pressure problem

[marantinj]

We will be producing HCl off gas from a chemical reaction (approximately 8.3kg/h). In order to dilute this, it will first go through a water rinse of 55kg/h to get it to 15% solution. I will need to determine the pressure which arises from this system.

Thereafter, the diluted HCl will go through a caustic scrubber (20% NaOH). I will need to determine the heat of this reaction as well as the pressure produced.

Can anyone help with this?

 

[Chance17]

HCL solutions begin to "fume" (boiling point) at 28%.
So if you absorb HCL into a 15% solution, the HCL vapor fraction will not generate pressure.

The main heat effect in the caustic scrubber is the physical "heat of dilution" for NAOH.
These data should be available from many sources.
You would likely see a moderate temperature increase.
There is no significant pressure generation so long as the temperature is below 212-F.

The HCL also has a heat of dilution but at 15% the heat is small.

 

[bimr]

I agree that is just a heat of reaction question.

If the resulting temperature rise is undesirable, all you need to do is add additional dilution water which will take away the heat generated by the reaction.

Since this reaction does not need to be contained, there is no pressure generated.