(92d) Process Intensification Framework for Reactive Separation Systems

Reactive separation (e.g., reactive distillation, membrane reactor, reactive absorption), which integrates multiple processing tasks into a single unit to maximize the synergy between multifunctional phenomena, is one of the major process intensification (PI) pathways towards breakthrough improvements [1-2]. As a classic example, significant energy and cost savings (15-80%) have been reported in reactive distillation processes over their conventional reactor-distillation counterparts [3].

Recent advances in the synthesis of reactive separation systems have been leveraging phenomena-based representation methods to come up with “out-of-the-box” PI process solutions beyond traditional unit operations [4-6]. However, the operational performances in these intensified designs under uncertainty and disturbances are mostly neglected at this synthesis stage, whereas their highly integrated schemes often decrease the degrees of freedom of the online decision maker, adversely affecting the process safety and limiting the operability of the systems [7]. Therefore, a holistic synthesis approach to derive such intensified systems with guaranteed safety, operability, and controllability performances is still lacking.

In this work, we propose a systematic process intensification framework to deliver operable reactive separation systems, which features: (i) phenomena-based process synthesis with the Generalized Modular Representation Framework (GMF) [8] to derive intensified reaction and/or separation design configurations, (ii) integrated flexibility and risk considerations to ensure steady-state operability and inherent safety performances [9], (iii) flowsheet identification and validation to translate the resulting phenomenological modular structure to intensified equipment/flowsheet, (iv) explicit model-based predictive controller design following the PAROC (PARametric Optimization and Control) framework [10] to ensure controllability under dynamic operation, and (v) simultaneous design and control with dynamic optimization strategies to close the loop for the design of verifiable, operable, and optimal reactive separation systems. The capabilities of the proposed framework are demonstrated with a case study on the production of methyl tertiary-butyl ether (MTBE), where design alternatives are systematically derived with guaranteed operability, safety, and controllability performances. Multiple process solutions can also be generated to show the tradeoffs between cost and operability performances for further decision making.

Reference

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