Mixed xylene deolefination refining device and method

Abstract

The invention discloses a mixed xylene deolefination refining device and method. The device comprises a pre-refining tank, a mixed xylene fractionation column, a refining tank, a feeding heat exchanger, a discharging heat exchanger and a centrifugal pump. A C8 fraction is withdrawn from the side line above some column plate in 1-5 column plates counted from the top of the mixed xylene fractionation column downwards and used for feeding of the top of the refining tank, and tank bottom discharging returns from the side line above some column plate in 6-10 column plates counted from the top of the mixed xylene fractionation column downwards; and the top of the refining tank is at the 5-column-plate distance from the withdrawing position of the side line of the mixed xylene fractionation column, and the bottom of the refining tank is at the 5-column-plate distance from the return position of the side line of the mixed xylene fractionation column, mixed xylene products are produced from the top of the column, and polymers are discharged along with column reactor C9+ heavy components. By the adoption of the mixed xylene deolefination refining device and method, the purpose that the polymers can be separated without additionally arranging a separation column or other equipment and the qualified mixed xylene products are obtained is achieved; the service cycle of a catalyst can be prolonged, the cost is lowered, and high-quality chemical raw materials are obtained; and the good comprehensive benefits are obtained.

Description

technical field [0001] The invention relates to the field of petrochemical industry, in particular to a device and method for refining mixed xylene deolefins. Background technique [0002] The mixed xylene product is one of the important chemical basic products, which is obtained from the reforming product oil fractionation tower of the continuous reforming unit. The oil produced by catalytic reforming is rich in aromatics and solvent oil fractions, but also contains a small amount of olefins. These olefins are active and easy to form colloids; the presence of olefins will also affect some subsequent processing processes such as extraction of aromatics. In order to produce qualified aromatics and solvent oil products, olefins must be removed. At present, the widely used deolefin refining unit in industry adopts hydrogenation and granular clay process for removal. The precious metals used in hydrorefining are expensive, and the presulfurization of catalysts will generate s...

AI Technical Summary

Problems solved by technology

The advantage of the former is that the high molecular product produced by the polymerization of deolefin refining agent (activated clay, modified clay or molecular sieve catalyst) can be cut off to the heavy fraction in the bottom of the tower through the mixed xylene tower. The disadvantage is that the whole fraction is refined, which increases the consumption of refining agent

The advantage of the latter is that it is only for the deolefinization of C8 fractions, which reduces the processing capacity and catalyst consumption. The disadvantage is that in order to avoid generating too many high-boiling components that affect product quality, the operating temperature of the refined preparation is reduced.

[0004] Both the patent CN103044184A and the patent CN103044177A optimize the operation by adjusting the heat exchange process and reforming reaction conditions, that is, by switching the mixed xylene clay tower before and after the tower mode and adjusting the reforming reaction conditions to improve the mixed xylene clay tower feed, Improve the yield of mixed xylene and prolong the service life of the clay tower, but there are also disadvantages such as more valves and pipelines and frequent switching

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