文摘
Benzeneacetic acid is an important carboxylic acid extensively used in pharmaceutical industries. Thus, interest has been growing in the scientific community toward its recovery from aqueous streams or fermentation broth. Extraction of carboxylic acids by reactive extraction using extractant-diluent is the emerging area of study. With this concept, the reactive extraction of benzeneacetic acid was carried out to study (i) effect of diluents, such as benzene, toluene, xylene, and hexanol; (ii) effect of concentration of extractant, tri-n-caprylyl amine; (iii) effect of pH; and (iv) equilibrium modeling, namely, relative basicity model and mass action law. The equilibrium results are discussed in terms of partition coefficient (P), dimerization constant (D), distribution coefficient (KD), extraction efficiency (η%), overall equilibrium complexation constant (Ke), and loading factor (ϕ). Distribution coefficient trend was observed as xylene > benzene > toluene > hexanol. The extraction efficiency of benzeneacetic acid was found to be 99.2% when 0.46 mol·kg–1 tri-n-caprylyl amine was employed in xylene. Moreover, equilibrium results were fitted with relative basicity and mass action law model and it was found that relative basicity model predicted the results better than mass action law for reactive extraction of benzeneacetic acid. The study will be useful in the design of reactive extraction process for the recovery of benzeneacetic acid.