CN1148341C - Process for synthesizing diisopropylamine - Google Patents

Abstract

The present invention discloses a synthesis method for diisopropylamine which is directly taken as a raw material, and the K/H beta zeolite-Al2 O3 is taken as a catalyst to synthesize the diisopropylamine. The method which simplifies the original synthesis process has the advantages of high percent conversion, good selectivity and simple reaction product composition, the production process is simplified, the flow is shortened and the product cost is reduced.

Description

Method for synthesizing diisopropylamine

The invention relates to a method for synthesizing diisopropylamine by using isopropylamine as a raw material.

Diisopropylamine is mainly used for producing rubber accelerators, medicines and pesticides, and is also used for producing surfactants, detergents, defoaming agents and the like.

There are two traditional methods for producing diisopropylamine (Liuchong, edited by Spiranthus indicus et al, handbook of petrochemical engineering, third minute volume, chemical industry publisher, 1987: 369; world fine chemical products-technical and economic handbook, published by scientific and technical information institute of the department of chemical industry, 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 contained 37 wt% of isopropylamine, 33 wt% of diisopropylamine, 12 wt% of isopropanol, 18 wt% of water, etc. 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 product contains 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 same defects that ① various raw materials are reacted, each raw material needs to be recycled, the production process is complex, the energy consumption is high, ② reaction products are complex in composition, difficult to separate, long in separation process, high in unit consumption of products and high in product cost.

The invention aims to overcome the defects of the two methods for synthesizing diisopropylamine, and innovations are made from the aspect of synthesis process so as to simplify the existing production process and reduce energy consumption and raw material unit consumption; the reaction conversion rate and the product selectivity are improved, and the product production cost is reduced.

The invention discloses a method for synthesizing diisopropylamine, which directly takes isopropylamine as a raw material and takes K/H β zeolite-Al₂O₃Is a catalyst. The weight percentages in the present invention are all expressed as "wt%".

Wherein K/H β zeolite-Al₂O₃The catalyst comprises the following components:

A：SiO₂/Al₂O₃the molecular ratio of the H β zeolite is 20-100, and the content is 50-95 wt%, preferably 58-93 wt%.

B: the potassium content is 0.2 to 4.0 wt%, preferably 0.9 to 3.2 wt%.

C: the balance being gamma-Al₂O₃。

The above reaction is carried out in the vapor phase, using a continuous process. The specific operating conditions are as follows: the reaction temperature is 200-300 ℃, the pressure is normal pressure-0.8 MPa, and the airspeed is 0.2-1.5 h^-1. Preferably, the reaction temperature is 220-270 ℃, the pressure is normal pressure-0.5 MPa, and the space velocity is 0.25-1.0 h^-1。

The invention takes isopropylamine as raw material to continuously synthesize diisoamine, simplifies the original synthesis process, has high conversion rate, good selectivity and simple reaction product composition, simplifies and shortens the separation process, reduces the energy consumption and the unit consumption of raw material, and reduces the product cost.

Example 1

70g of H β zeolite (SiO)₂/Al₂O₃The molecular ratio is 30) is added into 250ml of 0.2M KCl solution, ion exchange is carried out at the temperature of 90-95 ℃, and the exchange time is 2.0 h; then, filtering and washing the solution till no Cl exists^-Drying at 60 deg.C for 4.0 hr, drying at 110 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 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 potassium 0.9 wt%, H β zeolite 92.8 wt%, and gamma-Al for the rest₂O₃The catalyst is numbered PA-1.

Example 2

Taking 70g of H β zeolite (SiO)₂/Al₂O₃Molecular ratio 42), K/H β zeolite-Al was obtained according to the method described in example 1₂O₃Catalyst containing potassium 1.6 wt%, H β zeolite 85.8 wt%, and gamma-Al for the rest₂O₃And the catalyst is numbered PA-2.

Example 3

Taking 70g of H β zeolite (SiO)₂/Al₂O₃Molecular ratio 66) K/H β zeolite-Al was prepared according to the method described in example 1₂O₃Catalyst containing potassium 1.6 wt%, H β zeolite 85.8 wt%, and gamma-Al for the rest₂O₃And the catalyst is numbered PA-3.

Example 4

Taking 70g of H β zeolite (SiO)₂/Al₂O₃Molecular ratio of 78), according to the examples1 to obtain K/H β zeolite-Al₂O₃Catalyst containing potassium 3.2 wt%, H β zeolite 57.8 wt%, and gamma-Al for the rest₂O₃And 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.

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 Clothes (CN)The amount of the active carbon is added, g	reaction conditions			Composition of liquid phase product, wt%			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	0.5	0.25	83.66	16.28	0.06	18.57	99.65

As can be seen from the data in Table 1, the reaction under the process conditions of the present invention resulted in both higher conversion and better selectivity.

Example 11

110g of PA-2 catalyst with the granularity of 8-20 meshes is filled in a reactor with the inner diameter of 25mm and the length ofThe PA-2 catalyst was tested for 260 hours stability on stream in a 1500mm stainless steel reactor. 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 a separator 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, wt%			Conversion, mol%	Selectivity, 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, under the process conditions, the conversion rate of the reaction is more than 35%, the selectivity is more than 99%, and the catalyst has better stability.

Claims (6)

1. A process for synthesizing diisopropylamine features that isopropylamine is directly used as raw material and K/H β zeolite-Al₂O₃Is a catalyst.

2. The process of claim 1 wherein K/H β zeolite-Al₂O₃The catalyst comprises the following components:

A：SiO₂/Al₂O₃50-95 wt% of H β zeolite with a molecular ratio of 20-100;

b: potassium is 0.2 to 4.0 wt%;

c: the balance being gamma-Al₂O₃。

3. A synthesis process according to claim 2, wherein the catalyst consists of:

A：SiO₂/Al₂O₃58-93 wt% of H β zeolite with a molecular ratio of 20-100;

b: 0.9-3.2 wt% of potassium;

c: the balance being gamma-Al₂O₃。

4. The process of claim 1 wherein the reaction is carried out in the vapor phase using a continuous process.

5. The synthesis process according to claim 1, operating under the conditions:

the reaction temperature is 200-300 DEG C

The pressure is between normal pressure and 0.8MPa

The airspeed is 0.2-1.5 h^-1。

6. The synthesis process according to claim 1, operating under the conditions:

the reaction temperature is 220-270 DEG C

The pressure is between normal pressure and 0.5MPa

The airspeed is 0.25-1.0 h^-1。