Coking naphtha hydrofining method

Abstract

The invention discloses a coker naphtha hydrofining method which comprises the following steps: coker naphtha and hydrogen flow into a hydrogenation reactor in parallel to react with a catalyst; a hydrodesilication catalyst bed layer and n hydrofining catalyst bed layers are sequentially arranged in the hydrogenation reactor along the material flowing direction, wherein n is greater than or equal to 2; the n hydrofining catalyst bed layers are sequentially a first hydrofining catalyst bed layer, a second hydrofining catalyst bed layer,..., and an Nth hydrofining catalyst bed layer along a material flowing direction; the hydrodesiliconization catalyst bed accounts for 10-50% of the total catalyst bed volume; catalyst active metals in the n hydrofining catalyst bed layers are increased layer by layer from the first to the Nth. According to the method, the hydrodesiliconization agent and the hydrofining catalyst are combined and graded in stages and the hydrogen feeding mode is adjusted aiming at the technological processes of removal of impurity silicon in the coked naphtha and olefin hydrogenation saturation, so that the carbon deposition resistance and the desiliconization capability of the catalyst bed layers are improved.

Description

technical field [0001] The invention belongs to the field of petrochemical industry, and in particular relates to a method for hydrofining coking naphtha. Background technique [0002] Delayed coking is one of the important means of processing inferior heavy oil. The naphtha yield in the delayed coking process is usually about 15%, and these coking naphthas contain relatively high levels of impurities such as sulfur, nitrogen, olefins, and colloids. Poor stability, not suitable for motor gasoline, so many refineries are equipped with coker naphtha hydrogenation unit. In the process of coking naphtha hydrofining, on the one hand, due to the high content of olefins and colloids in coking naphtha, olefins are easy to be hydrogenated and saturated, and most of the reactions are usually completed in the upper part of the catalyst bed, resulting in a huge heat release. Taking coking gasoline containing 40% as an example, if it is fully reacted, the adiabatic reaction temperature ...

AI Technical Summary

Problems solved by technology

[0005] In the above scheme, the conventional hydrofining catalyst bed is a single bed. Considering that the exothermic heat of the olefin hydrogenation reaction is concentrated on the upper part of the refining catalyst, colloidal coking in the upper part will cause a rapid increase in pressure drop, and the single start-up period of the device will be short.

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