CN114558611A - Catalyst, preparation method thereof and application thereof in preparation of 2, 6-diisopropyl naphthalene - Google Patents

Abstract

The invention discloses a catalyst and a preparation method thereof and its application in the preparation of 2,6-diisopropylnaphthalene. The slurry containing molecular sieves, binders, rare earth metal salts, siloxane-based compounds and surfactants is spray-dried and formed, and further treated with high-temperature steam and ammonia to prepare a microsphere catalyst; the catalyst is applied to The preparation of 2,6-diisopropylnaphthalene in the isopropylation reaction of naphthalene or 2-isopropylnaphthalene has excellent performance.

Description

A kind of catalyst, its preparation method and its application in the preparation of 2,6-diisopropylnaphthalene

technical field

The invention relates to a catalyst, a preparation method thereof and an application in the preparation of 2,6-diisopropylnaphthalene, belonging to the field of chemical industry.

Background technique

2,6-Dialkylnaphthalene is a key raw material for the production of high-performance polyester fibers and plastics. Polyethylene naphthalate (PEN) is obtained by the polymerization of its oxidation product, 2,6-naphthalenedicarboxylic acid and ethylene glycol. It is a new type of polyester material with great potential and application prospects. PEN has unique heat resistance, mechanical properties, gas barrier properties, chemical stability and radiation resistance, etc., and can be widely used in electronic components, instrumentation, insulating materials, food packaging films, beer bottles, and aerospace and other manufacturing industries . At present, the bottleneck of large-scale application of PEN lies in the complicated preparation process and high production cost of its key raw material, 2,6-dialkylnaphthalene.

my country is rich in naphthalene resources. The synthesis of 2,6-dialkylnaphthalene with cheap and abundant naphthalene through alkylation can broaden the source of raw materials, increase the added value of naphthalene and methylnaphthalene, and shorten the process route. It is the preparation of 2,6-dialkylnaphthalene. - The ideal route for dialkylnaphthalenes. However, due to the large number of isomers and the similar boiling points of each isomer, the separation is very difficult, so how to improve the selectivity of 2,6-dialkylnaphthalene is the key to realize the preparation of 2,6-dialkylnaphthalene from naphthalene. Commonly used alkyl reagents are methanol, ethanol, isopropanol, propylene, isopropyl bromide, tert-amyl alcohol, cyclohexyl bromide, etc. Among them, the isopropylation process, 2,6-diisopropylnaphthalene (2,6-DIPN) has better selectivity and easier oxidation, and is considered to be a very promising process route. CN1793088A discloses a method for preparing 2,6-DIPN by isopropylation using mordenite molecular sieve. 35%, the selectivity of 2,6-DIPN in the disubstituted products was 58.37%～66.11%. CN107954812A discloses a method for alkylation of decalin in a fixed bed reaction, using ZSM 5/ZSM 12 composite molecular sieve modified by silanization as a catalyst, and the selectivity of 2,6-DIPN is only 41%. At present, the process of isopropylation of naphthalene mostly adopts the kettle reaction or fixed bed reaction process, and the catalyst is very easy to deactivate during the reaction process (Journal of Catalysis 220 (2003) 265-272), and it is difficult to realize the continuous preparation of 2,6-DIPN.

According to one aspect of the present application, there is provided a catalyst for preparing 2,6-diisopropylnaphthalene;

The catalyst is a microsphere catalyst of 10-100 microns;

The catalyst includes molecular sieves, binders, rare earth metal oxides and silica;

In the catalyst, the content of the molecular sieve is 20-60wt%; the upper limit is 60wt%, 50wt%, 40wt%, 30wt%; the lower limit is 20wt%, 30wt%, 40wt%, 50wt%;

The content of the binder is 35-55wt%; the upper limit is 55wt%, 50wt%, 45wt%, 40wt%; the lower limit is 35wt%, 40wt%, 45wt%, 50wt%;

The content of the rare earth metal oxide is 0.5-5.0%, based on the mass of the rare earth metal in the rare earth metal oxide; the upper limit is 5.0wt%, 4.5wt%, 4.0wt%, 3.5wt%, 3.0wt%, 2.5wt%, 2.0wt%, 1.5wt%, 1.0wt%; lower limit is 0.5wt%, 1.0wt%, 1.5wt%, 2.0wt%, 2.5wt%, 3.0wt%, 3.5wt%, 4.0wt%, 4.5wt%;

The content of the silica is 1-10%, the upper limit is 10wt%, 9wt%, 8wt%, 7wt%, 6wt%, 5wt%, 4wt%, 3wt%; the lower limit is 2wt%, 3wt%, 4wt%, 5wt%, 6wt%, 7wt%, 8wt%, 9wt%;

The molecular screen is selected from at least one of MOR, MCM-22, MCM-49 or SAPO-5;

The binder is selected from at least one of silica sol, alumina sol, kaolin or sepiolite;

The rare earth metal oxide is selected from at least one of oxides of lanthanum, cerium, praseodymium or samarium.

According to another aspect of the present application, a preparation method of the above-mentioned catalyst is provided, comprising at least the following steps:

i) mixing raw materials containing molecular sieves, binders, siloxane-based compounds, rare earth metal precursors, surfactants and water into a slurry, spray drying, and calcining at high temperature to obtain microspheres;

ii) The microspheres are treated with a mixture of high temperature water vapor and ammonia gas to prepare a microsphere catalyst.

The rare earth metal precursor is selected from at least one of lanthanum, cerium, praseodymium, samarium nitrate, sulfate or hydrochloride;

The siloxane-based compound is selected from at least one compound having the structure of formula I;

wherein, R ₁ , R ₂ , R ₃ and R ₄ are selected from alkyl groups with 1 to 10 carbon atoms;

The surfactant is at least one of sodium hexadecylbenzenesulfonate, polyethylene glycol, and sodium dodecylbenzenesulfonate;

The solid mass content in the slurry is 30-50 wt %, wherein the rare earth metal precursor is based on the mass of the oxide corresponding to the rare earth metal element, and the siloxane-based compound is based on the mass of the silicon dioxide produced by the solution. count;

The mass content of the surfactant in the solid is 1-5wt%, the upper limit is 5wt%, 4wt%, 3wt%, 2wt%; the lower limit is 1wt%, 2wt%, 3wt%, 4wt%;

The temperature of the high-temperature roasting is 400-700°C; the upper limits are 700°C, 600°C, and 500°C; the lower limits are 400°C, 500°C, and 600°C;

The high temperature roasting time is 4-12h, the upper limit is 12h, 11h, 10h, 9h, 8h, 7h, 6h, 5h; the lower limit is 4h, 5h, 6h, 7h, 8h, 9h, 10h, 11h.

The temperature of the water vapor and ammonia gas mixture treatment is 300-1000°C, the upper limit is 1000°C, 900°C, 800°C, 700°C, 600°C, 500°C, 400°C; the lower limit is 300°C, 400°C, 500°C °C, 600 °C, 700 °C, 800 °C, 900 °C;

The water vapor and ammonia gas mixture treatment time is 30min～6h;

The volume fraction of ammonia in the mixed gas is 20-90%.

According to another aspect of the present application, a preparation method of 2,6-diisopropylnaphthalene is provided, comprising at least the following steps:

contacting and reacting the raw material containing the naphthalene source and the alkylating agent with the catalyst to obtain a product containing 2,6-diisopropylnaphthalene;

The catalyst is selected from the above-mentioned catalysts or the catalysts prepared by the above-mentioned preparation methods.

Described naphthalene source is selected from naphthalene or/and 2-isopropylnaphthalene; Described naphthalene source is molten state;

The alkylating agent is selected from propylene or/and isopropanol;

The mass of the catalyst is 2-20wt% of the mass of the naphthalene source.

The temperature of the reaction is 150～300 ℃;

The pressure of the reaction is 0.1～10MPa;

The pressure of the reaction is 0.4～6.0MPa;

The reaction is carried out in tank reactors, loop reactors, tubular reactors.

The beneficial effects that this application can produce include:

1) Prepare a catalyst with a size of 20-100 microns by spray drying. The catalyst has high strength and is easy to separate from the material after the reaction. It is suitable for batch tank reactors, continuous tank reactors, loop reactors, and tubular reactions device.

2) In the process of spray drying, the acid sites on the outer surface of the catalyst are deactivated, and the catalyst has excellent performance in the isopropylation reaction of naphthalene or 2-isopropylnaphthalene.

3) The operation method provided by the present invention is simple, convenient to operate, low in cost, and has potential economic benefits.

Detailed ways

The present invention will be described in detail below with reference to the examples, but the present invention is not limited to these examples.

Unless otherwise specified, the raw materials in the examples of the present invention are all purchased through commercial channels.

Analytical method and conversion rate, selectivity are calculated as follows in the embodiment:

The qualitative and quantitative analysis of the product was performed off-line by an Agilent 7890A gas chromatograph, separated by an Agilent HP-INNOWAX capillary column, and detected and analyzed by a flame ionization detector (FID).

Conversion rate of naphthalene/2-isopropylnaphthalene=converted (moles of naphthalene+2-isopropylnaphthalene)/(total moles of naphthalene+2-isopropylnaphthalene)*100

DIPN selectivity = moles of DIPN in the product/total moles of the product*100;

2-IPN selectivity = moles of 2-IPN in the product/total moles of products*100;

2,6-DIPN selectivity=moles of 2,6-DIPN in the product/moles of DIPN in the product*100;

The ratios of ions in each embodiment are molar ratios unless otherwise specified.

Example 1 Catalyst preparation

Dissolve 0.10Kg La(NO ₃ ) ₃ ·6H ₂ O, 0.10Kg polyethylene glycol (molecular weight 4000) in 3.00Kg water, add 1.0Kg MOR molecular sieve (Si/Al=120), 1.0Kg kaolin, 5.0Kg aluminum sol (20%), 0.80Kg of tetraethyl silicate, mixed evenly, and stirred for 30 minutes to prepare a slurry. Shear with a colloid mill for 30 min.

It was formed by spray drying, the atomization temperature was 380°C, the particle size distribution was 20-50 microns, and the microspheres were obtained by roasting in a muffle furnace at 600°C for 6 hours, and the measured wear index was 1.2.

Take 250 g of microspheres and put them in a tube furnace, and heat up to 500 ° C under nitrogen protection, stop feeding nitrogen, inject 25% ammonia water, the feeding rate is 500 g/h, after 60 minutes of treatment, the feed is switched to nitrogen blowing Sweep for 30min to cool down. The obtained catalyst was named NPC-01.

Example 2 Catalyst preparation

Dissolve 0.20Kg La(NO ₃ ) ₃ ·6H ₂ O, 0.12Kg polyethylene glycol (molecular weight 4000) in 3.00Kg water, add 1.00Kg MOR molecular sieve (Si/Al=120), 1.00Kg kaolin, 5.00Kg aluminum sol (20%), 0.90Kg of isobutyltriethoxysilane, mixed evenly, and stirred for 30min to prepare a slurry. Shear with a colloid mill for 30 min.

It was formed by spray drying, the atomization temperature was 380 °C, the particle size distribution was 20-50 microns, and the microspheres were obtained by calcining at 600 °C for 6 hours in a muffle furnace, and the measured wear index was 1.1.

Take 250 g of microspheres and put them in a tube furnace, and heat up to 500 ° C under nitrogen protection, stop feeding nitrogen, inject 25% ammonia water, the feeding rate is 500 g/h, after 60 minutes of treatment, the feed is switched to nitrogen blowing Sweep for 30min to cool down. The resulting catalyst was named NPC-02.

Example 3 Catalyst preparation

Dissolve 0.50Kg La(NO ₃ ) ₃ ·6H ₂ O, 0.15Kg polyethylene glycol (molecular weight 4000) in 3.00Kg water, add 1.00Kg SAPO-5 molecular sieve (Si/(Si+P+Al)=0.20, mole ratio), 1.00Kg of kaolin, 5.00Kg of aluminum sol (20%), 0.50Kg of tetrapropyl silicate, mixed evenly, and stirred for 30 minutes to prepare a slurry. Shear with a colloid mill for 30 min.

It was formed by spray drying, the atomization temperature was 380 °C, the particle size distribution was 20-50 microns, and the microspheres were obtained by calcining at 600 °C for 6 hours in a muffle furnace, and the measured wear index was 1.1.

Take 250g of microspheres and put them in a tube furnace, and heat up to 600°C under nitrogen protection, stop feeding nitrogen, and inject 25% ammonia water, the feeding rate is 500g/h, after 120min of treatment, the feed is switched to nitrogen blowing Sweep for 30min to cool down. The obtained catalyst was named NPC-03.

Example 4 Catalyst preparation

Dissolve 0.02Kg La(NO ₃ ) ₃ ·6H ₂ O, 0.15Kg polyethylene glycol (molecular weight 4000) in 3.00Kg water, add 1.00Kg SAPO-5 molecular sieve (Si/(Si+P+Al)=0.20, mole ratio), 1.00Kg sepiolite, 3.20Kg silica sol (30%), 1.20Kg tetrapropyl silicate, mix well, and stir for 30 minutes to prepare a slurry. Shear with a colloid mill for 30 min.

It was formed by spray drying, the atomization temperature was 380°C, the particle size distribution was 20-50 microns, and the microspheres were obtained by roasting in a muffle furnace at 600°C for 6 hours, and the measured wear index was 1.2.

Take 250 g of microspheres and put them in a tube furnace, and heat up to 400°C under nitrogen protection, stop feeding nitrogen, inject 25% ammonia water, and feed 500 g/h. After 120 min of treatment, the feed is switched to nitrogen blowing. Sweep for 30min to cool down. The resulting catalyst was named NPC-04.

Example 5 Catalyst preparation

Dissolve 0.40Kg La(NO ₃ ) ₃ ·6H ₂ O and 0.10Kg cetyltrimethylammonium bromide in 3.00Kg water, add 1.00Kg MOR molecular sieve (Si/Al=120), 1.00Kg sepiolite , 3.20Kg of silica sol (30%), 0.125Kg of tetrapropyl silicate, mixed well, and stirred for 30min to form a slurry. Shear with a colloid mill for 30 min.

It was formed by spray drying, the atomization temperature was 380 °C, the particle size distribution was 20-100 microns, and the microspheres were prepared by calcining at 600 °C for 6 hours in a muffle furnace. The measured wear index was 1.2.

Take 250 g of microspheres and put them in a tube furnace, and heat up to 800 °C under nitrogen protection, stop feeding nitrogen, inject 25% ammonia water, and feed 500 g/h. After 120 min of treatment, the feed is switched to nitrogen blowing. Sweep for 30min to cool down. The obtained catalyst was named NPC-05.

Example 6 Catalyst preparation

Dissolve 0.20Kg La(NO ₃ ) ₃ ·6H ₂ O and 0.10Kg cetyltrimethylammonium bromide in 3.00Kg water, add 1.50Kg MOR molecular sieve (Si/Al=120), 1.00Kg sepiolite , 1.60Kg of silica sol (30%), and 1.00Kg of tetraethyl silicate, mixed evenly, and stirred for 30min to form a slurry. Shear with a colloid mill for 30 min.

It was formed by spray drying, the atomization temperature was 380 °C, the particle size distribution was 20-100 microns, and the microspheres were prepared by calcining at 600 °C for 6 hours in a muffle furnace. The measured wear index was 1.2.

Take 250g of microspheres and put them in a tube furnace, and heat up to 500°C under nitrogen protection, stop feeding nitrogen, inject 25% ammonia water, the feeding rate is 500g/h, and after 120min of treatment, switch the feed to nitrogen blowing Sweep for 30min to cool down. The obtained catalyst was named NPC-06.

Example 7 Catalyst preparation

Dissolve 0.20Kg Ce(NO ₃ ) ₃ ·6H ₂ O and 0.12Kg cetyltrimethylammonium bromide in 3.00Kg water, add 1.50Kg MOR molecular sieve (Si/Al=10), 1.00Kg sepiolite, 1.60Kg of silica sol (30%), 1.00Kg of tetraethyl silicate, mixed uniformly, and stirred for 30 minutes to prepare a slurry.

It was formed by spray drying, the atomization temperature was 380 °C, the particle size distribution was 20-100 microns, and the microspheres were prepared by calcining at 600 °C for 6 hours in a muffle furnace. The measured wear index was 1.2. Shear with a colloid mill for 30 min.

Take 250g of microspheres and put them in a tube furnace, and heat up to 500°C under nitrogen protection, stop feeding nitrogen, inject 25% ammonia water, the feeding rate is 500g/h, and after 120min of treatment, switch the feed to nitrogen blowing Sweep for 30min to cool down. The obtained catalyst was named NPC-07.

Example 8 Catalyst preparation

Dissolve 0.20Kg La(NO ₃ ) ₃ ·6H ₂ O, 0.15Kg polyethylene glycol (molecular weight 20000) in 3.00Kg water, add 1.50Kg MOR molecular sieve (Si/Al=10), 5.00Kg silica sol (30% ), 1.10Kg of tetraethyl silicate, mixed evenly, and stirred for 30 minutes to prepare a slurry. Shear with a colloid mill for 30 min.

It was formed by spray drying, the atomization temperature was 380 °C, the particle size distribution was 20-100 microns, and the microspheres were prepared by calcining at 600 °C for 6 hours in a muffle furnace. The measured wear index was 1.2.

Take 250g of microspheres and put them in a tube furnace, and heat up to 500°C under nitrogen protection, stop feeding nitrogen, inject 25% ammonia water, the feeding rate is 500g/h, and after 120min of treatment, switch the feed to nitrogen blowing Sweep for 30min to cool down. The resulting catalyst was named NPC-08.

Example 9 catalyst preparation

Dissolve 0.20Kg Pr(NO ₃ ) ₃ ·6H ₂ O, 0.04Kg polyethylene glycol (molecular weight 4000) in 3.00Kg water, add 1.00Kg MOR molecular sieve (Si/Al=120), 1.00Kg kaolin, 5.00Kg aluminum Sol (20%), 1.00Kg of tetraethyl silicate, mixed evenly, and stirred for 30 minutes to prepare a slurry.

It was formed by spray drying, the atomization temperature was 380°C, the particle size distribution was 20-50 microns, and the microspheres were obtained by roasting in a muffle furnace at 600°C for 6 hours, and the measured wear index was 1.2. Shear with a colloid mill for 30 min.

Take 250g of microspheres and put them in a tube furnace, and heat up to 500°C under nitrogen protection, stop feeding nitrogen, inject 25% ammonia water, the feeding rate is 500g/h, and after 120min of treatment, switch the feed to nitrogen blowing Sweep for 30min to cool down. The resulting catalyst was named NPC-09.

Comparative Example 1 Catalyst Preparation

Dissolve 0.15Kg polyethylene glycol (molecular weight 4000) in 3.00Kg water, add 1.00Kg MOR molecular sieve (Si/Al=120), 1.00Kg kaolin, and 5.00Kg aluminum sol (20%), mix well, and stir for 30 minutes to make a slurry material. Shear with a colloid mill for 30 min.

It was formed by spray drying, the atomization temperature was 380°C, the particle size distribution was 20-80 microns, and the microspheres were obtained by calcining at 600°C for 6 hours in a muffle furnace, and the measured wear index was 1.0. Designated as NPC-010.

Implementations 11 to 23 use a high-pressure reactor to evaluate the reaction performance of the catalyst

A 500mL reaction kettle was used for evaluation. 250 g of the catalyst was loaded into a tube furnace, activated under the protection of inert gas nitrogen at 500° C. for 240 min, and then lowered to room temperature. Take out the catalyst and add it to the batching kettle, add 5000 g of industrial naphthalene, stir evenly, replace it with inert gas nitrogen three times, seal the reaction kettle, and heat it to 100°C.

The autoclave was filled with 200 g of inert solvent, replaced with nitrogen, sealed, raised to 200 °C, and pressed to 3.0 MPa with nitrogen, and then injected into the slurry and propylene respectively. The slurry feeding rate was 50 g/h, and the propylene feeding rate was 32.5g/h, the gas is discharged from the reaction kettle after condensation, and the material entrained in the gas is refluxed through the condenser. When the total mass in the reactor reaches 300g, the overflow begins. Continue to respond. Continuous reaction 24h sampling analysis.

Analysis: Take 5.0 g of the reaction solution, dilute it 10 times with cyclohexane, add 1.0 g of n-dodecane as the internal standard for analysis, slowly stir for 30 s to make the liquid evenly mixed, draw the mixed solution with a disposable syringe and filter it through a filter membrane Transfer to chromatographic vials for subsequent analysis.

It can be seen from Table 2 that in the methods for preparing 2,6-diisopropylnaphthalene by alkylation of naphthalene and propylene in each embodiment of the present invention, higher naphthalene conversion rate and 2,6-DIPN selectivity are obtained. The conversion rate of naphthalene can reach more than 90%, and the selectivity of 2,6-DIPN is more than 75%.

The above are only a few embodiments of the present application, and are not intended to limit the present application in any form. Although the present application is disclosed as above with preferred embodiments, it is not intended to limit the present application. Without departing from the scope of the technical solution of the present application, any changes or modifications made by using the technical content disclosed above are equivalent to equivalent implementation cases and fall within the scope of the technical solution.

Claims (10)

1. a catalyzer is characterized in that this catalyzer is used to prepare 2,6-diisopropylnaphthalene, The catalyst is a microsphere catalyst of 10-100 microns; The catalyst includes molecular sieves, binders, rare earth metal oxides and silica; In the catalyst, the content of the molecular sieve is 20-60 wt%; The content of the binder is 35-55wt%; The content of the rare earth metal oxide is 0.5-5.0%, calculated by the mass of the rare earth metal in the rare earth metal oxide; The content of the silica is 1-10%. 2. catalyst according to claim 1 is characterized in that, The molecular screen is selected from at least one of MOR, MCM-22, MCM-49 or SAPO-5; The binder is selected from at least one of silica sol, alumina sol, kaolin or sepiolite; The rare earth metal oxide is selected from at least one of oxides of lanthanum, cerium, praseodymium or samarium. 3. a preparation method of the described catalyst of claim 1 or 2, is characterized in that, comprises the following steps at least: i) mixing raw materials containing molecular sieves, binders, siloxane-based compounds, rare earth metal precursors, surfactants and water into a slurry, spray drying, and calcining at high temperature to obtain microspheres; ii) The microspheres are treated with a mixture of high temperature water vapor and ammonia gas to prepare a microsphere catalyst. 4. the preparation method of catalyst according to claim 3 is characterized in that, The rare earth metal precursor is selected from at least one of lanthanum, cerium, praseodymium, samarium nitrate, sulfate or hydrochloride; The siloxane-based compound is selected from at least one compound having the structure of formula I;

wherein, R ₁ , R ₂ , R ₃ and R ₄ are selected from alkyl groups with 1 to 10 carbon atoms; The surfactant is selected from at least one of sodium hexadecylbenzenesulfonate, polyethylene glycol or sodium dodecylbenzenesulfonate. 5. the preparation method of catalyst according to claim 3, is characterized in that, The solid mass content in the slurry is 30-50 wt %, wherein the rare earth metal precursor is based on the mass of oxides corresponding to rare earth metal elements, and the siloxane-based compound is based on the mass of silicon dioxide produced by decomposition. count; The mass content of the surfactant in the solid is 1-5 wt %. 6. the preparation method of catalyst according to claim 3 is characterized in that, The temperature of the high-temperature roasting is 400-700°C; The high temperature roasting time is 4-12h. 7. the preparation method of catalyst according to claim 3 is characterized in that, The temperature of the water vapor and ammonia gas mixture treatment is 300-1000°C; The water vapor and ammonia gas mixture treatment time is 30min～6h; The volume fraction of ammonia in the mixed gas is 20-90%. 8. a preparation method of 2,6-diisopropylnaphthalene, is characterized in that, comprises the following steps at least: contacting and reacting the raw material containing the naphthalene source and the alkylating agent with the catalyst to obtain a product containing 2,6-diisopropylnaphthalene; The catalyst is selected from the catalyst according to claim 1 or 2 or the catalyst prepared by the preparation method according to any one of claims 3 to 7. 9. preparation method according to claim 8, is characterized in that, described naphthalene source is selected from naphthalene or/and 2-isopropylnaphthalene; Described naphthalene source is molten state; The alkylating agent is selected from propylene or/and isopropanol; The mass of the catalyst is 2-20wt% of the mass of the naphthalene source. 10. preparation method according to claim 8, is characterized in that, The temperature of the reaction is 150～300 ℃; The pressure of the reaction is 0.1～10MPa; Preferably, the pressure of the reaction is 0.4-6.0 MPa; The reaction is carried out in tank reactors, loop reactors, tubular reactors.