Heteroazeotropic distillation is used to dehydrated glycerine obtained after a previous operation of the process patented by PI 0804383-3. The objective of this work is to examine the influence of weir height, and operation conditions on the sieve tray performance. The process fluids employed were water, toluene and glycerine. The operating conditions (independent variables) studied were vapor flow rate, feed flow rate and initial concentration of glycerol. The variable response (dependent variable) was the increment of glycerol content [%wt.]. Our results demonstrated that, for heteroazeotropic distillation with a viscous liquid phase, in spite of having a positive effect of the weir height, the glycerol dehydration depends mainly on the operational conditions, for the range of 10 to 70 mm of weir height.