CN112934246A - Catalyst, preparation method thereof and synthesis method of diphenylamine - Google Patents

Catalyst, preparation method thereof and synthesis method of diphenylamine Download PDF

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CN112934246A
CN112934246A CN202110183933.9A CN202110183933A CN112934246A CN 112934246 A CN112934246 A CN 112934246A CN 202110183933 A CN202110183933 A CN 202110183933A CN 112934246 A CN112934246 A CN 112934246A
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catalyst
diphenylamine
lewis acid
aniline
bed reactor
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CN112934246B (en
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庞博湛
常贻文
孙春光
范小鹏
王利军
李海平
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Rianlon Corp
Rianlon Zhuhai New Material Co ltd
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Rianlon Corp
Rianlon Zhuhai New Material Co ltd
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    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
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    • B01J27/00—Catalysts comprising the elements or compounds of halogens, sulfur, selenium, tellurium, phosphorus or nitrogen; Catalysts comprising carbon compounds
    • B01J27/06—Halogens; Compounds thereof
    • B01J27/125—Halogens; Compounds thereof with scandium, yttrium, aluminium, gallium, indium or thallium
    • 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
    • B01J27/00—Catalysts comprising the elements or compounds of halogens, sulfur, selenium, tellurium, phosphorus or nitrogen; Catalysts comprising carbon compounds
    • B01J27/06—Halogens; Compounds thereof
    • B01J27/128—Halogens; Compounds thereof with iron group metals or platinum group metals
    • 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
    • B01J31/00—Catalysts comprising hydrides, coordination complexes or organic compounds
    • B01J31/02—Catalysts comprising hydrides, coordination complexes or organic compounds containing organic compounds or metal hydrides
    • B01J31/0215—Sulfur-containing compounds
    • B01J31/0225—Sulfur-containing compounds comprising sulfonic acid groups or the corresponding salts
    • B01J31/0227—Sulfur-containing compounds comprising sulfonic acid groups or the corresponding salts being perfluorinated, i.e. comprising at least one perfluorinated moiety as substructure in case of polyfunctional compounds
    • 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
    • B01J37/00—Processes, in general, for preparing catalysts; Processes, in general, for activation of catalysts
    • B01J37/0009—Use of binding agents; Moulding; Pressing; Powdering; Granulating; Addition of materials ameliorating the mechanical properties of the product catalyst
    • 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
    • B01J37/00—Processes, in general, for preparing catalysts; Processes, in general, for activation of catalysts
    • B01J37/02—Impregnation, coating or precipitation
    • B01J37/0201—Impregnation
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    • C07C209/00—Preparation of compounds containing amino groups bound to a carbon skeleton
    • C07C209/60—Preparation of compounds containing amino groups bound to a carbon skeleton by condensation or addition reactions, e.g. Mannich reaction, addition of ammonia or amines to alkenes or to alkynes or addition of compounds containing an active hydrogen atom to Schiff's bases, quinone imines, or aziranes
    • C—CHEMISTRY; METALLURGY
    • C07—ORGANIC CHEMISTRY
    • C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
    • C07C209/00—Preparation of compounds containing amino groups bound to a carbon skeleton
    • C07C209/82—Purification; Separation; Stabilisation; Use of additives
    • C07C209/84—Purification
    • 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
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    • Y02P20/10—Process efficiency

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Abstract

The invention provides a catalyst, a preparation method thereof and a synthesis method of diphenylamine. The preparation method of the catalyst comprises the following steps: supporting a lewis acid on a first support; and firing and forming the first carrier loaded with the Lewis acid and the ceramic powder to obtain the catalyst. The Lewis acid can catalyze aniline to synthesize diphenylamine, and the Lewis acid is firstly supported on a first carrier and then is fired and formed with ceramic powder, so that the distribution uniformity of the Lewis acid in the catalyst is improved, and the catalyst has a porous structure. The catalyst has the dual functions of the packing of the rectifying tower and the catalyst of the fixed bed, and can be applied to the industrial process of preparing diphenylamine by continuous reactive distillation of aniline. The catalyst is used as filler and added into a reactor to couple the synthesis reaction and the separation process of diphenylamine so as to realize the rectification process in the continuous reaction process, thereby simplifying the preparation process of diphenylamine and improving the yield of diphenylamine.

Description

Catalyst, preparation method thereof and synthesis method of diphenylamine
Technical Field
The invention relates to the field of diphenylamine synthesis, and particularly relates to a catalyst, a preparation method thereof and a synthesis method of diphenylamine.
Background
The prior document (CN87107052.9) provides a method for preparing diphenylamine by contacting aniline with an alumina catalyst at about 380-475 ℃.
The prior document CN95103700.5 provides a method for synthesizing diphenylamine from aniline, which comprises using aniline as raw material, reacting in hydrogen and beta-zeolite/Al2O3The method for synthesizing diphenylamine in the presence of a catalyst adopts a lower feeding mode, the reaction temperature is 250-400 ℃, the reaction pressure is 1.5-4.5MPa, and the aniline feeding airspeed is 0.05-1.0h-1And the volume ratio of the hydrogen to the aniline is 20-600. Under the condition, the diphenylamine content in the product is above 22%, and the by-product content is 0.5%, and the liquid reaction product and reaction are undergone the processes of gas-liquid separation, water absorption deamination and hydrogen drying under the reaction pressureThe generated ammonia and hydrogen are separated from each other, and the hydrogen is recycled.
The prior document (CN02112535.X) provides a method for synthesizing diphenylamine from aniline by adding nitrogen into a reactor, which comprises the following process steps in sequence: metering aniline, namely metering an aniline raw material through an aniline metering tank, a metering pump and a nitrogen buffer bag and feeding the aniline raw material into an aniline heater; heating aniline, and heating the metered aniline raw material to 330-370 ℃; reacting, namely arranging heated raw material aniline in a reactor filled with a catalyst, adding nitrogen into the reactor, wherein the pressure in the reactor is 1.6-2.5MPa, the air-speed ratio of the aniline and the catalyst is 0.15-0.2/h, and the temperature is 320-360 ℃, and then cooling by a raw material product heat exchanger to ensure that the temperature is below 150 ℃.
The prior document (chinese patent 201110058065.8) provides a preparation method of diphenylamine compounds, which comprises directly synthesizing diphenylamine compounds from aniline compounds and phenol compounds under high temperature and high pressure conditions and in the presence of catalytic amounts of cyclohexanone and a metal catalyst by an in-system condensation-dehydrogenation-hydrogenation process.
The prior document (chinese patent 201110313288.4) provides a method for continuously synthesizing diphenylamine from aniline, wherein aniline raw material is contacted with hydrogen before entering a reactor, so that hydrogen is dissolved in aniline raw material, the aniline raw material dissolved with hydrogen enters a reactor for continuously synthesizing diphenylamine from aniline, and the reaction for synthesizing diphenylamine from aniline is carried out through a catalyst bed layer, and no gas-phase hydrogen exists in the catalyst bed layer.
The reaction temperature of the disclosed diphenylamine synthesis method is 380-475 ℃ higher in some cases; adding hydrogen in some cases; some need to add nitrogen in the reaction process, and need follow-up ammonia recovery process and need constantly discharge noncondensable tail gas, and continuous discharge noncondensable tail gas is inevitable to carry with the ammonia and discharges.
In view of the above problems, it is necessary to provide a method for synthesizing diphenylamine, which has mild reaction conditions, high diphenylamine yield and low energy consumption.
Disclosure of Invention
The invention mainly aims to provide a catalyst, a preparation method thereof and a diphenylamine synthesis method, and aims to solve the problems of harsh reaction conditions, low diphenylamine yield and high energy consumption in the conventional diphenylamine synthesis process.
In order to achieve the above object, an aspect of the present invention provides a method for preparing a catalyst, the method comprising: supporting a lewis acid on a first support; and firing and forming the first carrier loaded with the Lewis acid and the ceramic powder to obtain the catalyst.
Further, the lewis acid is one or more selected from the group consisting of polyaluminium chloride, aluminium trichloride, ferric trichloride, titanium tetrachloride, lanthanum triflate, cerium triflate and scandium triflate; the first carrier is selected from one or more of the group consisting of montmorillonite, kaolin, bentonite and diatomaceous earth.
Further, in the step of firing and forming, the amount of the first carrier loaded with the lewis acid is 2-5% by weight of the catalyst, and the loading amount of the lewis acid on the first carrier is 0.3-0.5 mmol/g; preferably, the amount of the first carrier loaded with the Lewis acid is 3-4% by weight of the catalyst, and the loading amount of the Lewis acid on the first carrier is 0.3-0.4 mmol/g.
Furthermore, the temperature in the firing and forming process is 500-1200 ℃, and the firing time is 1-10 h.
In another aspect, the present application also provides a catalyst, which has a porous corrugated plate structure and is prepared by the above preparation method provided in the present application.
Furthermore, the catalyst is formed by laminating a plurality of corrugated plates, and the specific surface area is 100-500 m2/Kg。
In another aspect of the present application, there is provided a method for synthesizing diphenylamine, comprising: the catalyst provided by the application is loaded into a fixed bed reactor, and aniline is subjected to condensation reaction and rectification in the fixed bed reactor to obtain diphenylamine.
Further, in the fixed bed reactor, the feeding tower plate is positioned at the 1/3-1/2 height of the fixed bed reactorN is 5-7, preferably n is 6; the feeding hourly space velocity of the aniline is 0.01-0.05 h-1Preferably 0.02 to 0.04h-1More preferably 0.03h-1。
Further, diphenylamine is produced from the bottom of the fixed reactor or from a side draw-off outlet of the fixed reactor; preferably, the trays with the side draw outlets are distributed at the height of 1/5-1/4 of the fixed bed reactor and are positioned at theoretical trays n-1, 3 and 5, and more preferably n-3.
Further, the temperature of the condensation reaction is 320-370 ℃; the absolute pressure at the top of the tower is 150-2000 kPa, and the reflux ratio is (0.1-15): 1.
by applying the technical scheme of the invention, the Lewis acid is loaded on the first carrier and then is fired and formed with the ceramic powder, so that the distribution uniformity of the Lewis acid in the catalyst is improved; on the other hand, the ceramic powder has better thermoplasticity and dispersibility, the ceramic powder can be melted in the firing and forming process, so that the catalyst is convenient to be plasticized, and the catalyst can be fired and formed to form the corrugated plate layer catalyst with a porous structure. The catalyst has the dual functions of the packing of the rectifying tower and the catalyst of the fixed bed, and can be applied to the industrial process of preparing diphenylamine by continuous reactive distillation of aniline. The catalyst has more catalytic sites, the loading concentration and the number of the catalytic sites are convenient to adjust, and the catalyst can be conveniently adjusted according to the process conditions. And the catalyst has high structural regularity and strength, and can be conveniently installed and detached in a reactor.
Drawings
The accompanying drawings, which are incorporated in and constitute a part of this application, illustrate embodiments of the invention and, together with the description, serve to explain the invention and not to limit the invention. In the drawings:
FIG. 1 shows a process flow diagram for the preparation of diphenylamine provided in accordance with a preferred embodiment of the present invention;
FIG. 2 shows a process flow diagram for the preparation of diphenylamine provided in accordance with another preferred embodiment of the present invention;
FIG. 3 shows an outline of the catalyst 1 obtained in catalyst preparation example 1 according to the present invention.
Detailed Description
It should be noted that the embodiments and features of the embodiments in the present application may be combined with each other without conflict. The present invention will be described in detail with reference to examples.
As described in the background art, the existing diphenylamine synthesis process has the problems of harsh reaction conditions, low diphenylamine yield and high energy consumption. In order to solve the above technical problems, the present application provides a method for preparing a catalyst, the method comprising: supporting a lewis acid on a first support; and firing and forming the first carrier loaded with the Lewis acid and the ceramic powder to obtain the catalyst.
In the application, the Lewis acid is loaded on the first carrier and then is fired and formed with the ceramic powder, so that the distribution uniformity of the Lewis acid in the catalyst is improved; on the other hand, the ceramic powder has better thermoplasticity and dispersibility, the ceramic powder can be melted in the firing and forming process, so that the catalyst is convenient to be plasticized, and the catalyst can be fired and formed to form the corrugated plate layer catalyst with a porous structure. The catalyst has the dual functions of the packing of the rectifying tower and the catalyst of the fixed bed, and can be applied to the industrial process of preparing diphenylamine by continuous reactive distillation of aniline. The catalyst has more catalytic sites, the loading concentration and the number of the catalytic sites are convenient to adjust, and the catalyst can be conveniently adjusted according to the process conditions. And the catalyst has high structural regularity and strength, and can be conveniently installed and detached in a reactor.
In the above preparation method, the lewis acid may be selected from those commonly used in the art. Preferably, the lewis acid includes, but is not limited to, one or more of the group consisting of polyaluminum chloride, aluminum trichloride, ferric trichloride, titanium tetrachloride, lanthanum triflate, cerium triflate and scandium triflate. The Lewis acids can form a reaction active center with aniline, which is beneficial to improving the selectivity of diphenylamine, and further improving the yield of diphenylamine.
In the above-mentioned preparation method, the first carrier may be of a kind commonly used in the art. In a preferred embodiment, the first carrier includes, but is not limited to, one or more of the group consisting of montmorillonite, kaolin, bentonite, and diatomaceous earth. The carriers have strong adsorption capacity and dispersibility, and the adoption of the carriers is favorable for flexibly adjusting the content of Lewis acid in the catalyst and the number of catalyst sites, so that the catalytic activity of the catalyst is further improved. The method of supporting the lewis acid on the first support may be a method commonly used in the art, for example, the first support may be sufficiently impregnated with an aqueous solution of the lewis acid, filtered, and dried.
In the firing molding step, the amount of the first carrier and the supported amount of the lewis acid in the catalyst may be adjusted as needed. In order to better improve the catalytic activity of the catalyst, preferably, in the firing forming step, the amount of the first support loaded with the lewis acid is 2 to 5% by weight of the weight percentage of the catalyst, and the loading amount of the lewis acid on the first support is 0.3 to 0.5 mmol/g. More preferably, the amount of the first carrier loaded with the lewis acid is 3 to 4 percent based on the weight percentage of the catalyst, and the loading amount of the lewis acid on the first carrier is 0.3 to 0.4 mmol/g.
The ceramic powder has better thermoplasticity and dispersibility, and in the firing and forming process, the ceramic powder can be melted and fired with the first carrier loaded with the Lewis acid, so that the catalyst is convenient to plasticize. In a preferred embodiment, the temperature of the firing forming process is 500-1200 ℃, and the firing time is 1-10 h. The temperature of the firing and forming process is limited in the range, so that the ceramic powder can form molten liquid, and the impurities in the first carrier and the ceramic powder can be decomposed due to the influence of the impurity content in the catalyst on the catalytic activity of the ceramic powder, so that the catalytic activity and the reaction selectivity of the catalyst can be improved, and the yield of diphenylamine can be improved.
In another aspect of the present application, there is provided a catalyst having a corrugated plate structure with pores, and prepared by the above preparation method.
The Lewis acid can catalyze aniline to synthesize diphenylamine, and the Lewis acid is loaded on the first carrier and then is fired and molded with ceramic powder, so that the distribution uniformity of the Lewis acid in the catalyst is improved, and in the application process, the catalyst is added into a reactor as a filler, the diphenylamine synthesis reaction and the separation process of the diphenylamine synthesis reaction can be coupled, and the rectification process is simultaneously realized in the continuous reaction process, so that the preparation process of diphenylamine is greatly simplified, and the yield of diphenylamine is improved. Meanwhile, the whole preparation condition is mild, and the raw material cost and the energy consumption are relatively low. Simultaneously, the catalyst provided by the application is a monolithic catalyst, so that the replacement process is more convenient.
In a preferred embodiment, the catalyst is formed by laminating a plurality of corrugated plates, and the specific surface area of the catalyst is 100-500 m2Per Kg, in a specific example the specific surface area may be 200m2/Kg、300m2/Kg、400m2Perkg. Compared with other structures, the corrugated plate type ceramic plate has a large specific surface area, is convenient to prepare, and has a good liquid holdup in the reaction process, so that the catalytic effect is further improved, and the yield of diphenylamine is improved.
Yet another aspect of the present application also provides a method for synthesizing diphenylamine, comprising: the catalyst is loaded into a fixed bed reactor, and aniline is subjected to condensation reaction and rectification in the fixed bed reactor to obtain diphenylamine.
The catalyst prepared by the method is used in the process of preparing diphenylamine by aniline condensation, and can couple the synthesis reaction of diphenylamine and the separation process of diphenylamine so as to realize the rectification process while condensing, thereby greatly simplifying the preparation process of diphenylamine and improving the yield of diphenylamine. And the whole preparation condition is mild, and the raw material cost and the energy consumption are relatively low.
The above-mentioned corrugated plate type monolithic catalyst is generally used as a packing material of a reactor in such a manner that a plurality of corrugated plates are stacked in layers during use.
In the synthesis process of the diphenylamine, diphenylamine is produced from the bottom of the fixed reactor or from a side line extraction outlet of the fixed reactor.
In a preferred embodiment, shown in fig. 1, diphenylamine is produced from the bottom of a fixed reactor, and the diphenylamine synthesis method specifically comprises the following steps: aniline enters a fixed reactor after being preheated, and then aniline steam goes upward to pass through a catalyst bed layer to realize conversion, and part of the aniline steam is converted into diphenylamine; the produced low boiling point component is separated from diphenylamine and phenylamine on the catalyst bed layer, the light component by-product is extracted from tower top, and the mixture of diphenylamine and heavy component is extracted from tower bottom. And leading the tower top material out of the system through a gas-liquid separator. The light component by-products include, but are not limited to, 2-methylpyridine and one or more of aniline and diphenylamine. The recombination component is divided into mixed polycyclic aromatic ammonia compounds, including but not limited to one or more of diphenylamine, benzoquinoline, 2, 6-dimethyldiphenylamine, 4-isopropyldiphenylamine, 4 '-diisopropyldiphenylamine, triphenylamine, 2', 6,6 '-tetramethyltriphenylamine and 4, 4' -diisopropyltriphenylamine.
In another preferred embodiment, as shown in fig. 2, diphenylamine is withdrawn from the side-draw of the fixed reactor, and the synthesis method of diphenylamine specifically comprises: aniline enters a main reactor after being preheated, and then aniline steam ascends through a catalyst bed layer to realize conversion, and part of the aniline steam is converted into diphenylamine; the produced low boiling point component is separated from diphenylamine and phenylamine on the catalyst bed layer, and a light component byproduct is extracted from the tower top; a diphenylamine product is extracted from a side line extraction outlet below the feeding tower plate; and heavy component mixture is extracted from the bottom of the tower.
It should be noted that, in the process of synthesizing diphenylamine, the preheating process of aniline is an optional step.
The light component by-products include, but are not limited to, 2-methylpyridine and one or more of aniline and diphenylamine. The above-mentioned components are mixed polycyclic aromatic ammonia compounds, including but not limited to diphenylamine, benzoquinoline, 2, 6-dimethyldiphenylamine, 4-isopropyldiphenylamine, 4 '-diisopropyldiphenylamine, triphenylamine, 2', 6,6 '-tetramethyltriphenylamine and/or 4, 4' -diisopropyltriphenylamine.
In a preferred embodiment, in the fixed bed reactor, the feeding tray is located at the height of 1/3-1/2 of the fixed bed reactor, and is located at theoretical tray n-5-7, preferably n-6; the feeding hourly space velocity of the aniline is 0.01-0.05 h-1Preferably 0.02 to 0.04h-1More preferably 0.03h-1. The position of the feeding tower plate and the feeding hourly space velocity are limited in the range, so that the concentration of the fed materials is close to the concentration near the tower plate, the risk of material back mixing can be reduced, the rectification efficiency is improved, the separation degree of diphenylamine and other components is improved, and the purity of diphenylamine is improved.
In a preferred embodiment, in the fixed bed reactor, the trays where the side draw is located are distributed at the height of 1/5-1/4 of the fixed bed reactor and are located at theoretical trays n-1, 3 and 5. The composition of the product discharged from the position is stable, so that the diphenylamine product discharged from the position is beneficial to controlling the stability of the product quality. More preferably, the draw-off position is at theoretical plate n-3.
In the rectification process, the absolute pressure, the temperature and the reflux ratio in the working conditions of the tower top are controlled to be beneficial to improving the separation rate of diphenylamine, and preferably, in a preferred embodiment, the absolute pressure of the tower top of the fixed bed reactor is 150-2000 kPa, the temperature is 146-282 ℃, and the reflux ratio is (0.1-15): 1; preferably, the absolute pressure at the top of the fixed bed reactor is 500-1500 kPa, and the temperature is 200-263 ℃; more preferably, the absolute pressure at the top of the fixed bed reactor is 800-1000 kPa, and the temperature is 225-238 ℃.
In order to further improve the reaction rate of the diphenylamine synthesis reaction and the separation rate of diphenylamine, preferably, the catalyst is filled in the fixed bed reactor in 1-5 sections, and more preferably in 3-4 sections; with or without a liquid redistributor between each segment.
In a preferred embodiment, the condensation reaction is carried out at a temperature of 320 to 370 ℃.
The present application is described in further detail below with reference to specific examples, which should not be construed as limiting the scope of the invention as claimed.
Catalyst preparation examples
Example 1
The montmorillonite is dipped in 5 percent aqueous solution of polyaluminium chloride at room temperature and stirred slowly for 1 h. Filtering, drying the filter residue at 150 ℃ to obtain the loaded montmorillonite, wherein the detected load is 0.3 mmol/g. Adding the loaded montmorillonite into the ceramic powder according to the weight percentage of 2 percent to prepare the ceramic corrugated plate, wherein the temperature in the firing and forming process is 500 ℃, the firing time is 10 hours, and the specific surface area is 500m2Per Kg, denoted as catalyst 1. Fig. 3 is an outline view of the catalyst 1.
Example 2
At room temperature, montmorillonite was immersed in an 8% by mass aqueous solution of cerium trifluoromethanesulfonate, and stirred slowly for 1 h. Filtering, drying the filter residue at 150 ℃ to obtain the loaded montmorillonite, wherein the detected load is 0.5 mmol/g. Adding the loaded montmorillonite into the ceramic powder according to the weight percentage of 4 percent to prepare the ceramic corrugated plate, wherein the temperature in the firing and forming process is 1000 ℃, the firing time is 1h, and the specific surface area is 400m2Per Kg, denoted as catalyst 2.
Example 3
The montmorillonite was immersed in a 5% aqueous solution of scandium triflate at room temperature and stirred slowly for 1 h. Filtering, drying the filter residue at 150 ℃ to obtain the loaded montmorillonite, wherein the detected load is 0.4 mmol/g. Adding the loaded montmorillonite into the ceramic powder according to the weight percentage of 5 percent to prepare a ceramic corrugated plate, wherein the temperature in the firing and forming process is 800 ℃, the firing time is 3 hours, and the specific surface area is 300m2Per Kg, noted as catalyst 3.
Example 4
The montmorillonite is dipped in 8 percent ferric trichloride aqueous solution at room temperature and slowly stirred for 1 hour. Filtering, drying the filter residue at 150 ℃ to obtain the loaded montmorillonite, wherein the detected load is 0.5 mmol/g. Adding the loaded montmorillonite into the ceramic powder according to the weight percentage of 4 percent to prepare the ceramic corrugated plate, wherein the temperature in the firing and forming process is 600 ℃, the firing time is 8 hours, and the specific surface area is 200m2Per Kg, denoted as catalyst 4.
Example 5
The montmorillonite is dipped in 5 percent aqueous solution of polyaluminium chloride at room temperature and stirred slowly for 1.5 h. Filtering, drying the filter residue at 150 ℃ to obtain the loaded montmorillonite, wherein the detected load is 0.4 mmol/g. Adding the loaded montmorillonite into the ceramic powder according to the weight percentage of 5 percent to prepare the ceramic corrugated plate, wherein the temperature in the firing and forming process is 500 ℃, the firing time is 10 hours, and the specific surface area is 100m2Per Kg, denoted as catalyst 5.
Synthesis of diphenylamine-side draw example:
examples 1 to 1
3 sections of catalyst are filled in a fixed bed reactor, the filling amount is 670.3g/L, the catalyst is corrugated plate ceramic (catalyst 1) added with 2 percent of montmorillonite loaded aluminum chloride, and a liquid redistributor is added between each section.
The feed space velocity is set to 0.03h-1Aniline preheated to 200 ℃ is fed from a theoretical plate n-6, the reaction temperature is 340 ℃, the absolute pressure at the top of the tower is controlled at 900kPa, and the reflux ratio is 15: 1. Respectively taking out from three side lines of theoretical plate n-1, 3 and 5. After the system was operated stably, the compositions of the materials at the top, side and bottom were measured as shown in Table 1 below.
TABLE 1
Figure BDA0002942834710000071
The calculated conversion rate is 99%, the diphenylamine selectivity is 97-98%, and the conversion rate is not reduced obviously after the continuous operation for 720 hours.
Examples 1 to 2
3 sections of catalyst are filled in the fixed bed reactor, the filling amount is 670.3g/L, and the catalyst is corrugated plate ceramic added with 2 percent of montmorillonite supported aluminum chloride (catalyst 1).
The feed space velocity is set to 0.05h-1Aniline preheated to 200 ℃ is fed from a theoretical plate n-5, the reaction temperature is 340 ℃, the absolute pressure at the top of the tower is controlled at 2000kPa, and the reflux ratio is 15: 1. Respectively taking out from three side lines of theoretical plate n-1, 3 and 5. After the system is stably operated, the measuring towerThe composition of the top, side and bottom streams is shown in Table 2.
TABLE 2
Figure BDA0002942834710000081
The calculated conversion rate is 96 percent, the diphenylamine selectivity is 96 percent, and the conversion rate is not obviously reduced after the continuous operation for 720 hours.
Examples 1 to 3
The catalyst of 5 sections is filled in the fixed bed reactor, the filling amount is 670.3g/L, the catalyst is corrugated plate ceramic (catalyst 1) added with 2 percent of montmorillonite loaded aluminum chloride, and a liquid redistributor is added between each section. The feed space velocity is set to 0.02h-1Aniline preheated to 200 ℃ is fed from a theoretical plate n-7, the reaction temperature is 340 ℃, the absolute pressure at the top of the column is controlled at 150kPa, and the reflux ratio is 15: 1. Respectively taking out from three side lines of theoretical plate n-1, 3 and 5. After the system was operated stably, the compositions of the materials at the top, side and bottom were measured as shown in Table 3.
TABLE 3
Figure BDA0002942834710000082
Figure BDA0002942834710000091
The calculated conversion rate is 91 percent, the diphenylamine selectivity is 93 percent, and the conversion rate is not obviously reduced after the continuous operation for 720 hours.
Examples 1 to 4
3 sections of catalyst are filled in the fixed bed reactor, the filling amount is 670.3g/L, the catalyst is corrugated plate ceramic (catalyst 5) added with 2 percent of montmorillonite loaded aluminum chloride, and a liquid redistributor is added between the two sections. The feed space velocity is set to 0.04h-1Aniline preheated to 200 ℃ is fed from a theoretical plate n-6, the reaction temperature is 340 ℃, the absolute pressure at the top of the column is controlled at 500kPa, and the reflux ratio is 15: 1. From three sides of theoretical plate n ═ 1,3 and 5And (6) line extraction. After the system was operated stably, the compositions of the materials at the top, side and bottom were measured as shown in Table 4.
TABLE 4
Figure BDA0002942834710000092
The calculated conversion rate is 95 percent, the diphenylamine selectivity is 94 percent, and the conversion rate is not obviously reduced after the continuous operation for 720 hours.
Examples 1 to 5
A fixed bed reactor is filled with 4 sections of catalyst (catalyst 1), the filling amount is 670.3g/L, the catalyst is corrugated plate ceramic added with 2 percent of montmorillonite loaded aluminum chloride, and a liquid redistributor is added between each section. The feed space velocity is set to 0.02h-1Aniline preheated to 200 ℃ is fed from a theoretical plate n-5, the reaction temperature is 340 ℃, the absolute pressure of the top of the tower is controlled at 1500kPa, and the reflux ratio is 15: 1. Respectively taking out from three side lines of theoretical plate n-1, 3 and 5. After the system was operated stably, the compositions of the materials at the top, side and bottom were measured as shown in Table 5.
TABLE 5
Figure BDA0002942834710000101
The calculated conversion rate is 98 percent, the diphenylamine selectivity is 92 percent, and the conversion rate is not obviously changed after the continuous operation for 720 hours.
Examples 1 to 6
The differences from example 1-1 are: corrugated plate ceramic with 5% cerium trifluoromethanesulfonate added in catalyst and specific surface area of 400m2Perkg (catalyst 2).
The calculated conversion rate is 92%, the diphenylamine selectivity is 93%, and the conversion rate has no obvious change after the continuous operation for 720 hours.
Examples 1 to 7
The differences from example 1-1 are: the amount of the first carrier supporting the Lewis acid added to the catalyst was 4%, and the amount of the Lewis acid supported on the first carrier was 0.4 mmol/g.
The calculated conversion rate is 99 percent, the diphenylamine selectivity is 98 percent, and the conversion rate is not obviously changed after the continuous operation for 720 hours.
Examples 1 to 8
The differences from example 1-1 are: the feeding space velocity of the aniline is 0.03h-1The feed tray n is 6, the reaction temperature is 330 ℃, the reaction pressure is 1000KPa, and the reflux ratio is 8: 1.
The calculated conversion rate is 99 percent, the diphenylamine selectivity is 98 percent, and the conversion rate is not obviously changed after the continuous operation for 720 hours.
Examples 1 to 9
The differences from example 1-1 are: corrugated plate ceramic with 5% scandium trifluoromethanesulfonate added in catalyst and with specific surface area of 300m2Perkg (catalyst 3).
The calculated conversion rate is 94 percent, the diphenylamine selectivity is 94 percent, and the conversion rate is not obviously changed after the continuous operation for 720 hours.
Comparative example 1
The differences from examples 1 to 8 are: the catalyst is H beta molecular sieve and aluminum chloride, the loading capacity of the aluminum chloride is 0.3mmol/g, and the catalyst is loaded into a fixed bed reactor, and the addition amount is 2%. The operation lasts for 720h, the reaction conversion rate is 90%, the diphenylamine selectivity is 82%, and no obvious change exists in the operation period of 720 h.
Comparative example 2
The differences from examples 1 to 8 are: the catalyst is H beta molecular sieve, aluminum chloride and alkaline earth metal magnesium oxide, the loading capacity of the aluminum chloride and the alkaline earth metal magnesium oxide is 0.3mmol/g, and the catalyst is loaded into a fixed bed reactor, wherein the addition amount is 2%. After the operation is carried out for 720h, the reaction conversion rate is 92 percent, the diphenylamine selectivity is 80 percent, and no obvious change exists during the operation of 720 h.
In comparative examples 1 to 2, the composition and by-production rate of the liquid phase product are shown in Table 6.
TABLE 6
Figure BDA0002942834710000111
From the data, compared with the existing catalyst, the catalyst provided by the application is beneficial to greatly improving the selectivity of aniline condensation reaction and improving the yield of diphenylamine. Meanwhile, the yield of diphenylamine can be further improved by controlling the type of Lewis acid in the catalyst, the specific surface area of the catalyst and the process parameters of the rectification process.
Synthesis of Diphenylamine-bottom recovery example
Example 2-1
3 sections of catalyst are filled in a fixed bed reactor, the filling amount is 670.3g/L, the catalyst is corrugated plate ceramic (catalyst 1) added with 2 percent of montmorillonite loaded aluminum chloride, and a liquid redistributor is added between each section. The feed space velocity is set to 0.03h-1Aniline preheated to 200 ℃ is fed from a theoretical plate n-6, the reaction temperature is 340 ℃, the absolute pressure at the top of the tower is controlled at 900kPa, and the reflux ratio is 15: 1. After the system was operated stably, the compositions of the materials at the top and bottom of the column were measured as shown in Table 7.
TABLE 7
Composition of the overhead distillate (%) Composition of bottom extraction (%)
2-methylpyridine 97.8
Aniline 2.2
Diphenylamine 98.3
Benzoquinolines 0.1
Dimethyldiphenylamines 0.9
Isopropyl diphenylamine derivatives 0.3
Triphenylamine derivative 0.4
The calculated conversion rate is 99 percent, the diphenylamine selectivity is 95 percent, and the conversion rate is not obviously reduced after the continuous operation for 720 hours.
Examples 2 to 2
A fixed bed reactor is filled with 2 sections of catalyst, the filling amount is 670.3g/L, and the catalyst is corrugated plate ceramic added with 2 percent of montmorillonite supported aluminum chloride (catalyst 1). The feed space velocity is set to 0.05h-1Aniline preheated to 200 ℃ is fed from a theoretical plate n-5, the reaction temperature is 340 ℃, the absolute pressure at the top of the tower is controlled at 2000kPa, and the reflux ratio is 15: 1. After the system was operated stably, the compositions of the materials at the top and bottom of the column were measured and shown in Table 8.
TABLE 8
Composition of the overhead distillate (%) Composition of bottom extraction (%)
2-methylpyridine 99.2
Aniline 0.8 0.1
Diphenylamine 99.4
Benzoquinolines 0
Dimethyldiphenylamines 0.3
Isopropyl diphenylamine derivatives 0.2
Triphenylamine derivative 0
The calculated conversion rate is 96 percent, the diphenylamine selectivity is 94 percent, and no obvious conversion rate reduction exists after the continuous operation for 720 hours.
Examples 2 to 3
A fixed bed reactor is filled with 1 section of catalyst, the filling amount is 670.3g/L, the catalyst is corrugated plate ceramic (catalyst 1) added with 5 percent of montmorillonite loaded aluminum trichloride, and a liquid redistributor is added between each section. The feed space velocity is set to 0.02h-1Aniline preheated to 200 ℃ is fed from a theoretical plate n-7, the reaction temperature is 340 ℃, the absolute pressure at the top of the column is controlled at 150kPa, and the reflux ratio is 15: 1. After the system was operated stably, the compositions of the materials at the top and bottom of the column were measured as shown in Table 9.
TABLE 9
Composition of the overhead distillate (%) Composition of bottom extraction (%)
2-methylpyridine 97.9
Aniline 2.1
Diphenylamine 99.5
Benzoquinolines 0
Dimethyldiphenylamines 0.1
Isopropyl diphenylamine derivatives 0.1
Triphenylamine derivative 0.3
The calculated conversion rate is 91 percent, the diphenylamine selectivity is 93 percent, and the conversion rate is not obviously reduced after the continuous operation for 720 hours.
Examples 2 to 4
The catalyst is prepared by filling 2 sections of catalyst into a fixed bed reactor, wherein the filling amount is 670.3g/L, the catalyst is corrugated plate ceramic (catalyst 4) added with 4 percent of montmorillonite loaded ferric trichloride, and a liquid redistributor is added between the two sections. The feed space velocity is set to 0.04h-1Aniline preheated to 200 ℃ is fed from a theoretical plate n.6, the absolute pressure at the top of the column is controlled at 500kPa, and the reflux ratio is 15: 1. System stabilizationAfter the operation, the compositions of the materials at the top and bottom of the column were measured and shown in Table 10.
Watch 10
Composition of the overhead distillate (%) Composition of bottom extraction (%)
2-methylpyridine 97.1
Aniline 2.9 1.2
Diphenylamine 98.3
Benzoquinolines 0
Dimethyldiphenylamines 0.3
Isopropyl diphenylamine derivatives 0.2
Triphenylamine derivative 0
The calculated conversion rate is 95 percent, the diphenylamine selectivity is 94 percent, and the conversion rate is not obviously reduced after the continuous operation for 720 hours.
Examples 2 to 5
The catalyst of 4 sections is filled in the fixed bed reactor, the filling amount is 670.3g/L, the catalyst is corrugated plate ceramic (catalyst 1) added with 5 percent of montmorillonite loaded aluminum chloride, and a liquid redistributor is added between each section. The feed space velocity is set to 0.02h-1Aniline preheated to 200 ℃ is fed from a theoretical plate n-5, the absolute pressure at the top of the column is controlled at 1500kPa, and the reflux ratio is 15: 1. After the system was operated stably, the compositions of the materials at the top and bottom of the column were measured as shown in Table 11.
TABLE 11
Composition of the overhead distillate (%) Composition of bottom extraction (%)
2-methylpyridine 99.2
Aniline 0.8
Diphenylamine 97.3
Benzoquinolines 0.1
Dimethyldiphenylamines 0.9
Isopropyl diphenylamine derivatives 1.2
Triphenylamine derivative 0.5
The calculated conversion rate is 98 percent, the diphenylamine selectivity is 93 percent, no obvious conversion rate and no obvious change exist after the continuous operation for 720 hours, and the selectivity has a descending trend.
From the above description, it can be seen that the above-described embodiments of the present invention achieve the following technical effects:
the Lewis acid can catalyze aniline to synthesize diphenylamine, and the Lewis acid is loaded on the first carrier and then is fired and molded with ceramic powder, so that the distribution uniformity of the Lewis acid in the catalyst is improved, and the catalyst has a porous structure, so that in the application process, the catalyst is added into a reactor as a filler, the diphenylamine synthesis reaction and the separation process of the diphenylamine synthesis reaction can be coupled, the rectification process can be simultaneously realized in the continuous reaction process, the preparation process of diphenylamine is greatly simplified, and the yield of diphenylamine is improved. Meanwhile, the whole preparation condition is mild, and the cost of raw materials is relatively low.
It is noted that the terms first, second and the like in the description and in the claims of the present application are used for distinguishing between similar elements and not necessarily for describing a particular sequential or chronological order. It is to be understood that the terms so used are interchangeable under appropriate circumstances such that the embodiments of the application described herein are, for example, capable of operation in sequences other than those described or illustrated herein.
The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention, and various modifications and changes may be made by those skilled in the art. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims (10)

1. A method for preparing a catalyst, comprising:
supporting a lewis acid on a first support;
and firing and forming the first carrier loaded with the Lewis acid and ceramic powder to obtain the catalyst.
2. The method for preparing a catalyst according to claim 1, characterized in that:
the Lewis acid is selected from one or more of polyaluminium chloride, aluminium trichloride, ferric trichloride, titanium tetrachloride, lanthanum trifluoromethanesulfonate, cerium trifluoromethanesulfonate and scandium trifluoromethanesulfonate;
the first carrier is selected from one or more of the group consisting of montmorillonite, kaolin, bentonite and diatomaceous earth.
3. The method for preparing the catalyst according to claim 1 or 2, wherein in the firing molding step, the first support carrying the lewis acid is used in an amount of 2 to 5% by weight based on the weight percentage of the catalyst, and the amount of the lewis acid carried on the first support is 0.3 to 0.5 mmol/g;
preferably, the amount of the first carrier loaded with the lewis acid is 3 to 4 percent based on the weight percentage of the catalyst, and the loading amount of the lewis acid on the first carrier is 0.3 to 0.4 mmol/g.
4. The method for preparing the catalyst according to claim 1 or 2, wherein the temperature of the firing molding process is 500 to 1200 ℃, and the firing time is 1 to 10 hours.
5. A catalyst having a porous corrugated plate structure and produced by the production method according to any one of claims 1 to 4.
6. The catalyst according to claim 5, wherein the catalyst is formed by laminating a plurality of corrugated plates, and the specific surface area of the catalyst is 100-500 m2/Kg。
7. The method for synthesizing diphenylamine is characterized by comprising the following steps of:
the catalyst of claim 5 or 6 is loaded into a fixed bed reactor, and aniline is subjected to condensation reaction and rectification in the fixed bed reactor to obtain the diphenylamine.
8. A method for the synthesis of diphenylamine according to claim 7, wherein in the fixed-bed reactor, a feed tray is located at the height of 1/3-1/2 of the fixed-bed reactor, and is located at theoretical tray n-5-7, preferably n-6;
the feeding hourly space velocity of the aniline is 0.01-0.05 h-1Preferably 0.02 to 0.04h-1More preferably 0.03h-1。
9. A process for the synthesis of diphenylamine according to claim 8, wherein the diphenylamine is withdrawn from the bottom of the fixed reactor or from a side-draw outlet of the fixed reactor;
preferably, the trays where the side draw outlets are located are distributed at the 1/5-1/4 height of the fixed bed reactor and are located at theoretical trays n-1, 3 and 5, and more preferably n-3.
10. A synthesis method for diphenylamine according to any one of claims 7 to 9, characterized in that the temperature of the condensation reaction is 320-370 ℃; the absolute pressure at the top of the tower is 150-2000 kPa, and the reflux ratio is (0.1-15): 1.
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Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB1439838A (en) * 1973-07-13 1976-06-16 Ici Ltd Process for the preparation of diphenylamine and substituted derivatives thereof
US5625097A (en) * 1994-09-14 1997-04-29 Bayer Aktiengesellschaft Process for preparing diphenylamines and catalysts usable for this purpose
CN1363422A (en) * 2001-01-10 2002-08-14 中国科学院成都有机化学研究所 Cermet catalyst
CN1669640A (en) * 2004-12-31 2005-09-21 南开大学 Catalyst for synthesizing diphenylamine by aniline condensation and preparing process thereof

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB1439838A (en) * 1973-07-13 1976-06-16 Ici Ltd Process for the preparation of diphenylamine and substituted derivatives thereof
US5625097A (en) * 1994-09-14 1997-04-29 Bayer Aktiengesellschaft Process for preparing diphenylamines and catalysts usable for this purpose
CN1363422A (en) * 2001-01-10 2002-08-14 中国科学院成都有机化学研究所 Cermet catalyst
CN1669640A (en) * 2004-12-31 2005-09-21 南开大学 Catalyst for synthesizing diphenylamine by aniline condensation and preparing process thereof

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