CN110511121B - Method for separating p-cresol by liquid phase adsorption - Google Patents

Method for separating p-cresol by liquid phase adsorption Download PDF

Info

Publication number
CN110511121B
CN110511121B CN201810495848.4A CN201810495848A CN110511121B CN 110511121 B CN110511121 B CN 110511121B CN 201810495848 A CN201810495848 A CN 201810495848A CN 110511121 B CN110511121 B CN 110511121B
Authority
CN
China
Prior art keywords
molecular sieve
silicalite
core
adsorbent
cresol
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
Application number
CN201810495848.4A
Other languages
Chinese (zh)
Other versions
CN110511121A (en
Inventor
高宁宁
王辉国
王德华
马剑锋
王红超
杨彦强
李犇
乔晓菲
刘宇斯
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Sinopec Research Institute of Petroleum Processing
China Petroleum and Chemical Corp
Original Assignee
Sinopec Research Institute of Petroleum Processing
China Petroleum and Chemical Corp
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by Sinopec Research Institute of Petroleum Processing, China Petroleum and Chemical Corp filed Critical Sinopec Research Institute of Petroleum Processing
Priority to CN201810495848.4A priority Critical patent/CN110511121B/en
Publication of CN110511121A publication Critical patent/CN110511121A/en
Application granted granted Critical
Publication of CN110511121B publication Critical patent/CN110511121B/en
Active legal-status Critical Current
Anticipated expiration legal-status Critical

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
    • B01J20/10—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
    • B01J20/186—Chemical treatments in view of modifying the properties of the sieve, e.g. increasing the stability or the activity, also decreasing the activity
    • 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
    • B01J20/28019—Spherical, ellipsoidal or cylindrical
    • C—CHEMISTRY; METALLURGY
    • C07—ORGANIC CHEMISTRY
    • C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
    • C07C37/00—Preparation of compounds having hydroxy or O-metal groups bound to a carbon atom of a six-membered aromatic ring
    • C07C37/68—Purification; separation; Use of additives, e.g. for stabilisation
    • C07C37/70—Purification; separation; Use of additives, e.g. for stabilisation by physical treatment
    • C07C37/82—Purification; separation; Use of additives, e.g. for stabilisation by physical treatment by solid-liquid treatment; by chemisorption

Landscapes

  • Chemical & Material Sciences (AREA)
  • Organic Chemistry (AREA)
  • Analytical Chemistry (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Inorganic Chemistry (AREA)
  • Solid-Sorbent Or Filter-Aiding Compositions (AREA)
  • Silicates, Zeolites, And Molecular Sieves (AREA)

Abstract

A method for separating p-cresol by liquid phase adsorption comprises the steps of enabling a cresol raw material to contact an adsorbent at the temperature of 150-260 ℃ and under the pressure of 0.1-1.8 MPa, enabling the p-cresol to be adsorbed by the adsorbent, discharging unadsorbed components serving as raffinate, introducing a desorbent into the adsorbent, desorbing the adsorbed components to obtain extract liquid, wherein the adsorbent comprises 85-98 mass% of an X/Silicalite-1 core/shell molecular sieve and 2-15 mass% of a binder, the core of the X/Silicalite-1 core/shell molecular sieve is an X molecular sieve, the shell of the X/Silicalite-1 core/shell molecular sieve is a Silicalite-1 molecular sieve, and the cation position of the X/Silicalite-1 core/shell molecular sieve is occupied by IIA group metal ions or occupied by IIA group metal ions and IA group metal ions. The method can obviously improve the selectivity of p-cresol.

Description

Method for separating p-cresol by liquid phase adsorption
Technical Field
The invention relates to a method for adsorbing and separating para-isomer, in particular to a method for adsorbing and separating para-cresol from a cresol isomer mixture.
Background
The cresol isomers are important fine chemical intermediates. However, since the difference between the atmospheric boiling points of m-cresol and p-cresol is less than 1.0 ℃, it is difficult to obtain high-purity m-cresol and p-cresol products by conventional distillation methods. Currently, methods for separating cresol isomers include azeotropic distillation, high-pressure crystallization, adsorption separation, complexation separation, alkylation, and the like. Wherein, the adsorption separation method is a separation method with low operation energy consumption and high product purity. Industrially, one of the key technologies for realizing the adsorptive separation of cresol isomers is the preparation of high-performance adsorbents.
US3014078 discloses an adsorbent for separating cresol isomers, the active component of which is Ca2+Or Na+The type X molecular sieve has higher adsorption selectivity to p-cresol.
CN104815612A discloses a molecular sieve adsorbent for m-cresol and p-cresol adsorptive separation and a preparation method thereof. Firstly, tetrapropylammonium hydroxide, silica gel and aluminium hydroxide are used as raw materials to synthesize molecular sieve raw powder, then the calcined molecular sieve raw powder and forming adhesive are mixed according to a certain proportion, and then the mixture is rolled and formed, and then the deposition agent Si (OCH) is adopted3)4The formed molecular sieve is chemically modified, and the obtained adsorbent can realize the adsorption separation of m/p-cresol.
Disclosure of Invention
The invention aims to provide a method for separating p-cresol by liquid phase adsorption, which uses an adsorbent with an active component of X/Silicalite-1 core/shell molecular sieve and has higher p-cresol adsorption selectivity.
The method for separating p-cresol by liquid phase adsorption comprises the steps of contacting a cresol raw material with an adsorbent at the temperature of 150-260 ℃ and under the pressure of 0.1-1.8 MPa, wherein the p-cresol is adsorbed by the adsorbent, unadsorbed components are discharged as raffinate, introducing a desorbent into the adsorbent, and desorbing the adsorbed components to obtain an extract, wherein the adsorbent comprises 85-98 mass% of an X/Silicalite-1 core/shell molecular sieve and 2-15 mass% of a binder, the core of the X/Silicalite-1 core/shell molecular sieve is an X molecular sieve, the shell of the X/Silicalite-1 core/shell molecular sieve is a Silicalite-1 molecular sieve, and the cation position of the X/Silicalite-1 core/shell molecular sieve is occupied by IIA group metal ions or occupied by IIA group metal ions and IA group metal ions.
The method adopts X/Silicalite-1 core/shell molecular sieve as the active component of the adsorbent, the cation site of the X/Silicalite-1 core/shell molecular sieve is occupied by IIA group metal ions or occupied by IIA group metal ions and IA group metal ions together, and the X/Silicalite-1 core/shell molecular sieve is used for adsorbing and separating cresol isomers and can obviously improve the selectivity of p-cresol.
Drawings
FIG. 1 is an XRD pattern of a Na form of X/Silicalite-1 core/shell molecular sieve prepared in accordance with example 1 of the invention.
FIG. 2 is a Scanning Electron Micrograph (SEM) of the Na form of the X/Silicalite-1 core/shell molecular sieve prepared in accordance with example 1 of the present invention.
FIG. 3 is a schematic diagram of adsorption separation in a small simulated moving bed.
Detailed Description
According to the invention, the cresol isomers are adsorbed and separated by adopting the adsorbent of the core/shell molecular sieve with the active component of X/Silicalite-1, the X molecular sieve is used as the core of the core/shell molecular sieve of the X/Silicalite-1, and the Silicalite-1 shell layer is used as the outer layer, so that when the adsorbent is used for adsorbing and separating the cresol isomers, the paracresol adsorbed by the X molecular sieve can slowly pass through the Silicalite-1 molecular sieve layer due to the shape selective property of the Silicalite-1 shell layer, and the metacresol can easily pass through the Silicalite-1 molecular sieve layer, thereby improving the adsorption selectivity of the molecular sieve. In addition, the cation site in the X/Silicalite-1 core/shell molecular sieve is exchanged by IIA metal cation or the cation of IA metal and IIA metal, so that the adsorption selectivity of the X/Silicalite-1 core/shell molecular sieve on p-cresol can be further improved.
The adsorbent in the method preferably contains 90-98 mass% of X/Silicalite-1 core/shell molecular sieve and 2-10 mass% of binder.
Said IIA group goldThe metal ion is Mg2+、Ca2+、Sr2+Or Ba2+Preferably Ba2+. The IA group metal ion is Li+、Na+、K+、Rb+And Cs+At least one of (1).
SiO of the X molecular sieve with the core of the X/Silicalite-1 core/shell molecular sieve2/Al2O3The molar ratio is preferably 2.0 to 3.0. The grain size of the inner core X molecular sieve is preferably 0.2-5.0 microns, and more preferably 0.4-2.0 microns. The thickness of the Silicalite-1 shell layer is 30-800 nanometers, and preferably 40-200 nanometers.
The binder is selected from kaolinite, dickite, nacrite, refractory stone, halloysite or mixtures thereof, preferably kaolin.
The adsorbent provided by the invention is preferably in a pellet shape, and the average particle size of the pellet is preferably 300-850 micrometers.
The preparation method of the adsorbent provided by the invention comprises the following steps:
(1) mixing NaX/Silicalite-1 core/shell molecular sieve or KNaX/Silicalite-1 core/shell molecular sieve with a binder according to the weight ratio of 85-98: 2-15, rolling ball forming, drying and roasting,
(2) and (2) carrying out cation exchange on the pellets prepared in the step (1) by using a solution containing the IIA metal compound or a solution containing the IIA metal and a compound containing the IA metal, and then washing, drying and activating.
The method (1) comprises the step of mixing the molecular sieve with a binder and then carrying out rolling ball molding, wherein the used X/Silicalite-1 core/shell molecular sieve can be Na type or NaK type, and Na and K in the NaKX/Silicalite-1 core/shell molecular sieve come from an X molecular sieve or a synthesis system used in the preparation of the core/shell molecular sieve.
The binder of step (1) is preferably kaolinite, dickite, nacrite, firestone, halloysite or a mixture thereof. The content of the crystallized substance in the binder is at least 90 mass%, preferably 93-99 mass%.
(1) The equipment for the step-rolling ball forming can be a rotary table, a sugar coating pan or a roller. When the rolling ball is formed, the uniformly mixed solid raw materials are put into rotating equipment, and water is sprayed while rolling to enable solid powder to be adhered and agglomerated into small balls. The addition amount of water in the rolling process is 2-20% of the total mass of the solid, and the preferable amount is 5-15%.
(1) Rolling the balls to form balls, sieving, drying and roasting to obtain adsorbent. The drying temperature is preferably 60-110 ℃, the time is preferably 2-10 hours, the roasting temperature is preferably 480-600 ℃, and the time is preferably 1.0-6.0 hours.
The grain size of the core X molecular sieve in the NaX/Silicalite-1 or NaKX/Silicalite-1 core/shell molecular sieve is preferably 0.2-5.0 microns, and more preferably 0.4-2.0 microns. The thickness of the Silicalite-1 shell layer is 30-800 nanometers, and preferably 40-200 nanometers.
The preparation method of the NaX/Silicalite-1 core/shell molecular sieve or the KNaX/Silicalite-1 core/shell molecular sieve comprises the following steps:
(a) uniformly mixing a silicon source, a template agent (R), water and optional inorganic base to obtain an alkaline Silicalite-1 synthesis system, wherein the amount of the silicon source is SiO2The amount of inorganic base is calculated as M2Calculated by O, the molar ratio of each material in the synthesis system is R/SiO2＝0.05～0.70，H2O/SiO2＝10～150，M2O/SiO20 to 0.05, M is Na or K,
(b) adding NaX molecular sieve into the synthetic system obtained in step (a), mixing uniformly, adding NaX molecular sieve and SiO contained in the synthetic system2The mass ratio of (A) to (B) is 0.2-20: 1,
(c) and (c) carrying out hydrothermal crystallization treatment on the mixture obtained in the step (b) at the temperature of 80-160 ℃, and drying and roasting the obtained solid product.
The step (a) of the method is a synthesis system for preparing the Silicalite-1, and the silicon source is at least one of tetraethoxysilane, silica sol, water glass, sodium silicate, silica gel and white carbon black. The template agent (R) is at least one selected from ethylamine, n-butylamine, hexamethylenediamine, tetraethylammonium hydroxide, tetrapropylammonium bromide and tetrapropylammonium chloride. (a) The inorganic base is an optional alkaline compound selected from NaOH or KOH and used for keeping the alkalinity of the Silicalite-1 synthesis system, and if the alkalinity of the raw materials is too strong, a proper amount of acid can be added to neutralize part of the alkali.
(a) In the synthesis system prepared in the step (A), the molar ratio of each material is preferably as follows: R/SiO2＝0.1～0.6，H2O/SiO2＝10～100，M2O/SiO20 to 0.03, and M is Na or K.
The step (b) is to add NaX molecular sieve into the synthesis system of Silicalite-1, wherein the SiO of the NaX molecular sieve2/Al2O3The preferred mol ratio is 2.0-3.0, the added NaX molecular sieve and SiO contained in the synthesis system in the step (a)2The mass ratio of (A) to (B) is preferably 0.5-10: 1, more preferably 2 to 8: 1. adding a NaX molecular sieve into the synthesis system of the Silicalite-1, and uniformly stirring to obtain a core/shell molecular sieve synthesis mixture.
The step (c) of the method is to prepare the shell molecular sieve by hydrothermal crystallization, wherein the temperature of the hydrothermal crystallization treatment is preferably 100-160 ℃, and the time of the hydrothermal crystallization treatment is preferably 10-80 hours. And after crystallization is finished, collecting a solid product, and filtering, washing, drying and roasting to obtain the X molecular sieve wrapped by the Silicalite-1 molecular sieve, namely the X/Silicalite-1 core/shell molecular sieve. The drying temperature is preferably 80-120 ℃, the time is preferably 4-12 hours, the roasting temperature is preferably 520-560 ℃, and the time is preferably 2-6 hours.
In the above preparation method, the step (2) is to perform cation exchange on the pellet (also referred to as matrix pellet) prepared in the step (1), and the group IIA metal-containing compound is selected from nitrate or chloride thereof, preferably barium nitrate or barium chloride. The group IA metal-containing compound is selected from one of nitrate, chloride and carbonate thereof, such as chloride, carbonate or nitrate of lithium, sodium, potassium, rubidium and cesium.
The cation exchange can be carried out in a tank or column vessel, preferably a continuous exchange in a column vessel. The exchange temperature is preferably 40-120 ℃, more preferably 85-95 ℃, the time is preferably 5-25 hours, more preferably 8-16 hours, and the volume space velocity of the exchange liquid is preferably 0.2-10 hours-1More preferably 2 to 8 times-1. If the adsorbent contains both group IIA metal ions and group IA metal ions, a group IIA metal compound and group IA metal may be usedThe mixed solution of the group metal compound may be prepared by simultaneously performing ion exchange of the group IIA metal and the group IA metal, or by separately preparing solutions of the group IIA metal compound and the group IA metal compound, and performing ion exchange of the group IIA metal and then the group IA metal, or by performing ion exchange of the group IA metal and then the group IIA metal. After cation exchange, washing, drying and activation are carried out to remove sodium ions and water.
(2) The drying and activating can be carried out in flowing hot air or nitrogen, the drying temperature is preferably 40-120 ℃, more preferably 60-110 ℃, and the time is preferably 5-60 hours, more preferably 18-40 hours. The activation temperature is preferably 150-250 ℃, more preferably 160-220 ℃, and the time is preferably 5-20 hours, more preferably 5-10 hours.
The adsorption separation of the method is liquid phase adsorption separation, can be carried out by adopting a multi-column series connection mode, and can also be carried out by adopting a simulated moving bed realized by a rotary valve or an electromagnetic valve group. The operation pressure of the adsorption separation is preferably 0.3-1.0 MPa, and the operation temperature is preferably 150-220 ℃.
The selectivity is the ratio of the concentration of the two components in the adsorption phase to the concentration of the two components in the non-adsorption phase at adsorption equilibrium. The adsorption equilibrium refers to the state when no component net transfer occurs between the adsorption phase and the non-adsorption phase after the cresol isomer mixture is contacted with the adsorbent. The specific calculation formula is as follows:
Figure BDA0001668916090000041
wherein C and D represent the two components to be separated, ACAnd ADRespectively representing the concentrations of C, D two components in the adsorption phase, UCAnd UDThe concentrations of C, D in the non-adsorbed phase are shown separately. When the selectivity beta of the two components is approximately equal to 1.0, the adsorption capacity of the adsorbent to the two components is equivalent, and the components which are preferentially adsorbed are not present. When β is greater or less than 1.0, it indicates that one component is preferentially adsorbed. Specifically, when beta is>1.0, the adsorbent preferentially adsorbsA component C; when beta is<At 1.0, the adsorbent preferentially adsorbs the D component. In terms of ease of separation, adsorption separation is easier to perform as β value is larger. The absorption and desorption speed is high, the dosage of the absorbent and the desorbent is reduced, the product yield is improved, and the operation cost of the absorption and separation device is reduced.
The present invention will be described in further detail with reference to examples, but the present invention is not limited thereto.
Example 1
The adsorbent of the present invention is prepared.
(1) Preparation of X/Silicalite-1 composite molecular sieve
Under the condition of continuous stirring, 6.67 kg of silica sol, 9.47 kg of tetrapropylammonium hydroxide (R) aqueous solution with the concentration of 25 mass percent and 9.25 kg of deionized water are added into a stainless steel reaction kettle with a polytetrafluoroethylene lining, and the mixture is stirred vigorously to obtain a system for synthesizing the Silicalite-1, wherein the molar ratio of the materials is as follows: R/SiO2＝0.35，H2O/SiO2＝35，Na2O/SiO2＝0。
Take 4 kg of SiO2/Al2O3The NaX molecular sieve with the molar ratio of 2.35 has the grain size of 0.6-1.2 microns, is added into the Silicalite-1 synthesis system prepared in the step (1) and is stirred uniformly, and the added NaX molecular sieve and SiO contained in the Silicalite-1 synthesis system are mixed2The mass ratio of (A) to (B) is 3: 1. statically crystallizing at 130 ℃ for 36 hours under a closed condition, cooling a crystallized product to 25 ℃, filtering, fully washing a solid with deionized water, drying at 100 ℃ for 10 hours, and roasting at 540 ℃ for 4 hours to obtain the Na-type X/Silicalite-1 composite molecular sieve, wherein an XRD (XRD) diagram is shown in figure 1, a Scanning Electron Microscope (SEM) diagram is shown in figure 2, and the thickness of a Silicalite-1 shell layer is 80 nanometers.
(2) Preparation of the adsorbent
Rolling ball forming: uniformly mixing 90 kg (based on burned weight, the same below) of NaX/Silicalite-1 core/shell molecular sieve powder with the particle size of 0.6-1.2 microns with 8 kg of kaolin (the mass fraction of the kaolinite is 92%), putting the mixture into a turntable, rolling and spraying a proper amount of deionized water to enable the solid powder to be aggregated into small balls, wherein the amount of water sprayed during rolling is 8% of the amount of the solid powder. And then screening, taking the small balls with the particle size of 300-850 microns, drying at 80 ℃ for 12 hours, and roasting at 540 ℃ for 4 hours.
Ion exchange: loading 130 ml of the pellet obtained in step (1) into an ion exchange column for cation exchange, and using a mixed solution of 0.18M barium nitrate and 0.08M potassium chloride at 6.0 ℃ under normal pressure and 94 DEG C-1The volume space velocity of (A) was continuously exchanged for 8 hours, and the total amount of the mixed solution was 5000 ml. After the exchange was completed, the pellet was washed with 700 ml of deionized water at 70 ℃ and dried in a nitrogen atmosphere at 70 ℃ for 24 hours, and then dehydrated and activated at 180 ℃ in a nitrogen atmosphere for 6 hours to obtain adsorbent A, the composition of which is shown in Table 1.
Example 2
The adsorbent is prepared according to the method of example 1, except that the grain size of the NaX molecular sieve added for preparing the X/Silicalite-1 core/shell molecular sieve in the step (1) is 0.4-0.8 micron, and the Silicalite-1 shell thickness of the prepared X/Silicalite-1 core/shell molecular sieve is 60 nanometers. The composition of adsorbent B obtained by subjecting it to roll ball formation and ion exchange in the process of step (2) is shown in Table 1.
Example 3
An adsorbent was prepared as in example 1, except that (1) step X/Silicalite-1 core/shell molecular sieves was prepared by adding 1.67 kg of silica sol (silicon source), 2.37 kg of 25% by mass aqueous tetrapropylammonium hydroxide (R) solution, and 2.31 kg of deionized water to a stainless steel reaction vessel lined with polytetrafluoroethylene, and vigorously stirring to obtain a reaction mixture system for the synthesis of Silicalite-1, the molar ratio of each material being: R/SiO2＝0.35，H2O/SiO2＝35，Na2O/SiO20, SiO of NaX molecular sieve added2/Al2O3The molar ratio is 2.52, and the thickness of the Silicalite-1 shell layer of the prepared core/shell molecular sieve is 45 nanometers. The composition of adsorbent C obtained by subjecting it to roll ball formation and ion exchange in the process of step (2) is shown in Table 1.
Example 4
An adsorbent was prepared as in example 1, except that the calcined pellets were subjected to ion exchange in step (2) using a mixed solution of 0.08M lithium chloride, 0.08M potassium chloride and 0.16M barium nitrate in barium nitrate, the total amount of the exchange solution being 5000 ml, and the composition of the prepared adsorbent D was as shown in Table 1.
Example 5
An adsorbent was prepared as in example 1, except that the calcined pellets were subjected to ion exchange in the step (2) using a mixed solution of 0.12M barium nitrate and 0.04M potassium chloride, the total amount of the exchange solution was 2000 ml, and the composition of the adsorbent E obtained was as shown in Table 1.
Comparative example 1
An adsorbent was prepared by the method of steps 1(2) except that 45 kg of NaX molecular sieve powder (SiO) having a particle size of 0.6 to 1.2 μm was used2/Al2O3The molar ratio is 2.35) and 5 kg of kaolin are evenly mixed, put into a turntable to be shaped by rolling balls, and then are screened, dried and roasted. The beads were then ion-exchanged as described in (2) of example 1, and the composition of adsorbent F is shown in Table 1.
Examples 6 to 11
The sorbent performance was evaluated using a pulse experiment.
The pulse experimental device comprises a feeding system, an adsorption column, a heating furnace, a pressure control valve and the like. The adsorption column is a stainless steel tube with phi 6 multiplied by 1800 mm. The inlet at the lower end of the adsorption column is connected with a feeding and nitrogen system, and the outlet at the upper end is connected with a pressure control valve and then connected with an effluent collector. The desorbent used for the experiment was 70% by volume of n-pentanol and 30% by volume of n-heptane. The composition of the pulse feed liquid was 68.46 vol% for n-heptane, 9.99 vol% for n-nonane, 13.51 vol% for p-cresol, 7.6 vol% for m-cresol, and 0.45 vol% for 2, 6-xylenol.
The specific determination process of selectivity is as follows: filling 50 ml of adsorbent into an adsorption column, compacting, and dehydrating and activating at 160-190 ℃ in a nitrogen atmosphere; then introducing a desorbent to remove gas in the system; then the system pressure is increased to 1.0MPa, the temperature is increased to 177 ℃, the introduction of the desorbent is stopped, and the time is 1.0-1After 8 ml of pulse liquid was introduced at the same volume space velocity, the desorbent was switched and introduced at the same volume space velocity, and 3 drops of the desorption liquid were sampled every 2 minutes and analyzed by gas chromatography. Taking the volume of the desorption agent for desorption as the abscissa, the concentration of each component of n-nonane, 2, 6-xylenol, m-cresol and p-cresolEnvelope curves of the above components are plotted as ordinate. Wherein, the n-nonane is not adsorbed and can be used as a tracer to obtain the dead volume of an adsorption system. And (3) taking the middle point of the half-peak width of the tracer as a zero point, measuring the net retention volume R from the middle point of the half-peak width of each component of 2, 6-xylenol, m-cresol and p-cresol to the zero point, wherein the net retention volume of any component is in direct proportion to the distribution coefficient in adsorption balance, reflecting the acting force between each component and the adsorbent, and the ratio of the net retention volumes of the two components is the selectivity beta.
The adsorbents used in each example and the results of the liquid phase pulse experiments performed are shown in table 2.
Example 12
The p-cresol separation experiment was carried out on a continuous countercurrent small simulated moving bed with adsorbent A.
The small-sized simulated moving bed device comprises 24 adsorption columns which are connected in series, wherein each column is 195 mm long, the inner diameter of each column is 30 mm, and the total filling amount of the adsorbent is 3200 ml. The head and the tail of the 24 columns connected in series are connected by a circulating pump to form a closed loop, as shown in figure 3. Four feeding and discharging materials of adsorption raw materials, desorbent, extracting solution (extract liquid) and raffinate (raffinate) divide 24 adsorption columns into four sections, namely 7 adsorption columns between the adsorption raw materials (column 15) and the raffinate (column 21) are adsorption areas, 9 adsorption columns between the extracting solution (column 6) and the adsorption raw materials (column 14) are purification areas, 5 adsorption columns between the desorbent (column 1) and the extracting solution (column 5) are desorption areas, and 3 adsorption columns between the raffinate (column 22) and the desorbent (column 24) are buffer areas. The temperature of the whole adsorption system is controlled to be 177 ℃, and the pressure is 0.8 MPa.
During the operation, n-pentanol as the desorbent and the raw material were continuously injected into the simulated moving bed at 1847 ml/hr and 456 ml/hr, respectively, and the extract and the raffinate were withdrawn from the apparatus at 937 ml/hr and 1366 ml/hr, respectively. The raw material consists of 32.6 percent of paracresol, 67.3 percent of meta-cresol and 0.1 percent of 2, 6-xylenol by mass fraction. When the circulation pump flow rate was set to 3976 ml/hr, four streams of the material were simultaneously moved every 80 seconds in the same direction as the liquid flow direction by 1 adsorption column (from the position of the solid line to the position of the broken line, and so on), and the purity of p-cresol was 99.66 mass% and the yield was 91.85 mass% in a stable operation state.
Comparative example 2
A small simulated moving bed apparatus was charged with a comparative adsorbent F, and an experiment for separating cresol isomers by adsorption was carried out in the same manner as in example 12, whereby p-cresol was obtained in a stable operation state at a purity of 99.53% by mass and a yield of 87.27% by mass.
TABLE 1
Figure BDA0001668916090000081
The exchange degree is metal cation oxide (excluding Na) after the exchange of the adsorbent2O) in the amount of Na before exchange2Percentage of the amount of substance O.
TABLE 2
Figure BDA0001668916090000082

Claims (9)

1. A method for separating p-cresol by liquid phase adsorption comprises the steps of enabling a cresol raw material to contact an adsorbent at the temperature of 150-260 ℃ and under the pressure of 0.1-1.8 MPa, enabling the p-cresol to be adsorbed by the adsorbent, discharging unadsorbed components serving as raffinate, introducing a desorbent into the adsorbent, desorbing the adsorbed components to obtain extract liquid, wherein the adsorbent comprises 85-98 mass% of an X/Silicalite-1 core/shell molecular sieve and 2-15 mass% of a binder, the core of the X/Silicalite-1 core/shell molecular sieve is an X molecular sieve, the shell of the X/Silicalite-1 core/shell molecular sieve is a Silicalite-1 molecular sieve, the cation position of the X/Silicalite-1 core/shell molecular sieve is occupied by IIA group metal ions or occupied by IIA group metal ions and IA group metal ions, and the desorbent is C4～C5Alcohol of (1), C5～C6Is a ketone of (A) or is C4～C5Alcohol or C5～C6Ketone of (2) and C7～C10A mixture of alkanes.
2. The method of claim 1 wherein the group IIA metal ion is Mg2+、Ca2+、Sr2+Or Ba2 +。
3. The method of claim 1 wherein the group IA metal ion is Li+、Na+、K+、Rb+And Cs+At least one of (1).
4. The method of claim 1, wherein the X/Silicalite-1 core/shell molecular sieve core is SiO of the X molecular sieve2/Al2O3The molar ratio is 2.0-3.0.
5. The method according to claim 1, wherein the silica-1 shell layer thickness of the X/silica-1 core/shell molecular sieve is 30 to 800 nm.
6. The method of claim 1, wherein the binder is selected from the group consisting of kaolinite, dickite, nacrite, firestone, halloysite, and mixtures thereof.
7. The method of claim 1, wherein the adsorbent is in the form of pellets having an average particle size of 300 to 850 microns.
8. The process of claim 1, wherein the desorbent is C4～C5Alcohol or C5～C6Ketone of (2) and C7～C10Mixtures of alkanes, wherein C4～C5Alcohol or C5～C6The ketone content of (a) is 60 to 80 vol%.
9. The method of claim 1, wherein C is4～C5The alcohol is butanol, methyl butanol or pentanol, the C5～C6The ketone of (a) is 2-hexanone or 3-pentanone.
CN201810495848.4A 2018-05-22 2018-05-22 Method for separating p-cresol by liquid phase adsorption Active CN110511121B (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN201810495848.4A CN110511121B (en) 2018-05-22 2018-05-22 Method for separating p-cresol by liquid phase adsorption

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN201810495848.4A CN110511121B (en) 2018-05-22 2018-05-22 Method for separating p-cresol by liquid phase adsorption

Publications (2)

Publication Number Publication Date
CN110511121A CN110511121A (en) 2019-11-29
CN110511121B true CN110511121B (en) 2022-02-08

Family

ID=68621813

Family Applications (1)

Application Number Title Priority Date Filing Date
CN201810495848.4A Active CN110511121B (en) 2018-05-22 2018-05-22 Method for separating p-cresol by liquid phase adsorption

Country Status (1)

Country Link
CN (1) CN110511121B (en)

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN113457212A (en) * 2021-06-25 2021-10-01 中触媒新材料股份有限公司 Preparation and use method of trapping agent for simultaneously improving purity and chromaticity of m-methylphenol

Citations (11)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3014078A (en) * 1959-02-02 1961-12-19 Union Oil Co Separation of cresol isomers
GB902724A (en) * 1960-02-15 1962-08-09 Union Oil Co Separation of aromatic isomers
CN1448213A (en) * 2002-03-29 2003-10-15 中国石油化工股份有限公司 Adsorbent for adsorption stripping dimethyl benzene and its preparing process
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
CN104511183A (en) * 2013-09-29 2015-04-15 中国石油化工股份有限公司 Simulated moving bed adsorption separation method
CN104556094A (en) * 2013-10-22 2015-04-29 中国石油化工股份有限公司 Y/Silicalite-1 composite molecular sieve and preparation method thereof
CN104815612A (en) * 2015-04-28 2015-08-05 程志宇 Preparation method of molecular sieve adsorbent for metacresol and paracresol adsorption separation, and adsorbent prepared thereby
CN105542835A (en) * 2015-12-11 2016-05-04 中国海洋石油总公司 Method for adsorption separation of polycyclic aromatic hydrocarbons with simulated moving bed
WO2016164870A1 (en) * 2015-04-10 2016-10-13 Battelle Memorial Institute Bpa-free coatings
CN106943993A (en) * 2017-04-03 2017-07-14 上海复榆新材料科技有限公司 Separate zeolite adsorbent of paracresol and meta Cresol Isomeric Compound and preparation method thereof
CN107879900A (en) * 2017-12-22 2018-04-06 中触媒新材料股份有限公司 A kind of process of cresols mixed isomers separating-purifying

Family Cites Families (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US10000703B2 (en) * 2015-05-08 2018-06-19 Anellotech, Inc. Catalytic fast pyrolysis process

Patent Citations (11)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3014078A (en) * 1959-02-02 1961-12-19 Union Oil Co Separation of cresol isomers
GB902724A (en) * 1960-02-15 1962-08-09 Union Oil Co Separation of aromatic isomers
CN1448213A (en) * 2002-03-29 2003-10-15 中国石油化工股份有限公司 Adsorbent for adsorption stripping dimethyl benzene and its preparing process
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
CN104511183A (en) * 2013-09-29 2015-04-15 中国石油化工股份有限公司 Simulated moving bed adsorption separation method
CN104556094A (en) * 2013-10-22 2015-04-29 中国石油化工股份有限公司 Y/Silicalite-1 composite molecular sieve and preparation method thereof
WO2016164870A1 (en) * 2015-04-10 2016-10-13 Battelle Memorial Institute Bpa-free coatings
CN104815612A (en) * 2015-04-28 2015-08-05 程志宇 Preparation method of molecular sieve adsorbent for metacresol and paracresol adsorption separation, and adsorbent prepared thereby
CN105542835A (en) * 2015-12-11 2016-05-04 中国海洋石油总公司 Method for adsorption separation of polycyclic aromatic hydrocarbons with simulated moving bed
CN106943993A (en) * 2017-04-03 2017-07-14 上海复榆新材料科技有限公司 Separate zeolite adsorbent of paracresol and meta Cresol Isomeric Compound and preparation method thereof
CN107879900A (en) * 2017-12-22 2018-04-06 中触媒新材料股份有限公司 A kind of process of cresols mixed isomers separating-purifying

Non-Patent Citations (2)

* Cited by examiner, † Cited by third party
Title
间甲酚与对甲酚的分离研究;安颖;《CNKI优秀硕士学位论文全文库》;20060615;第B016-7页 *
间甲酚与对甲酚的分离精制;武海涛等;《天然气化工C1化学与化工》;20161231;第41卷;第78-90页 *

Also Published As

Publication number Publication date
CN110511121A (en) 2019-11-29

Similar Documents

Publication Publication Date Title
KR101597342B1 (en) Agglomerated zeolite adsorbent and preparation method thereof
RU2323775C2 (en) Agglomerated zeolite adsorbing materials, process to manufacture and application thereof
CN108264052B (en) X/ZSM-5 core/shell molecular sieve and preparation method thereof
CN112138628B (en) Composite layer coalescence type adsorbent and preparation method thereof
CN109692656B (en) Mesoporous Y zeolite, adsorbent and preparation method of adsorbent
US9162899B2 (en) BaX type Zeolite granule and process for preparing the same
CN110508240B (en) Preparation method of coalescence type adsorbent
CN109692659B (en) Binder-free spherical paraxylene adsorbent and preparation method thereof
CN111097370B (en) Spherical meta-xylene adsorbent and preparation method thereof
CN110511122B (en) Method for separating cresol isomer by liquid phase adsorption
CN108262004B (en) Paraxylene adsorbent and preparation method thereof
CN111097372B (en) Preparation method of m-xylene adsorbent
CN110511121B (en) Method for separating p-cresol by liquid phase adsorption
CN108262005B (en) Small ball adsorbent for adsorbing and separating p-xylene and preparation method thereof
CN109692657B (en) Mesoporous X zeolite, adsorbent and preparation method of adsorbent
CN110508241B (en) Coalescence type adsorbent and preparation method thereof
CN108525643B (en) Paraxylene adsorbent and preparation method thereof
CN110511118B (en) Method for separating paracresol by liquid phase adsorption
CN108525641B (en) Small ball adsorbent for adsorbing and separating p-xylene and preparation method thereof
CN111097371B (en) Preparation method of paraxylene adsorbent
TW202216284A (en) Meta-xylene adsorbate and preparation method therefor
CN112642391A (en) Coalescence type p-disubstituted benzene adsorbent and preparation method thereof
CN108525650B (en) X/Silicalite-1 core/shell molecular sieve and preparation method thereof
CN110871053B (en) Adsorbent for adsorbing and separating ethylbenzene and preparation method thereof
CN114425297B (en) Para-disubstituted benzene adsorbent and preparation method thereof

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