CN108816276A - Molecular sieve catalyst for producing pyridine base and preparation method thereof - Google Patents

Abstract

The invention relates to the technical field of chemical industry, in particular to a molecular sieve catalyst for producing pyridine base and a preparation method thereof. A molecular sieve catalyst for producing pyridine base is composed of 20-60% of molecular sieve and 40-80% of adhesive by mass percent; wherein the molecular sieve is ZSM-5 type molecular sieve, SiO₂、Al₂O₃The molar ratio of the zinc salt to the manganese salt is 40-50, wherein 0.1-2% of tin salt, 0.1-2% of zinc salt and 0.1-2% of manganese salt are loaded by mass, the tin salt, the zinc salt and the manganese salt are taken as auxiliary agents, and the auxiliary agent is one or a mixture of more of the tin salt, the zinc salt and the manganese salt. Through the pretreatment of the molecular sieve and the optimization of the formula, the yield of the prepared catalyst in the pyridine base is improved by 8-10 percent compared with that of a foreign catalyst, and the yield is improvedThe benefit and the competitiveness of pyridine manufacturers are improved.

Description

Molecular sieve catalyst for producing pyridine base and preparation method thereof

technical field

The invention relates to the technical field of chemical industry, in particular to a molecular sieve catalyst for producing pyridine base and a preparation method thereof.

Background technique

Pyridine is a six-membered heterocyclic compound formed by replacing carbon atoms on the benzene ring with nitrogen atoms. Pyridine and alkylpyridine are collectively referred to as pyridine bases, mainly including pyridine, 2-picoline, 3-picoline, etc. As chemical industrial products, pyridine series raw materials are important organic materials for the production of high value-added fine chemical products, and are widely used in the fields of medicine, pesticides, dyes, spices, feed additives, food additives, rubber additives, and synthetic materials.

In 1924, Chichbabin proposed an industrial method for mass production of pyridine bases using aldehyde and ammonia as raw materials. After continuous improvement of the catalyst, the yield has increased from 40-50% in the 1950s to about 80%. With the oil and gas industry Considering the cost of raw materials, there has been a method for catalytically synthesizing pyridine bases with ketones, alcohols, olefins, and alkynes as raw materials, but the process is still immature and the yield is low. At present, 95% of pyridine bases in the world are still synthesized from aldehydes and ammonia as raw materials through catalytic synthesis.

The earliest catalysts used in the synthesis of pyridine bases were amorphous aluminosilicate catalysts and modified amorphous aluminate catalysts, such as SiO ₂ -Al ₂ O ₃ compounds reported in US Patent No. 2507618; US3946020 and US3932431. And halogen and PO43-modified SiO ₂ -Al ₂ O ₃ compounds, but the overall yield of pyridine base is generally not high (<50%).

U.S. Patent No. 4,861,894 (1989) discloses a molecular sieve made of high-silicon ZSM-5 zeolite with a SiO ₂ /Al ₂ O ₃ molar ratio of 225 as a raw material and SiO ₂ as a binder as a catalyst for pyridine base synthesis. Under the reaction conditions of acetaldehyde/formaldehyde molar ratio of 1.4, ammonia/aldehyde molar ratio of 1.5, and reaction pressure of normal pressure, the yield of catalyst was 47%, and the yield of picoline was 14%. The overall yield of pyridine was 61%.

U.S. Patent US5218122 (1993) discloses crystalline zeolite modified by tungsten, zinc or tin as a catalyst for pyridine base synthesis. The molar ratio of formaldehyde/acetaldehyde is 1, and the molar ratio of ammonia/aldehyde is 1.2. The reaction temperature is 450 Under the reaction conditions of ℃, the yield of pyridine of the tungsten modified catalyst was 32%, the yield of 3-picoline was 16%, and the yield of 2-picoline was 1%. Under the same reaction conditions, zinc or tin modified catalyst, its pyridine yield is 16%, 2-picoline yield is 34%, 3-picoline yield is 14%, 2-picoline yield The yield is 1%. The catalyst modified with zinc and tin at the same time has a pyridine yield of 34%, a 3-picoline yield of 16%, and a 2-picoline yield of 1%.

US Patent No. 5,395,940 (1995) discloses a catalyst for the synthesis of pyridine and 3-picoline using a specific crystal type zeolite such as MCM-22 or MCM-49. Under the reaction conditions of acetaldehyde/formaldehyde/ammonia molar ratio of 1.4/1/3.6 and reaction temperature of 427°C, the yield of pyridine was 9.3%, the yield of 3-picoline was 4.1%, and the yield of 2-picoline The yield of 0.6%, the yield of 4-picoline is 0.9%. Although the content of 2-picoline and 4-picoline in pyridine and 3-picoline synthesized by the above method is very small, the total yield of pyridine and 3-picoline is too low, without any industrial application possible.

Contents of the invention

In order to overcome the shortcomings of existing catalyst production, the invention provides a molecular sieve catalyst for producing pyridine base and a preparation method thereof.

The technical solution adopted by the present invention to solve the technical problem is: a molecular sieve catalyst for producing pyridine base, the catalyst is composed of 20-60% molecular sieve and 40-80% binder according to mass percentage;

Among them, the molecular sieve is ZSM-5 molecular sieve, the molar ratio of SiO ₂ and Al ₂ O ₃ is between 40-50, which is loaded with 0.1-2% tin salt, 0.1-2% zinc salt and 0.1-2% % of manganese salt, tin salt, zinc salt and manganese salt are additives, and the additives are one or more mixtures. .

According to another embodiment of the present invention, further comprising,

The tin salt is tin chloride, tin nitrate or tin sulfate;

The zinc salt is zinc chloride, zinc nitrate, zinc sulfate, zinc acetate or zinc silicate;

The manganese salt is manganese nitrate, manganese sulfate or manganese oxalate.

According to another embodiment of the present invention, it further includes that the binder is one or more of bentonite, kaolin, boehmite, silica sol, and aluminum sol.

A kind of preparation method for the molecular sieve catalyst that is used to produce pyridine base, adopts following steps:

(1) Mixing: use a planetary ball mill to mix ZSM-5 molecular sieve with tin salt, zinc salt, and manganese salt according to the mass ratio, and grind for 1 hour;

(2) Reaction: Put the above-mentioned (1) mixed materials into a box-type electric furnace, keep the constant temperature at 100°C, and keep the constant temperature for 1 hour. The temperature in the reaction kettle is 65-90°C, the pressure is 20KPa, and it is stirred for more than 2 hours;

(3) Filtration: The above (2) reaction materials are naturally cooled to room temperature, filtered and washed, and the liquid mother liquor will continue to be used in step (2), and the solid materials are dried at 100°C-150°C for 4-6h, and then roasted in a calciner , the calcination temperature is 400°C-600°C, and the calcination is for 4 hours to obtain the modified molecular sieve;

(4) The above steps (1), (2), and (3) are repeated at least once;

(5) Mix the molecular sieve prepared in the above step (3) with the binder at a ratio of 1:0.8-2.0 by mass, add deionized water, control the solid content to 20-40%, and grind the slurry through a colloid mill 0.5h, homogenizer disperse for 2h, the obtained slurry is spray-dried and molded, and the spray-dried material is roasted at 500-600°C for 5-6h in a roaster to make a catalyst.

The beneficial effect of the invention is that, through molecular sieve pretreatment and formula optimization, the yield of pyridine base of the prepared catalyst is increased by 8-10 percentage points compared with foreign catalysts, and the benefit and competitiveness of pyridine manufacturers are improved.

Detailed ways

A molecular sieve catalyst for producing pyridine base, the catalyst is composed of 20-60% molecular sieve and 40-80% binder according to mass percentage;

Among them, the molecular sieve is ZSM-5 molecular sieve, the molar ratio of SiO ₂ and Al ₂ O ₃ is between 40-50, which is loaded with 0.1-2% tin salt, 0.1-2% zinc salt and 0.1-2% % of manganese salt, tin salt, zinc salt and manganese salt are additives, and the additives are one or more mixtures. .

According to another embodiment of the present invention, further comprising,

The tin salt is tin chloride, tin nitrate or tin sulfate;

The zinc salt is zinc chloride, zinc nitrate, zinc sulfate, zinc acetate or zinc silicate;

The manganese salt is manganese nitrate, manganese sulfate or manganese oxalate.

According to another embodiment of the present invention, it further includes that the binder is one or more of bentonite, kaolin, boehmite, silica sol, and aluminum sol.

A kind of preparation method for the molecular sieve catalyst that is used to produce pyridine base, adopts following steps:

(1) Mixing: use a planetary ball mill to mix ZSM-5 molecular sieve with tin salt, zinc salt, and manganese salt according to the mass ratio, and grind for 1 hour;

(2) Reaction: Put the above-mentioned (1) mixed materials into a box-type electric furnace, keep the constant temperature at 100°C, and keep the constant temperature for 1 hour. The temperature in the reaction kettle is 65-90°C, the pressure is 20KPa, and it is stirred for more than 2 hours;

(3) Filtration: The above (2) reaction materials are naturally cooled to room temperature, filtered and washed, and the liquid mother liquor will continue to be used in step (2), and the solid materials are dried at 100°C-150°C for 4-6h, and then roasted in a calciner , the calcination temperature is 400°C-600°C, and the calcination is for 4 hours to obtain the modified molecular sieve;

(4) The above steps (1), (2), and (3) are repeated at least once;

(5) Mix the molecular sieve prepared in the above step (3) with the binder at a ratio of 1:0.8-2.0 by mass, add deionized water, control the solid content to 20-40%, and grind the slurry through a colloid mill 0.5h, homogenizer disperse for 2h, the obtained slurry is spray-dried and molded, and the spray-dried material is roasted at 500-600°C for 5-6h in a roaster to make a catalyst.

Use a planetary ball mill to grind for 1 hour, then put it into a box-type electric furnace at a constant temperature of 100°C for 1 hour, put the molecular sieve into hot water to maintain a constant temperature while it is still hot, the effective modification temperature is 65-90°C, the time is 2 hours, and the pressure is maintained at 20KPa during this period. The obtained slurry needs to be filtered and rinsed with water 4 times, and the obtained filter cake needs to be dried at 120° C. for 4 h. The above steps were repeated for the second modification, and after the third modification, the filter cake was calcined at 500° C. for 4 hours.

Molecular sieve pretreatment

Divide 1000g molecular sieve and 20g additives into 4 parts and put them into 4 jars of planetary ball mill, grind for 1h, take them out and put them in a box-type electric furnace at 100℃ for 1h, take them out and put them into a glass reaction kettle with 5000mL hot water while hot After keeping the pressure at 20KPa and keeping the temperature at constant temperature for 2 hours, the materials were discharged, filtered, rinsed and dried, and the above steps were repeated twice, and the finally obtained filter cake was roasted at 500°C for 4 hours to obtain the modified molecular sieve.

Example 1

Mix 1,000g of molecular sieve, 1,200g of kaolin (stir while adding to prevent uneven mixing), 800g of aluminum sol, and 6,000g of deionized water, spray dry and shape, and roast to obtain catalyst A. The solid content of the scheme slurry is 30%, the inlet temperature of the spray drying conditions is 300-360°C, the outlet temperature is 100-160°C, the nozzle pressure is 0.3Mpa, and the calcination temperature is 550°C for 4 hours. The prepared catalyst contains Sn , Zn, Mn total content is 0.912%.

Example 2

Mix 1000g molecular sieve, 1000g kaolin (stir while adding to prevent uneven bottom sinking), 800g silica sol, and 6500g deionized water, add dilute nitric acid dropwise until the pH is about 1, then spray dry and shape, and roast Catalyst B was obtained. The solid content of the scheme slurry is 33%, the inlet temperature of the spray drying conditions is 300-360°C, the outlet temperature is 100-160°C, the nozzle pressure is 0.3Mpa, and the calcination temperature is 550°C for 4 hours. The prepared catalyst contains Sn , Zn, Mn total content is 1.105%.

Example 3

Mix 1,000g of molecular sieve, 1,000g of kaolin (stir while adding to prevent uneven mixing), 900g of boehmite, and 8,700g of deionized water, spray dry and shape, and roast to obtain catalyst C. The solid content of the scheme slurry is 25%, the inlet temperature of the spray drying conditions is 300-360°C, the outlet temperature is 100-160°C, the nozzle pressure is 0.3Mpa, and the calcination temperature is 550°C for 4 hours. , Zn, Mn total content is 1.200%.

Example 4

1000g of molecular sieve, 1000g of kaolin (stirring while adding to prevent uneven bottom sinking), 800g of aluminum sol, 7200g of deionized water (mixed uniformly, spray-dried and formed, and roasted to obtain catalyst D. The solid content of the scheme slurry is 30 %, increased the content of kaolin, wherein the inlet temperature of the spray drying conditions was 300-360°C, the outlet temperature was 100-160°C, the nozzle pressure was 0.3Mpa, and the roasting temperature was 550°C for 4 hours. The Sn, Zn , The total Mn content is 1.415%.

Example 5

Mix 1,000g of molecular sieve, 800g of kaolin (stir while adding to prevent uneven mixing), 800g of alumina sol, 500g of boehmite, and 8,200g of deionized water, spray dry and shape, and roast to obtain catalyst E. The solid content of the modified slurry is 30%, the inlet temperature of the spray drying condition is 300-360°C, the outlet temperature is 100-160°C, the nozzle pressure is 0.3Mpa, and the roasting temperature is 550°C for 4 hours. The total content of Sn, Zn and Mn is 1.112%.

The present invention compares the application of products under different schemes in the synthesis of pyridine base from formaldehyde acetaldehyde ammonia. In the fluidized bed reaction tube, install 400g of catalysts A-E, the reaction temperature is 450-500°C, the reaction pressure is 25-35kpa, the raw material is a mixture of formaldehyde, acetaldehyde and ammonia, and the feed ratio is 1:1.5:1.2. The test evaluation results are as follows:

Table 1 Evaluation results of self-made pyridine catalyst

In the fluidized bed reaction tube, 300g of foreign catalysts were installed, and the following results were obtained according to the above test method.

Table 2 Evaluation results of foreign catalysts

Comparing Tables 1 and 2, it can be found that the yield of catalysts (A, B, C, D, E) prepared by the present invention has been higher than that of foreign catalysts.

The above description is only illustrative, rather than restrictive, to the present invention. Those skilled in the art understand that many modifications, changes or the like can be made without departing from the spirit and scope defined by the appended claims. effect, but all will fall within the protection scope of the present invention.

Claims (4)

1. a kind of for producing the molecular sieve catalyst of pyridine base, characterized in that the catalyst is according to mass percent by 20- 60% molecular sieve and 40-80% adhesive composition；

Wherein molecular sieve is type ZSM 5 molecular sieve, SiO₂、Al₂O₃Molar ratio between 40-50, wherein load has the quality to be The manganese salt of the pink salt of 0.1-2%, the zinc salt of 0.1-2% and 0.1-2%, pink salt, zinc salt and manganese salt are auxiliary agent, and auxiliary agent is a kind of or more Kind mixture.

2. according to claim 1 for producing the molecular sieve catalyst of pyridine base, characterized in that

Pink salt is stannic chloride, nitric acid tin or STANNOUS SULPHATE CRYSTALLINE；

Zinc salt is zinc chloride, zinc nitrate, zinc sulfate, zinc acetate or zinc silicate；

Manganese salt is manganese nitrate, manganese sulfate or manganese oxalate.

3. according to claim 1 for producing the molecular sieve catalyst of pyridine base, characterized in that adhesive is swelling One of soil, kaolin, boehmite, silica solution, Aluminum sol are a variety of.

4. it is a kind of according to claim 1-3 for producing the preparation method of the molecular sieve catalyst of pyridine base, It is characterized in that using following steps：

（1）Mixing：Type ZSM 5 molecular sieve is mixed with pink salt, zinc salt, manganese salt example in mass ratio using planetary ball mill, is ground Mill, mixed grinding time are 1h；

（2）Reaction：It will be above-mentioned（1）The material of mixing is put into cabinet-type electric furnace, and 100 DEG C of thermostat temperature, constant temperature time 1h, taking-up is taken advantage of Heat, which is added, to shift to an earlier date in the ready reaction kettle added with 80 DEG C of hot water, controls 65~90 DEG C of reactor temperature, pressure 20KPa, Stir 2h or more；

（3）Filtering：It is above-mentioned（2）Reaction mass cooled to room temperature, through filtration washing, liquid mother liquor continues to be used in step （2）, solid material dry 4-6h at 100 DEG C -150 DEG C roasts, 400 DEG C -600 DEG C of maturing temperature using calcining furnace, roasts 4h obtains modified molecular screen；

（4）Above-mentioned steps（1）, (2), (3) recycle at least 1 time；

（5）By above-mentioned steps（3）The molecular sieve and adhesive of preparation are 1 according to mass percent:The ratio of 0.8-2.0 mixes, And deionized water is added, control solid content is 20-40%, and slurry grinds 0.5h through colloid mill, and homogenizer disperses 2h, obtains slurry In roaster, through 500-600 DEG C of roasting 5-6h, catalyst is made in spray-dried molding, the material of spray drying.