Identification and optimization of thermally safe operating conditions for single kinetically controlled reactions with arbitrary orders in isoperibolic liquid-liquid semibatch reactors

Abstract

To obtain thermally safe operating conditions for kinetically controlled liquid-liquid reactions occurring in isoperibolic semibatch reactors (SBRs), an extreme scenario in which the product (UA) of the overall heat transfer coefficient (U) and the area (A) is equal to its initial value, (UA)0, was studied and combined with the ideal scenario where the UA is proportional to the liquid volume. Under both scenarios, the jacket temperature evolution of the maximum temperature of synthesis reactions (MSTR) after cooling failure and the corresponding time (θMTSR) for isoperibolic liquid-liquid SBRs was thoroughly investigated, and it was found that four types of thermal behaviors, namely IS (inherently safe), NI (non-ignition), TR (thermal runaway) and QFS (quick onset, fair conversion and smooth temperature condition) can be effectively identified by the variations of θMTSR. Then, a thermal behavior identification criterion was proposed. Subsequently, a series of boundary diagrams based on the proposed criterion were developed along with the corresponding novel adiabatic temperature diagrams to directly provide information about the maximum value of MTSR in the case of cooling failure for any operating points in the boundary diagrams. Further, synthesizing the information from the boundary diagrams and the adiabatic temperature diagrams allows for convenient attainment of generalized thermally safe operating conditions with considerable practicability and sufficient thermal safety even in adiabatic situations.