CN1137782C - Catalyst for synthesizing diisopropylamine and its preparing process - Google Patents

Abstract

The present invention provides a solid acid catalyst for synthesizing diisopropylamine by using isopropylamine, which is composed of: 50 to 95w% of H beta zeolite, and the molecular ratio of SiO2 to Al2 O3 in the H beta zeolite is from 20 to 100, 0.2 to 4.0 w% of potassium, and gamma-Al2 O3 as the rest. The catalyst of the present invention has the advantages of high conversion rate and favorable selectivity, simplifies the existing production process of diisopropylamine and reduces the equipment investment, energy consumption in production and the production cost of diisopropylamine.

Description

Catalyst for synthesizing diisopropylamine and preparation thereof

The invention relates to a catalyst for synthesizing diisopropylamine by using isopropylamine and a preparation method thereof.

Diisopropylamine is an organic chemical raw material, is mainly used for synthesizing pesticides, herbicides, No. 1 and No. 2 avenanthramides, is used for synthesizing medicines such as Gangle, fenfluramine, propamin and Prussian, and is also used for synthesizing dyes, rubber vulcanization accelerators, surfactants, detergents, defoaming agents and the like.

There are two traditional methods for producing diisopropylamine (Liuchong, edited by Spiranthus sapiensis et al, handbook of petrochemical engineering, third minute volume, chemical industry publisher, 1987: 369; published by scientific and technical information institute of Ministry of chemical industry of the world Fine chemical products-technical and economic handbook, 1988: 247). The first method is isopropanol hydrogenation and amination method to produce diisopropylamine, and the reaction is divided into the following two steps: the first step is as follows: the second step is that:

the reaction product contains 37 w% of isopropylamine, 33 w% of diisopropylamine, 12 w% of isopropanol, 18 w% of water and the like. The reaction product is extracted, rectified and dehydrated to obtain the product.

The second method is acetone hydrogenation and amination to prepare diisopropylamine, and the reaction is also divided into the following two steps: the first step is as follows: the second step is that:

the reaction products include isopropylamine, diisopropylamine, isopropanol, water, acetone and the like. The reaction product also needs to be extracted, rectified, dehydrated and the like to obtain the product.

The two production methods of diisopropylamine have the common defects of various ① raw materials, complex composition of reaction products, difficult separation, long ② process route, complex operation and high product cost.

The invention aims to provide a catalyst for synthesizing diisopropylamine from isopropylamine and a preparation method thereof, wherein the catalyst has high conversion rate and good selectivity, simplifies the existing production process and reduces the production cost.

The invention discloses a solid acid catalyst for synthesizing diisopropylamine from isopropylamine, which comprises 50-95 w% of H β zeolite A, preferably 58-93 w% of B, 0.2-4.0 w% of potassium, preferably 0.9-3.2 w% of C, and the balance of gamma-Al₂O₃。

In which the SiO of zeolite H β₂/Al₂O₃The molecular ratio is 20 to100.

The preparation method of the catalyst comprises the following steps:

1. preparing a KCl solution;

2. mixing H β zeolite with the KCl solution, and performing ion exchange at 80-95 ℃ for 0.5-4.0H;

3. the resulting solution was filtered and washed to Cl free^-And drying.

4. Adding aluminum hydroxide powder, nitric acid and deionized water into the solution, wherein the adding amount of the nitric acid accounts for 0.5-2.0W% of the dry materials; the addition amount of the deionized water is based on the capability of kneading and extruding strips.

5. Kneading, extruding, drying and roasting to obtain the catalyst of the invention.

In the preparation method of the catalyst, the potassium can be added by adopting a spray-dipping method.

In the step 2, the solid-liquid volume ratio of H β zeolite to KCl solution is 1: 2-1: 6, and the exchange frequency is 1-3;

the drying in step 3 may be: drying for 4.0-8 h at 50-60 ℃; drying for 4.0-8 h at 100-110 ℃;

in the step 5, the drying temperature can be 50-110 ℃, and the time is 2-8 h; the roasting temperature can be 400-580 ℃, and the time is 3-16 h.

The invention uses K/H β zeolite-Al₂O₃Catalyst, so that isopropylamine can be directly synthesized into diisopropyPropylamine has high conversion rate and good selectivity of reaction; the existing diisopropylamine production process is simplified, the equipment investment is reduced, the energy consumption in the production is reduced, and the production cost of diisopropylamine is reduced.

Example 1A: preparation of KCl solution

Weighing 15g of KCl, dissolving in 1000ml of deionized water, stirring until the solution is transparent, and standing for later use. B: preparation of the catalyst

70g of H β zeolite (SiO)₂/Al₂O₃Molecular ratio of 30) was added to 250ml of 0.2M KCl solution, and ion exchange was carried out at a temperature of 90 ℃ for 2.0 hours; then, filtering and washing the solution till no Cl exists^-Drying at 50 deg.C for 4.0 hr, drying at 100 deg.C for 4.0 hr, mixing with 10g of aluminium hydroxide powder, adding nitric acid and deionized water, kneading and extruding to form strips, drying at 50 deg.C for 4.0 hr, drying at 110 deg.C for 4.0 hr, and calcining at 550 deg.C for 4.0 hr to obtain K/H β zeolite-Al₂O₃Catalyst containing K0.9 w%, H β zeolite 92.8 w%, and gamma-Al for the rest₂O₃The catalyst is numbered PA-1.

Example 2

70g of H β zeolite (SiO)₂/Al₂O₃Molecular ratio of 42) was added to 250ml of 0.2M KCl solution, ion-exchanged at a temperature of 90 ℃ for 2.5 hours, and then filtered and washed to be free of Cl^-Repeating ion exchange once under the same conditions as the first one, drying at 50 ℃ for 4.0H, drying at 100 ℃ for 4.0H, mixing with 20g of aluminum hydroxide powder, adding nitric acid and deionized water, kneading on a strip extruding machine, extruding into strips and forming, wherein the adding amount of the nitric acid accounts for 1.0 w% of the dry materials, the adding amount of the deionized water is based on the kneading and the strip extruding, drying the strip catalyst at 50 ℃ for 4.0H, drying at 110 ℃ for 4.0H, roasting in a muffle furnace at 450 ℃ for 8.0H, and obtaining K/H β zeolite-Al in the same way as in the example 1 for the rest₂O₃Catalyst containing 1.6 w% of potassium and Hβ Zeolite 85.8 w%, and gamma-Al for the rest₂O₃And the catalyst is numbered PA-2.

Example 3

70g of H β zeolite (SiO)₂/Al₂O₃Molecular ratio of 66) was added to 250ml of 0.2M KCl solution, ion-exchanged at a temperature of 95 ℃ for 2.5 hours, and then filtered and washed to be free of Cl^-Repeating ion exchange once under the same conditions as those of the first step, drying at 60 ℃ for 8.0H, drying at 110 ℃ for 8.0H, mixing with 20g of aluminum hydroxide powder, adding nitric acid and deionized water, kneading and extruding the mixture on an extruding machine to form strips, wherein the adding amount of the nitric acid accounts for 2.0 w% of dry materials, the adding amount of the deionized water is based on the kneading and extruding, drying the strip catalyst at 50 ℃ for 4.0H, drying at 110 ℃ for 4.0H, roasting in a muffle furnace at 550 ℃ for 12H, and obtaining K/H β zeolite-Al in the same way as in example 1 for the rest₂O₃The catalyst contains potassium 1.6 wt%, H β zeolite 85.8 wt%, and gamma-Al for the rest₂O₃And the catalyst is numbered PA-3.

Example 4

70g of H β zeolite (SiO)₂/Al₂O₃Molecular ratio of 78) was added to 350ml of 0.2M KCl solution, and ion exchange was carried out at a temperature of 95 ℃ for 3.5 hours; then, filtering and washing the solution till no Cl exists^-(ii) a The ion exchange was repeated twice again, under the same conditions as for the first time. Drying at 60 deg.C for 8.0h, at 110 deg.C for 8.0 h; then mixed with 60g of aluminum hydroxide powder and addedMixing nitric acid and deionized water, kneading and extruding into strips on a strip extruding machine, wherein the adding amount of the nitric acid accounts for 2.0 w% of the dry material,the adding amount of the deionized water is based on the mixing and extruding, the strip catalyst is dried for 4.0H at 50 ℃, dried for 4.0H at 110 ℃, and roasted for 12H at 450 ℃ in a muffle furnace, and the rest is the same as the example 1, thus obtaining the K/H β zeolite-Al₂O₃The catalyst contains potassium 3.2 w%, H β zeolite 57.8 w%, and gamma-Al₂O₃And the catalyst is numbered PA-4.

Examples 5 to 10

The catalysts in examples 1-4 were crushed to 8-20 mesh, a certain amount of catalyst was loaded into a stainless steel reactor with an inner diameter of 12mm and a length of 650mm, the reaction was top-fed, the reaction mass flowed out of the bottom of the reactor, cooled and then fed into a separator, gaseous ammonia was discharged from the top of the separator, the bottom liquid was sampled at regular times, the composition was analyzed by gas chromatography, and the specific reaction conditions and results are listed in table 1. As can be seen from the data in Table 1, the catalyst of the present invention has high conversion rate and good selectivity in the synthesis of diisopropylamine from isopropylamine.

TABLE 1 reaction conditions and results

Fruit of Chinese wolfberry Applying (a) to Example (b)	Catalysis Agent weaving Number (C)	Catalyst and process for preparing same Is loaded into Amount, g	Reaction conditions			Composition of liquid phase product, w%			Transformation of The ratio of the total weight of the particles, mol％	selecting The nature of the Chinese herbal medicine is that, mol％
											temperature of ℃	Pressure of MPa	Airspeed h-1	Isopropyl ester Amines as pesticides	Two different kinds of Propylamines	By-product of the reaction
			5	PA-1	20	225	Atmospheric pressure	0.25									79.72	20.21	0.07	22.86	99.48
6	PA-2	20							240	Atmospheric pressure	0.25	67.18	32.70	0.11	36.26	99.67
			7	PA-2	20	265	Atmospheric pressure	0.25									56.24	43.25	0.51	47.76	98.25
8	PA-2	20							225	Atmospheric pressure	0.5	85.68	14.27	0.05	16.29	99.66
			9	PA-3	20	225	Atmospheric pressure	1.0									90.01	9.96	0.03	11.45	99.71
10	PA-4	20							240	Atmospheric pressure	0.25	83.66	16.28	0.06	18.57	99.65

Example 11

110g of PA-2 catalyst with the granularity of 8-20 meshes is filled into a stainless steel reactor with the inner diameter of 25mm and the length of 1500mm, and the PA-2 catalyst is subjected to260 hours stability running test. The reaction pressure is normal pressure, the reaction temperature is 240 ℃, and the space velocity of the reaction volume is 0.25h^-1The reaction is fed upwards, the reaction material flows out from the bottom of the reactor, and enters aseparator after cooling, gas phase ammonia is discharged from the top of the separator, the bottom liquid phase is sampled at regular time, the composition is analyzed by gas chromatography, and the specific reaction conditions and results are listed in table 2.

Table 2, 260-hour stability running test.

Cumulative operation Time, h	Composition of liquid phase product, w%			The conversion rate of the mixed solution is higher than that of the mixed solution, mol％	the selectivity of the reaction is improved by the following steps, mol％
						isopropylamine	Diisopropylamine	By-product of the reaction
	50	66.05	33.84						0.11	37.55	99.59
100				66.23	33.68	0.09	37.36	99.51
	150	67.16	32.71						0.13	36.40	99.40
200				66.38	33.51	0.11	37.21	99.50
	260	67.75	32.11						0.14	35.78	99.34

As can be seen from the data in Table 2, the PA-2 catalyst shows better activity and stability in the 260h stability experiment.

Claims (8)

1. A solid acid catalyst for synthesizing diisopropylamine from isopropylamine comprises the following components:

a is 50-95 w% of H β zeolite,

b: 0.2 to 4.0w% of potassium,

c: the balance being/gamma-Al₂O₃；

In which the SiO of H β zeolite₂/Al₂O₃The molecular ratio is 20 to 100.

2. The catalyst according to claim 1, wherein the content of H β zeolite is 58-93 w%.

3. The catalyst according to claim 1, wherein the content of potassium is 0.9 to 3.2 w%.

4. A method of preparing the catalyst of claim 1:

(1) preparing a KCl solution with the concentration of 0.2M;

(2) mixing H β zeolite with the KCl solution, and carrying out ion exchange at 80-95 ℃ for 0.5-4.0H, wherein the solid-liquid volume ratio of H β zeolite to KCl solution is 1: 2-1: 6, and the exchange frequency is 1-3;

(3) the resulting solution was filtered and washed to Cl free^-And drying;

(4) adding aluminum hydroxide powder, nitric acid and deionized water into the solution, wherein the adding amount of the nitric acid accounts for 0.5-2.0W% of the dry materials;

(5) kneading, extruding, drying and roasting to obtain the catalyst of the invention.

5. The method according to claim 4, wherein the potassium is added by spraying.

6. The process according to claim 4, wherein the solid-liquid volume ratio of H β zeolite to KCl solution is 1: 4.

7. The method according to claim 4, wherein the drying in step 3 is: drying for 4.0-8 h at 50-60 ℃; drying for 4.0-8 h at 100-110 ℃.

8. The process according to claim 4, wherein the drying temperature in the step (5) is 50 to 110 ℃ for 2 to 8 hours; the roasting temperature is 400-580 ℃, and the roasting time is 3-16 h.