Activated carbon regeneration

Some say the regeneration temperature for activated carbon is 100-110 degrees, while others claim it can reach 120 degrees. Activation and regeneration are different; it can reach 130-150 degrees. Moreover, the hydrogen flow rate during regeneration is also uncertain; for example, the hydrogen flow rate required to regenerate 17 tons of activated carbon is only 90 M3/H, which is truly questionable. I’m not sure what the experts think; those who know would be so kind as to advise me!

This post was last edited by BIERGAI on 2009-9-14 at 22:34. I’m also thinking about this issue! The desorption temperature needs to be determined based on the desorption pressure and the desorption medium; it’s not necessarily 120 degrees. Desorption is carried out to facilitate better adsorption. The fact that “the hydrogen flow rate for regenerating 17 tons of activated carbon is only 90 M3/H” is because the adsorption tower continues to be heated during desorption, and the increase in temperature acts as a driving force for desorption (the lower the pressure, the higher the temperature; moreover, the lower the partial pressure of chlorosilane in the gas phase, the easier desorption becomes). Using an appropriate desorption temperature can reduce the amount of hydrogen required for desorption (increasing the yield of product hydrogen) and ensure safety. The more thorough the desorption, the better for absorption (but high hydrogen partial pressure and low absorption temperature are still required during absorption, so there must also be a process of using hydrogen to equalize pressure and cool down). If conditions permit, the desorption temperature should be above 145 degrees. If you’re working with this in practice, could you share some data? Maybe I can be helpful to you! (It might help reduce energy consumption and prevent wear on the heating coils in the adsorption tower.)

We are carrying out the operation in practice, but it is said that a resolution of 145 degrees can easily cause cracking of the activated carbon. We are currently using around 110 degrees with a pressure of 0.16 MPa; I’m not sure whether this is appropriate, as there are no specific figures available at the moment

We are currently using 17-ton activated carbon columns, with the regeneration temperature controlled at around 100 degrees. Experts have said that the partial pressure should be 0.18 MPa, but based on the current performance, it’s only average. I don’t know which reason it is exactly. (It can be considered, if what you say is true.)

Solutions for activated carbon poisoning and caking

We suspect that caking has occurred inside our activated carbon columns; currently, the pressure rises slowly when replacing the columns. Others say that the only option is to re-activate them, but is it possible to carry out major repairs at present? I wonder if any experts have a better solution. Find another expert to explain carbon monoxide poisoning and its solutions

I’ve already sent you a text message! First of all, I want to thank you for your trust. I hope you can give me more guidance! The specific values, such as the partial pressure of chlorosilane in the gas phase during desorption and the desorption temperature, need to be determined based on the proportions of various components entering the adsorption tower. You’re absolutely right – although a higher temperature facilitates desorption, an excessively high temperature can cause coking of the activated carbon. I hope to have more discussions with you in the future!

No one here has calculated this voltage division; we don’t have the necessary analysis equipment. Could you explain how to calculate it and what auxiliary tools are required? If possible, I’ll try to do the calculation myself

If the concentration of chlorosilane coming from the HCL adsorption tower is high, and the operating temperature in the H2 adsorption tower is low, it may lead to the condensation of chlorosilane; the cause should be sought in the HCL adsorption tower. Additionally, since I am not aware of the structure of your H2 adsorption tower, if no distributor is used for the inlet gas during adsorption and desorption, dead zones will form at the upper and lower ends of the activated carbon column, near the wall of the cylinder – areas that cannot participate in the adsorption and desorption processes – which also affects the efficiency of the activated carbon column. Moreover, if internal coils with external jackets are used for heating, the heat transfer gradient may result in certain areas not reaching the desired desorption or adsorption temperatures, again affecting the efficiency of the activated carbon column.

"The adsorption operation temperature of the H2 adsorption tower is relatively low, which may lead to the condensation of chlorosilanes. What exactly constitutes a low temperature? And if clumping occurs, are there any solutions?