Rigorous Design and Simultaneous Optimization of Extractive Distillation Systems Considering the Effect of Column Pressures

Publication date: Available online 3 April 2019Source: Chemical Engineering and Processing - Process IntensificationAuthor(s): Chengtian Cui, Jinsheng SunAbstractColumn pressure is one of the most important decision variables in the design and optimization of energy-efficient extractive distillation (ED) as it impacts on phase equilibrium, column temperature, and azeotropic concentration. However, many previous works fixed column pressure heuristically before optimization, resulting in divergence from the global optimum with variable column pressures. This ignorance gives this work the target to simultaneously optimize ED systems with fully considering the effect of column pressures. In detail, the task is carried out through combining the genetic algorithm programmed in MATLAB with Aspen Plus. Three binary systems are investigated to demonstrate the importance of pressure optimization – two sensitive (n-heptane/isobutanol and acetonitrile/water) and one insensitive (isopropanol/water) to pressure. Significant economic benefits are validated through optimizing pressure in the results for pressure sensitive systems, with the pressure insensitive system on the contrary. This suggests an optional pre-exclusion of pressure optimization, which requires to decipher the pressure sensitivity of the target system.

Source: Chemical Engineering and Processing: Process Intensification - April 5, 2019 Category: Chemistry Source Type: research