# Does dalton's law hold for liquids?

1. Feb 21, 2009

### jimRH9

hullo, i was wondering; does dalton's law ( pressure*mole fraction = partial pressure) hold for liquids?

I'm doing a design project in uni on natural gas production. I'm trying to do a mass balance for the "hydrocarbon dewpoint contol" aspect of the "plant" which is oil absorption. I'm trying to find out how much hydrocarbon components (methane, ethane, propane, butane and pentane) the oil will absorb. I read in a book that it ereaches equilibrium when partial pressure of the liquid = partial pressure of the gas, so I tried to work out what the partial pressure of the gas will be (by the antoine equation, since both liquid and gas phases exist partial pressure = vapour pressure... right?) so I'm trying to work out all the mole fractions of the liquid phase (by deviding this by the pressure in the tower) but it gives me stupid answers - the oil should adsorb more of the heavier components than the lighter ones.

I thought it might have something to do with henry's law, I thought i might be able to get a table of henry's law constants for methane, ethane, propane, butane and pentane in some non polar solvent similar to my oil, but I can't seem to find any such table.

...as you can probably tell, I'm a little confused! I'll see if I can attach my half-baked mass balance for a bit of clarity:

#### Attached Files:

• ###### material balance.xls
File size:
32.5 KB
Views:
48
Last edited: Feb 21, 2009