THEORETICAL AND EXPERIMENTAL-STUDY ON MEMBRANE DISTILLATION IN THE CONCENTRATION OF ORANGE JUICE

Membrane distillation is a relatively new membrane process in which tw o solutions at different temperatures are separated by a microporous h ydrophobic membrane. This process can be used to concentrate fruit jui ces. The transport phenomena involved in membrane distillation for the concentration of fruit juices are described. Heat and mass transfer b alances have been formulated, accounting for the geometry and morpholo gy of the membrane and the properties of juice solutions. An experimen tal study of the concentration of orange juice with a hydrophobic poly (vinylidene fluoride) flat membrane is also presented in this paper. T he experiments mainly inspect the transient phenomena, the flux decay with respect to concentration increase, the effects of operating condi tions on the permeate flux, and the membrane retention of orange juice compositions. The results show that membrane distillation is a potent ial and feasible concentration technique.