Screening of pervaporation membranes for the separation of methanol-methyl acetate mixtures: an approach based on the conceptual design of the pervaporation-distillation hybrid process

FIGUEROA PAREDES, DANILO A.; LAORETANI, DANIELA S.; ZELIN, JUAN; VARGAS, RAFAEL; VECCHIETTI, ALDO R.; ESPINOSA, JOSÉ

SEPARATION AND PURIFICATION TECHNOLOGY

ELSEVIER SCIENCE BV

Año: 2017

1383-5866

In this work, the pervaporation-distillation hybrid process is proposed to accomplish the separation of the azeotropicmixture methanol-methyl acetate. First, the separation performance of four membranes of a medium-high flux (Pervap2256, Pervap 2255-30, PolyAl TypM1 and PolyAn) is analyzed with the aid the pervaporation separation index (PSI).For the commercial Pervap 2256 membrane, pervaporation experiments were conducted to characterize its separationperformance especially at compositions of the mixture around the azeotrope. Then, a novel screening approach, whichis based on the overall cost of the separation corresponding to the optimal Hybrid process design, is proposed. Forfeed compositions in the range 0.1 - 0.9 mol/mol, several process configurations are optimized varying thecompositions of the retentate and distillate streams. Quasi-optimal operation temperatures, with correspond tomaximum feasible ones, are 348.15 K for the Pervap membranes and 363.15 K for the PolyAn membranes,respectively. The studied membranes are successfully and consistently classified by their respective total cost. Thedesigns corresponding to PolyAl TypM1 and Pervap 2256 membranes present the lowest overall costs. Finally,detailed costs of the vacuum condensing system were also taken into account for the case of the Pervap 2256membrane to include the permeate pressure as an optimization variable. The optimal value of the permeate pressureis 100 mbar and the corresponding condensation temperature is about 272 K.