Loading...

Comparison of Dynamic and Static Performances of a Quaternary Distillation Sequence

Baghmisheh, Gholmarez | 2010

660 Viewed
  1. Type of Document: Ph.D. Dissertation
  2. Language: Farsi
  3. Document No: 42022 (06)
  4. University: Sharif University of Technology
  5. Department: Chemical and Petroleum Engineering
  6. Advisor(s): Shahrokhi, Mohammad; Bozorgmehri, Ramin
  7. Abstract:
  8. In this work steady state and dynamic performances of quaternary distillation column sequences designed based on steady state and dynamic cost functions have been investigated. To quantify the dynamic performance, product loss due to disturbances has been considered in the objective function. In addition, variations of operating costs such as utilities have been considered in the objective function. To separate a quaternary mixture into four products, twenty two configurations have been used. It has been observed that the feed composition, disturbance frequency and magnitude affect the dynamic behavior strongly. To decrease the optimization computational load, a scheme that provides a suboptimal result has been proposed. By performing simultaneous optimization that requires much more computational time, it has been shown that the highest ranking configurations obtained by the proposed method are the same as those provided by simultaneous technique. The simulation results indicate that there is no clear pattern for configuration ranking based on column sequences specifications. Also in this work the design and optimization of thermally coupled distillation for the separation of a quaternary components mixtures has been studied. A new representation is proposed for the simulation and optimization of complex separation. The proposed method in the simulation convergence and GA optimization methodology involving the redundant cases in neighborhood, the dynamically ranged specs and the simultaneous simulation of all column sections, are very effective in the optimization of thermally coupled schemes. By means of these methods, computation cost has been considerably reduced. Also in some cases the suggested methodology not also decrease the computation cost, but also prevents to achieve local optimum. The improvements of suggested method increased significantly by increasing the degree of freedom or complexity of sequences. Also a modification on thermally coupled has been presented these schemes presented energy savings between 0 and 15% in contrast to the thermally coupled schemes
  9. Keywords:
  10. Distillation Columns Sequence (DCS) ; Static Behavior ; Dynamic Behavior ; Genetic Algorithm ; Process Optimization ; Termally Coupled

 Digital Object List

 Bookmark

No TOC