화학공학소재연구정보센터
Separation Science and Technology, Vol.36, No.15, 3473-3485, 2001
Distribution behavior of aminobenzoic acids by extraction with di(2-ethylhexyl)phosphoric acid and trioctylamine
Extraction based on reversible chemical complexation can be a high-capacity and high-selectivity technique for separating polar organic solutes from dilute solution. Aminobenzoic acid is a valuable chemical product. However, the downstream processing technology for the recovery of aminobenzoic acid presents a challenging separation problem. Aminobenzoic acid is resistant to biodegradation, so a method for treating wastewater that contains aminobenzoic acid needs to be developed. In this paper, we present a series of extraction equilibrium experiments for aminobenzoic acid with di(2-ethylhexyl)phosphoric acid (D2EHPA) dissolved in a mixture of n-octane and n-octanol and in trioctylamine dissolved in n-octanol. The effects of extractant concentration and pH on the distribution ratio are discussed in detail. Both (1: 1) and (1:2) complexes are formed in the extraction of aminobenzoic acid with D2EHPA. Expressions for the equilibrium distribution ratio are proposed, and the experimental data are in good agreement to the proposed expressions.