Method and reaction system for liquid phase cycling hydrotreatment

Abstract

The invention discloses a method and a reaction system for liquid phase cycling hydrotreatment. In the method, part of a liquid phase product after the hydrotreatment is mixed with fresh raw oil in a cycling mode to form a liquid phase material; hydrogen is mixed into the liquid phase material; the hydrogen mixed amount is 1 to 20 times that of the dissolved hydrogen which makes the reaction system saturated under a reaction condition; the liquid phase material mixed and dissolved with the hydrogen is put into a reactor; a hydrogenation catalyst bed is arranged in the reactor and is immersed in the liquid phase material; the upper part of the reactor is provided with a gas phase space; a pressure control system communicated with the gas phase space is arranged on the reactor and controls the pressure in the reactor by controlling the gas exhaust quantity; and the liquid phase material dissolved with the hydrogen is put into the hydrogenation catalyst bed of the reactor to perform hydrogenation reaction. Compared with the prior art, the method ensures that the liquid phase cycling hydrotreatment can be controlled and operated stably, and obtain an ideal reaction effect.

Description

technical field [0001] The invention relates to a liquid-phase circulating hydrogenation treatment method and a reaction system, in particular to a liquid-phase hydrogenation treatment method and a reaction system by increasing dissolved hydrogen through liquid-phase product circulation. Background technique [0002] Reducing the content of sulfur and aromatics in diesel can reduce the emission of solid particles in the exhaust of diesel vehicles and reduce air pollution. my country's light diesel oil specifications and standards will soon be implemented with reference to the Euro III standard, which requires the sulfur to be less than 350 μg / g, and the Euro IV standard, which requires the sulfur to be less than 50 μg / g. In order to cope with the production of diesel oil with new emission standards, on the one hand, it is necessary to solve key technical problems, build a hydrogenation unit to carry out deep hydrodesulfurization of diesel oil, increase the cetane number, and...

AI Technical Summary

Problems solved by technology

For example, in the liquid-phase hydrogenation reaction system disclosed in CN200680018017.3, the pressure and liquid level in the reactor are further controlled by controlling the amount of mixed hydrogen in the liquid-phase feed. The liquid level or pressure changes constantly, and the amount of supplemented hydrogen may be less than the amount of hydrogen required for the reaction. For example, when there are more small molecule hydrocarbons produced under abnormal conditions, the liquid level in the reactor will drop. At this time, the control system The best adjustment method is to reduce the amount of mixed hydrogen in the liquid phase raw material. If it is reduced too much, the amount of hydrogen may not be enough to maintain the normal hydrogenation reaction, which will have an adverse effect on the stability of the reaction.

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