화학공학소재연구정보센터
Chemical Engineering Research & Design, Vol.123, 152-164, 2017
Improved plantwide control structure for extractive divided-wall columns with vapor recompression
The conventional extractive distillation flowsheet for dehydration of low-concentration bioethanol uses three-columns: a pre-concentrator, an extractive column and a solvent recovery column. A recent paper studied the control of a process using a single divided-wall column. The complex flowsheet uses both main and intermediate reboilers. Ethanol goes overhead, water is removed as a liquid sidestream and solvent is recovered from the base. The control challenges of such a complex multivariable interacting process are obvious. The published control structure is complex and dynamically very sensitive. Only slow ramp disturbances can be handled. The purpose of this paper is to develop a more simple control scheme that is robust and is capable of handling large step disturbances. The key feature of the modified process is to only compress what is needed in the side reboiler. (C) 2017 Institution of Chemical Engineers. Published by Elsevier B.V. All rights reserved.