HCl-Air-Water Vapor Equilibrium Question
HCl-Air-Water Vapor Equilibrium Question
(OP)
Hi guys. I have a dumb mechanical engineer question. I am trying to determine the composition of the gas mixture that is present in the vapor space above the liquid inside an atmospheric storage tank. The tank contains 35.2% HCl. So I fired up my trusty simulator to run a flash calc to determine the composition, and it is 85.2 mole % air, 3.9% H20, and 10.9% HCl vapor at 115° F and 0 psig. OK, nice. Now the question is, since HCl is about 2x heavier than equilibrium saturated air (air-water vapor mixture), will this gas mixture segregate into layers over time? If so, how do I determine the time?
I need the vapor phase composition to support the sizing of the PVRV for the tank and also for the tank vent vapor scrubber. Never fails, I shoulda been a ChE. Life is a cruel teacher; it makes you take the exam before you've even had a chance to study. Thanks guys!
I need the vapor phase composition to support the sizing of the PVRV for the tank and also for the tank vent vapor scrubber. Never fails, I shoulda been a ChE. Life is a cruel teacher; it makes you take the exam before you've even had a chance to study. Thanks guys!





RE: HCl-Air-Water Vapor Equilibrium Question
RE: HCl-Air-Water Vapor Equilibrium Question
Good luck,
Latexman
Technically, the glass is always full - 1/2 air and 1/2 water.
RE: HCl-Air-Water Vapor Equilibrium Question
The API 2000 tables are based on hexane. This particular vapor phase is far far away from Hexane so I did not feel I could defend a decision to use the tables vs. actually running the calcs.