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In our electrolysis of brine, $\ce{Cl2}$ and $\ce{H2}$ are produced as gaseous products along with aqueous $\ce{NaOH}$. In this scenario I require what amount of maximum moisture can $\ce{Cl2}$ and $\ce{H2}$ hold up at specific temperature & pressure (precisely 85 celsius & 1.2bar absolute). Two coolers (shell/tube exchanger with chilled water on shell side) are planned to dehumidify these two gases.

I have searched hard but without proper psychrometric data am unable to even estimate preliminary values. Link to data or other alternatives are highly welcome.

regards,

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I have searched hard but without proper psychrometric data am unable to even estimate preliminary values.

You have to google for 'vapor pressure' of water and ideal gas model. In cases ideal gas model is close enough to true, the total pressure is divided into partial pressures, attributed to different gases, and the partial pressures are proportional to amount of molecules in the gas mixture. So, in the case the equilibrium partial pressure of water vapors above the liquid can be found in any table of vapor pressures, the rest of the pressure would be other gases. In the case of vapor above saline water, the equilibrium pressure is reduced by the fact that the salt is present. The exact reduction is guarded by Raoult's Law and is linearly proportional to the concentration of the salt.

Two coolers (shell/tube exchanger with chilled water on shell side) are planned to dehumidify these two gases.

To dehumidify these gases effectively, if this is really required, consider bubbling them through layer of concentrated $\ce{H2SO4}$, it is a quite common and easy way to dehumidify gases.

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  • $\begingroup$ Thanks for replying but I don't know the amount of water vapour being carried by say per kg Cl2 at given conditions. If this is known your method of obtaining water's vapour pressure & hence Cl2 partial pressure is valid, but thats why I need psychrometric data. What we do know is all about Cl2 its temperature & quantity & total absolute pressure (Cl2 + H2O) $\endgroup$
    – nightcrawler
    Aug 30 '14 at 7:35
  • $\begingroup$ @nightcrawler water vapor pressures: en.wikipedia.org/wiki/Vapour_pressure_of_water | $pV=\nu RT$ allows to move from the partial pressure to moles of water per liter, and the rest of absolute pressure is the partial pressure chlorine, from which you can get moles of chlorine per liter. From here you can get equilibrium percentage of water vapors in chlorine at any given temperature and total pressure. Seriously, read about partial pressures and ideal gas model, they appear in chemistry regularly. $\endgroup$
    – permeakra
    Aug 30 '14 at 7:44

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