Moving bed catalytic process for preparing p-xylene by alkylating aromatic hydrocarbon

Abstract

The invention relates to a moving bed catalytic process for preparing p-xylene by alkylating aromatic hydrocarbon. By the moving bed catalytic process, the problems of high temperature rise of a reaction bed, insufficient stability of a catalyst and difficulty in implementing continuous production in the prior art are mainly solved. In the moving bed catalytic process, the aromatic hydrocarbon serving as a raw material and dimethyl ether serving as an alkylating reagent are subjected to mixed feeding and are conveyed to a moving bed reactor, the catalyst which is to be regenerated and comes out of the bottom of a moving bed enters a regenerator, and the regenerated catalyst returns to the moving bed reactor to be recycled. Through the technical scheme, the problems are better solved. The moving bed catalytic process can be applied to industrial production of the p-xylene by alkylating the aromatic hydrocarbon.

Description

technical field

[0001] The invention relates to a moving bed catalytic process for producing p-xylene by alkylation of aromatic hydrocarbons. Background technique

[0002] P-xylene is an important organic chemical raw material. Its main purpose is to synthesize terephthalic acid through oxidation, and then conduct polycondensation reaction with ethylene glycol to produce polymer materials polyethylene terephthalate (polyester), polyester It is a polyester material with excellent performance and great demand, which is widely used in the fields of textile and packaging materials.

[0003] At present, the most commonly used p-xylene production method in industry is disproportionation of toluene and transalkylation of C-nine aromatic hydrocarbons. Due to the limitation of thermodynamic equilibrium, the C-eight aromatic hydrocarbon products obtained by this method usually only contain about 24% p-xylene, while Demand for xylene The demand for p-xylene in the market accounts for ...

Examples

Embodiment 1

[0035] The aromatic hydrocarbon alkylation reaction was carried out according to the steps and conditions described in Comparative Example 2, but dimethyl ether was used instead of methanol as the alkylation reagent. The reaction evaluation results are listed in Table 1 for comparison.

[0036] Table 1

[0037]

Embodiment 2～5

[0039] The alkylation reaction was carried out according to the steps and conditions described in Example 1, but the catalyst regeneration conditions were adjusted. The specific regeneration conditions and reaction evaluation results are listed in Table 2 for comparison.

[0040] Table 2

[0041]

Embodiment 6～9

[0043] According to the steps and conditions described in Example 1, the aromatic hydrocarbon alkylation reaction was carried out, but the aromatic hydrocarbon feed was a mixture of benzene and toluene. The specific aromatic hydrocarbon feed ratio and reaction evaluation results were listed in Table 3 for comparison. The alkylation reagent was almost completely converted. , which will not be explained below.

[0044] table 3

[0045]

technical field

[0001] The invention relates to a moving bed catalytic process for producing p-xylene by alkylation of aromatic hydrocarbons. Background technique

[0002] P-xylene is an important organic chemical raw material. Its main purpose is to synthesize terephthalic acid through oxidation, and then conduct polycondensation reaction with ethylene glycol to produce polymer materials polyethylene terephthalate (polyester), polyester It is a polyester material with excellent performance and great demand, which is widely used in the fields of textile and packaging materials.

[0003] At present, the most commonly used p-xylene production method in industry is disproportionation of toluene and transalkylation of C-nine aromatic hydrocarbons. Due to the limitation of thermodynamic equilibrium, the C-eight aromatic hydrocarbon products obtained by this method usually only contain about 24% p-xylene, while Demand for xylene The demand for p-xylene in the market accounts for ...

Examples

Embodiment 1

[0035] The aromatic hydrocarbon alkylation reaction was carried out according to the steps and conditions described in Comparative Example 2, but dimethyl ether was used instead of methanol as the alkylation reagent. The reaction evaluation results are listed in Table 1 for comparison.

[0036] Table 1

[0037]

Embodiment 2～5

[0039] The alkylation reaction was carried out according to the steps and conditions described in Example 1, but the catalyst regeneration conditions were adjusted. The specific regeneration conditions and reaction evaluation results are listed in Table 2 for comparison.

[0040] Table 2

[0041]

Embodiment 6～9

[0043] According to the steps and conditions described in Example 1, the aromatic hydrocarbon alkylation reaction was carried out, but the aromatic hydrocarbon feed was a mixture of benzene and toluene. The specific aromatic hydrocarbon feed ratio and reaction evaluation results were listed in Table 3 for comparison. The alkylation reagent was almost completely converted. , which will not be explained below.

[0044] table 3

[0045]

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