Device and method for refining dimethylbenzene

Abstract

The invention discloses a device and a method for refining the dimethylbenzene of a continuous catalytic reforming device. The device comprises that a heat exchanger I and a heat exchanger II are arranged on a material supply pipeline, changeover valves B are respectively arranged on the heat exchanger I and the heat exchanger II, a pipeline a is led out from a part between the heat exchanger I and the changeover valve B to the top of a carclazyte tower, and a changeover valve A is arranged on the pipeline a; another pipeline b is led out from the top of the carclazyte tower, a changeover valve D is arranged on the pipeline b, a pipeline c on an outlet on the bottom of the carclazyte tower is communicated with the pipeline between the changeover valve B and the heat exchanger II, and a changeover valve C is arranged on the pipeline c; and a changeover valve E is arranged on a pipeline d, connecting pipelines are arranged behind the respective changeover valves and between the pipeline b on the top of the carclazyte tower and the pipeline d on the bottom of the carclazyte tower, and changeover valves F are respectively arranged on the connecting pipelines. The method comprises: during the initial stage and the last stage of operation, through controlling the changeover valves, carclazyte tower postposition and carclazyte tower preposition modes are respectively adopted. By the device and the method, the dimethylbenzene yield can be increased, and the service life of the carclazyte tower is prolonged.

Description

technical field [0001] The invention relates to the field of petrochemical industry, in particular to a refining device and method for xylene in a continuous reforming device. Background technique [0002] With the rapid development of my country's petrochemical and textile industries, the market demand for aromatics, especially xylene, is also increasing. Mixed xylene products are obtained by fractional distillation of continuous reformer gasoline products. Continuously reformed gasoline contains trace amounts of olefins due to reactions such as cracking and dehydrogenation. In order to meet quality indicators such as mixed xylene pickling colorimetry, bromine index and color, olefins can be removed by selective hydrogenation or clay refining. This right involves optimizing the operation by adjusting the heat exchange process and reforming reaction conditions to prolong the service life of the xylene clay tower and reduce investment accordingly. [0003] At present, there...

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Problems solved by technology

[0006] The advantage of this process is that it can make full use of the catalysis of the acid center of clay to promote the polymerization and alkylation of olefins to generate high-boiling polymers. The polymer is partially adsorbed by clay and cut to the bottom of the tower through fractionation in the xylene tower. It is used as a gasoline component extraction device; the disadvantage is that about 1 / 3 of the C8+ gasoline at the bottom of the C7 removal tower is mixed xylene and the other 2 / 3 is C9 components. Reduced clay consumption and investment

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