The issue of water content in petroleum benzene
Thread Content
Dear experts from Haichuan, how is the issue of water content in petroleum benzene handled in current extraction units? The device currently has a water content of around 400 ppm; will the new coalescer be able to handle this? Are there any other ways to handle it? Thank you.
For free water, coagulators can solve the problem, but they are ineffective against dissolved water. Water has a higher solubility in benzene than in saturated hydrocarbons, and more stringent measures are required for dehydration
Previously, when I communicated with the coalescer manufacturers, they said that the water content reduction achieved by their coalescers could be reduced to below 200 ppm. However, it’s definitely abnormal for benzene to contain water. Check whether there is too much free water in the feed to the benzene distillation tower, and also see if there is more water in the dehydration unit of the reflux tank compared to before; verify as well whether the reflux ratio is appropriate, and compare it with the design parameters. In our benzene, the water content is just a few dozen ppm
You can check the solubility data sheet; water has a very high solubility in benzene. At room temperature, it exceeds 4–500 ppm. In this state, the water is in a dissolved form; as the person above mentioned, coagulators are ineffective against dissolved water. You need to try other dehydration separation methods
Are you using distillation extraction or liquid-liquid extraction?
Does 400PPM refer to the total water content? In that case, it is not very meaningful to use a coalescer, as a coalescer can only separate free water. You can start by making adjustments to the process, and then consider installing equipment; I hope this helps.
The water content is too high; find out where the problem lies and address it at its root!
At 40°C, the solubility of water in benzene is approximately 1140 ppm (wt); therefore, this is also the maximum water content that can be achieved after treatment with a coalescer. A coalescer can only remove free water; it is unable to remove dissolved water.