Distribution equilibrium of mercury (II) chloride between water and air applied to flue gas scrubbing

In the literature, different values of the distribution coefficient KH for HgCl2 between water and air are present in a range that spans more than 3 orders of magnitude. In order to determine if a waste incineration scrubber solution could become saturated with regard to HgCl2, an accurate experimental determination of the distribution constant of HgCl2 at elevated temperatures is needed. In this work, the coefficient has been determined at four different temperatures between 10 and 50 degrees C. The Arrhenius expression obtained is 5.5 x 10(5) x exp[-(8060 +/- 2200)/T] with a corresponding enthalpy for the process HgCl2(aq)<==>HgCl2(g) of 67 +/- 20 kJ/mole. KH at 293 K was found to be approximately 5 x 10(-7) atm M-1, which is in almost perfect agreement with an earlier study. Applying the obtained KH values to waste incineration scrubber conditions shows that no major saturation effect will occur.