EXPERIMENTAL INVESTIGATION OF MULTIPLE STEADY-STATES AND PARAMETRIC SENSITIVITY IN AZEOTROPIC DISTILLATION

In this work, a laboratory scale sieve plate distillation column was c onstructed to study the dynamic behavior of the isopropyl alcohol(IPA) , cyclohexane(CyH) and water(H2O) azeotropic distillation. Two types o f profiles that produce high purity IPA product were found. One passes around the IPA+CyH azeotrope. It is characterized by a plateau at 70 degrees C. The bottom impurity is mainly cyclohexane. The other profil e passes around the IPA+H2O azeotrope. It is characterized by a lot of stages having heterogeneous liquid splitting at the top. The bottom i mpurity is mainly water. A slight increase or decrease of reboiler dut y will cause the temperature front to move towards the top or the bott om of the column and result in the loss of IPA purity. Moreover, the o riginal steady state cannot be recovered after a cyclic series of step -changes in reboiler duty. This hysteresis phenomenon is caused by cha nges in amount of entrainer in the column.