화학공학소재연구정보센터
Journal of Chemical and Engineering Data, Vol.55, No.9, 3501-3506, 2010
Effect of 2,2',2''-Nitrilotrisethanol on the Vapor-Liquid Equilibria of the Ethanol plus Water System at Atmospheric Pressure
Extractive distillation processes with a variety of extracting agents such as solvents, salts, salt(s) dissolved in solvents, and organic solutes have been studied to produce anhydrous ethanol. These studies indicate that there are merits and demerits associated with each of the extracting agents identified. An organic compound, 2,2',2 ''-nitrilotrisethanol (commonly known as triethanolamine), has been identified as useful as an extracting agent for the production of anhydrous ethanol. It has infinite solubility in ethanol as well as water, and hence it can be used in any proportion. Its effect on the vapor-liquid equilibria of the ethanol + water system has been studied using an Othmer-type recirculation still. The relative volatility of ethanol + water solution of fixed composition is found to increase linearly with an increase in concentration of 2,2',2 ''-nitrilotrisethanol up to 1.55 kmol . m(-3). The enhancement in relative volatility of the ethanol + water system at atmospheric pressure in the presence of 2,2',2 ''-nitrilotrisethanol at a concentration of more than about 0.88 kmol . m(-3) is sufficient enough to eliminate the azeotrope formation completely. Therefore, anhydrous ethanol can be produced by the extractive distillation process employing 2,2',2 ''-nitrilotrisethanol at the concentration of more than about 0.88 kmol . m(-3).