Simultaneous heat and mass transfer with liquid film vacuum distillation

The problem of simultaneous heat and mass transfer associated with the vacuum distillation of a thin liquid film is solved by analyzing the system as a conjugated boundary value problem. The solution is developed in terms of well-known tabulated functions using a Green's function approach. The effects of heat transfer, liquid phase diffusion and effusion at the surface on the rate processes are elucidated, and separation efficiencies are predicted as functions of the length of the heated wall over which the film flows. The theoretical analysis is applied to calculate mass transfer rates for the separation of fatty acids from tall oil.