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This study reports significant energy savings of combined reaction and distillation in a single reactive dividing wall column (RDWC) for the concurrent production of pure n-amyl and nhexyl esters, which are the stable node (SN) in each phase diagram of the quaternary reaction system. The continuous removal of the byproduct, water, from the unstable node (UN) azeotrope by L-L decantation drives the two esterifications in the forward direction and enables the production of the pure ester products. A vapor recompression heat pump (VRHP) is introduced to the RDWC and the annual operating cost is reduced to 62.5% of the case without the VRHP. Implementing the multiple reactions with V-L-L separation in a single RDWC and its heat integration through the VRHP may provide chemical industries with enhanced economic feasibility.

The combination of a porous carbon cathode and an interlayer having strong interactions with polysulfides is a very promising strategy for advanced lithium–sulfur batteries. This work prepares a hierarchical porous carbon through CO2 conversion using a reduction agent of NaBH4 with a CaCO3 nanotemplate. A free-standing carbon sheet is also synthesized by the CO2 treatment by adding NaBH4 to the conventional electrospinning process, which leads to significant porosity with a high nitrogen content of 15.5 atom % in the carbon paper and 30% reduced weight due to its meso-porosity, compared to typical electrospun fibers. This modified method induces lower density and higher active sites, different from the typical process involving further treatment and a mass increase to generate additional active sites to existing carbon surfaces. The hierarchical carbon is used as a cathode of the lithium–sulfur battery to provide high sulfur content and facile transport of the lithium ions. The resultant carbon paper for the interlayer suppresses the polysulfide shuttle and accelerates the kinetics of redox reactions. As a result, the cells assembled with them have a capacity of 707 mAh g–1 after 500 cycles at 0.5 C. In addition, it can maintain a capacity of 697 mAh g–1, even at a high current density of 7.0 C.

This paper introduces multiple esterification reactions of three alcohols occurring in a single reactive distillation (RD) column and reports significant energy savings by combining three reactions in the single unit. To realize a feasible integration of the three reactions, the removal of the common water product from the unstable heterogeneous azeotrope should be possible through liquid–liquid decantation in the eight-component system. For this multireaction system, only the direct sequence can produce three esters with a purity higher than 99.0 mol % due to the behavior of liquid–liquid phase equilibrium. We demonstrate an economic evaluation of the direct sequence of a single RD column simultaneously producing the three esters by comparing the direct sequence with the two parallel RD sequences in the same design basis. The total annual cost of the triple esterification direct sequence is reduced by 21.3–25.2% compared to that of the parallel esterification system.

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