A study on the effects of feed temperature and concentration on design of a multi-stage pervaporation system for isopropanol-water separation using commercial available modules with inter-stage heating

Developing a reliable and adequate model for designing and simulation of pervaporation processes can be very useful for industrial purposes. This work explains particular design criteria on which a pervaporation system may be based. Initially, a semi-empirical trans-membrane flux model was developed considering the recognized characteristics of multicomponent permeation, flux coupling, and thermodynamic interaction. Later, the developed model was implemented to simulate a single unit of pervaporation as well as multi-stage arrangements, integrated with external interstage heaters, for dehydration of isopropanol under adiabatic and ideal isothermal conditions. Two multi-stage arrangements, including modules with either equal temperature drop or surface area per each stage, were purposed for this aim. Regarding a specific separation case study, the ideal isothermal condition underestimated the membrane area required even more than 47 times. While the implementation of multi-stage arrangements resulted in more than 97% reduction of the required membrane surface area. The results revealed that the multi-stage arrangement with equal temperature drop per stage was more efficient due to the utilization of not only less membrane area but also less number of sequential stages. To draw a technical comparison, the profiles of critical parameters were depicted along with the modules. The results obtained in this work proved that the validated flux model along with the design procedure can be considered as a reasonable tools to be used in the process simulation software packages.