화학공학소재연구정보센터
Computers & Chemical Engineering, Vol.23, No.S, S249-S252, 1999
Experimental investigation of optimal conventional control strategy for a heterogeneous azeotropic distillation column
In this work, a laboratory scale sieve plate distillation column was constructed-to investigate the optimum conventional control strategy of an isopropyl alcohol(IPA), cyclohexane(CyH) and water(H2O) heterogeneous azeotropic distillation column. Steady state process analysis showed that the optimal operation point should be located at a critical reflux, a transition point at which the distillation path switches from a route that passes through IPA+H2O azeotrope to one that passes through IPA+CyH azeotrope. At this critical reflux, a high purity IPA product can be obtained with minimum energy consumption and maximum product recovery. However, the steady state is extremely sensitive to feed disturbances. A good control strategy must be able to maintain a steady column temperature profile that shows a plateau near 70 degreesC to ensure passage around IPA+CyH azeotrope. In this study, a inverse double loop control strategy were recommended. Through experimental testing, the proposed control strategy was demonstrated to keep the product IPA purity at the desired high-purity level under all feed disturbance changes.