Due to the increase in the catalyst circulation rate, the carbon difference between the raw catalyst and the regenerated catalyst decreases, thereby improving the effective activity of the catalyst...

1. Who reduces the carbon difference and by how much? It is the carbon content of the raw material minus the carbon content determined by the regenerating agent. 2. Is the decrease in the carbon difference due to a higher carbon content determined by the regenerating agent, or a lower carbon content of the raw material? Why? They rise simultaneously; this situation can easily occur in carbon stacks, and it is not recommended to use this approach unless there is an excess of new catalysts. 3. Is it related to the reduction in active centers and carbon difference, or to an increase in circulation volume? The increase in carbon content due to the regenerant can only result from a reduction in the effective active centers ； The circulation rate is determined by the regeneration temperature and the tube orientation, with little relation to the carbon difference.

Second question: The coking effect is generally constant, so the carbon content determined by the regenerator remains roughly the same. The overall effect of the unreacted catalyst is a decrease in coke content (the total amount of coke produced may increase due to an increased catalyst circulation rate, but the amount of coke per unit of catalyst decreases), resulting in a reduction in the carbon difference. Third question: as the circulation volume increases, the active centers of the catalyst naturally increase as well.

1. Who reduces the carbon difference and by how much? It is the carbon content of the raw material minus the carbon content determined by the regenerating agent. Understood. 2. Is the decrease in the carbon difference due to a higher carbon content determined by the regenerating agent, or a lower carbon content of the raw material? Why? They rise simultaneously; this situation can easily occur in carbon stacks, and it is not recommended to use this approach unless there is an excess of new catalysts. The simultaneous increase is caused by an increased circulation volume and a shortened residence time. 3. Is it related to a decrease in active centers and carbon difference, or is it related to the increased circulation volume? The increase in carbon content due to the regenerant can only result from a reduction in the effective active centers ； The circulation rate is determined by the regeneration temperature and the tube orientation, with little relation to the carbon difference. The technical Q&A clearly mentions an \"increase in effective active centers\" – how should this be understood? ? ? ? ?

This post was last edited by “IAskYou” on June 7, 2015, at 22:58. Second question: The coking effect is generally constant; therefore, the fixed carbon content in the regenerated catalyst remains largely unchanged. For the spent catalyst, the overall effect is a reduction in coke content (although the total amount of coke formed may increase due to the higher circulation rate of the catalyst, the amount of coke formed per unit of catalyst decreases), and the difference in carbon content between the two types of catalysts is also reduced. “The total amount of coke formation may increase, but the amount of coke formation per catalyst decreases. What does \"amount of coke formation per catalyst\" mean? Does the carbon fixation of the green body refer to the total coke content? The total amount of char formed increases; when the carbon content of the regenerant remains constant, the difference in carbon content increases as well. Why? ? ? ? ? ? ? ? ? Third question: as the circulation volume increases, the active centers of the catalyst naturally increase as well. The premise of the third question is that an increase in the oil-to-agent ratio leads to a reduction in carbon defects and an increase in effective active centers. After analyzing the conclusions you provided, it seems to me that you have only taken into account the volume of circulation, without considering the effect of the increased carbon content on reducing the number of effective active centers. I’m not sure if I understand correctly.

Secondly, I think that if the processing volume remains unchanged and the reaction temperature as well as the hydrogen-to-oil ratio stay the same, the total amount of coke produced will remain constant. Since the catalyst circulation rate increases, the carbon content in the regenerator decreases. Thirdly, the number of active centers increases due to the increased catalyst circulation rate

“The total amount of coke formed may increase, but the amount of coke formed per unit of catalyst decreases. I struggled with this for a long time without being able to figure it out; however, during today’s training session, when explaining the catalyst-to-oil ratio, it suddenly became clear: assume that, with constant raw materials and reaction conditions, the amount of coke formed remains fixed. At this point, by increasing the catalyst circulation rate, the amount of coking generated is distributed over more catalysts; as a result, the amount of coking per unit of catalyst decreases. Is this the correct way to understand it?

Many problems in catalysis require one or more prerequisites; otherwise, many of these problems cannot be addressed!

Thank you to all the sea friends for your replies; I’ve learned a lot from them.