【Q&A Question 293】November 7, 2017
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[Q&A Question 293] November 7, 2017: What is the impact of various key operating parameters on the hydrogenation reaction? (System pressure, hydrogen partial pressure, recycle hydrogen flow rate, recycle hydrogen purity, reaction temperature) ① System pressure: A higher pressure is favorable for the hydrogenation reaction, but it is limited by the operating pressure of the equipment. ②Hydrogen partial pressure: An increase in the hydrogen partial pressure can inhibit coking reactions, promote hydrogenation saturation reactions, and reduce the rate of catalyst deactivation; therefore, the hydrogen partial pressure should be increased as much as possible within the limits permitted by the equipment and operating conditions. ③Cyclic hydrogen flow rate: Its role is to maintain a high hydrogen partial pressure and remove the heat generated by the reaction in the catalyst bed; maintaining a high cyclic hydrogen flow rate as much as possible is beneficial for the hydrogenation reaction. ④Cyclic hydrogen purity: An increased purity of cyclic hydrogen ensures an adequate hydrogen partial pressure, which is beneficial for the hydroprocessing reaction. ⑤Reaction temperature: Increasing the temperature can accelerate the reaction rate and enhance the degree of reaction ； However, the deactivation rate of the catalyst increases at high temperatures, especially as localized high temperatures have the most adverse effect on the catalyst’s service life. A reasonable temperature should be controlled based on the performance of the catalyst in each bed layer, in order to ensure an optimal temperature distribution as much as possible and thus extend the catalyst’s service life. (Unless otherwise specified, all questions and answers are based on hydrogenation units.) ) For management purposes, if you need to view content from a few days ago, please go through the summary post below. 2017 Q&A Summary Thread (updates have begun) http://bbs.hcbbs.com/thread-1657793-1-1.html 2017 Daily Question Summary Thread (updates have begun) http://bbs.hcbbs.com/thread-1657794-1-1.html 2016 Q&A Summary Thread (updates completed) http://bbs.hcbbs.com/thread-1597792-1-1.html (Source: Haichuan Chemical Industry Forum)
1) System pressure: High pressure is favorable for the hydrogenation reaction, but it is limited by the operating pressure of the equipment. (2) Hydrogen partial pressure: An increase in the hydrogen partial pressure can inhibit coking reactions, promote hydrogenation saturation reactions, and reduce the catalyst deactivation rate; therefore, the hydrogen partial pressure should be increased as much as possible within the limits permitted by the equipment and operating conditions. (3) Circulating hydrogen flow rate: Its role is to maintain a high hydrogen partial pressure and remove the heat generated by the reaction in the catalyst bed; maintaining a high circulating hydrogen flow rate as much as possible is beneficial for the hydrogenation reaction
(1) System pressure: High pressure is favorable for the hydrogenation reaction, but it is limited by the operating pressure of the equipment. (2) Hydrogen partial pressure: An increase in the hydrogen partial pressure can inhibit coking reactions, promote hydrogenation saturation reactions, and reduce the catalyst deactivation rate; therefore, the hydrogen partial pressure should be increased as much as possible within the limits permitted by the equipment and operating conditions. (3) Circulating hydrogen flow rate: Its role is to maintain a high hydrogen partial pressure and remove the heat generated by the reaction in the catalyst bed. Maintaining a high circulating hydrogen flow rate as much as possible is beneficial for the hydrogenation reaction.
Answer: Influence of various main operating parameters on the hydrogenation reaction: ① System pressure – A higher pressure is favorable for the hydrogenation reaction, but it is limited by the operating pressure of the equipment. ②Hydrogen partial pressure: An increase in hydrogen partial pressure can inhibit coking reactions, promote hydrogenation saturation reactions, and reduce the rate of catalyst deactivation; therefore, the hydrogen partial pressure should be increased as much as possible, within the limits permitted by the equipment and operating conditions. ③Cyclic hydrogen flow rate: Its role is to maintain a high hydrogen partial pressure and remove the heat generated by the reactions in the catalyst bed. Maintaining a high cyclic hydrogen flow rate as much as possible is beneficial for the hydrogenation reaction. ④Cyclic hydrogen purity: An increase in the purity of cyclic hydrogen ensures an adequate hydrogen partial pressure, which is beneficial for the hydroprocessing reactions. ⑤Reaction temperature: An increase in temperature can accelerate the reaction rate and enhance the degree of reaction ； However, the deactivation rate of the catalyst increases at high temperatures, especially as localized high temperatures have the most adverse effect on the catalyst’s service life. A reasonable temperature should be controlled based on the performance of the catalyst in each bed layer, in order to ensure an optimal temperature distribution as much as possible and thus extend the catalyst’s service life.
1) System pressure: High pressure is favorable for the hydrogenation reaction, but it is limited by the operating pressure of the equipment. (2) Hydrogen partial pressure: An increase in the hydrogen partial pressure can inhibit coking reactions, promote hydrogenation saturation reactions, and reduce the catalyst deactivation rate; therefore, the hydrogen partial pressure should be increased as much as possible within the limits permitted by the equipment and operating conditions. (3) Circulating hydrogen flow rate: Its role is to maintain a high hydrogen partial pressure and remove the heat generated by the reaction in the catalyst bed; maintaining a high circulating hydrogen flow rate as much as possible is beneficial for the hydrogenation reaction
High pressure, fast response, low coking rate； High hydrogen partial pressure, low coking rate ； The flow rate of recycled hydrogen is high, the processing volume is large, and the reaction rate increases ； The purity of the recycled hydrogen is high ； High hydrogen partial pressure, low coking rate, high reaction temperature, and high reaction depth
1) System pressure: High pressure is favorable for the hydrogenation reaction, but it is limited by the operating pressure of the equipment. (2) Hydrogen partial pressure: An increase in the hydrogen partial pressure can inhibit coking reactions, promote hydrogenation saturation reactions, and reduce the catalyst deactivation rate; therefore, the hydrogen partial pressure should be increased as much as possible within the limits permitted by the equipment and operating conditions. (3) Circulating hydrogen flow rate: Its role is to maintain a high hydrogen partial pressure and remove the heat generated by the reaction in the catalyst bed; maintaining a high circulating hydrogen flow rate as much as possible is beneficial for the hydrogenation reaction
System pressure: High pressure is favorable for the hydrogenation reaction, but it is limited by the operating pressure of the equipment. Hydrogen partial pressure: An increase in the hydrogen partial pressure can inhibit coking reactions, promote hydrogenation saturation reactions, and reduce the rate of catalyst deactivation; therefore, the hydrogen partial pressure should be increased as much as possible within the limits permitted by the equipment and operating conditions. Cyclic hydrogen flow rate: Its role is to maintain a high hydrogen partial pressure and remove the heat generated by the reaction in the catalyst bed; maintaining a high cyclic hydrogen flow rate as much as possible is beneficial for the hydrogenation reaction.
Effect of various main operating parameters on the hydrogenation reaction: 1) System pressure – A higher pressure is favorable for the hydrogenation reaction, but it is limited by the operating pressure of the equipment. 2) Hydrogen partial pressure: An increase in the hydrogen partial pressure can inhibit coking reactions, promote hydrogenation saturation reactions, and reduce catalyst deactivation. Therefore, within the limits permitted by the equipment and operating conditions, the hydrogen partial pressure should be increased as much as possible. 3) Circulating hydrogen flow rate: Its role is to maintain a high hydrogen partial pressure and remove the heat generated by reactions in the catalyst bed. Maintaining a high circulating hydrogen flow rate will be beneficial for the hydrogenation reaction. 4) Circulating hydrogen purity: An increase in the purity of circulating hydrogen ensures an adequate hydrogen partial pressure, which is beneficial for the hydroprocessing reaction. 5) Reaction temperature: An increase in temperature can accelerate the reaction rate and enhance the degree of reaction ； However, the deactivation rate of the catalyst increases at high temperatures; in particular, localized high temperatures have the most adverse effect on the catalyst’s service life. It is necessary to control the temperature appropriately based on the performance of the catalyst in each bed, in order to achieve the best temperature distribution and thus extend the catalyst’s service life as much as possible.
1) System pressure: A high pressure is favorable for the hydrogenation reaction, but it is limited by the operating pressure of the equipment. 2) Hydrogen partial pressure: An increase in the hydrogen partial pressure can inhibit coking reactions, promote hydrogenation saturation reactions, and reduce catalyst deactivation. Therefore, within the limits permitted by the equipment and operating conditions, the hydrogen partial pressure should be increased as much as possible. 3) Circulating hydrogen flow rate: Its role is to maintain a high hydrogen partial pressure and remove the heat generated by reactions in the catalyst bed. Maintaining a high circulating hydrogen flow rate will be beneficial for the hydrogenation reaction. 4) Circulating hydrogen purity: An increase in the purity of circulating hydrogen ensures an adequate hydrogen partial pressure, which is beneficial for the hydroprocessing reaction. 5) Reaction temperature: An increase in temperature can accelerate the reaction rate and enhance the degree of reaction ； However, the deactivation rate of the catalyst increases at high temperatures; in particular, localized high temperatures have the most adverse effect on the catalyst’s service life. It is necessary to control the temperature appropriately based on the performance of the catalyst in each bed, in order to achieve the best temperature distribution and thus extend the catalyst’s service life as much as possible.