Synthesis framework for distillation sequence with sidestream columns: Application in reaction-separation-recycle system

• Published in: Chemical engineering research & design 2021-02, Vol.166, p.172-190
• Main Authors: Ye, Haotian, Zou, Xiong, Zhu, Weixuan, Yang, Yang, Dong, Hongguang, Bi, Mingshu
• Format: Article
• Language: English
• Subjects: Chemical synthesis; Collocation methods; Distillation; Finite element analysis; Heat transfer; Model accuracy; Modules; Non-sharp split; Nuclear reactors; olumn; Optimization; Process synthesis; Reaction-Separation; Separation; Sidestream c; Superstructure; Superstructures; Vacuum distillation
• ISSN: 0263-8762; 1744-3563
• DOI: 10.1016/j.cherd.2020.12.005

•State-Task Network representation for distillation sequence with sidestream column•Nonsharp distillation design through modified Fenske-Underwood-Gilliland method•Four-component case with mass interaction between reaction and separation systems•14.11% and 5.70% reduction in operational cost and TAC for reference case In this work, a comprehensive design method for three-section sidestream columns along with a novel State Task Network representation including both conventional and sidestream distillation sequence configurations is present. The distillation network is embedded in the superstructure-based framework for reaction-separation-recycle process synthesis to explore the mass interaction in different sub-systems. In the superstructure, complete interconnections among reactor modules as well as necessary connections between reactor modules and distillation columns are involved to guarantee opportune coupled degree. Based on this, component distribution in distillation through Underwood equations is introduced to provide desired products with required purity and multiple component mixtures as feedback to the reactor network, achieving the optimization of mass interaction in the whole flowsheet. Furthermore, Fenske-Underwood-Gilliland shortcut method to design columns with and without sidestream, and finite element with orthogonal collocation approach to design PFRs are employed, so that reasonable tradeoff between model accuracy and solution difficulty is achieved. Finally, two literature examples are performed to demonstrate the feasibility and validity of the proposed methodology.