Reactive Extraction of Oxoethanoic Acid (Glyoxylic Acid) Using Amberlite-LA2 in Different Diluents

Abstract

An equilibrium distribution study of oxoethanoic acid (also known as glyoxylic acid, 0.93 kmol·m–3) between water and Amberlite-LA2 (0.24 to 1.67 kmol·m–3) is carried out at constant temperature, 298 ± 0.5 K. The extract phase is prepared using Amberlite-LA2 as extractant, and hexane, kerosene, methylbenzene (toluene), butane-2-one (methyl ethyl ketone, MEK), 2,6 dimethyl-4-heptanone (diisobutylketone, DIBK), hexane-2-one, and decane-1-ol as diluents. The equilibrium data are presented by calculating parameters like loading factor, Z, extraction efficiency, %E, and distribution coefficients, KD. The highest value of KD is found to be 92 at higher concentration (1.67 kmol·m–3) of Amberlite-LA2 in hexane-2-one. The extraction ability of Amberlite-LA2 in different diluents in terms of KD and % E is found to be in the order of hexane-2-one > methylbenzene > hexane > kerosene > DIBK > MEK > decane-1-ol. The values of stoichiometric coefficient (m) and equilibrium complexation constants (KE, K11, K21, and K12) are determined from the mass action law and using experimental data. From the values of m, it is proposed that the interaction between acid and amine molecule is mostly by 1:1 type but the values of m less than 1 indicate possible formation of 1:2 type complex and diluents also extract some acid molecule by physical extraction. The values of m greater than 1 point out the formation of little amount of 2:1 type complex in the organic phase.