Aromatic hydrocarbon alkyl transfer method for producing benzene and p-xylene

Abstract

The invention relates to an aromatic hydrocarbon alkyl transfer method for producing benzene and p-xylene, and the method is mainly used for solving the problems that in the prior art, an isomerization unit and a disproportionation unit of p-xylene just respectively process C8 aromatic hydrocarbon and toluene, and the equipment investment is large. The method comprises the following steps: a) feeding mixed xylene containing o-xylene and m-xylene and a toluene material into an aromatic hydrocarbon alkyl transfer process unit so as to generate an aromatic hydrocarbon alkyl transfer reaction under the hydrogen condition so as to generate an aromatic hydrocarbon material flow containing benzene and p-xylene after reaction; (b) successively passing the aromatic hydrocarbon material flow containing the benzene and the p-xylene through a benzene tower, a toluene tower and a xylene tower so as to separate out the benzene and the mixed xylene; and (c) feeding the mixed xylene in a absorption separation or freezing crystalline separation unit so as to generate the p-xylene, and feeding the unreacted toluene and xylene in the aromatic hydrocarbon alkyl transfer unit, wherein a composite catalyst bed layer is adopted in the aromatic hydrocarbon alkyl transfer process unit, aromatic hydrocarbon alkyl transfer reaction occurs to the upper catalyst bed layer, and toluene selectivity disproportional reaction is carried out on the lower catalyst bed layer with a shape-selective function. By using the technical scheme, the problem can be well solved; and the method can be applied to production of benzene and p-xylene.

Description

technical field

[0001] The invention relates to an aromatic hydrocarbon transalkylation method for producing benzene and p-xylene, in particular to an aromatic hydrocarbon transalkylation method capable of simultaneously processing toluene and C8 aromatics to produce benzene and p-xylene. Background technique

[0002] Paraxylene (PX) and benzene (B) are important basic organic chemical raw materials related to the national economy and people's livelihood. They can be widely used in many fields such as polyester, chemical fiber, rubber, and pesticides. The domestic consumption has reached tens of millions of tons, and their output value is huge. have an important impact on the development of the national economy. Paraxylene is almost exclusively used in the production of polyester fibers, resins and films via terephthalic acid (PTA) or diethyl terephthalate (DMT) intermediates. Benzene is a versatile basic petrochemical feedstock that can be used to produce many different pr...

Examples

Embodiment 1

[0024] Take 150 grams of high silicon-aluminum ratio hydrogen type ZSM-5 molecular sieve with a silicon-aluminum molar ratio of 180, and 70 grams of pseudo-boehmite. After kneading, extrude, dry, and roast to obtain the catalyst body, pass through an equal volume of chloroplatinic acid solution. Dipping to obtain platinum with a platinum content of 0.05% by weight, drying and roasting to obtain ethylbenzene deethylated C 8 A aromatic hydrocarbon transalkylation catalyst. Take 160 grams of low-silicon-aluminum-ratio hydrogen ZSM-5 molecular sieves with a silicon-aluminum molar ratio of 15, add 100 grams of silica sol with a silicon dioxide content of 40, knead, extrude, dry, and roast to obtain the catalyst body. The catalyst body is impregnated with base silicone oil, dried and then roasted. In this way, the silicone oil modification process is carried out twice to obtain a toluene shape-selective disproportionation catalyst.

[0025] Under the condition of hydrogen, the tolu...

Embodiment 2

[0032] Take 160 grams of hydrogen-type ZSM-5 molecular sieve with a silicon-aluminum molar ratio of 45, 80 grams of pseudo-boehmite, knead, extrude, dry, and roast to obtain the catalyst body, and obtain the platinum content by equal-volume impregnation with chloroplatinic acid solution. 0.06% by weight of platinum, after drying and roasting, ethylbenzene deethylation type C can be obtained 8 A aromatic hydrocarbon transalkylation catalyst. Take 160 grams of low-silicon-aluminum-ratio hydrogen ZSM-5 molecular sieves with a silicon-aluminum molar ratio of 25, add 100 grams of silica sol with a silicon dioxide content of 40, knead, extrude, dry, and roast to obtain the catalyst body. The catalyst body is impregnated with base silicone oil, dried and then roasted. In this way, the silicone oil modification process is carried out twice to obtain a toluene shape-selective disproportionation catalyst.

[0033] Under the condition of hydrogen, the toluene and C 8 Investigation on t...

Embodiment 3

[0039] Take 150 grams of high silicon-aluminum ratio hydrogen type ZSM-11 molecular sieve with a silicon-aluminum molar ratio of 110, and 70 grams of pseudo-boehmite, knead, extrude, dry, and roast to obtain the catalyst body, pass through an equal volume of chloroplatinic acid solution Dipping to obtain platinum with a platinum content of 0.05% by weight, drying and roasting to obtain ethylbenzene deethylated C 8 A aromatic hydrocarbon Wanyl transfer catalyst. Take 160 grams of low-silicon-aluminum-ratio hydrogen ZSM-5 molecular sieves with a silicon-aluminum molar ratio of 37, add 100 grams of silica sol with a silicon dioxide content of 40, knead, extrude, dry, and roast to obtain the catalyst body. The catalyst body is impregnated with base silicone oil, dried and then roasted. In this way, the silicone oil modification process is carried out twice to obtain a toluene shape-selective disproportionation catalyst.

[0040] Under the condition of hydrogen, the toluene and C ...

technical field

[0001] The invention relates to an aromatic hydrocarbon transalkylation method for producing benzene and p-xylene, in particular to an aromatic hydrocarbon transalkylation method capable of simultaneously processing toluene and C8 aromatics to produce benzene and p-xylene. Background technique

[0002] Paraxylene (PX) and benzene (B) are important basic organic chemical raw materials related to the national economy and people's livelihood. They can be widely used in many fields such as polyester, chemical fiber, rubber, and pesticides. The domestic consumption has reached tens of millions of tons, and their output value is huge. have an important impact on the development of the national economy. Paraxylene is almost exclusively used in the production of polyester fibers, resins and films via terephthalic acid (PTA) or diethyl terephthalate (DMT) intermediates. Benzene is a versatile basic petrochemical feedstock that can be used to produce many different pr...

Examples

Embodiment 1

[0024] Take 150 grams of high silicon-aluminum ratio hydrogen type ZSM-5 molecular sieve with a silicon-aluminum molar ratio of 180, and 70 grams of pseudo-boehmite. After kneading, extrude, dry, and roast to obtain the catalyst body, pass through an equal volume of chloroplatinic acid solution. Dipping to obtain platinum with a platinum content of 0.05% by weight, drying and roasting to obtain ethylbenzene deethylated C 8 A aromatic hydrocarbon transalkylation catalyst. Take 160 grams of low-silicon-aluminum-ratio hydrogen ZSM-5 molecular sieves with a silicon-aluminum molar ratio of 15, add 100 grams of silica sol with a silicon dioxide content of 40, knead, extrude, dry, and roast to obtain the catalyst body. The catalyst body is impregnated with base silicone oil, dried and then roasted. In this way, the silicone oil modification process is carried out twice to obtain a toluene shape-selective disproportionation catalyst.

[0025] Under the condition of hydrogen, the tolu...

Embodiment 2

[0032] Take 160 grams of hydrogen-type ZSM-5 molecular sieve with a silicon-aluminum molar ratio of 45, 80 grams of pseudo-boehmite, knead, extrude, dry, and roast to obtain the catalyst body, and obtain the platinum content by equal-volume impregnation with chloroplatinic acid solution. 0.06% by weight of platinum, after drying and roasting, ethylbenzene deethylation type C can be obtained 8 A aromatic hydrocarbon transalkylation catalyst. Take 160 grams of low-silicon-aluminum-ratio hydrogen ZSM-5 molecular sieves with a silicon-aluminum molar ratio of 25, add 100 grams of silica sol with a silicon dioxide content of 40, knead, extrude, dry, and roast to obtain the catalyst body. The catalyst body is impregnated with base silicone oil, dried and then roasted. In this way, the silicone oil modification process is carried out twice to obtain a toluene shape-selective disproportionation catalyst.

[0033] Under the condition of hydrogen, the toluene and C 8 Investigation on t...

Embodiment 3

[0039] Take 150 grams of high silicon-aluminum ratio hydrogen type ZSM-11 molecular sieve with a silicon-aluminum molar ratio of 110, and 70 grams of pseudo-boehmite, knead, extrude, dry, and roast to obtain the catalyst body, pass through an equal volume of chloroplatinic acid solution Dipping to obtain platinum with a platinum content of 0.05% by weight, drying and roasting to obtain ethylbenzene deethylated C 8 A aromatic hydrocarbon Wanyl transfer catalyst. Take 160 grams of low-silicon-aluminum-ratio hydrogen ZSM-5 molecular sieves with a silicon-aluminum molar ratio of 37, add 100 grams of silica sol with a silicon dioxide content of 40, knead, extrude, dry, and roast to obtain the catalyst body. The catalyst body is impregnated with base silicone oil, dried and then roasted. In this way, the silicone oil modification process is carried out twice to obtain a toluene shape-selective disproportionation catalyst.

[0040] Under the condition of hydrogen, the toluene and C ...

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