25.12.2012 Views

Aspen Physical Property System - Physical Property Models

Aspen Physical Property System - Physical Property Models

Aspen Physical Property System - Physical Property Models

SHOW MORE
SHOW LESS

Create successful ePaper yourself

Turn your PDF publications into a flip-book with our unique Google optimized e-Paper software.

Where:<br />

�solv = Dielectric constant of the solvent mixture<br />

cca a<br />

Vm l<br />

3 Transport <strong>Property</strong> <strong>Models</strong> 293<br />

=<br />

= Liquid molar volume calculated by the Clarke<br />

model<br />

Apparent electrolyte mole fractions are computed from the true ion molefractions<br />

and ionic charge number. They are also computed if you use the<br />

apparent component approach. See Apparent Component and True<br />

Component Approaches in the Electrolyte Calculation chapter for a more<br />

detailed discussion of this method.<br />

Above salt concentration 0.03 M, the slope of surface tension vs. mole<br />

fraction is taken to be constant at the value from 0.03 M.<br />

You must provide parameters for the General Pure Component Liquid Surface<br />

Tension model, used for the calculation of the surface tension of the solvent<br />

mixture.<br />

Parameter<br />

Name/Element<br />

Symbol Default Lower<br />

Limit<br />

Upper<br />

Limit<br />

CHARGE z 0.0 — — —<br />

References<br />

(2)<br />

Units<br />

A. L. Horvath, Handbook of Aqueous Electrolyte Solutions, (Chichester: Ellis,<br />

Ltd. 1985).<br />

Modified MacLeod-Sugden<br />

The modified MacLeod-Sugden equation for mixture liquid surface tension can<br />

be derived from the standard MacLeod-Sugden equation by assuming that the<br />

density of the vapor phase is zero. The modified MacLeod-Sugden equation is:<br />

Where:<br />

�i *,l = Surface tension for pure component i, calculated using<br />

the General Pure Component Liquid Surface Tension<br />

model.<br />

Vi *,l = Liquid molar volume for pure component i, calculated<br />

using the General Pure Component Liquid Molar Volume<br />

model.

Hooray! Your file is uploaded and ready to be published.

Saved successfully!

Ooh no, something went wrong!