Separation and Recovery of Sulfuric Acid with TEHA

Separation of sulfuric acid with TEHA and Cyanex 923 from acidic solution through solvent extraction method has been investigated. Adsorption of sulfuric acid with TEHA and Cyanex 923 is an exothermic reaction and the enthalpy changes of the reaction were found to be -762R and -269R, respectively. Comprehensive study on determining stoichiometric coefficients of sulfuric acid in sulfuric acid extraction equation using slope analysis method led to a new approach for this method. It has been shown that each mole of TEHA extracts 2 moles sulfuric acid when organic phase extracts less than 100 g/l sulfuric acid. Also, when organic phase extracts more than 100 g/l sulfuric acid, the number of adsorbed sulfuric acid molecules, n, is estimated to be 1. In addition, the value of n, using Cyanex 923 as extractant, is estimated to be 1. Based on McCabe-Thiele results, after 4 stages, sulfuric acid concentration in aqueous phase is reduced from initial value of 200 g/L to 30 and 5 g/L when octanol concentration in organic phase was %20 and 40%, respectively. While, using Cyanex 923 as extractant, 5 stages is needed to reduce sulfuric acid concentration from 100 g/L to 5 g/L.

کلیدواژه ها:

sulfuric acid ، solvent extraction ، TEHA ، octanol ، McCabe-Thiele ، extraction percent