EFFECT OF DISSOLVED SALTS ON THE VAPOR-LIQUID-EQUILIBRIUM RELATIONSHIPS OF 3 MISCIBLE BINARY-SYSTEMS AT THE PRESSURE OF 101.3 KPA

The effect of the salts sodium chloride, calcium chloride and zinc chl oride on the vapor-liquid equilibria (VLE) of three miscible binary sy stem viz,, benzene-pyridine, water-pyridine and methanol-benzene has b een experimentally investigated at atmosphere pressure using a Smith a nd Bonner type of equilibrium still, The salts were dissolved in the s olvent in which they are preferentially soluble, to concentrations upt o 20 percent by weight whenever possible, In the case of benzene-pyrid ine system, the salts calcium chloride and zinc chloride cause the ''s alting out'' of benzene. As for the azeotropic system, water-pyridine, while sodium chloride increases the pyridine content in the vapor pha se, calcium chloride and zinc chloride bring about ''salting out'' of water and ''phase splitting''. In respect of the third binary, methano l-benzene which is also azeotropic, shift in the azeotropic compositio n and 'crossover effect' are observed upon addition of calcium chlorid e and zinc chloride. The experimental VLE data have been correlated us ing Wilson and NRTL models after ascertaining their thermodynamic cons istency.