CN115805056B - Meta-xylene adsorbent and preparation method and application thereof - Google Patents
Meta-xylene adsorbent and preparation method and application thereof Download PDFInfo
- Publication number
- CN115805056B CN115805056B CN202310058943.9A CN202310058943A CN115805056B CN 115805056 B CN115805056 B CN 115805056B CN 202310058943 A CN202310058943 A CN 202310058943A CN 115805056 B CN115805056 B CN 115805056B
- Authority
- CN
- China
- Prior art keywords
- molecular sieve
- halloysite
- prepared
- chelating agent
- weight
- 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.)
- Active
Links
Images
Classifications
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
- Y02P20/00—Technologies relating to chemical industry
- Y02P20/50—Improvements relating to the production of bulk chemicals
- Y02P20/52—Improvements relating to the production of bulk chemicals using catalysts, e.g. selective catalysts
Abstract
The invention provides a meta-xylene adsorbent, and a preparation method and application thereof, and belongs to the technical field of adsorbents. Pretreating halloysite nanotubes, modifying the surface poly-dopamine, coalescing with a NaY molecular sieve, roasting to obtain a coalescent, adding the coalescent into an alkaline solution containing sodium ions, heating to react to obtain molecular sieve particles, partially dealuminizing under the action of a chelating agent, then performing ion exchange in a solution containing iron ions, filtering, washing, drying and activating to obtain the m-xylene adsorbent. The adsorbent prepared by the invention has the advantages of high adsorption capacity, high adsorption selectivity, high speed of adsorption-desorption of m-xylene molecules, long service life, stable operation conditions and the like, the purity of the m-xylene obtained by adsorption is more than 99.5%, the adsorption selectivity is high, the adsorption efficiency is high, the cost is low, the preparation method is simple, and the application prospect is wide.
Description
Technical Field
The invention relates to the technical field of adsorbents, and particularly relates to a m-xylene adsorbent as well as a preparation method and application thereof.
Background
Meta-xylene (MX) is an important basic organic chemical raw material and is widely applied to the fields of synthetic resins, pesticides, medicines, coatings, dyes and the like. Mixing C 8 The aromatic hydrocarbon includes Paraxylene (PX) and metaxyleneThe boiling point difference of four isomers of (MX), o-xylene (OX) and Ethylbenzene (EB) is very small, in particular, the boiling point difference of p-xylene and m-xylene is only 0.6 ℃, and the adsorption separation method is generally adopted in industry to produce high-purity m-xylene. The adsorption separation technology is formed by a zeolite adsorbent and a simulated moving bed continuous countercurrent separation process, and the core of the adsorption separation technology is the development and application of a high-efficiency adsorbent. In the adsorption tower, the different selective adsorption capacities of different isomers of mixed xylene are utilized by an adsorbent, the m-xylene is continuously concentrated through repeated countercurrent mass transfer exchange, the concentrated m-xylene is desorbed by a desorbent, and the desorbent is recovered from a rectification extract to obtain the high-purity m-xylene.
The adsorbent is the basis and core of adsorption separation technology, is mostly composed of certain type of zeolite, and is divided according to adsorption selectivity, the adsorbent used for separating m-xylene in the prior art is mainly divided into two types, one type is to preferentially adsorb non-MX components, and m-xylene products are extracted from raffinate. Techniques using such adsorbents, such as CN1132192a, in which KY or KBaY is used as an adsorption active component, bentonite is used as a binder to prepare the adsorbent, paraxylene is preferentially adsorbed by a gas phase, and MX having a purity of 99.5% is obtained from a raffinate phase, are limited to processing a raw material containing no ethylbenzene. CN1136549A adopts Silicalite-1 zeolite adsorbent, preferentially adsorbs ethylbenzene and paraxylene in raw materials, and then rectifies the absorption residual phase to obtain MX. US6137024 uses hydrogen form beta zeolite as adsorbent, preferentially selects and adsorbs paraxylene, ortho-xylene and ethylbenzene in raw material, and obtains MX product from raffinate. However, the adsorption capacity of zeolites such as Silicalite-1 and beta is low, and the application thereof is limited.
The other type of adsorbent preferentially adsorbs meta-xylene, so that MX in the raw material firstly enters an adsorption phase to be separated from other isomers, then enters an extract flow through desorption of a proper desorbent, and finally is rectified to recover the desorbent, so that the high-purity meta-xylene is obtained, and the NaY-type zeolite is a typical representative of the adsorbents.
US5464593 mentions the forming of zeolite raw powder mixed with silica alumina in an oil amine column, US3878127, US3878129 and CN1275926A, CN1347339a etc. to make the zeolite raw powder and kaolin into granular agglomerates, which can be in the form of pellets, flakes or extruded particles. The oil amine column molding process in the technology is complex, the cost is high, and the preparation of the small ball adsorbents with different particle size distributions is difficult to conveniently prepare. In comparison, the rolling forming operation is simple, and the particle size distribution of the adsorbent spheres is easier to control. Generally, in the rolling forming process, powders are contacted and adhered to each other to increase the agglomeration of particles, and the particles are always contacted with the powder with the same composition in the agglomeration process to make the inside and the outside uniform, but the compression strength of the particles obtained in this way is poor.
Disclosure of Invention
The invention aims to provide a meta-xylene adsorbent, a preparation method and application thereof, and the meta-xylene adsorbent has the advantages of high adsorption capacity, high adsorption selectivity, high adsorption-desorption speed on meta-xylene molecules, long service life, stable operation conditions and the like, the purity of the meta-xylene obtained by adsorption is more than 99.5%, the adsorption selectivity is high, the adsorption efficiency is high, the cost is low, the preparation method is simple, and the meta-xylene adsorbent has a wide application prospect.
The technical scheme of the invention is realized as follows:
the invention provides a preparation method of a m-xylene adsorbent, which comprises the steps of soaking halloysite nanotubes in acid liquor for pretreatment, coating and modifying the surfaces of the halloysite nanotubes with polydopamine, mixing the modified halloysite nanotubes with a NaY molecular sieve for coalescence, roasting to obtain a coalescent, adding the coalescent into an alkaline solution containing sodium ions, heating for reaction to obtain molecular sieve particles, partially dealuminizing under the action of a chelating agent to obtain a dealuminized molecular sieve, adding the dealuminized molecular sieve into a solution containing iron ions for ion exchange, filtering, washing, drying and activating to obtain the m-xylene adsorbent.
As a further improvement of the invention, the method comprises the following steps:
s1, pretreatment of halloysite: soaking the halloysite nanotube in acid liquor for treatment, centrifuging, washing and drying to obtain a pretreated halloysite nanotube;
s2, preparing modified halloysite: adding the pretreated halloysite nanotube prepared in the step S1 into water, uniformly dispersing, adding dopamine hydrochloride and a catalyst, heating for reaction, centrifuging, washing and drying to obtain modified halloysite;
s3, coalescence: mixing the modified halloysite prepared in the step S2 and NaY zeolite, then agglomerating the mixture into particles, roasting the particles, and carrying out ball milling on the particles to obtain an agglomerate;
s4, preparing molecular sieve particles: adding the conglomerate prepared in the step S3 into an alkaline solution containing sodium ions, heating for reaction, filtering, washing and drying to obtain molecular sieve particles;
s5, preparation of a chelating agent: mixing different chelating agents uniformly to obtain a chelating agent;
s6, dealuminizing by using a chelating agent: dissolving the chelating agent prepared in the step S5 in water, adding the molecular sieve particles prepared in the step S4, uniformly dispersing, heating for reaction, filtering, washing and drying to prepare a dealuminized molecular sieve;
s7, preparing a meta-xylene adsorbent: and (4) adding the dealuminized molecular sieve prepared in the step (S6) into the solution containing iron ions, heating for reaction, filtering, washing, drying and activating to obtain the meta-xylene adsorbent.
As a further improvement of the invention, the acid solution in step S1 is HCl or sulfuric acid solution with pH value of 2-3; the solid-to-liquid ratio of the halloysite nanotubes to the acid liquor is 1:5-7g/mL; the treatment time is 1-3h; the centrifugation condition is 5000-7000r/min for 15-20min.
As a further improvement of the invention, the mass ratio of the pretreated halloysite nanotubes, dopamine hydrochloride and catalyst in the step S2 is 10; the catalyst is a Tris-HCl solution with pH value of 4-6 and containing cobalt ions; the heating reaction is carried out at the temperature of 70-90 ℃ for 1-3h; in the step S3, the mixing stirring speed is 300-500r/min, and the mixing time is 30-50min; the roasting temperature is 400-500 ℃, and the roasting time is 1-3h; the ball milling time is 2-4h; the mass ratio of the modified halloysite to the NaY zeolite is 8-12.
As a further improvement of the invention, the alkaline solution containing sodium ions in step S4 is a NaOH solution with a pH value of 8-10 or a mixture solution of NaOH and sodium silicate with a pH value of 8-10, wherein the mass ratio of NaOH to sodium silicate is 3-5:1; the heating reaction temperature is 50-70 ℃, and the time is 0.5-1h.
As a further development of the invention, the chelating agent in step S5 is selected from H 4 At least two of EDTA, citric acid, acetic acid, oxalic acid, tartaric acid, malic acid, oxalic acid and cyclopentanedioic acid, preferably, the chelating agent is H 4 A mixture of EDTA and citric acid with the mass ratio of 4-7:3; in the step S6, the mass ratio of the chelating agent to the molecular sieve particles is 2-4:7; the heating reaction temperature is 90-95 ℃, and the time is 2-3h; the uniform dispersion is 1000-1500W ultrasonic dispersion for 20-30min.
As a further improvement of the invention, the solution containing iron ions in the step S7 is a solution containing 5-10wt% of ferric chloride or ferric sulfate; the solid-liquid ratio of the dealuminization molecular sieve to the solution containing the iron ions is 1:3-5g/mL; the heating reaction is carried out at the temperature of 60-80 ℃ for 2-3h; the activation method comprises roasting and activating for 5-7h at the temperature of 450-550 ℃.
As a further improvement of the invention, the method specifically comprises the following steps:
s1, pretreatment of halloysite: soaking the halloysite nanotube in HCl or sulfuric acid solution with the pH of 2-3 for treatment for 1-3h, wherein the solid-to-liquid ratio of the halloysite nanotube to the HCl or sulfuric acid solution with the pH of 2-3 is 1:5-7g/mL, centrifuging at 5000-7000r/min for 15-20min, washing, and drying to obtain the pretreated halloysite nanotube;
s2, preparing modified halloysite: adding 10 parts by weight of the pretreated halloysite nanotube prepared in the step S1 into water, uniformly dispersing, adding 15-17 parts by weight of dopamine hydrochloride and 0.5-1 part by weight of catalyst, heating to 70-90 ℃, reacting for 1-3h, centrifuging, washing, and drying to obtain modified halloysite;
the catalyst is a Tris-HCl solution with pH value of 4-6 and containing cobalt ions;
s3, coalescence: stirring and mixing 8-12 parts by weight of the modified halloysite prepared in the step S2 and 90 parts by weight of NaY zeolite at a speed of 300-500r/min for 30-50min, agglomerating into particles, roasting at 400-500 ℃ for 1-3h, and ball-milling for 2-4h to obtain an agglomerate;
s4, preparing molecular sieve particles: adding 10 parts by weight of the agglomerate obtained in the step S3 into 20-30 parts by weight of alkaline solution containing sodium ions, heating to 50-70 ℃ for reaction for 0.5-1h, filtering, washing and drying to obtain molecular sieve particles;
the alkaline solution containing sodium ions is a NaOH solution with the pH value of 8-10 or a mixture solution of NaOH and sodium silicate with the pH value of 8-10, wherein the mass ratio of NaOH to sodium silicate is 3-5:1;
s5, preparation of a chelating agent: mixing different chelating agents uniformly to obtain a chelating agent;
the chelating agent is H 4 A mixture of EDTA and citric acid, the mass ratio is 4-7:3;
s6, dealuminizing by using a chelating agent: dissolving 2-4 parts by weight of the chelating agent prepared in the step S5 in water, adding 7 parts by weight of the molecular sieve particles prepared in the step S4, performing ultrasonic dispersion for 20-30min at 1000-1500W, heating to 90-95 ℃, reacting for 2-3h, filtering, washing, and drying to obtain a dealuminized molecular sieve;
s7, preparing a meta-xylene adsorbent: and (2) adding the dealuminized molecular sieve prepared in the step (S6) into a solution containing 5-10wt% of ferric chloride or ferric sulfate, wherein the solid-to-liquid ratio of the dealuminized molecular sieve to the solution containing ferric ions is 1:3-5g/mL, heating to 60-80 ℃, reacting for 2-3h, filtering, washing, drying, and roasting and activating for 5-7h at 450-550 ℃ to obtain the m-xylene adsorbent.
A meta-xylene adsorbent prepared by the preparation method.
An application of the above meta-xylene adsorbent in adsorption and separation of meta-xylene.
The invention has the following beneficial effects:
the method comprises the steps of treating halloysite with surface acid liquor, performing ball milling to form small-particle-size particles, releasing hydroxyl on the surface of the particles to facilitate poly-dopamine modification on the surface of the particles, enabling the modified particles to have excellent viscosity, mixing the modified particles with a NaY molecular sieve subjected to ball milling, uniformly dispersing the modified particles and well bonding the modified particles together, roasting and performing ball milling to obtain small-particle-size particles, and further performing heating treatment with sodium ion-containing alkali liquor to crystallize the halloysite into NaY zeolite in situ so as to obtain molecular sieve particles;
the method comprises the steps of carrying out dealumination treatment on molecular sieve particles, carrying out dealumination by using a chelating agent and a NaY molecular sieve, wherein the chelating agent breaks Si-O-Al bonds due to acidity of the chelating agent, so that aluminum atoms are separated from a molecular sieve framework, the chelating agent further has a coordination effect with the aluminum atoms of the non-framework, and the aluminum from which the framework is separated is eluted out of a molecular sieve pore channel, so that the aluminum-silicon ratio of the molecular sieve can be improved, the hydrothermal stability of the molecular sieve is improved, the roughness of the surface of the molecular sieve is improved due to defect sites introduced in the dealumination process, the pore diameter and electric field distribution of the molecular sieve are adjusted, and a foundation is laid for further modification of the molecular sieve in the following process;
equation of reaction (in H) 4 EDTA for example) as follows:
according to the invention, the chelating agent with a proper amount is adopted for dealumination, so that part of aluminum in the molecular sieve structure is removed, the aluminum-silicon ratio of the molecular sieve is obviously improved, the prepared dealuminated molecular sieve also has good stability and roughness, the adsorption sites of p-m-xylene are greatly improved, and the adsorption efficiency is obviously improved;
in addition, the chelating agent adopted by the invention is H 4 Mixture of EDTA and citric acid, citric acid being a weak acid, by H 4 EDTA and citric acid's mixed use not only can play better dealuminization effect, simultaneously, plays the effect of adjusting solution pH value to when having avoided pH value too low, whole sodium ion can be replaced into H, thereby influences the subsequent aperture of molecular sieve and adjusts.
Further, partial ion exchange is carried out on sodium ions and hydrogen ions in the prepared molecular sieve by adopting iron ions to form the NaFeHY molecular sieve, and after the iron ions, the sodium ions and the hydrogen ions are cooperatively distributed, main channels are partially blocked, so that the effective aperture of the prepared molecular sieve is obviously reduced, and the aperture with a proper size is formed; in addition, when iron ions, sodium ions and hydrogen ions exist simultaneously, an asymmetric electric field is formed in the molecular sieve supercage, the paraxylene is a nonpolar molecule, the induced dipole moment cannot be balanced with the direction of the electric field, so that the energy is greatly improved, the paraxylene is unstable in the electric field, the induced dipole moment of the paraxylene is rotated to a proper position, the energy is greatly reduced, and the stability is obviously improved, so that the stability of the paraxylene is optimal, the paraxylene can be stably adsorbed, and the paraxylene has no adsorption effect, so that the selectivity of the adsorbent is improved.
The invention adopts iron ions to partially exchange sodium ions and hydrogen ions in the molecular sieve, and regulates the aperture and the electric field of the molecular sieve by reasonably regulating the proportion of the iron ions, the sodium ions and the hydrogen ions, thereby obviously improving the selective adsorption of the molecular sieve on m-xylene.
The meta-xylene adsorbent has the advantages of high adsorption capacity, high adsorption selectivity, high adsorption-desorption speed on meta-xylene molecules, long service life, stable operation conditions and the like. The molecular sieve structure of the adsorbent prepared by the invention has uniform micropores, mainly comprises silicon, aluminum, oxygen and other metal cations, and the pore diameter of the molecular sieve structure is equivalent to the molecular size of m-xylene, so that the adsorbent can efficiently adsorb the m-xylene, the purity of the adsorbed m-xylene is more than 99.5 percent, the adsorption selectivity is high, the adsorption efficiency is high, the cost is low, the preparation method is simple, and the adsorbent has a wide application prospect.
Drawings
In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to these drawings without creative efforts.
FIG. 1 is an SEM photograph of a meta-xylene adsorbent prepared according to example 1 of the present invention.
Detailed Description
The technical solutions in the embodiments of the present invention will be clearly and completely described below, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and 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.
Specific information for halloysite nanotubes is as follows: the diameter is 30-50nm, and the specific surface area is 60m 2 The length of the product is 100-500nm, and the product is provided by Hebei Qingtai mineral products, inc.
NaY zeolite: supplied by catalyst works at southern kayak university.
Examples
The embodiment provides a preparation method of a meta-xylene adsorbent, which specifically comprises the following steps:
s1, pretreatment of halloysite: soaking a halloysite nanotube in a sulfuric acid solution with the pH value of 2 for treatment for 1h, wherein the solid-to-liquid ratio of the halloysite nanotube to the sulfuric acid solution with the pH value of 2 is 1;
s2, preparing modified halloysite: adding 10 parts by weight of the pretreated halloysite nanotube prepared in the step S1 into water, uniformly dispersing, adding 15 parts by weight of dopamine hydrochloride and 0.5 part by weight of catalyst, heating to 70 ℃, reacting for 1h, centrifuging for 15min at 5000r/min, washing with clear water, and drying for 2h at 105 ℃ to obtain modified halloysite;
the catalyst is a Tris-HCl solution with the pH value of 4 and containing 3wt% of cobalt ions;
s3, coalescence: stirring and mixing 8 parts by weight of the modified halloysite prepared in the step S2 and 90 parts by weight of NaY zeolite at a speed of 300r/min for 30min, agglomerating into particles, roasting at 400 ℃ for 1h, and ball-milling for 2h to obtain an agglomerate;
s4, preparing molecular sieve particles: adding 10 parts by weight of the agglomerate prepared in the step S3 into 20 parts by weight of NaOH solution with the pH value of 8, heating to 50 ℃, reacting for 0.5h, filtering, washing with clear water, and drying at 105 ℃ for 2h to obtain molecular sieve particles;
s5, preparation of a chelating agent: mixing different chelating agents uniformly to obtain a chelating agent;
the chelating agent is H 4 A mixture of EDTA and citric acid in a mass ratio of 4:3;
s6, dealuminizing by using a chelating agent: dissolving 2 parts by weight of the chelating agent prepared in the step S5 in water, adding 7 parts by weight of the molecular sieve particles prepared in the step S4, performing ultrasonic dispersion for 20min at 1000W, heating to 90 ℃, reacting for 2h, filtering, washing with clear water, and drying at 105 ℃ for 2h to prepare a dealuminized molecular sieve;
s7, preparing a meta-xylene adsorbent: and (2) adding the dealuminized molecular sieve prepared in the step (S6) into a ferric chloride solution containing 5wt%, wherein the solid-to-liquid ratio of the dealuminized molecular sieve to the ferric chloride solution is 1. Fig. 1 is an SEM image of the resulting m-xylene adsorbent.
Examples
The embodiment provides a preparation method of a meta-xylene adsorbent, which specifically comprises the following steps:
s1, pretreatment of halloysite: soaking a halloysite nanotube in an HCl solution with the pH of 3 for treatment for 3h, wherein the solid-to-liquid ratio of the halloysite nanotube to the HCl solution with the pH of 3 is 1;
s2, preparing modified halloysite: adding 10 parts by weight of the pretreated halloysite nanotube prepared in the step S1 into water, uniformly dispersing, adding 17 parts by weight of dopamine hydrochloride and 1 part by weight of catalyst, heating to 90 ℃, reacting for 3h, centrifuging for 15min at 5000r/min, washing with clear water, and drying for 2h at 105 ℃ to obtain modified halloysite;
the catalyst is a Tris-HCl solution with the pH value of 6 and containing 3wt% of cobalt ions;
s3, coalescence: stirring and mixing 12 parts by weight of the modified halloysite prepared in the step S2 and 90 parts by weight of NaY zeolite at a speed of 500r/min for 50min, agglomerating into particles, roasting at 500 ℃ for 3h, and ball-milling for 4h to obtain an agglomerate;
s4, preparing molecular sieve particles: adding 10 parts by weight of the agglomerate prepared in the step S3 into 30 parts by weight of a mixture solution of NaOH and sodium silicate with the pH value of 10, wherein the mass ratio of NaOH to sodium silicate is 5:1, heating to 70 ℃, reacting for 1h, filtering, washing with clear water, and drying at 105 ℃ for 2h to obtain molecular sieve particles;
s5, preparation of a chelating agent: mixing different chelating agents uniformly to obtain a chelating agent;
the chelating agent is H 4 A mixture of EDTA and citric acid with a mass ratio of 7:3;
s6, dealuminizing by using a chelating agent: dissolving 4 parts by weight of the chelating agent prepared in the step S5 in water, adding 7 parts by weight of the molecular sieve particles prepared in the step S4, carrying out 1500W ultrasonic dispersion for 30min, heating to 95 ℃, reacting for 3h, filtering, washing with clear water, and drying at 105 ℃ for 2h to prepare an aluminum-removed molecular sieve;
s7, preparing a meta-xylene adsorbent: and (3) adding the dealuminized molecular sieve prepared in the step (S6) into a ferric sulfate solution containing 10wt%, wherein the solid-to-liquid ratio of the dealuminized molecular sieve to the ferric sulfate solution containing 10wt% is 1.
Examples
The embodiment provides a preparation method of a meta-xylene adsorbent, which specifically comprises the following steps:
s1, pretreatment of halloysite: soaking a halloysite nanotube in a sulfuric acid solution with the pH of 2.5 for treatment for 2h, wherein the solid-to-liquid ratio of the halloysite nanotube to the sulfuric acid solution with the pH of 2.5 is 1;
s2, preparing modified halloysite: adding 10 parts by weight of the pretreated halloysite nanotube prepared in the step S1 into water, uniformly dispersing, adding 16 parts by weight of dopamine hydrochloride and 0.7 part by weight of catalyst, heating to 80 ℃, reacting for 2h, centrifuging at 5000r/min for 15min, washing with clear water, and drying at 105 ℃ for 2h to obtain modified halloysite;
the catalyst is a Tris-HCl solution with the pH value of 5 and containing 3wt% of cobalt ions;
s3, coalescence: stirring and mixing 10 parts by weight of the modified halloysite prepared in the step S2 and 90 parts by weight of NaY zeolite at a speed of 400r/min for 40min, agglomerating into particles, roasting at 450 ℃ for 2h, and ball-milling for 3h to obtain an agglomerate;
s4, preparing molecular sieve particles: adding 10 parts by weight of the agglomerate prepared in the step S3 into 25 parts by weight of NaOH solution with the pH value of 9, heating to 60 ℃, reacting for 1 hour, filtering, washing with clear water, and drying at 105 ℃ for 2 hours to obtain molecular sieve particles;
s5, preparation of a chelating agent: mixing different chelating agents uniformly to obtain a chelating agent;
the chelating agent is H 4 A mixture of EDTA and citric acid with a mass ratio of 6:3;
s6, dealuminizing by using a chelating agent: dissolving 3 parts by weight of the chelating agent prepared in the step S5 in water, adding 7 parts by weight of the molecular sieve particles prepared in the step S4, performing 1250W ultrasonic dispersion for 25min, heating to 92 ℃, reacting for 2.5h, filtering, washing with clear water, and drying at 105 ℃ for 2h to prepare a dealuminized molecular sieve;
s7, preparing a meta-xylene adsorbent: and (3) adding the dealuminized molecular sieve prepared in the step (S6) into a solution containing 7wt% of ferric chloride, wherein the solid-to-liquid ratio of the dealuminized molecular sieve to the solution containing 7wt% of ferric chloride is 1.
Examples
The difference compared to example 3 is that the chelating agent in step S5 is a single H 4 EDTA。
Examples
The difference compared to example 3 is that the chelating agent in step S5 is a single citric acid.
Examples
Compared with the example 3, the difference is that the mass ratio of the chelating agent to the molecular sieve particles in the step S6 is 1:10.
examples
Compared with the example 3, the difference is that the mass ratio of the chelating agent to the molecular sieve particles in the step S6 is 1:1.
examples
The difference compared to example 3 was that the solution containing 7wt% of ferric chloride was replaced with a solution containing 20wt% of ferric chloride.
Examples
Compared with example 3, except that the solution containing 7wt% of ferric chloride was replaced with a solution containing 1wt% of ferric chloride.
Comparative example 1
The difference from example 3 is that step S1 is not performed.
The method specifically comprises the following steps:
s1, preparing modified halloysite: adding 10 parts by weight of halloysite nanotubes into water, uniformly dispersing, adding 16 parts by weight of dopamine hydrochloride and 0.7 part by weight of catalyst, heating to 80 ℃, reacting for 2h, centrifuging at 5000r/min for 15min, washing with clear water, and drying at 105 ℃ for 2h to obtain modified halloysite;
the catalyst is a Tris-HCl solution with the pH value of 5 and containing 3wt% of cobalt ions;
s2, coalescence: stirring and mixing 10 parts by weight of the modified halloysite prepared in the step S1 and 90 parts by weight of NaY zeolite at a speed of 400r/min for 40min, agglomerating into particles, roasting at 450 ℃ for 2h, and ball-milling for 3h to obtain an agglomerate;
s3, preparing molecular sieve particles: adding 10 parts by weight of the conglomerate prepared in the step S2 into 25 parts by weight of NaOH solution with the pH value of 9, heating to 60 ℃, reacting for 1 hour, filtering, washing with clear water, and drying at 105 ℃ for 2 hours to obtain molecular sieve particles;
s4, preparation of a chelating agent: mixing different chelating agents uniformly to obtain a chelating agent;
the chelating agent is H 4 A mixture of EDTA and citric acid with a mass ratio of 6:3;
s5, dealuminizing by using a chelating agent: dissolving 3 parts by weight of the chelating agent prepared in the step S4 in water, adding 7 parts by weight of the molecular sieve particles prepared in the step S3, performing 1250W ultrasonic dispersion for 25min, heating to 92 ℃, reacting for 2.5h, filtering, washing with clear water, and drying at 105 ℃ for 2h to prepare a dealuminized molecular sieve;
s6, preparing a meta-xylene adsorbent: and (3) adding the dealuminized molecular sieve prepared in the step (S5) into a solution containing 7wt% of ferric chloride, wherein the solid-to-liquid ratio of the dealuminized molecular sieve to the solution containing 7wt% of ferric chloride is 1.
Comparative example 2
The difference from example 3 is that step S2 is not performed.
The method specifically comprises the following steps:
s1, pretreatment of halloysite: soaking a halloysite nanotube in a sulfuric acid solution with the pH of 2.5 for treatment for 2h, wherein the solid-to-liquid ratio of the halloysite nanotube to the sulfuric acid solution with the pH of 2.5 is 1;
s2, coalescence: stirring and mixing 10 parts by weight of the pretreated halloysite nanotube prepared in the step S1 and 90 parts by weight of NaY zeolite at a speed of 400r/min for 40min, agglomerating into particles, roasting at 450 ℃ for 2h, and ball-milling for 3h to obtain an agglomerate;
s3, preparing molecular sieve particles: adding 10 parts by weight of the agglomerate obtained in the step S2 into 25 parts by weight of NaOH solution with the pH value of 9, heating to 60 ℃, reacting for 1 hour, filtering, washing with clear water, and drying at 105 ℃ for 2 hours to obtain molecular sieve particles;
s4, preparation of a chelating agent: mixing different chelating agents uniformly to obtain a chelating agent;
the chelating agent is H 4 A mixture of EDTA and citric acid with a mass ratio of 6:3;
s5, dealuminizing by using a chelating agent: dissolving 3 parts by weight of the chelating agent prepared in the step S4 in water, adding 7 parts by weight of the molecular sieve particles prepared in the step S3, performing 1250W ultrasonic dispersion for 25min, heating to 92 ℃, reacting for 2.5h, filtering, washing with clear water, and drying at 105 ℃ for 2h to prepare a dealuminized molecular sieve;
s6, preparing a meta-xylene adsorbent: and (3) adding the dealuminized molecular sieve prepared in the step (S5) into a solution containing 7wt% of ferric chloride, wherein the solid-to-liquid ratio of the dealuminized molecular sieve to the solution containing 7wt% of ferric chloride is 1.
Comparative example 3
The difference compared to example 3 is that the modified halloysite in step S3 was replaced by an equal amount of kaolin.
The method specifically comprises the following steps:
s1, coalescence: stirring and mixing 10 parts by weight of kaolin and 90 parts by weight of NaY zeolite at a speed of 400r/min for 40min, agglomerating to form particles, roasting at 450 ℃ for 2h, and ball-milling for 3h to obtain an agglomerate;
s2, preparing molecular sieve particles: adding 10 parts by weight of the agglomerate prepared in the step S3 into 25 parts by weight of NaOH solution with the pH value of 9, heating to 60 ℃, reacting for 1 hour, filtering, washing with clear water, and drying at 105 ℃ for 2 hours to obtain molecular sieve particles;
s3, preparation of a chelating agent: mixing different chelating agents uniformly to obtain a chelating agent;
the chelating agent is H 4 A mixture of EDTA and citric acid with a mass ratio of 6:3;
s4, chelating agent dealuminization: dissolving 3 parts by weight of the chelating agent prepared in the step S3 in water, adding 7 parts by weight of the molecular sieve particles prepared in the step S2, performing 1250W ultrasonic dispersion for 25min, heating to 92 ℃, reacting for 2.5h, filtering, washing with clear water, and drying at 105 ℃ for 2h to prepare a dealuminized molecular sieve;
s5, preparing a meta-xylene adsorbent: and (3) adding the dealuminized molecular sieve prepared in the step (S4) into a solution containing 7wt% of ferric chloride, wherein the solid-to-liquid ratio of the dealuminized molecular sieve to the solution containing 7wt% of ferric chloride is 1.
Comparative example 4
The difference from example 3 is that step S4 is not performed.
The method specifically comprises the following steps:
s1, pretreatment of halloysite: soaking a halloysite nanotube in a sulfuric acid solution with the pH of 2.5 for treatment for 2h, wherein the solid-to-liquid ratio of the halloysite nanotube to the sulfuric acid solution with the pH of 2.5 is 1;
s2, preparing modified halloysite: adding 10 parts by weight of the pretreated halloysite nanotube prepared in the step S1 into water, uniformly dispersing, adding 16 parts by weight of dopamine hydrochloride and 0.7 part by weight of catalyst, heating to 80 ℃, reacting for 2h, centrifuging for 15min at 5000r/min, washing with clear water, and drying for 2h at 105 ℃ to obtain modified halloysite;
the catalyst is a Tris-HCl solution with the pH value of 5 and containing 3wt% of cobalt ions;
s3, coalescence: stirring and mixing 10 parts by weight of the modified halloysite prepared in the step S2 and 90 parts by weight of NaY zeolite at a speed of 400r/min for 40min, agglomerating into particles, roasting at 450 ℃ for 2h, and ball-milling for 3h to obtain an agglomerate;
s4, preparation of a chelating agent: mixing different chelating agents uniformly to obtain a chelating agent;
the chelating agent is H 4 A mixture of EDTA and citric acid in a mass ratio of 6:3;
s5, dealuminizing by using a chelating agent: dissolving 3 parts by weight of the chelating agent prepared in the step S4 in water, adding 7 parts by weight of the agglomerate prepared in the step S3, performing 1250W ultrasonic dispersion for 25min, heating to 92 ℃, reacting for 2.5h, filtering, washing with clear water, and drying at 105 ℃ for 2h to prepare an dealuminized molecular sieve;
s6, preparing a meta-xylene adsorbent: and (3) adding the dealuminized molecular sieve prepared in the step (S5) into a solution containing 7wt% of ferric chloride, wherein the solid-to-liquid ratio of the dealuminized molecular sieve to the solution containing 7wt% of ferric chloride is 1.
Comparative example 5
The difference from example 3 is that step S6 is not performed.
The method specifically comprises the following steps:
s1, pretreatment of halloysite: soaking a halloysite nanotube in a sulfuric acid solution with the pH of 2.5 for treatment for 2h, wherein the solid-to-liquid ratio of the halloysite nanotube to the sulfuric acid solution with the pH of 2.5 is 1;
s2, preparing modified halloysite: adding 10 parts by weight of the pretreated halloysite nanotube prepared in the step S1 into water, uniformly dispersing, adding 16 parts by weight of dopamine hydrochloride and 0.7 part by weight of catalyst, heating to 80 ℃, reacting for 2h, centrifuging at 5000r/min for 15min, washing with clear water, and drying at 105 ℃ for 2h to obtain modified halloysite;
the catalyst is a Tris-HCl solution with the pH value of 5 and containing 3wt% of cobalt ions;
s3, coalescence: stirring and mixing 10 parts by weight of the modified halloysite prepared in the step S2 and 90 parts by weight of NaY zeolite at a speed of 400r/min for 40min, agglomerating into particles, roasting at 450 ℃ for 2h, and ball-milling for 3h to obtain an agglomerate;
s4, preparing molecular sieve particles: adding 10 parts by weight of the agglomerate prepared in the step S3 into 25 parts by weight of NaOH solution with the pH value of 9, heating to 60 ℃, reacting for 1 hour, filtering, washing with clear water, and drying at 105 ℃ for 2 hours to obtain molecular sieve particles;
s5, preparing a meta-xylene adsorbent: and (3) adding the molecular sieve particles prepared in the step (S4) into a solution containing 7wt% of ferric chloride, wherein the solid-to-liquid ratio of the molecular sieve particles to the solution containing 7wt% of ferric chloride is 1.
Comparative example 6
The difference from example 3 is that step S7 is not performed.
The method specifically comprises the following steps:
s1, pretreatment of halloysite: soaking a halloysite nanotube in a sulfuric acid solution with the pH of 2.5 for treatment for 2h, wherein the solid-to-liquid ratio of the halloysite nanotube to the sulfuric acid solution with the pH of 2.5 is 1;
s2, preparing modified halloysite: adding 10 parts by weight of the pretreated halloysite nanotube prepared in the step S1 into water, uniformly dispersing, adding 16 parts by weight of dopamine hydrochloride and 0.7 part by weight of catalyst, heating to 80 ℃, reacting for 2h, centrifuging at 5000r/min for 15min, washing with clear water, and drying at 105 ℃ for 2h to obtain modified halloysite;
the catalyst is a Tris-HCl solution with the pH value of 5 and containing 3wt% of cobalt ions;
s3, coalescence: stirring and mixing 10 parts by weight of the modified halloysite prepared in the step S2 and 90 parts by weight of NaY zeolite at a speed of 400r/min for 40min, agglomerating into particles, roasting at 450 ℃ for 2h, and ball-milling for 3h to obtain an agglomerate;
s4, preparing molecular sieve particles: adding 10 parts by weight of the agglomerate prepared in the step S3 into 25 parts by weight of NaOH solution with the pH value of 9, heating to 60 ℃, reacting for 1 hour, filtering, washing with clear water, and drying at 105 ℃ for 2 hours to obtain molecular sieve particles;
s5, preparation of a chelating agent: mixing different chelating agents uniformly to obtain a chelating agent;
the chelating agent is H 4 A mixture of EDTA and citric acid with a mass ratio of 6:3;
s6, dealuminizing by using a chelating agent: dissolving 3 parts by weight of the chelating agent prepared in the step S5 in water, adding 7 parts by weight of the molecular sieve particles prepared in the step S4, performing 1250W ultrasonic dispersion for 25min, heating to 92 ℃, reacting for 2.5h, filtering, washing with clear water, and drying at 105 ℃ for 2h to prepare the dealuminized molecular sieve, namely the m-xylene adsorbent.
Test example 1
The meta-xylene adsorbents obtained in examples 1 to 5 and comparative examples 1 to 10 were subjected to performance tests, and the results are shown in Table 1.
The parameters of the specific surface area, pore volume and the like of the sample were measured by using an ASAP2460 full-automatic specific surface and porosity analyzer manufactured by Micromeritics instruments of America.
TABLE 1
As can be seen from the above table, the meta-xylene adsorbents obtained in examples 1 to 3 of the present invention have a larger specific surface area and an increased pore volume.
Test example 2
The m-xylene adsorbents obtained in examples 1 to 5 and comparative examples 1 to 10 were subjected to adsorption performance tests, and the results are shown in Table 2.
TABLE 2
As can be seen from the above table, the meta-xylene adsorbent of the present invention has a higher adsorption selectivity for meta-xylene.
Test example 3
The results of the combination of properties of the meta-xylene adsorbents obtained in examples 1 to 5 and comparative examples 1 to 10 are shown in Table 3.
TABLE 3
As can be seen from the above table, the meta-xylene adsorbent of the present invention is not easily broken and has a higher adsorption capacity.
In comparative example 1, compared with example 3, without performing step S1, the crushing rate was increased and the specific surface area and pore volume were slightly decreased. According to the invention, halloysite is subjected to surface acid solution treatment, particles with small particle size are formed after ball milling, and hydroxyl is released on the surface, so that surface modification with polydopamine is easy to carry out, the surface viscosity of a halloysite nanotube is enhanced, a molecular sieve is well agglomerated into particles, and the breaking rate of the prepared adsorbent is lower.
Comparative example 2 compared with example 3, without step S2, the breakage rate was increased and the specific surface area and pore volume were slightly decreased. The surface of the halloysite nanotube pretreated by the method is modified by polydopamine, and the modified halloysite nanotube has abundant hydroxyl, amino, carboxyl and other groups on the surface, so that the modified halloysite nanotube has excellent viscosity, can be mixed with a NaY molecular sieve subjected to ball milling, is uniformly dispersed and well bonded together, and is roasted and ball-milled to obtain small-particle-size particles, so that the bonding performance is better, the breaking rate of the prepared adsorbent is lower, and the specific surface area is large.
Comparative example 3 compared to example 3, the modified halloysite was replaced with an equal amount of kaolin in step S3. Comparative example 4 compared with example 3, without step S4, the breakage rate was increased, the specific surface area, the pore volume were decreased, and the adsorption selectivity was decreased. The halloysite is subjected to surface acid liquid treatment, small-particle-size particles are formed after ball milling, hydroxyl is released from the surface of the halloysite, polydopamine modification is convenient to perform on the surface of the halloysite, the modified halloysite has excellent viscosity and can be mixed with NaY molecular sieves subjected to ball milling, the groups such as hydroxyl, amino and carboxyl are rich on the surface of the halloysite, the halloysite is uniformly dispersed and well bonded together, small-particle-size particles are obtained after roasting and ball milling, and the halloysite is crystallized in situ into NaY zeolite after further heating treatment by alkali liquor containing sodium ions, so that the molecular sieve particles are obtained, the bonding performance is better, the breaking rate of the prepared adsorbent is lower, and the specific surface area is large.
Examples 4 and 5 in comparison with example 3, the chelating agent in step S5 was H alone 4 EDTA or citric acid, which has a slightly decreased pore volume, has a decreased adsorption selectivity. The chelating agent adopted by the invention is H 4 Mixture of EDTA and citric acid, citric acid being a weak acid, by H 4 The EDTA and the citric acid are mixed for use, so that a good dealuminization effect can be achieved, and meanwhile, the effect of adjusting the pH value of the solution is achieved, so that the problem that when the pH value is too low, all sodium ions can be replaced by H, and the subsequent aperture adjustment of the molecular sieve is influenced is avoided.
Examples 6 and 7 compared with example 3, the mass ratio of the chelating agent to the molecular sieve particles in step S6 was 1:10 or 1:1. in example 6, the specific surface area is reduced, the pore volume is reduced, the adsorption selectivity is reduced, and in example 7, the breakage rate is increased, and the burning base bulk density is reduced. Comparative example 5 compared to example 3, without performing step S6, the pore volume was significantly decreased and the adsorption selectivity was significantly decreased. The chelating agent with proper amount is adopted for dealumination, so that partial aluminum in the molecular sieve structure is removed, the aluminum-silicon ratio of the molecular sieve is obviously improved, the prepared dealuminated molecular sieve also has better stability and roughness, the adsorption sites of the p-xylene and the meta-xylene are greatly improved, and the adsorption efficiency is obviously improved.
Examples 8 and 9 compared with example 3, the replacement of a solution containing 7wt% of ferric chloride with a solution containing 20wt% of ferric chloride or a solution containing 1wt% of ferric chloride reduced the specific surface area, pore volume and adsorption selectivity. Comparative example 6 compared with example 3, without performing step S7, the specific surface area decreased, the pore volume decreased, and the adsorption selectivity decreased significantly. According to the invention, iron ions are adopted to perform partial ion exchange on sodium ions and hydrogen ions in the prepared molecular sieve to form the NaFeHY molecular sieve, and after the iron ions, the sodium ions and the hydrogen ions are cooperatively distributed, main channels are partially blocked, so that the effective aperture of the prepared molecular sieve is obviously reduced, and an aperture with a proper size is formed; in addition, when iron ions, sodium ions and hydrogen ions exist simultaneously, an asymmetric electric field is formed in the molecular sieve supercage, p-xylene is a nonpolar molecule, the induced dipole moment cannot be balanced with the direction of the electric field, so that the energy is greatly improved and is unstable in the electric field, and the induced dipole moment of the m-xylene rotates to a proper position, so that the energy is greatly reduced and the stability is obviously improved, therefore, the stability of the m-xylene is optimal, the m-xylene can be stably adsorbed, no adsorption effect is generated on the m-xylene, and the selectivity of the adsorbent is improved. The method has the advantages that the selective adsorption of the molecular sieve to m-xylene is obviously improved by reasonably regulating the proportion of iron ions, sodium ions and hydrogen ions and regulating the aperture and the electric field of the molecular sieve, and compared with the prior art in which expensive metal ions such as metal silver ions, strontium ions and the like are adopted, the method has the advantages that the source of the iron ion raw material is wide, the price is low, the preparation cost of the adsorbent is low, the adsorption effect is good, and the separation degree is high.
The above description is only for the purpose of illustrating the preferred embodiments of the present invention and is not to be construed as limiting the invention, and any modifications, equivalents, improvements and the like that fall within the spirit and principle of the present invention are intended to be included therein.
Claims (9)
1. The preparation method of the m-xylene adsorbent is characterized by comprising the following steps:
s1, pretreatment of halloysite: soaking the halloysite nanotube in acid liquor for treatment, centrifuging, washing and drying to obtain a pretreated halloysite nanotube;
s2, preparing modified halloysite: adding the pretreated halloysite nanotube prepared in the step S1 into water, uniformly dispersing, adding dopamine hydrochloride and a catalyst, heating for reaction, centrifuging, washing and drying to obtain modified halloysite; the catalyst is a Tris-HCl solution with pH value of 4-6 and containing cobalt ions;
s3, coalescence: mixing the modified halloysite prepared in the step S2 and NaY zeolite, then agglomerating the mixture into particles, roasting the particles, and carrying out ball milling on the particles to obtain an agglomerate;
s4, preparing molecular sieve particles: adding the conglomerate prepared in the step S3 into an alkaline solution containing sodium ions, heating for reaction, filtering, washing and drying to obtain molecular sieve particles;
s5, preparation of a chelating agent: mixing different chelating agents uniformly to obtain a chelating agent;
the chelating agent is H 4 A mixture of EDTA and citric acid with the mass ratio of 4-7:3;
s6, chelating agent dealuminization: dissolving the chelating agent prepared in the step S5 in water, adding the molecular sieve particles prepared in the step S4, uniformly dispersing, heating for reaction, filtering, washing and drying to prepare a dealuminized molecular sieve;
s7, preparing a meta-xylene adsorbent: and (4) adding the dealuminized molecular sieve prepared in the step (S6) into the solution containing iron ions, heating for reaction, filtering, washing, drying and activating to obtain the meta-xylene adsorbent.
2. The method according to claim 1, wherein the acid solution in step S1 is HCl or sulfuric acid solution having pH of 2 to 3; the solid-to-liquid ratio of the halloysite nanotubes to the acid liquor is 1:5-7g/mL; the treatment time is 1-3h.
3. The method for preparing according to claim 1, wherein the mass ratio of the pretreated halloysite nanotubes, dopamine hydrochloride and catalyst in step S2 is 10-15 to 17; the heating reaction is carried out at the temperature of 70-90 ℃ for 1-3h; in the step S3, the mixing stirring speed is 300-500r/min, and the mixing time is 30-50min; the roasting temperature is 400-500 ℃, and the roasting time is 1-3h; the ball milling time is 2-4h; the mass ratio of the modified halloysite to the NaY zeolite is 8-12.
4. The preparation method according to claim 1, wherein the alkaline solution containing sodium ions in step S4 is a NaOH solution having a pH of 8 to 10 or a mixture solution of NaOH and sodium silicate having a pH of 8 to 10, wherein the mass ratio of NaOH and sodium silicate is 3 to 5:1; the heating reaction is carried out at the temperature of 50-70 ℃ for 0.5-1h.
5. The method according to claim 1, wherein the mass ratio of the chelating agent to the molecular sieve particles in step S6 is 2-4:7; the heating reaction is carried out at the temperature of 90-95 ℃ for 2-3h; the uniform dispersion is 1000-1500W ultrasonic dispersion for 20-30min.
6. The production method according to claim 1, wherein the solution containing iron ions in step S7 is a solution containing 5 to 10wt% of ferric chloride or ferric sulfate; the solid-liquid ratio of the dealuminization molecular sieve to the solution containing iron ions is 1:3-5g/mL; the heating reaction is carried out at the temperature of 60-80 ℃ for 2-3h; the activation method comprises roasting and activating for 5-7h at 450-550 ℃.
7. The preparation method according to claim 1, comprising the steps of:
s1, pretreatment of halloysite: soaking the halloysite nanotube in HCl or sulfuric acid solution with the pH of 2-3 for treatment for 1-3h, wherein the solid-to-liquid ratio of the halloysite nanotube to the HCl or sulfuric acid solution with the pH of 2-3 is 1:5-7g/mL, centrifuging at 5000-7000r/min for 15-20min, washing, and drying to obtain the pretreated halloysite nanotube;
s2, preparing modified halloysite: adding 10 parts by weight of the pretreated halloysite nanotube prepared in the step S1 into water, uniformly dispersing, adding 15-17 parts by weight of dopamine hydrochloride and 0.5-1 part by weight of catalyst, heating to 70-90 ℃, reacting for 1-3h, centrifuging, washing, and drying to obtain modified halloysite;
the catalyst is a Tris-HCl solution with pH value of 4-6 and containing cobalt ions;
s3, coalescence: stirring and mixing 8-12 parts by weight of the modified halloysite prepared in the step S2 and 90 parts by weight of NaY zeolite at a speed of 300-500r/min for 30-50min, agglomerating into particles, roasting at 400-500 ℃ for 1-3h, and ball-milling for 2-4h to obtain an agglomerate;
s4, preparing molecular sieve particles: adding 10 parts by weight of the conglomerate prepared in the step S3 into 20-30 parts by weight of alkaline solution containing sodium ions, heating to 50-70 ℃, reacting for 0.5-1h, filtering, washing and drying to obtain molecular sieve particles;
the alkaline solution containing sodium ions is a NaOH solution with the pH value of 8-10 or a mixture solution of NaOH and sodium silicate with the pH value of 8-10, wherein the mass ratio of NaOH to sodium silicate is 3-5:1;
s5, preparation of a chelating agent: mixing different chelating agents uniformly to obtain a chelating agent;
the chelating agent is H 4 A mixture of EDTA and citric acid with the mass ratio of 4-7:3;
s6, dealuminizing by using a chelating agent: dissolving 2-4 parts by weight of the chelating agent prepared in the step S5 in water, adding 7 parts by weight of the molecular sieve particles prepared in the step S4, performing ultrasonic dispersion for 20-30min at 1000-1500W, heating to 90-95 ℃, reacting for 2-3h, filtering, washing, and drying to obtain a dealuminized molecular sieve;
s7, preparing a meta-xylene adsorbent: and (2) adding the dealuminized molecular sieve prepared in the step (S6) into a ferric chloride or ferric sulfate solution containing 5-10wt%, wherein the solid-to-liquid ratio of the dealuminized molecular sieve to the solution containing iron ions is 1:3-5g/mL, heating to 60-80 ℃, reacting for 2-3h, filtering, washing, drying, roasting at 450-550 ℃ and activating for 5-7h to obtain the m-xylene adsorbent.
8. A meta-xylene adsorbent produced by the production method as claimed in any one of claims 1 to 7.
9. Use of the meta-xylene adsorbent of claim 8 for adsorbing and separating meta-xylene.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202310058943.9A CN115805056B (en) | 2023-01-19 | 2023-01-19 | Meta-xylene adsorbent and preparation method and application thereof |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202310058943.9A CN115805056B (en) | 2023-01-19 | 2023-01-19 | Meta-xylene adsorbent and preparation method and application thereof |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN115805056A CN115805056A (en) | 2023-03-17 |
| CN115805056B true CN115805056B (en) | 2023-04-07 |
Family
ID=85487438
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202310058943.9A Active CN115805056B (en) | 2023-01-19 | 2023-01-19 | Meta-xylene adsorbent and preparation method and application thereof |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN115805056B (en) |
Citations (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1124241A (en) * | 1993-08-23 | 1996-06-12 | 环球油品公司 | Improved adsorptive separation of metalxylene from aromatic hydrocarbons |
| US6403856B1 (en) * | 1998-10-19 | 2002-06-11 | Uop Llc | Process for separating alkylaromatic hydrocarbons |
| CN101745364A (en) * | 2008-12-18 | 2010-06-23 | 中国石油化工股份有限公司 | Adsorbent for adsorption separation of m-Xylene and preparation method thereof |
| CN102951655A (en) * | 2012-11-27 | 2013-03-06 | 华东师范大学 | Modified method of Y-type molecular sieve |
| CN111097370A (en) * | 2018-10-29 | 2020-05-05 | 中国石油化工股份有限公司 | Spherical meta-xylene adsorbent and preparation method thereof |
| CN112808298A (en) * | 2019-11-18 | 2021-05-18 | 中国石油化工股份有限公司 | Catalyst containing hierarchical pore Y-type molecular sieve and preparation method thereof |
| WO2021123664A1 (en) * | 2019-12-20 | 2021-06-24 | IFP Energies Nouvelles | Zeolite adsorbent for the separation of hydrocarbon isomers |
| CN114618430A (en) * | 2020-12-10 | 2022-06-14 | 中国科学院大连化学物理研究所 | Y-type molecular sieve and preparation method and application thereof |
-
2023
- 2023-01-19 CN CN202310058943.9A patent/CN115805056B/en active Active
Patent Citations (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1124241A (en) * | 1993-08-23 | 1996-06-12 | 环球油品公司 | Improved adsorptive separation of metalxylene from aromatic hydrocarbons |
| US6403856B1 (en) * | 1998-10-19 | 2002-06-11 | Uop Llc | Process for separating alkylaromatic hydrocarbons |
| CN101745364A (en) * | 2008-12-18 | 2010-06-23 | 中国石油化工股份有限公司 | Adsorbent for adsorption separation of m-Xylene and preparation method thereof |
| CN102951655A (en) * | 2012-11-27 | 2013-03-06 | 华东师范大学 | Modified method of Y-type molecular sieve |
| CN111097370A (en) * | 2018-10-29 | 2020-05-05 | 中国石油化工股份有限公司 | Spherical meta-xylene adsorbent and preparation method thereof |
| CN112808298A (en) * | 2019-11-18 | 2021-05-18 | 中国石油化工股份有限公司 | Catalyst containing hierarchical pore Y-type molecular sieve and preparation method thereof |
| WO2021123664A1 (en) * | 2019-12-20 | 2021-06-24 | IFP Energies Nouvelles | Zeolite adsorbent for the separation of hydrocarbon isomers |
| CN114618430A (en) * | 2020-12-10 | 2022-06-14 | 中国科学院大连化学物理研究所 | Y-type molecular sieve and preparation method and application thereof |
Also Published As
| Publication number | Publication date |
|---|---|
| CN115805056A (en) | 2023-03-17 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US8377842B2 (en) | Adsorbent for selective adsorption of carbon monoxide and process for preparation thereof | |
| US6053966A (en) | Absorbent having heterogeneous exchange factor and PSA process employing such an absorbent | |
| KR0140513B1 (en) | Improved absorbent beds for pressure swing absorption operation | |
| CN109692656B (en) | Mesoporous Y zeolite, adsorbent and preparation method of adsorbent | |
| CN108940188B (en) | Preparation method of binder-free all-silicon MCM-41 molecular sieve adsorbent | |
| US9162899B2 (en) | BaX type Zeolite granule and process for preparing the same | |
| CN112387250A (en) | Imprinted-similar MOF adsorbent and preparation method and application thereof | |
| CN110961080A (en) | Adsorption separation C8Aromatic hydrocarbon adsorbent and preparation method thereof | |
| CN113351157A (en) | Modified lithium low-silicon zeolite molecular sieve and preparation method thereof | |
| CN113371730A (en) | Modified calcium low-silicon zeolite molecular sieve and preparation method thereof | |
| WO2020259595A1 (en) | Composite layer coalescing adsorbent and preparation method therefor | |
| CN115805056B (en) | Meta-xylene adsorbent and preparation method and application thereof | |
| CN111097372B (en) | Preparation method of m-xylene adsorbent | |
| CN110548481B (en) | Hollow-structure CO adsorbent with nano CuO coated by Y-type molecular sieve and preparation method and application thereof | |
| CN114425298B (en) | Meta-xylene adsorbent and preparation method thereof | |
| WO2023151561A1 (en) | Adsorbent for separating ethylbenzene from c8 aromatic hydrocarbons and preparation method therefor | |
| CN102451664A (en) | Preparation method of adsorbent used for whole naphtha adsorption separation process | |
| CN111229184B (en) | Silicon source-controllable modified mesoporous and microporous adsorbent and preparation method and application thereof | |
| KR20090122027A (en) | Process for preparing spherical zeolite granule | |
| CN110511121B (en) | Method for separating p-cresol by liquid phase adsorption | |
| EP1486254A1 (en) | Molecular sieve with enhanced performance in air separation | |
| CN110510630B (en) | Nanoscale X molecular sieve grain spherical self-assembly substance and preparation method thereof | |
| CN110871053B (en) | Adsorbent for adsorbing and separating ethylbenzene and preparation method thereof | |
| CN110511118B (en) | Method for separating paracresol by liquid phase adsorption | |
| CN108946760A (en) | A method of total silicon ZSM-5 molecular sieve is synthesized using total silicon Beta crystallization mother liquor |
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 | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |