Simultaneous Solution of Concentration Profiles in Vapor-liquid Phases of Wetted-wall Distillation Column for H₂O-HTO Isotope Separation

Abstract

A simulation model was proposed for prediction of H₂O-HTO separative performances of water distillation by a wetted-wall column. A wetted-wall column was assumed to be a circular tube, and mole-fraction profiles in the tube were obtained by coupling the equations which describe diffusion processes of both vapor and liquid phases and by solving the equations simultaneously. It was found that the calculations for constant mole-fraction boundary with high mass-transfer rate resulted in overestimations of degree of separation. The relative difference of the HETP value for constant mole-fraction boundary from that for the present model was −19% when P = 101.3kPa, T = 373K, R = 0.8 cm, H = 100 cm, k _v,A = 1.0 × 10⁴ cm/s and Re_v = 660.

KEYWORDS:

• isotope separation
• water distillation
• wetted-wall column
• degree of separation
• mass transfer
• vapor-liquid interface
• numerical solutions
• mole-fraction profile
• tritiated water
• WTO
• simulation