Rigorous optimization of heat-integrated and Petlyuk column distillation configurations based on feed conditions

The steady-state design and rigorous simulation of conventional distillation configurations and several energy-integrated configurations has been studied for ternary mixture separation. The studied configurations are optimized rigorously based on total annual cost as the economic objective function. The energy-integrated distillation configurations are compared with conventional configurations to find the maximum achievable total annual cost savings. Changing feed conditions is considered as one of the optimization variables by investigating different states of feed conditions; feed at 15.5°C temperature, liquid at bubble point and vapor at dew point. The investigated configurations are conventional direct and indirect separation sequence, heat-integrated direct sequences, Petlyuk column, heat-integrated sloppy sequence, and double heat-integrated sloppy sequence. Optimization results indicate that saving in energy and total annual cost of the configurations is affected by the states of the feed conditions.