CN108689966A - A kind of preparation method of propylene oxide - Google Patents

Abstract

The invention discloses a kind of preparation methods of propylene oxide, its main feature is that the Titanium Sieve Molecular Sieve with MSE topological structures is used to carry out in the reaction system of propylene and hydrogen peroxide catalyzing and synthesizing propylene oxide for catalyst, the weight ratio of the propylene and catalysts and solvents is 1:0.03~0.15:1~15;The catalyst is the assembly of Ti-MSE molecular sieves or the molecular sieve containing Ti-MSE;The solvent is arbitrary one or more kinds of mixing in water, acetone, acetonitrile, methanol, ethyl alcohol, isopropanol and the tert-butyl alcohol.The present invention has catalytic activity good compared with prior art, and post-processing is easy, and propylene oxide yield is up to 93%, and selecting property is up to 99%, and environmental-friendly, reaction condition is mild, and there is certain industrialization promotion to use foreground and significant economic value.

Description

A kind of preparation method of propylene oxide

technical field

The invention relates to the technical field of organic chemical synthesis, in particular to a method for preparing propylene oxide using titanium-silicon molecular sieve as a catalyst and propylene and hydrogen peroxide as a reaction system.

Background technique

Propylene oxide is an important organic chemical raw material. Nearly three quarters of propylene oxide is used to produce polyether polyols, which are further processed into polyurethanes; the remaining quarter is used to produce propylene glycol, alcohol ethers, carbonic acid Acrylate and other fine chemicals. At present, the industrial production methods of propylene oxide mainly include: chlorohydrin method, ethylbenzene hydroperoxide method, tert-butyl hydroperoxide method, cumene hydroperoxide method and hydrogen peroxide direct oxidation method. The chlorohydrin method will produce a large amount of chlorine-containing wastewater by-products, which will not only cause environmental pollution, but also have strong corrosiveness to equipment. It is replaced by oxidation technologies such as cumene hydroperoxide method and hydrogen peroxide direct oxidation method.

The direct hydrogen peroxide oxidation method uses propylene and hydrogen peroxide as raw materials and oxidant respectively, and produces propylene oxide under the catalysis of titanium silicon molecular sieve. It has the characteristics of mild reaction conditions, high activity, good selectivity, and no pollution. An environmentally friendly propylene oxide production process.

Patent (US 4833260) discloses a method for the synthesis of propylene oxide as a catalyst with TS-1 titanium silicon molecular sieve of MFI topology, document (Studies in Surface Science and Catalysis, 2007, Vol.170, p1236-1243; Journal of Catalysis, 2016, Vol.342, p173-183) reported a method for the synthesis of propylene oxide using a Ti-MWW titanium-silicon molecular sieve with a MWW topology as a catalyst. Recently, with the development of titanium-silicon molecular sieve synthesis technology, more and more titanium-silicon molecular sieve catalyst materials with novel structure and open channels have been developed, which is expected to further promote the development of propylene oxide production process.

Literature (Green Chemistry, 2016, Vol.18, p735-741) reported the preparation of a titanium-silicon molecular sieve with MSE structure and its performance in catalyzing the hydroxylation of phenol. A report on the synthesis of propylene oxide from propylene catalyzed by silica molecular sieves. Based on the excellent catalytic performance of titanium-silicon molecular sieves with MSE structure in liquid-phase oxidation reactions, it is expected to efficiently catalyze the epoxidation of propylene to prepare propylene oxide.

Contents of the invention

The purpose of the present invention is to provide a kind of preparation method of propylene oxide in view of the deficiencies in the prior art, adopting the titanium silicon molecular sieve with MSE topological structure as the reaction system of catalyzer and propylene and hydrogen peroxide to catalyze the synthesis of propylene oxide, High selectivity, good catalytic activity, environmental friendliness, easy post-treatment, propylene oxide yield as high as 93%, selectivity as high as 99%, mild reaction conditions, expanding the application field of molecular sieves, providing a new type of environmentally friendly The synthesis route of propylene oxide has a certain prospect of industrial application and significant economic value.

The concrete technical scheme that realizes the object of the present invention is: a kind of preparation method of propylene oxide, it is characterized in that the titanium silicon molecular sieve with MSE topological structure is adopted as catalyst to carry out catalytic synthesis of propylene oxide in the reaction system of propylene and hydrogen peroxide, Concrete preparation comprises the following steps:

Step a: Stir and mix propylene, catalyst and solvent in a weight ratio of 1:0.03 to 0.15:1 to 15 to form a reaction system, the catalyst is Ti-MSE molecular sieve or a combination containing Ti-MSE molecular sieve; the solvent is Any one or a mixture of two or more of water, acetone, acetonitrile, methanol, ethanol, isopropanol and tert-butanol;

Step b: add hydrogen peroxide with a mass concentration of 2 to 65% dropwise to the reaction system at a temperature of 30 to 120° C. for 0.1 to 3 hours, and continue to react for 0.1 to 3 hours after the addition is completed. The mol ratio of hydrogen peroxide and propylene is 1:1～5;

Step c: after the reaction is finished, the catalyst is filtered out, and the filtrate is separated by distillation, and the product obtained is propylene oxide.

The reaction temperature is preferably 50-80° C.; the dropping time is preferably 0.1-2 hours.

The mass concentration of the hydrogen peroxide is preferably 5-40%, and the molar ratio of hydrogen peroxide to propylene is preferably 1:1-3.

Compared with the prior art, the present invention has good catalytic activity, convenient post-treatment, propylene oxide yield as high as 93%, selectivity as high as 99%, environmental friendliness, mild reaction conditions, certain industrialized application prospects and significant economic value.

Detailed ways

The preparation and application of the present invention will be further described in detail through specific examples below.

Example 1

Step 1: Add 0.1g of Ti-MSE molecular sieve catalyst, 10g of tert-butanol and 2g of gaseous propylene into the reactor, and stir the obtained reaction system evenly.

Step 2: When the temperature of the reaction system was raised to 60° C., 2.5 ml of hydrogen peroxide with a mass concentration of 30% was added dropwise to the reaction system for 0.5 hours, and the reaction was continued for 1 hour after the addition was completed.

The third step: after the reaction was completed, the catalyst was separated by a conventional filtration method, and then 1.30 g of product propylene oxide was isolated according to a conventional distillation operation, and the yield was 92.6%, and the selectivity of propylene oxide was 99.0%.

Example 2

Step 1: add 0.1g of Ti-MSE molecular sieve catalyst, 5g of acetone and 1g of gaseous propylene into the reactor, and stir the obtained reaction system evenly.

Second step: when the temperature of the reaction system was raised to 60° C., 0.8 ml of hydrogen peroxide with a mass concentration of 30% was added dropwise to the reaction system for 0.5 hours, and the reaction was continued for 1.5 hours after the addition was completed.

The third step: after the reaction was completed, the catalyst was separated by a conventional filtration method, and then operated by conventional distillation to obtain 0.41 g of product propylene oxide, with a yield of 91.0% and a selectivity of propylene oxide of 98.2%.

Example 3

Step 1: Add 0.1g of Ti-MSE molecular sieve catalyst, 10g of tert-butanol and 2g of gaseous propylene into the reactor, and stir the obtained reaction system evenly.

The second step: when the temperature of the reaction system was raised to 75° C., 2 ml of hydrogen peroxide with a mass concentration of 30% was added dropwise to the reaction system for 1.5 hours, and the reaction was continued for 0.5 hours after the addition was completed.

The third step: after the completion of the reaction, the catalyst was separated by conventional filtration, and then by conventional distillation, 1.05 g of product propylene oxide was isolated, with a yield of 93.5% and a selectivity of propylene oxide of 99.2%.

Example 4

Step 1: Add 0.08g Ti-MSE molecular sieve and 0.02g TS-1 molecular sieve as a catalyst, add 10g tert-butanol and 2g gaseous propylene into the reactor, and stir to obtain a reaction system.

Second step: when the temperature of the reaction system was raised to 60° C., 2.5 ml of hydrogen peroxide with a mass concentration of 40% was added dropwise to the reaction system for 1.5 hours, and the reaction was continued for 0.5 hours after the addition was completed.

The third step: after the reaction was completed, the catalyst was separated by a conventional filtration method, and then 1.31 g of product propylene oxide was isolated according to a conventional distillation operation, and the yield was 93.2%, and the selectivity of propylene oxide was 99.5%.

Example 5

Step 1: Add 0.1g of Ti-MSE molecular sieve catalyst, 20g of tert-butanol and 2g of gaseous propylene into the reactor, and stir the obtained reaction system evenly.

Step 2: When the temperature of the reaction system was raised to 60° C., 2.5 ml of hydrogen peroxide with a mass concentration of 30% was added dropwise to the reaction system for 0.5 hours, and the reaction was continued for 1 hour after the addition was completed.

The third step: after the reaction was completed, the catalyst was separated by a conventional filtration method, and then 1.32 g of product propylene oxide was isolated according to a conventional distillation operation, and the yield was 94.0%, and the selectivity of propylene oxide was 99.5%.

Example 6

Step 1: Add 0.07g of Ti-MSE molecular sieve and 0.03g of Ti-MWW molecular sieve as a catalyst, add 10g of tert-butanol and 2g of gaseous propylene into the reactor, and stir to obtain a reaction system.

Second step: when the temperature of the reaction system was raised to 60° C., 1.7 ml of hydrogen peroxide with a mass concentration of 30% was added dropwise to the reaction system for 1.5 hours, and the reaction was continued for 0.5 hours after the addition was completed.

The third step: after the completion of the reaction, the catalyst was separated by conventional filtration, and then by conventional distillation operation, 0.88g of product propylene oxide was isolated, with a yield of 92.2% and a selectivity of propylene oxide of 99.5%.

Example 7

Step 1: Add 0.05g of Ti-MSE molecular sieve and 0.05g of Ti-MOR molecular sieve as a catalyst, add 10g of acetonitrile and 2g of gaseous propylene into the reactor, and stir to obtain a reaction system.

Second step: when the temperature of the reaction system was raised to 60° C., 1.7 ml of hydrogen peroxide with a mass concentration of 30% was added dropwise to the reaction system for 1.5 hours, and the reaction was continued for 1.5 hours after the addition was completed.

The third step: after the completion of the reaction, the catalyst was separated by conventional filtration, and then by conventional distillation operation, 0.88g of product propylene oxide was isolated, with a yield of 92.2% and a selectivity of propylene oxide of 99.5%.

Example 8

Step 1: Add 0.1g of Ti-MSE molecular sieve catalyst, 10g of tert-butanol and 2g of gaseous propylene into the reactor, and stir the obtained reaction system evenly.

Second step: when the temperature of the reaction system was raised to 80° C., 1.8 ml of hydrogen peroxide with a mass concentration of 30% was added dropwise to the reaction system for 2.0 hours, and the reaction was continued for 0.5 hours after the addition was completed.

The third step: after the completion of the reaction, the catalyzer was separated by a conventional filtration method, and then 0.95 g of product propylene oxide was separated by a conventional distillation operation, and the yield was 93.4%, and the selectivity of propylene oxide was 99.5%.

The Ti-MSE molecular sieves in each of the above examples were prepared according to the literature method (Chemical Communication, 2008, Vol.5, p6224-6226), and the analysis of reactants and products was carried out by gas chromatography (Shimadzu GC2014, Rt-Wax capillary column 30m× 0.25mm × 0.25μm), with cyclopentanone as the internal standard, the method of temperature programming is used for quantification, and the yield and selectivity of propylene oxide are calculated according to the following formula:

The above embodiments are only to further illustrate the present invention, and are not used to limit the patent of the present invention. All equivalent implementations of the present invention should be included in the scope of claims of the patent of the present invention.

Claims (3)

1. a preparation method of propylene oxide is characterized in that adopting the titanium silicon molecular sieve with MSE topological structure is that catalyzer carries out catalytic synthesis propylene oxide in the reaction system of propylene and hydrogen peroxide, and concrete preparation comprises the following steps: Step a: Stir and mix propylene with catalyst and solvent in a weight ratio of 1: 0.03 to 0.15: 1 to 15 Form a reaction system, the catalyst is Ti-MSE molecular sieve or a combination containing Ti-MSE molecular sieve; the solvent is any one or two of water, acetone, acetonitrile, methanol, ethanol, isopropanol and tert-butanol a mixture of the above; Step b: add hydrogen peroxide with a mass concentration of 2 to 65% dropwise to the reaction system at a temperature of 30 to 120°C, and the dropwise addition time is 0.1 to 3 hours, and the reaction is continued for 0.1 to 3 hours after the dropwise addition is completed. The mol ratio of hydrogen peroxide and propylene is 1: 1 ~ 5; Step c: after the reaction is finished, the catalyst is filtered out, and the filtrate is separated by distillation, and the product obtained is propylene oxide. 2. according to the preparation method of the described propylene oxide of claim 1, it is characterized in that described temperature of reaction is preferably 50～80 ℃; Described dropping time is preferably 0.1～2 hours. 3. according to the preparation method of the described propylene oxide of claim 1, it is characterized in that the mass concentration of described hydrogen peroxide is preferably 5 ~ 40%, and the mol ratio of hydrogen peroxide and propylene is preferably 1: 1 ~ 3.