A kind of start-up preparation method of hydrorefining unit

Abstract

The invention discloses a start-up preparation method of a hydrofining device. The method aims at the starting process of the ex-situ prevulcanization type hydrotreating catalyst containing the dihydroxy compound, and particularly in the airtight process, a constant-pressure heating section, a constant-pressure constant-temperature section and a constant-pressure heating section are arranged, so heat generated by hydrogenolysis of sulfide and / or auxiliaries in the airtight starting process is reasonably distributed and controlled, the phenomenon of centralized heat release is avoided, and therisks of over-temperature and temperature runaway are reduced. According to the method, obstacles in the industrial application process of the catalyst are thoroughly solved, the use activity of the catalyst is improved, meanwhile, the environment-friendly hidden danger of leakage of a vulcanizing agent is eliminated, and the invention has a good application prospect.

Description

technical field [0001] The invention relates to a preparation method for start-up of a hydrorefining unit, in particular to an airtight method for reducing the risk of overtemperature during the airtight process of an external presulfurized type II active center catalyst. Background technique [0002] The hydrogenation process is the process of hydrogenation, high temperature conditions and the action of catalysts to make raw oil hydrodesulfurization, hydrodenitrogenation, polycyclic aromatic hydrocarbons hydrogenation saturation, etc., so as to convert it into clean oil or intermediate blends. The hydrogenation catalysts currently produced in the domestic industry are basically oxidation-type. New catalysts or regenerated catalysts produced in industry contain active metal components (Mo, Ni, Co, W) in the oxidation state (MoO 3 , NiO, CoO, WO 3 ) exists in the form of The practice of basic research and industrial application shows that most of the active metal component...

AI Technical Summary

Problems solved by technology

[0006] The application of this combination of catalysts still has risks to a certain extent, so it limits its large-scale industrial application

First of all, the external presulfided catalyst is prone to concentrated exothermic phenomenon during the heating process, and the auxiliary agent added to the second type of active center catalyst will also release a large amount of heat after hydrogenolysis, which is different from the above external presulfurized catalyst. The superposition of heat will cause overheating or overheating of the catalyst bed in severe cases

Especially in the airtight process of hydrogenation devices, because there is only a low-flow circulating medium in the system at this time, the heat carrying capacity is extremely low, and the heat superimposed on the exothermic heat of the catalyst cannot be carried out, and the risk of overheating or overheating will further increase, which affects the smooth operation of the device, and also limits the popularization and application of external presulfided type II active center catalysts

[0007] In addition, due to the limitation of "hydrogen embrittlement" conditions, the airtight process of hydrogenation devices strictly requires the lower limit of the boosting temperature of the high-pressure part, that is, the subsequent pressurization and airtight operation of the high-pressure part can only be carried out after the temperature exceeds a certain value. The application conditions are contrary to the application conditions, which further limits the popularization and application of external presulfided type II active center catalysts

[0008] Chinese patents CN103773436A and CN102443412A introduced the start-up method of the hydrogenation catalyst of the second type of active center presulfurized outside the device, which can make better use of the characteristics of the catalyst without affecting the performance of the hydrogenation catalyst of the second type of active center, simplify the The start-up process can reduce the energy consumption of the device or help the catalyst to form more second-type hydrogenation active centers, which is conducive to improving the performance of the catalyst. However, the start-up process still uses the second-type active center. The external presulfurized catalyst is bound to There is a risk of catalyst bed overheating during activation and airtightness, and if the energy released by the two is superimposed, the probability of risk will be further increased

[0010] Chinese patent CN102311766A introduces the start-up method of hydrogenation catalysts with second-type active centers. Although more second-type active centers can be generated under this method, the release of a certain amount of heat is not enough to cause the catalyst bed to overheat, but the catalyst is not carried out. External pre-sulfurization treatment, so it does not have the characteristics of environmental protection and simple start-up process of external pre-sulfurization catalysts

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