【Q&A Question 012】2017.01.12
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This post was last edited by 955559 on 2017-7-21 at 13:00. [Q&A Question No. 012] January 12, 2017: What are the harms of water to catalysts? The reference answers will be visible after responding; points are awarded by identifying the key points. (Unless otherwise specified, all questions and answers are based on hydrogenation units.) ) 1. A small amount of water is in gaseous form within the reaction system; its low concentration has virtually no effect on the catalyst’s activity or stability. 2. When liquid water or high-concentration water vapor comes into contact with the catalyst, it causes metal agglomeration on the catalyst, crystal deformation, and changes in the catalyst’s shape, thereby compromising its mechanical strength, activity, and stability. 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 Xinchang Cup – 2016 Haichuan Top 10 Selection – Please recommend candidates http://bbs.hcbbs.com/thread-1654112-1-1.html Third Round of Haichuan Outstanding Management Members Selection http://bbs.hcbbs.com/thread-1655902-1-1.html (Source: Haichuan Chemical Forum)
Water reduces the mechanical strength of the catalyst
1) The moisture in the feed oil affects the strength of the catalyst carrier; when the moisture content is high, it can lead to a decrease in the catalyst’s surface area, as well as to the breakdown or pulverization of the catalyst carrier, resulting in an increase in system pressure drop and a loss of active components. (2) At relatively low levels, the moisture in the feed oil has little effect on the active metal components of the catalyst; however, at higher levels, it causes aggregation of these metal components, thereby reducing or even eliminating their catalytic activity. (3) Moisture in the feed oil also affects the system pressure drop – higher moisture levels lead to an increased pressure drop, which raises the energy consumption of the facility. In severe cases, this can cause the recycle hydrogen compressor to become overloaded and forced to shut down.
Water has a significant impact on the activity and strength of catalysts; in severe cases, it can affect the catalyst’s service life. When water vaporizes, it absorbs a large amount of heat, which increases the thermal load on the reactor F-4101. After water vaporizes, the system pressure rises, leading to pressure fluctuations or even overpressure. Additionally, when the feed oil contains a high amount of water, the large amount of heat absorbed during water vaporization causes the bed temperature to drop. Once the feed oil contains little or no water, the bed temperature rises again. If the cold hydrogen valve does not function properly or there is insufficient cold hydrogen, the bed temperature may rise excessively, even to the point of \"temperature runaway.\" Sudden temperature fluctuations can cause the catalyst to break down
Water has a significant impact on the activity and strength of catalysts; in severe cases, it can affect the catalyst’s service life. When water vaporizes, it absorbs a large amount of heat, which increases the thermal load on the reaction furnace F-4101. After water vaporizes, the system pressure rises, leading to pressure fluctuations or even overpressure. Additionally, when the feed oil contains a high amount of water, the large amount of heat absorbed during water vaporization causes the bed temperature to drop. Once the feed oil contains little or no water, the bed temperature rises again. If the cold hydrogen valve does not function properly or there is insufficient cold hydrogen, the bed temperature may rise excessively, even to the point of \"temperature runaway.\" Sudden temperature fluctuations can cause the catalyst to break down.
It has a significant impact on the catalyst’s activity and strength; in severe cases, it affects the catalyst’s service life. The vaporization of water requires the absorption of a large amount of heat, which increases the thermal load on the reaction furnace. After water vaporizes, it raises the system pressure, leading to pressure fluctuations or even overpressure.
It damages the structure of the catalyst carrier, causing the catalyst to become damaged and reducing its mechanical strength. . .
In a reaction system, the majority of the water present is in gaseous form. At low concentrations, it has little effect on the catalyst’s activity and stability. However, when liquid water or high-concentration water vapor comes into contact with the catalyst, it can cause metal aggregation on the catalyst, crystal deformation, and changes in the catalyst’s shape, thereby compromising its mechanical strength as well as its activity and stability.
At relatively low levels, moisture has little effect on the active metal components of the catalyst; however, at higher levels, it causes metal agglomeration of these active metal components, leading to the breakdown or pulverization of the catalyst carrier. This results in an increase in system pressure drop and a loss of active components.