Mass transfer in heterogeneous distillation

An experimental study on mass transies- if! heterogeneous distillation was made with wetied-wau columns of different lengths for an etbanol-henzene-water system under tota! reflux conditions- The observed jurat diffusion Eluxi-s obtained from Ihe data of shorter dssiiSIation paths agree well with the theoretics! values of mass transfer in a tube, but the average diffusion fiisxes of Songer distillation paths deviate from the theoretical ones. simulation of hetergenous distillation with a wetted-wall column is carried out using the theoretical diffusion flux in a tube. The predicted concentrations and refiiix Row rstes at the top of the column showed good agreement with the observed data of longer distiitation paths obtained by a Songer rntunin. The simulation resuats show thal a large concentration driving force causes a large path and results a large variation along the the deviation of the average diffusion flux from the theoretical vahie is demonstrated and expjamed by being itiade dimensionless with the average or non-Iotal concentration driving force. Furthermore, the length of the distillation psth is affected considerably by the bottom concentration and the vapor phase Revnolds number. Copyright ©1998 The Society of Chemical Engineers.