I would like to know why the use of benzene removal agents and coconut shell activated carbon yields poor results in removing trace amounts of benzene from carbon dioxide
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I would like to ask the experts: Our factory plans to produce food-grade carbon dioxide. The benzene content in the raw gas is 10–20 ppb, and even after using benzene removal agents and coconut shell activated carbon, the benzene level remains at 6–10 ppb; thus, the benzene removal effect is poor. The process conditions are a flow rate of 3,000–6,000 cubic meters per hour, a total amount of 12 cubic meters of debenzing agent and coconut shell activated carbon, and an operating temperature of -7°C. I would like to ask the expert what causes the poor debenzing effect
Have you ever had any successful cases of using this process to reduce benzene levels from 20 to the desired value? What are the differences between the current conditions and those in those successful cases?
Our another branch company uses a process similar to ours; they are able to reduce the benzene level from 80 ppb to levels undetectable by instruments. The main difference between their process and ours lies in the operating temperature – theirs is 15°C, while ours is -7°C. I found online that benzene is in solid form at 5 degrees Celsius, but by raising the operating temperature to 8°C, the benzene removal efficiency improves slightly, allowing us to achieve levels of 3–7 ppb.
Too low a temperature is not necessarily a good thing. Activated carbon absorbs not only benzene but also carbon dioxide; if the temperature is too low, its ability to absorb carbon dioxide becomes too strong, which hinders its absorption of benzene
So, what range of temperatures is considered the best for the adsorption of activated carbon like this?
I don’t know; the optimal temperature varies depending on the two components that need to be separated
Oh, thank you. I’ll try the adsorption effect at different temperatures again.