next up previous
Next: Application to Mineral Extraction Up: The Second Law of Previous: The Second Law of



The entropy per mole of an n-component ideal mixture is given by

where tex2html_wrap_inline140 is the mole fraction of the ith constituent. If there are only two constituents, we have


If the mixture has tex2html_wrap_inline144 moles of the second constituent, we get

The energy required to separate the mixture is


For those who didn't follow the derivation, of (4), we summarize. R is the universal gas constant 8.314 joules per mole per degree Kelvin, T is the absolute temperature at which the separation takes place and x is the mole fraction in the mixture of the substance being extracted.

John McCarthy
Thu Aug 21 09:12:21 PDT 1997