Experimental investigation of multiple steady states and parametric sensitivity in azeotropic distillation

[[abstract]]©1997 Elsevier - In this work, a laboratory scale sieve plate distillation column was constructed to study the dynamic behavior of the isopropyl alcohol(IPA), cyclohexane(CyH) and water(H2O) azeotropic distillation. Two types of profiles that produce high purity IPA product were found. One passes around the IPA+CyH azeotrope. It is characterized by a plateau at 70°C. The bottom impurity is mainly cyclohexane. The other profile passes around the IPA+ H2O azeotrope. It is characterized by a lot of stages having heterogeneous liquid splitting at the top. The bottom impurity is mainly water. A slight increase or decrease of reboiler duty will cause the temperature front to move towards the top or the bottom of the column and result in the loss of IPA purity. Moreover, the original steady state cannot be recovered after a cyclic series of step-changes in reboiler duty This hysteresis phenomenon is caused by changes in amount of entrainer in the column.[[department]]化學工程學