A Strategy For Synthesis And Design Of Vapor Recompressed Kaibel Dividing-wall Distillation Columns

Vapor recompression heat pump(VRHP)and dividing-wall distillation column(DWDC)are both promising energy-saving technologies for distillation,and their combination has aroused the research interest of academics.So far,the research on vapor recompression heat pump assisted dividing-wall distillation column(VRHP-DWDC)is too numerous to enumerate.The application of VRHP-DWDC at various dividing-wall locations to separate different component-dominated mixtures is found to be able to improve energy efficiency,bring about economic benefits,and enhance steady-state performance.However,Kaibel dividing-wall distillation column(KDWDC)has more separation sections compared with DWDC,and its various combinations with VRHP will not only increase the complexity of modeling and optimization calculations but also seriously impact the effectiveness of the KDWDC process renovation,which will ultimately impede the development and application of the vapor recompression heat pump assisted Kaibel dividing-wall distillation column(VRHP-KDWDC).In this work,based on the thermodynamic characteristics of KDWDC in separating an ideal quaternary mixture,a strategy for synthesis and design of VRHP-KDWDC is proposed following the decreasing order of temperatures of the available heat sources,and the corresponding development procedure is also provided.More specifically,the high-temperature heat source around the second intermediate product is used in the first step to fully explore the economic feasibility of the VRHP-KDWDC topological configuration in intensifying,and the low-temperature heat source at the common rectifying section is employed in the second step,and finally the optimum topological configuration of the VRHP-KDWDC is obtained.This design strategy allows maximizing the steady-state economic performance of the VRHP-KDWDC with low complication and computational intensity.The effectiveness of the synthesis and design strategy is verified by comparing the steady-state economic performance of KDWDC and the VRHP-KDWDC topological configurations in two wide boiling-point quaternary mixtures with and without component dominance in feed.The total annual cost is taken as the objective function for optimization programme.The results obtained show that the proposed synthesis and design strategy can quickly and efficiently identify the optimum design of the VRHP-KDWDC,regardless of whether there is component dominance in feed.Compared to KDWDC,the resulting design of VRHP-KDWDC in four systems yields the best economic benefits,reducing total annual cost by 10.47%,11.02%,12.26%,and 7.91%,respectively.These simulation outcomes can confirm the rationality of proposing the synthesis and design strategy of VRHP-KDWDC and the effectiveness of the development procedure.