Method for producing ethylene cracking material by hydrogenation of dry gas

Abstract

The present invention discloses a method for producing an ethylene cracking material through dry gas hydrogenation. According to the method, olefin-containing dry gas and optional supplemented hydrogen enter a fixed bed hydrogenation reactor in a co-current flow manner, and contact a hydrogenation catalyst under a hydrogenation process condition, a reaction is performed, and the obtained reaction products are separated to obtain the dry gas having the saturated olefin; and the hydrogenation reactor comprises four reaction sections, and according to the sequence of the contact between the material and the catalyst, the law of the hydrogenation activity metal contents in the catalysts in each reaction section is the low content, the high content, the low content and the high content. According to the present invention, with the method, the relatively average reaction rate of the inlet section of the catalyst bed layer is reduced, the problem that the relatively average reaction rate of the inlet section of the catalyst bed layer is high is solved, the difference among the average reaction rates of each section of the bed layer is substantially reduced, and the relatively average reaction rates of each section are uniform; and with the method, the deep oxygen removal can be ensured.

Description

technical field [0001] The invention relates to a low-carbon olefin hydrogenation treatment process, more specifically, a method for hydrogenating olefin-containing dry gas to prepare ethylene cracking material. Background technique [0002] At present, most of the raw materials used in my country's ethylene plants are naphtha (naphtha accounts for 64%, hydrogenated tail oil accounts for 10%, and light diesel oil accounts for 10%). Ethylene raw materials are the most important factor affecting the cost of ethylene. Raw materials It accounts for 70% to 75% of the total cost, or even higher. In recent years, domestic petrochemical enterprises have built and expanded several sets of large-scale ethylene production units. Although the source of raw materials has been expanded in actual production, the raw materials for ethylene cracking are still quite tight; It also rises accordingly, and the economics of ethylene production units become worse. The reality forces companies to ...

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Problems solved by technology

Solved three of the above four difficulties, and compared with CN1800308A, it also simplified the process, but the problem of concentrated heat release and excessively high hot spot temperature (or temperature bulb) was still unsolved

[0008] In addition, the composition of dry gas produced by various enterprises is quite different. Generally, the olefin content in the dry gas produced is 4%~6%, and the oxygen content is 200~300 mg∙m -3 , but some enterprises produce dry gas with olefin content of 8%~14% and oxygen content of 5000~9000 mg∙m -3 , this kind of dry gas hydrogenation reaction heat is very large, if it is still produced according to CN103450941A, the reaction temperature will exceed the upper limit of catalyst use

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