CN113351243B - Catalyst for producing m-cresol from o-cresol in isomeric mode and preparation method of catalyst - Google Patents

Catalyst for producing m-cresol from o-cresol in isomeric mode and preparation method of catalyst Download PDF

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CN113351243B
CN113351243B CN202110687668.8A CN202110687668A CN113351243B CN 113351243 B CN113351243 B CN 113351243B CN 202110687668 A CN202110687668 A CN 202110687668A CN 113351243 B CN113351243 B CN 113351243B
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CN113351243A (en
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吉向飞
赵晓强
曲令多
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Shanxi University
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    • 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
    • B01J29/00—Catalysts comprising molecular sieves
    • B01J29/04—Catalysts comprising molecular sieves having base-exchange properties, e.g. crystalline zeolites
    • B01J29/06—Crystalline aluminosilicate zeolites; Isomorphous compounds thereof
    • B01J29/40—Crystalline aluminosilicate zeolites; Isomorphous compounds thereof of the pentasil type, e.g. types ZSM-5, ZSM-8 or ZSM-11, as exemplified by patent documents US3702886, GB1334243 and US3709979, respectively
    • 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
    • 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
    • B01J2229/00—Aspects of molecular sieve catalysts not covered by B01J29/00
    • B01J2229/10—After treatment, characterised by the effect to be obtained
    • B01J2229/18—After treatment, characterised by the effect to be obtained to introduce other elements into or onto the molecular sieve itself
    • B01J2229/186—After treatment, characterised by the effect to be obtained to introduce other elements into or onto the molecular sieve itself not in framework positions
    • 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
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    • 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

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Abstract

The invention discloses a catalyst for producing m-cresol from o-cresol by isomerization, a preparation method thereof and application of the catalyst in the process of preparing m-cresol from o-cresol by isomerization. The catalyst comprises a Ca-ZSM-5 molecular sieve and a binder, wherein the content of the Ca-ZSM-5 molecular sieve is 60-90 wt% and the content of the binder is 10-40 wt% based on the weight of a dry catalyst base. Compared with the prior technical process for preparing m-cresol, the catalyst provided by the invention is used for the reaction for preparing m-cresol from o-cresol by isomerization, the selectivity of m-cresol is high, side reaction products are few, the stability is good, and the catalytic process is more environment-friendly compared with the prior process.

Description

Catalyst for producing m-cresol from o-cresol by isomerization and preparation method thereof
Technical Field
The invention belongs to the field of molecular sieves, and particularly relates to a catalyst for producing m-cresol from o-cresol in an isomeric manner, and a preparation method and application thereof.
Background
Hydroxyl, methyl and benzene rings of cresol can all react to generate a series of derivatives, which are important raw materials of fine chemical engineering and are mainly applied to the key fields of pesticides, medicines, dyes, spices, antioxidants and the like. With the development of domestic industrialization, the yield of m-cresol is seriously short of demand, and a large amount of m-cresol needs to be imported every year to maintain the operation of an industrial system, so that foreign m-cresol production enterprises are liable to sell at home, and the production environment of the domestic m-cresol production enterprises is seriously influenced.
At present, the methods for preparing m-cresol include natural separation method, toluene sulfonation alkali dissolution method, toluene chlorination hydrolysis method, phenol alkylation method, isopropyl toluene method, toluene direct oxidation and other chemical synthesis methods. Most chemical synthesis methods cannot be built and put into production in China due to various factors such as serious pollution, large technical difficulty, low economic benefit and the like, and the industrial production in China is realized at present by a toluene chlorination hydrolysis method, so that the method has a lot of byproducts and serious pollution, and the high-quality m-cresol monomer cannot be obtained. The p-chlorotoluene developed on the basis can be hydrolyzed to obtain the m-cresol and the p-cresol in a ratio of 1:1, but the method has harsh production process conditions and is not suitable for large-scale industrial production.
In order to solve many problems of m-cresol production process, a new m-cresol production process is proposed, namely, m-cresol is prepared by isomerizing o-cresol. US4503269, US4691063 reports a fixed bed isomerization catalyst having a total meta and para cresol selectivity of 50% and a catalytic performance which decreases gradually with the time of catalysis, and frequent regeneration or shutdown for catalyst replacement is required in industrial applications. Tianjin chemical industry (first 1994) reported HCl-AlCl 3 The catalyst is used for cresol isomerization reaction to obtain mixed cresol with m-cresol content up to 68%, but the method adopts batch production, so that the catalyst is complicated to recover, the energy consumption is high, and large-scale industrial production cannot be realized.
Disclosure of Invention
The invention aims to overcome the defects of the prior art and provides a catalyst for preparing m-cresol from o-cresol by isomerization, a preparation method thereof and application of the catalyst in the reaction for preparing m-cresol from o-cresol by isomerization. When the catalyst is used for the reaction of preparing m-cresol from o-cresol by isomerization, the m-cresol has high selectivity, less side reaction and good catalyst stability.
The invention provides a catalyst for preparing m-cresol from o-cresol by isomerization, which comprises the following components: ca-ZSM-5 molecular sieve and binder, the content of Ca-ZSM-5 molecular sieve is 60wt% -90 wt%, preferably 60wt% -85 wt% based on the dry weight of the catalyst; in the Ca-ZSM-5 molecular sieve, the content of Ca expressed by elements is 0.1wt percent to 1.5wt percent, and preferably 0.1wt percent to 1wt percent; siO 2 2 /Al 2 O 3 The molar ratio is from 100 to 400, preferably from 200 to 400.
The Ca-ZSM-5 molecular sieve is prepared by enriching Ca from ZSM-5 molecular sieve raw powder 2+ The solution exchange modification treatment is carried out, and the exchange modification conditions are as follows: ca 2+ Ca with a concentration of 0.1-1 mol/L 2+ The liquid-solid volume ratio of the solution to the ZSM-5 molecular sieve is 4: 1-6: 1, the temperature is 70-80 ℃, and the treatment time is 1-4 h.
The Ca 2+ The solution is one of calcium chloride, calcium oxalate, calcium acetate and calcium fluoride solution.
The preparation method of the catalyst provided by the invention comprises the following steps: uniformly mixing the Ca-ZSM-5 molecular sieve and the binder component, kneading, molding, drying and roasting to obtain the catalyst.
Sesbania powder can be added when the Ca-ZSM-5 molecular sieve and the binder component are uniformly mixed, and the addition amount of the sesbania powder is 0.5 to 5 percent of the total weight of the Ca-ZSM-5 molecular sieve and the binder component; the binder is silica sol or kaolin.
The drying and roasting conditions are as follows: the drying temperature is 60-120 ℃, and the drying time is 2-6 h; the roasting temperature is 500-550 ℃, and the roasting time is 4-6 h.
The catalyst is suitable for the catalytic process of preparing m-cresol from o-cresol by isomerization, and the operating conditions in the fixed bed process are as follows: the mass space velocity of o-cresol is 0.5-2 h -1 The reaction temperature is 350-380 deg.C, and the pressure is 0-1.0 MPa.
Compared with the prior art, the invention has the beneficial effects that: the catalyst is used in the process of preparing m-cresol from o-cresol by isomerization, the selectivity of m-cresol is as high as 89.64 percent, and the catalytic process is more green and pollution-free compared with the prior art.
Drawings
FIG. 1 is an X-ray diffraction pattern (XRD) of the ZSM-5 molecular sieve prepared (silica to alumina ratio of 200).
FIG. 2 is a Scanning Electron Microscope (SEM) image of the ZSM-5 molecular sieve prepared (silica to alumina ratio of 200).
FIG. 3 is an X-ray diffraction pattern (XRD) of the ZSM-5 molecular sieve prepared (silica to alumina ratio of 400).
FIG. 4 is a Scanning Electron Microscope (SEM) image of the ZSM-5 molecular sieve prepared (silica to alumina ratio of 400).
Detailed Description
The present invention will be described in further detail with reference to examples. Wherein, the wt% is mass percent.
Example 1:
SiO of ZSM-5 molecular sieve raw powder 2 /Al 2 O 3 The molar ratio is 200, and the following modification method is adopted: firstly, using CaCl with the concentration of 0.1mol/L for ZSM-5 molecular sieve raw powder 2 Aqueous solution exchange modification of CaCl 2 The liquid-solid volume ratio of the aqueous solution to the ZSM-5 molecular sieve raw material is 5:1, treating at 80 ℃ for 2h to obtain the Ca-ZSM-5 molecular sieve. XRD andSEM is shown in figure 1 and figure 2.
Adding 1wt% sesbania powder of the dry basis weight of the Ca-ZSM-5 molecular sieve and the silica sol into the Ca-ZSM-5 molecular sieve and the silica sol, kneading, extruding into strips, drying at 100 ℃ for 5h, and roasting at 550 ℃ for 4h to obtain the catalyst. Based on the weight of the catalyst, the content of the Ca-ZSM-5 molecular sieve is 70 percent, and the balance is silicon oxide.
The isomerization reaction of preparing m-cresol by isomerization of o-cresol adopts a toluene solution of o-cresol (the mass ratio of o-cresol to toluene is 1: 1.5g of catalyst sample is filled into a fixed bed reactor, the catalytic performance of the catalyst is evaluated, the reaction temperature is 380 ℃, the pressure is normal pressure, and the mass space velocity of the sample injection is 1h -1 The flow rate of the carrier gas was 20mL/min, and the results of the reaction evaluation are shown in Table 1 below,
Figure BDA0003125182250000031
as can be seen from the data in Table 1, the selectivity of m-cresol in the reaction for isomerizing o-cresol to m-cresol using the catalyst of the present invention was 87.53%. The catalyst of the invention has higher selectivity to m-cresol.
Example 2:
SiO of ZSM-5 molecular sieve raw powder 2 /Al 2 O 3 The molar ratio is 400, and the following modification method is adopted: firstly, using CaCl with the concentration of 0.1mol/L for ZSM-5 molecular sieve raw powder 2 Aqueous solution exchange modification of CaCl 2 The liquid-solid volume ratio of the aqueous solution to the ZSM-5 molecular sieve raw material is 5:1, treating at 80 ℃ for 2h to obtain the Ca-ZSM-5 molecular sieve. The XRD and SEM are shown in figure 3 and figure 4.
Adding sesbania powder which accounts for 1wt% of the dry basis weight of the Ca-ZSM-5 molecular sieve and the silica sol into the Ca-ZSM-5 molecular sieve and the silica sol, kneading, extruding, forming, drying at 100 ℃ for 5 hours, and roasting at 550 ℃ for 4 hours to obtain the catalyst. Based on the weight of the catalyst, the content of the Ca-ZSM-5 molecular sieve is 70 percent, and the balance is silicon oxide.
The reaction evaluation was carried out under the reaction conditions described in example 1, and the results of the reaction evaluation are shown in Table 2 below.
Figure BDA0003125182250000032
Figure BDA0003125182250000041
As can be seen from the data in Table 2, the selectivity of m-cresol in the reaction for preparing m-cresol from o-cresol is 89.53% by using the catalyst of the present invention. The catalyst of the present invention has high selectivity to m-cresol. The data in Table 1 show that the Ca-ZSM-5 molecular sieve with high silica-alumina ratio has higher m-cresol selectivity.
Comparative example 1
SiO of ZSM-5 molecular sieve raw powder 2 /Al 2 O 3 The molar ratio is 200, and the following modification method is adopted: firstly using 1mol/L NH for ZSM-5 molecular sieve raw powder 4 Aqueous Cl solution exchange modification, NH 4 The liquid-solid volume ratio of the Cl aqueous solution to the ZSM-5 molecular sieve raw material is 5:1, treating at 80 ℃ for 2H to obtain the H-ZSM-5 molecular sieve. The XRD and SEM are shown in figures 1 and 2.
Adding the H-ZSM-5 molecular sieve and silica sol into sesbania powder which accounts for 1wt% of the dry basis weight of the H-ZSM-5 molecular sieve and the silica sol, kneading, extruding into strips, drying at 100 ℃ for 5H, and roasting at 550 ℃ for 4H to obtain the catalyst. Based on the weight of the catalyst, the content of the ZSM-5 molecular sieve is 70 percent, and the balance is silicon oxide.
The evaluation reaction was carried out under the reaction conditions described in example 1, and the results of the reaction evaluation are shown in Table 3.
Figure BDA0003125182250000042
As can be seen from the data in Table 3, without using the catalyst of the present invention, the H-ZSM-5 molecular sieve catalyst with the same silica/alumina ratio is directly used, and the selectivity of m-cresol in the o-cresol isomerization reaction is 64.24%, which is far lower than 87.53% of the catalyst using the present invention.
Comparative example 2
SiO of ZSM-5 molecular sieve raw powder 2 /Al 2 O 3 The molar ratio is 400, and the following modification method is adopted: firstly using 1mol/L NH for ZSM-5 molecular sieve raw powder 4 Aqueous Cl solution exchange modification, NH 4 The liquid-solid volume ratio of the Cl aqueous solution to the ZSM-5 molecular sieve raw material is 5:1, treating for 2 hours at the treatment temperature of 80 ℃ to obtain the H-ZSM-5 molecular sieve. The XRD and SEM are shown in figure 3 and figure 4.
Adding sesbania powder which accounts for 1wt% of the dry basis weight of the H-ZSM-5 molecular sieve and the silica sol into the H-ZSM-5 molecular sieve and the silica sol, kneading, extruding, forming, drying at 100 ℃ for 5 hours, and roasting at 550 ℃ for 4 hours to obtain the catalyst. Based on the weight of the catalyst, the content of the ZSM-5 molecular sieve is 70 percent, and the rest is silicon oxide.
The evaluation reaction was carried out under the reaction conditions described in example 1, and the results of the reaction evaluation are shown in Table 4.
Figure BDA0003125182250000051
As can be seen from the data in Table 4, without using the catalyst of the present invention, the H-ZSM-5 molecular sieve catalyst with the same silica/alumina ratio was directly used, and the selectivity of m-cresol in the o-cresol isomerization reaction was 79.17%, which is lower than 89.64% of that of the catalyst directly used.

Claims (9)

1. The application of a catalyst in the reaction of isomerizing o-cresol to m-cresol is characterized in that the catalyst comprises the following components: the Ca-ZSM-5 molecular sieve and the adhesive, the content of the Ca-ZSM-5 molecular sieve is 60wt percent to 90wt percent based on the dry weight of the catalyst;
the Ca-ZSM-5 molecular sieve contains Ca 0.1-1.5 wt% and SiO 2 /Al 2 O 3 The molar ratio is 100-400.
2. The use according to claim 1, wherein the catalyst comprises 60wt% to 85wt% of the Ca-ZSM-5 molecular sieve based on the total dry content of the catalyst.
3. Use according to claim 1, wherein said Ca is present in an amount of 0.1 to 1% by weight expressed as element.
4. Use according to claim 1, wherein said SiO is 2 /Al 2 O 3 The molar ratio is 200-400.
5. The use of claim 1, wherein the Ca-ZSM-5 molecular sieve is prepared by enriching Ca in ZSM-5 molecular sieve raw powder 2+ The solution exchange modification treatment is carried out, and the exchange modification conditions are as follows: ca 2+ The concentration is 0.1-1 mol/L, ca 2+ The liquid-solid volume ratio of the solution to the ZSM-5 molecular sieve is 4: 1-6: 1, the temperature is 70-80 ℃, and the treatment time is 1-4 h.
6. Use according to claim 5, characterized in that said Ca 2+ The solution is one of calcium chloride, calcium oxalate, calcium acetate and calcium fluoride solution.
7. The use of any one of claims 1 to 6, wherein the catalyst is prepared by a process comprising the steps of: uniformly mixing the Ca-ZSM-5 molecular sieve and the binder component, kneading, molding, drying and roasting to obtain the catalyst.
8. The use according to claim 7, wherein sesbania powder is added when the Ca-ZSM-5 molecular sieve and the binder component are uniformly mixed, and the addition amount of the sesbania powder is 0.5 to 5 weight percent of the total weight of the Ca-ZSM-5 molecular sieve and the binder component on a dry basis; the binder is silica sol or kaolin.
9. Use according to claim 7, characterized in that the drying and baking conditions are: the drying temperature is 60-120 ℃, and the drying time is 2-6 h; the roasting temperature is 500-550 ℃, and the roasting time is 4-6 h.
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Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE2804537A1 (en) * 1978-02-03 1979-08-09 Union Rheinische Braunkohlen METHOD OF CATALYTIC ISOMERIZATION OF O-KRESOL
CN101966467A (en) * 2010-09-27 2011-02-09 同济大学 Catalyst for C8 aromatics isomerization reaction technology and preparation method thereof

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GB2012271B (en) * 1978-01-03 1982-07-07 Union Rheinische Braunkohlen Catalytic isomerisation process
US7041774B2 (en) * 2003-09-30 2006-05-09 General Electric Company Functionalized zeolite compositions and methods for their preparation and use
WO2014101374A1 (en) * 2012-12-25 2014-07-03 中国科学院大连化学物理研究所 A process for the production of cresol
CN103341363B (en) * 2013-07-25 2016-05-18 北京旭阳化工技术研究院有限公司 Movable bed catalyst of M-and P-cresols and preparation method thereof is prepared in orthoresol isomerization
CN104923293B (en) * 2015-06-17 2017-08-22 湖南长岭石化科技开发有限公司 Orthoresol isomerization catalyst, its preparation method and the method that M-and P-cresols is catalyzed and synthesized using it

Patent Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE2804537A1 (en) * 1978-02-03 1979-08-09 Union Rheinische Braunkohlen METHOD OF CATALYTIC ISOMERIZATION OF O-KRESOL
CN101966467A (en) * 2010-09-27 2011-02-09 同济大学 Catalyst for C8 aromatics isomerization reaction technology and preparation method thereof

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