[Q&A Question 218] 2016.11.24
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【Q&A Question 218】November 24, 2016: What are the hazards of too low feed rate to the device? A reference ** will be shown after responding; scoring is achieved by answering the key points. 1. At the same temperature, a low space velocity and long residence time result in intense hydrogenation reactions, which can make it difficult to control the bed temperature ； 2. Too low an air velocity increases the likelihood of condensation reactions, leading to coking on the catalyst surface ； 3. Too low an air velocity will increase the content of light components in the products, especially the amount of gas ； 4. Too low an air velocity can lead to channeling in the reaction bed ； 4. A low air velocity increases the operational difficulty of the distillation system. Summary post of Q&A from 2016 (updated as of November~~~~) http://bbs.hcbbs.com/thread-1597792-1-1.html Seeking sponsors for the “2016 Haichuan Top 10 Members Selection Contest” http://bbs.hcbbs.com/thread-1628108-1-1.html (Source: Haichuan Chemicals Forum)
Too low an air velocity can cause the pump to stall and suffer damage; it can also lead to flow deviation, resulting in an uneven temperature distribution in the reactor bed, which affects the catalyst. Too low an air velocity reduces the reaction heat, increasing the energy consumption of the heating furnace
1. At the same temperature, a low space velocity and long residence time result in intense hydrogenation reactions, which can make it difficult to control the bed temperature； 2. An excessively low space velocity increases the likelihood of condensation reactions, leading to coking on the catalyst surface ； 3. An excessively low air velocity results in a higher content of light components in the products, especially an increase in the amount of gas ； 4. Too low an air velocity can cause channeling in the reaction bed ； 5. When the feed rate is too low, the operation of the distillation system becomes more difficult.
1. At the same temperature, a low space velocity and long residence time result in intense hydrogenation reactions, which can make it difficult to control the bed temperature； 2. Too low an air velocity increases the likelihood of condensation reactions, leading to coking on the catalyst surface ； 3. Too low an air velocity will increase the content of light components in the products, especially the amount of gas ； 4. Too low an air velocity can lead to channeling in the reaction bed ； 4. A low air velocity increases the operational difficulty of the distillation system.
1\ Low feed rate results in a low space velocity, which leads to coking. 2. Low feed rate leads to cracking reactions, altering the product distribution. 3. The unit processing cost will increase
1. First, for the reaction, if the feed amount is too low, the reaction space velocity becomes too low; as the degree of reaction increases, side reactions also increase. A insufficient feed amount can lead to material channeling. 2. A decrease in the feed rate reduces the steam rise velocity, which can lead to a dry tower and liquid leakage; this is detrimental to mass transfer and reduces the efficiency of distillation. Therefore, during low-load operation, the reflux ratio can be appropriately increased to raise the velocity of the rising steam inside the tower, thereby improving the mass transfer efficiency.
1. At the same temperature, a low space velocity and long residence time result in intense hydrogenation reactions, which can make it difficult to control the bed temperature； 2. Too low an air velocity increases the likelihood of condensation reactions, leading to coking on the catalyst surface ； 3. Too low an air velocity will increase the content of light components in the products, especially the amount of gas ； 4. Too low an air velocity can lead to channeling in the reaction bed ； 4. A low air velocity increases the operational difficulty of the distillation system.
The disadvantages of too low a feed rate are: (1) at the same temperature, the space velocity is low and the residence time is long, resulting in intense hydrogenation reactions that make it difficult to control the bed temperature； (2) Too low an air velocity increases the likelihood of condensation reactions, leading to coking on the catalyst surface ； (3) An excessively low air velocity results in a higher content of light components in the products, especially an increase in the amount of gas ； (4) Too low an air velocity can cause channeling in the reaction bed ； (5) When the feed rate is too low, the operation of the diversion system becomes more difficult.
High energy consumption, prone to coking, high reaction depth, catalyst prone to overheating