A new alternative route for achieving energy saving in intensified reactive-extractive distillation system with a surprise discovery

• Almost all intensified RED cannot provide energy savings. • An unexpected discovery of energy-saving intensified RED (i.e., TC-DCRED). • Propose two alternative intensified RED that can provide energy savings. • Combination of thermally-coupled with side stream intensified RED. • Provides energy savings of up to 13 % compared to conventional RED. In contrast to other intensified distillation processes, it has been well-reported that the intensified reactive-extractive distillation (RED) cannot provide any energy savings with respect to its non-intensified counterpart. Motivated by this limitation, this study aims to explore other alternative intensified configurations to improve RED system performance. Specifically, we investigate the combined use of thermally-coupled and side-stream as a hybrid process intensification (PI) technique to enhance energy efficiency, as most existing studies have applied these techniques individually without examining their potential synergy. We begin by selecting a ternary azeotropic mixture that has been previously studied using both RED and intensified thermally-coupled RED (T-DCRED). Using these configurations as base case, we further investigate 2 other alternative hybrid side-stream thermally-coupled RED (ST-DCRED) configurations to evaluate their energy savings potential. During our investigation, we unexpectedly discovered that the T-DCRED could achieve 12 % energy savings compared to the conventional RED, which contradicts with previous studies Additionally, our study into 2 newly proposed ST-DCRED configurations also showed potential energy savings of up to 13 % compared to conventional RED. These results suggest that hybrid ST-DCRED offer a promising alternative to traditional PI methods, such as thermally-coupled or dividing-wall configurations, for improving energy efficiency in RED systems.