Industrial & Engineering Chemistry Research, Vol.57, No.3, 1102-1108, 2018
Controllability Evaluation for Reactive Distillation Columns with Multiple Reactive Sections Disproportionating Trichlorosilane to Silane Disproportionating Trichlorosilane to Silane
In our recent work, the arrangement of multiple reactive sections is found to greatly enhance the steady-state performance of reactive distillation columns disproportionating trichlorosilane to silane. In the current research, process dynamics and controllability are studied through in-depth comparative analysis of open-loop and closed-loop behaviors between three reactive distillation columns with, respectively, a single reactive section (RDC-SRS), double reactive sections (RDC-DRS), and triple reactive sections (RDC-TRS). In the regulation path, although the arrangement of double and triple reactive sections reduces slightly the process gains between the bottom product composition and reboiler heat duty in the RDC-DRS and RDC-TRS, it helps to alleviate the coupling between the bottom product composition and reflux flow rate, thereby gaining increases in process controllability as compared with the RDC-SRS. In the disturbance path, the arrangement of double and triple reactive sections results in no intensified sensitivities to the disturbances from feed flow rate and composition. The dosed-loop operation tests coincide with the open-loop analysis and demonstrate that the RDC-TRS and RDC-DRS exhibit substantially improved antidisturbance and set-point tracking capabilities as compared with the RDC-SRS. These outcomes highlight evidently the great importance of arranging multiple reactive sections to the dynamics and controllability of reactive distillation columns separating reacting mixtures with unfavorable and complicated reaction kinetics.