A method for preparing ethylene cracking material 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...

Examples

Embodiment 1

[0048] The reaction adopts a fixed-bed reactor and feeds upwards. The catalyst is loaded in four stages, from top to bottom, the catalyst volume fraction of each stage is: 10%, 15%, 25%, 50%. The reaction is divided into four stages to feed hydrogen, and the amount of hydrogen fed to each stage of the bed is respectively: the amount of hydrogen entering the first catalyst bed in the first stage is 30v% of the chemical hydrogen consumption required for the reaction, and the amount of hydrogen entering the second catalyst bed in the second stage The amount of hydrogen in the bed is 30v% of the chemical hydrogen consumption required for the reaction, the amount of hydrogen entering the third catalyst bed in the third stage is 30v% of the chemical hydrogen consumption required for the reaction, and the fourth stage enters the fourth catalyst bed The amount of hydrogen is 50v% of the chemical hydrogen consumption required for the reaction. In addition to the liquefied gas, the rea...

Embodiment 2

[0061] Raw material used in this embodiment, catalyst are the same as embodiment 1. Distillate oil (coker gasoline) was not introduced during the reaction. The hydrogenation process conditions and results are listed in Table 7. The amount of carbon deposited in each section of the catalyst bed after operation is shown in Table 8.

[0062] Table 7 Operating conditions and results of liquefied gas hydrogenation reactor

[0063] Reaction conditions

[0064] Table 8 Coke analysis data of bed catalysts in each section after operation

[0065] Coke deposition in each section of the reactor bed

[0066] From the reaction results in Tables 7 and 8, it can be seen that the method of introducing hydrogen in stages in the scheme of the present invention is adopted, and distillate oil (coker gasoline) is not introduced during the reaction. The temperature rise of each section of the catalyst bed is higher than that in Example 1, and the amount of carbon deposits in ...

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...

Examples

Embodiment 1

[0048] The reaction adopts a fixed-bed reactor and feeds upwards. The catalyst is loaded in four stages, from top to bottom, the catalyst volume fraction of each stage is: 10%, 15%, 25%, 50%. The reaction is divided into four stages to feed hydrogen, and the amount of hydrogen fed to each stage of the bed is respectively: the amount of hydrogen entering the first catalyst bed in the first stage is 30v% of the chemical hydrogen consumption required for the reaction, and the amount of hydrogen entering the second catalyst bed in the second stage The amount of hydrogen in the bed is 30v% of the chemical hydrogen consumption required for the reaction, the amount of hydrogen entering the third catalyst bed in the third stage is 30v% of the chemical hydrogen consumption required for the reaction, and the fourth stage enters the fourth catalyst bed The amount of hydrogen is 50v% of the chemical hydrogen consumption required for the reaction. In addition to the liquefied gas, the rea...

Embodiment 2

[0061] Raw material used in this embodiment, catalyst are the same as embodiment 1. Distillate oil (coker gasoline) was not introduced during the reaction. The hydrogenation process conditions and results are listed in Table 7. The amount of carbon deposited in each section of the catalyst bed after operation is shown in Table 8.

[0062] Table 7 Operating conditions and results of liquefied gas hydrogenation reactor

[0063] Reaction conditions

[0064] Table 8 Coke analysis data of bed catalysts in each section after operation

[0065] Coke deposition in each section of the reactor bed

[0066] From the reaction results in Tables 7 and 8, it can be seen that the method of introducing hydrogen in stages in the scheme of the present invention is adopted, and distillate oil (coker gasoline) is not introduced during the reaction. The temperature rise of each section of the catalyst bed is higher than that in Example 1, and the amount of carbon deposits in ...

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