SIMULTANEOUS HEAT AND MASS-TRANSFER IN BINARY DISTILLATION

Measurements of simultaneous heat and mass transfer in binary distillation of the methanol-water and the ethanol-water systems at total reflux were made with a small vertical flat-plate wetted-wall column. A new theoretical approach was used which takes into account the effect of bulk flow caused by the mass fluxes of the more-and the less-volatile component on the rate of heat and mass transfer in the binary distillation. From measurements of the vapor-phase temperature profiles during binary distillation, the individual vapor-and liquid-phase resistances were evaluated so as to show that the former was controlling. Observed vapor-phase sensible heat fluxes and diffusion fluxes were compared with theoretical values by a laminar boundary layer theory with mass injection or suction at the interface and showed good agreement. © by THE SOCIETY OF CHEMICAL ENGINEERS, JAPAN.