comparative example 1) were respectively measured, and the measurement results are shown in the following table:
compared with the comparative examples 1-5 and the comparative example 1 (sold in the market), the carbon molecular sieve particles prepared by the technical scheme of the invention have developed pores and better adsorbability; as can be seen from comparative examples 1-2 and 4-5, the pore size of the carbon molecular sieve can be adjusted by adjusting the carbon activation atmosphere and temperature.
The above-mentioned embodiments, which further illustrate the objects, technical solutions and advantages of the present invention, should be understood that the above-mentioned embodiments are only preferred embodiments of the present invention, and should not be construed as limiting the present invention, and any modifications, equivalents, improvements and the like made within the spirit and principle of the present invention should be included in the protection scope of the present invention.
The above examples are only intended to illustrate the technical solution of the present invention, but not to limit it; although the present invention has been described in detail with reference to the foregoing embodiments, it will be understood by those of ordinary skill in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some technical features may be equivalently replaced; and such modifications or substitutions do not depart from the spirit and scope of the corresponding technical solutions of the embodiments of the present invention.
Claims (10)
1. A preparation method of a pore size controllable carbon molecular sieve particle adsorbent is characterized by comprising the following steps:
1) preparing rice husk charcoal: the rice hulls are collected, screened and dried at low temperature, then carbonized under reducing gas and pure oxygen, and the carbonized materials are cooled and deironized to obtain rice hull carbon;
2) preparing silicate/carbon slurry: mixing the rice hull carbon obtained in the step 1) with an alkali solution, grinding by a wet method, then feeding into a normal-pressure stirring reaction kettle, and introducing steam or hot water to control the temperature and the material concentration to obtain silicate/carbon slurry;
3) preparing carbon molecular sieve gel: uniformly mixing the silicate/carbon slurry obtained in the step 2) with an acid solution containing an aluminum source in proportion, controlling the reaction pH to 2.5-3.5, and then standing and aging to perform a gel reaction to obtain a carbon molecular sieve gel;
4) preparing raw powder of a carbon molecular sieve: adding the carbon molecular sieve gel obtained in the step 3) into a micro-acid solution for acid treatment and soaking, blowing compressed air for homogenization during the acid treatment, and filtering, washing with hot water and drying after the reaction is finished to obtain raw powder of the carbon molecular sieve;
5) preparing a carbon molecular sieve particle adsorbent: adding the raw powder of the carbon molecular sieve obtained in the step 4) into an organic binder solution and an inorganic binder for mixing and pugging, then carrying out molding granulation and low-temperature drying and shaping, conveying to an activation furnace filled with reducing gas, water vapor and carbonized tail gas for activation, and cooling and screening the activated material to obtain the carbon molecular sieve particle adsorbent.
2. The method for preparing the pore size controllable carbon molecular sieve particle adsorbent according to claim 1, wherein the low-temperature drying temperature in the step 1) is 100-160 ℃, and the moisture content of the dried material is less than 5%.
3. The method for preparing the pore size controllable carbon molecular sieve particle adsorbent according to claim 1, wherein in the step 1), the carbonization temperature is controlled to be 550-750 ℃, and the carbonization time is 60-180 min; the volume concentration of the reducing gas in the carbonization stage is 0.01-5% of the total atmosphere volume concentration, and the volume concentration of the pure oxygen in the total atmosphere volume concentration is 1-10%.
4. The preparation method of the pore diameter controllable carbon molecular sieve particle adsorbent according to claim 1, wherein the reducing gas is one or more of methane, ethane, propane, butane, natural gas and hydrogen, and the volume mass ratio of the consumption of the reducing gas to the raw material is 150-200: 1 (m)3T); the purity of the pure oxygen is more than 90%.
5. The method for preparing the pore size controllable carbon molecular sieve particle adsorbent of claim 1, wherein the alkali solution in the step 2) is 20-30% of sodium hydroxide solution or potassium hydroxide solution, and the alkali metal oxide M is contained in the solution2O; introducing steam or hot water, controlling the temperature to be 80-100 ℃, and reacting for 1-6 h; of silicates in the silicate/carbon slurrySiO2/M2The molar ratio of the O modulus is 2.5-3.5, and the concentration of the silicon dioxide is 15-25%.
6. The preparation method of the pore diameter controllable carbon molecular sieve particle adsorbent according to claim 1, wherein a drum-type rotary kettle is adopted in wet grinding in the step 2), the volume of ball grinding balls in the rotary kettle accounts for 20-50% of the volume of the rotary kettle, and the size of the ball grinding balls is 5-15 mm; the wet grinding time is 5-10 min.
7. The method for preparing the pore diameter controllable carbon molecular sieve particle adsorbent according to claim 1, wherein in the step 3), the aluminum source is one of sodium aluminate, aluminum sulfate, aluminum chloride and aluminum nitrate, the aluminum source accounts for 0.5-5% of the mass concentration of the acid solution, the mass concentration of the acid solution is 20-35%, and the standing and aging time is more than 20 h.
8. The method for preparing the pore size controllable carbon molecular sieve particle adsorbent according to claim 1, wherein in the step 4), the acid concentration of the slightly acidic solution is 0.5-3.0%, and the acid treatment time is 1-6 h.
9. The method for preparing the pore size controllable carbon molecular sieve particle adsorbent according to claim 1, wherein the temperature of hot water for washing in the step 4) is 50-80 ℃, and the washing is carried out until the pH value of the product is more than 4; drying at 100-160 deg.c to water content lower than 30%.
10. The method for preparing the pore size controllable carbon molecular sieve particle adsorbent according to claim 1, wherein the mass concentration of the organic binder solution in the step 5) is 0.05-5%; the organic binder is one or more of hydroxypropyl methylcellulose, carboxymethyl cellulose, methyl cellulose and polyvinyl alcohol, and the inorganic binder is one or two of attapulgite and diatomite;
the drying and shaping temperature is 80-160 ℃, and the moisture of the dried particles is within 10%;
the activation temperature is 750-950 ℃, the activation time is 30-120 min, the activation atmosphere adopts fully-combusted high-temperature hot air of the carbonization tail gas, and reducing gas and water vapor are introduced; the atmosphere concentration of the water vapor accounts for 20-60% of the total activated gas; the volume concentration of the reducing gas in the activation stage is 0.1-10% of the total atmosphere.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202111310411.7A CN114029033A (en) | 2021-11-04 | 2021-11-04 | Preparation method of pore diameter controllable carbon molecular sieve particle adsorbent |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202111310411.7A CN114029033A (en) | 2021-11-04 | 2021-11-04 | Preparation method of pore diameter controllable carbon molecular sieve particle adsorbent |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN114029033A true CN114029033A (en) | 2022-02-11 |
Family
ID=80143101
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202111310411.7A Pending CN114029033A (en) | 2021-11-04 | 2021-11-04 | Preparation method of pore diameter controllable carbon molecular sieve particle adsorbent |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN114029033A (en) |
Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2000016896A1 (en) * | 1998-09-23 | 2000-03-30 | Agritec, Inc. | Highly activated carbon from caustic digestion of rice hull ash and method |
| CN101891167A (en) * | 2010-08-13 | 2010-11-24 | 宁乡县亮之星米业有限公司 | Method for industrially producing silicate phosphate from rice husk carbon |
| CN101935032A (en) * | 2010-09-03 | 2011-01-05 | 同济大学 | Preparation method and use of carbon molecular sieve |
| CN103896265A (en) * | 2012-12-29 | 2014-07-02 | 苏州格瑞展泰再生能源有限公司 | Method for producing activated carbon and inorganic silicon compounds from rice hulls |
| CN106379913A (en) * | 2016-08-26 | 2017-02-08 | 曹蕊 | Method for synthesizing P zeolite molecular sieve from rice husk |
| CN108249456A (en) * | 2018-01-23 | 2018-07-06 | 中国石油大学(华东) | A kind of method that grade hole Y type molecular sieve is prepared using rice husk as raw material |
| WO2019179507A1 (en) * | 2018-03-22 | 2019-09-26 | 丰海（盘锦）水稻生物科技有限公司 | Biomass white carbon black, preparation method therefor and use thereof |
-
2021
- 2021-11-04 CN CN202111310411.7A patent/CN114029033A/en active Pending
Patent Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2000016896A1 (en) * | 1998-09-23 | 2000-03-30 | Agritec, Inc. | Highly activated carbon from caustic digestion of rice hull ash and method |
| CN101891167A (en) * | 2010-08-13 | 2010-11-24 | 宁乡县亮之星米业有限公司 | Method for industrially producing silicate phosphate from rice husk carbon |
| CN101935032A (en) * | 2010-09-03 | 2011-01-05 | 同济大学 | Preparation method and use of carbon molecular sieve |
| CN103896265A (en) * | 2012-12-29 | 2014-07-02 | 苏州格瑞展泰再生能源有限公司 | Method for producing activated carbon and inorganic silicon compounds from rice hulls |
| CN106379913A (en) * | 2016-08-26 | 2017-02-08 | 曹蕊 | Method for synthesizing P zeolite molecular sieve from rice husk |
| CN108249456A (en) * | 2018-01-23 | 2018-07-06 | 中国石油大学(华东) | A kind of method that grade hole Y type molecular sieve is prepared using rice husk as raw material |
| WO2019179507A1 (en) * | 2018-03-22 | 2019-09-26 | 丰海（盘锦）水稻生物科技有限公司 | Biomass white carbon black, preparation method therefor and use thereof |
Non-Patent Citations (1)
| Title |
|---|
| 卫延安,朱永义,朱春山,蔡春,吕春绪: "提高稻壳灰制备活性炭、白炭黑质量的方法研究", 郑州工程学院学报, no. 01 * |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| Hu et al. | Porous extruded-spheronized Li4SiO4 pellets for cyclic CO2 capture | |
| JP5650948B2 (en) | Apparatus and method for roasting lignocellulosic materials | |
| CN112675814B (en) | Silicon-rich biomass-based biochar/mesoporous silica composite material and preparation method and application thereof | |
| JP2017222547A (en) | Method for producing activated carbon, and activated carbon production system | |
| CN114797766A (en) | Porous biochar and preparation method and application thereof | |
| CN101423213A (en) | Method for preparing active carbon | |
| CN106395816A (en) | Method for extracting humic acid from lignite and then using residues to prepare adsorbent | |
| CN108014750A (en) | A kind of preparation method of coal base desulfurization activated carbon | |
| CN112456488A (en) | Hierarchical pore biochar and preparation method and application thereof | |
| CN113003572A (en) | Method for preparing activated carbon from sludge and activated carbon | |
| CN114479950B (en) | Biomass pyrolysis gasification hydrogen production method and system | |
| CN108557820A (en) | A kind of preparation method of COD high removal rates activated carbon from bamboo | |
| CN108249456B (en) | Method for preparing hierarchical-pore Y-type molecular sieve by taking rice hulls as raw materials | |
| CN113231009A (en) | Ammonia adsorbent and preparation method thereof | |
| Hu et al. | Li4SiO4 pellets templated by rice husk for cyclic CO2 capture: Insight into the modification mechanism | |
| CN113800517B (en) | Preparation method of water-resistant rice hull-based granular activated carbon | |
| CN107055507B (en) | A kind of preparation method of carbon molecular sieve | |
| CN100588457C (en) | Shaping method for super absorbent charcoal powder body for adsorbing CO2 | |
| CN113735119B (en) | Method for co-producing medium-pore developed active carbon and high-modulus silicate by using rice hulls | |
| CN114029033A (en) | Preparation method of pore diameter controllable carbon molecular sieve particle adsorbent | |
| CN106587053A (en) | Preparation process of special activated carbon for desulfurization | |
| CN110791305A (en) | Method and system for preparing active coke by co-pyrolysis of biomass and coal | |
| CN116161658A (en) | Bamboo columnar activated carbon and preparation method and application thereof | |
| CN110451506A (en) | Grading-hole activated coke preparation method with needle-shaped mesoporous channels and its application in flue gas desulfurization | |
| CN111187087B (en) | Preparation method of lightweight castable aggregate |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination |