CS269162B1 - Process for the production of an aluminum chloride catalyst complex - Google Patents

Abstract

A method for producing a catalytic complex of aluminum chloride for catalysis in organic syntheses from a suspension of aluminum chloride in aromatic hydrocarbons, in which 1,2-dichloroethane or another chlorinated hydrocarbon releasing chlorine and water is fed as a promoter in a ratio of 5 to 1,500 kg based on 100 kg of 1,2-dichloroethane. The promoted catalytic complex is produced according to the invention separately from the ongoing organic synthesis, or simultaneously with it in one environment.

Description

The present invention relates to an improved process for the preparation of a catalyst complex based on aluminum chloride and fluorocarbons, which uses 1,2-dichloroethane or another chlorinated hydrocarbon and water as a further component of the catalyst.

In organic technology, for example in the production of ethylbenzene or cumene by alkylation and benzene with the appropriate olefin, a liquid complex is used as a catalyst, the basic component of which is aluminum chloride, the other components being aromatic hydrocarbons. However, in the production of the complex, it is necessary to use a promoter (cocatalyst), which is either the carrier of hydrogen chloride itself or causes the release of hydrogen chloride from the aluminum chloride present.

Conventionally, the catalyst complex is prepared by introducing into the suspension of aluminum chloride in aromatic hydrocarbons a vigorous stirring promoter, which may be hydrogen chloride gas, ethyl chloride, water or water vapor. As the aromatic hydrocarbon, for example, ethylbenzene, a mixture of diethylbenzenes and triethylbenzenes containing optionally benzene or another suitable aromatic fraction available in the respective organic synthesis can be used.

The most industrially industrial example of the use of an aluminum chloride catalyst complex is the Briedel-Crafts alkylae of benzene with ethylene, where the main product of the reaction is monoethylbenzene. In this case, as the aromatic hydrocarbon for the preparation of the complex, a diethylbenzene fraction is usually fed, separated during the distillation of the alkylation products and returned to the trynsalkylation process in order to increase the yield of ethylbenzene.

Another important product produced by the catalytic action of an aluminum chloride complex is cumene (isopropylbenzene), in which propylene is fed in addition to benzene as a raw material.

The activity of a catalyst complex produced by any of the methods described can be assessed simply by measuring its electrical conductivity. Simple dependencies have been published describing the relationship between this easily measurable physical property and the catalas. political activity. The higher the value of the catalytic activity corresponds to the higher electrical conductivity of the complex.

A process has now been found for the production of an aluminum chloride catalyst complex with a high value of electrical conductivity and catalytic activity.

The process for the preparation of an aluminum chloride catalytic complex for catalysis in organic syntheses from a suspension of aluminum chloride in aromatic hydrocarbons, such as ethylbenzene, diethylbenzenes, polyalkylbenzenes or fractions of alkylaromatic hydrocarbons falling off in organic syntheses and an initial boiling point of 125 ° C. In the production of the catalyst complex, a component consisting of 1,2-dichloroethane or another chlorinated hydrocarbon releasing hydrogen chloride in an amount of at most 200 kg per 1,000 kg of aluminum chloride and, if appropriate, water in proportion to the suspension of aluminum chloride in aromatic hydrocarbons. 5 to 1,500 kg based on 100 kg of 1,2-dichloroethane. The catalyst complex is produced in a separate process separated from the stage of organic synthesis by stirring, whereby 1,2-dichloroethane and, if appropriate, water in liquid or vapor state are added to the suspension of aluminum chloride in aromatic hydrocarbons. The water required to promote the catalyst complex can be added in the form of a solution in the incoming aromatic hydrocarbons to the catalyst complex production step or to the organic synthesis step. Alternatively, the catalyst complex can also be produced according to the invention in the technological step of organic synthesis catalyzed by this catalyst complex, into which the components of the complex, i.e. aluminum chloride, 1,2-dichloroethane and optionally also water, are metered in, 1,2-dichloroethane optionally dissolving in advance in the individual raw materials entering the organic synthesis stage and as an aromatic hydrocarbon for the production of the complex, the mixture of reaction components contained in the organic synthesis stage, i.e. for example in an alkylation reactor, then serves. In the preparation of the catalyst complex, 1,2-dichloroethane can be replaced in whole or in part by some other chlorinated hydrocarbon releasing hydrogen chloride, such as per i

AND

CB 269 162 Bl chloroethylene, ethyl chloride or a mixture of chlorinated hydrocarbons evaporating during production! acetaldehyde, vinyl chloride or alkyl chloride. |

The increased activity of the catalyst complex prepared by the process of the invention leads to a reduction in the consumption of aluminum chloride as the basic and most expensive catalyst component. At the same time, it leads to an improvement in the quality of ethylbenzene due to a reduction in the supply of elemental chlorine to the system together with aluminum chloride and to a reduction in the consumption of other raw materials. .

Example 1 '

Example 1 illustrates the dependence of the electrical conductivity and the catalytic activity of the aluminum chloride complex characterized by it on the method of its preparation.

The diethylbenzene fraction was introduced into a glass vessel equipped with a stirrer. Aluminum chloride and promoters were added with stirring in the order listed in Table 1. The liquid complex formed in about one hour, the initial temperature during its preparation was 25 ° C and the final temperature 40 ° C. After separation of the upper layer containing excess diethylbenzene, the conductivity of the complex was determined as a measure of its catalytic activity. The procedure in column I with water as the known promoter is given for comparison.

Table 1

Ingredient, grams 1 experiment number • 2 ‘ 3 4 diethylbenzene fraction 110.0 110.0 110.0 110.0 aluminum chloride 43.0 43.0 43.0 43.0 1,2-dichloroethane 0 2.6 5.3 7.9 water 2.9 1.9 1.0 0 conductivity of the complex, mS 4.26 4.60 5.95 5.90

Example 2.

As an example 2, a practical possibility of a recipe for the operational preparation of a catalyst complex is given.

A 600 kg part of the ethylbenzene fraction separated in the ethylbenzene production process, the temperature of which was 40 ° C, was also introduced into a stainless steel autoclave equipped with a stirrer. With constant stirring, 1000 kg of aluminum chloride were gradually poured in, then 150 kg of 1,2-dichloroethane were gradually added. The exothermic reaction was terminated after about 1 hour at 50 ° C to form a homogeneous catalytic complex in the form of a liquid. The complex was fed to an alkylation reactor where it catalyzed the alkylation of benzene with ethylene. Benzene and recycled diethylbenzene fraction introduced water into the alkylation reactor in a ratio of 7 kg of water per 100 kg of 1,2-dichloroethane used to prepare the complex.

Claims (5)

A process for the preparation of an aluminum chloride catalyst complex for catalysis in organic syntheses from a suspension of aluminum chloride in aromatic hydrocarbons, such as ethylbenzene, diethylbenzenes, polyalkylbenzenes or fractions of alkylaromatic hydrocarbons falling off in organic syntheses with an initial boiling point above 125 ° C. that in the production of the catalyst complex, the aluminum chloride suspension CS 269 162 in aromatic hydrocarbons is introduced as a promoter by the component it forms. 1,2-dichloroethane or other chlorinated hydrocarbon, releasing hydrogen chloride in a quantity not exceeding 200 kg per 1 000 kg of aluminum chloride and, where appropriate, water in a ratio of 5 ni 1,900 kg based on 100 kg of 1,2-dichloroethane. 2. The process according to claim 1, characterized in that the catalyst complex is produced in a separate process separated from the organic synthesis stage with stirring, 1,2-dichloroethane and optionally also water in liquid or liquid water being added to the suspension of aluminum chloride in aromatic hydrocarbons. vapor state. 3. The process according to items 1 and 2, characterized in that the water required for promoting the catalyst complex is added in the form of a solution in the incoming aromatic hydrocarbons to the catalyst complex production step or to the organic synthesis step. 4. The process according to item 1, characterized in that the catalyst complex is produced in the technological step of organic synthesis catalyzed by this catalyst complex, into which the components of the complex, i.e. aluminum chloride, 1,2-dichloroethane and optionally also water, are metered, wherein 1 The 2-dichloroethane is optionally pre-dissolved in the individual raw materials entering the organic synthesis step and the mixture of reactants present in the organic synthesis step serves as the aromatic hydrocarbon for the production of the complex. 5. The process according to items 1 to 4, characterized in that perchlorethylene, ethyl chloride or a mixture of chlorinated hydrocarbons leaving the production of acetaldehyde, vinyl chloride or alkyl chloride is fed as a promoter component.