Advertisement

Vacuum membrane distillation: Experiments and modeling

Authors

  • Serena Bandini,

    1. Dipartimento di Ingegneria Chimica, Mineraria e delle Tecnologie Ambientali, Universitá degli Studi di Bologna, I-40136 Bologna, Italy
    Search for more papers by this author
  • Aldo Saavedra,

    1. Dipartimento di Ingegneria Chimica, Mineraria e delle Tecnologie Ambientali, Universitá degli Studi di Bologna, I-40136 Bologna, Italy
    Current affiliation:
    1. Departamento de Ingeniería Quimíca, Universidad de Santiago de Chile, Av Lib. Bdo. O'Higgins 3363, Santiago, Chile
    Search for more papers by this author
  • Giulio Cesare Sarti

    Corresponding author
    1. Dipartimento di Ingegneria Chimica, Mineraria e delle Tecnologie Ambientali, Universitá degli Studi di Bologna, I-40136 Bologna, Italy
    • Dipartimento di Ingegneria Chimica, Mineraria e delle Tecnologie Ambientali, Universitá degli Studi di Bologna, I-40136 Bologna, Italy
    Search for more papers by this author

Abstract

Vacuum membrane distillation is a membrane-based separation process considered here to remove volatile organic compounds from aqueous streams. Microporous hydrophobic membranes are used to separate the aqueous stream from a gas phase kept under vacuum. The evaporation of the liquid stream takes place on one side of the membrane, and mass transfer occurs through the vapor phase inside the membrane. The role of operative conditions on the process performance is widely investigated in the case of dilute binary aqueous mixtures containing acetone, ethanol, isopropanol, ethylacetate, methylacetate, or methylterbutyl ether. Temperature, composition, flow rate of the liquid feed, and pressure downstream the membrane are the main operative variables. Among these, the vacuum-side pressure is the major design factor since it greatly affects the separation efficiency. A mathematical model description of the process is developed, and the results are compared with the experiments. The model is finally used to predict the best operative conditions in which the process can work for the case of benzene removal from waste waters.

Ancillary