Method for preparing ethylene cracking feed by hydrogenation of liquefied gas

Abstract

The invention discloses a method for preparing ethylene cracking feed by hydrogenation of liquefied gas. Liquefied gas and hydrogen pass through a hydrogenation reactor in a parallel flow manner and is in contact with hydrogenation catalysts for reaction; two or more hydrogenation catalyst bed layers are arranged in the hydrogenation reactor; the hydrogen enters the two or more hydrogenation catalyst bed layers from different feeding openings respectively; the amounts of the hydrogen entering all the hydrogenation catalyst bed layers are 5 to 95 volume percent of chemical hydrogen consumption required by reaction separately; except the last hydrogenation catalyst bed layer, the sum of total amounts of the hydrogen entering other hydrogenation catalyst bed layers is smaller than the required chemical hydrogen consumption. According to the method disclosed by the invention, by controlling partial pressures of the hydrogen entering different catalyst bed layers, the reaction speed is effectively controlled, and accurate control over the conversion rate is realized, so that reaction temperature rise of all sections of catalyst bed layers in the reactor is reduced, further the carbon deposit speed of the catalyst is retarded, and the single-pass service life of the catalyst is prolonged.

Description

technical field [0001] The invention relates to a method for preparing ethylene cracking material through hydrogenation of liquefied gas, more specifically, a process involving the stepwise feeding of hydrogen through a reactor to adjust the partial pressure of reactive hydrogen. Background technique [0002] With the development of oil refining industry, especially the continuous improvement of catalytic cracking technology, people pay more and more attention to the deep processing of refinery gas. There are many ways to utilize refinery gas, among which hydrogenation of liquefied gas is one of the topics that people generally pay attention to. Liquefied petroleum gas can be used for many purposes after hydrogenation, such as ethylene raw material, raw material for the synthesis of maleic anhydride, and liquefied gas for vehicles. Among them, liquefied petroleum gas is used as ethylene raw material because of its large amount and involves many production devices, so it is p...

AI Technical Summary

Problems solved by technology

This method solves the C 4 The stability of the distillate hydrogenation process solves the problem that the olefin content in the hydrocoked gasoline obtained from the coker gasoline hydrogenation unit is high, and it is difficult to meet the quality requirements of steam cracking raw materials

However, in actual industrial installations, when the olefin content in the liquefied petroleum gas feedstock is high (35v%-50v%), the problem that the hot spot temperature (or temperature bulb) is too high will easily cause the catalyst bed to deposit carbon quickly has not yet been solved. be better resolved, thereby affecting the single-pass service life of the catalyst

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