ISSN print edition: 0366-6352 ISSN electronic edition: 1336-9075 Registr. No.: MK SR 9/7 Published monthly

Kinetic studies on propionic and malic acid reactive extraction using trioctylamine in 1-decanol

Victoria Inyang and David Lokhat

Reactor Technology Research Group, School of Engineering, University of KwaZulu-Natal, Durban, South Africa

E-mail: vickyinyang@yahoo.com

Received: 16 March 2020  Accepted: 7 May 2020

Abstract:

The effectiveness and efficiency of the reactive extraction technique for recovery of propionic acid and malic acid from aqueous solution were investigated. Kinetic studies for the solute (acid)–solvent (trioctylamine dissolved in 1-decanol) system were carried out and mass transfer coefficients experimentally determined. These parameters are necessary for the proper design of an extraction unit. The studies were carried out using dilute solutions of the acids with a concentration range of 0.2–0.6 kmol/m³ and trioctylamine (10%v/v) in 1-decanol as extractant at 303.15 K. The effect of stirring speed, acid and extractant concentration at different time intervals was studied. The kinetic process parameters such as reaction order, mass transfer coefficient and rate constant were evaluated using the experimental data. From the results obtained, the reaction was found to be an instantaneous second-order chemical reaction occurring in the organic diffusion film. The values of the rate constants were found to be 0.430 m³/mol s and 0.332 m³/mol s, respectively, for propionic acid and malic acid, while the mass transfer coefficient, k_m, was also obtained for propionic acid (9 × 10⁻⁶ m/s) and malic acid (3 × 10⁻⁶ m/s). These are useful for the design of an extraction unit for carboxylic acid recovery from dilute aqueous solutions.

Keywords: Propionic acid; Malic acid; Reactive extraction; Kinetic studies

Full paper is available at www.springerlink.com.

DOI: 10.1007/s11696-020-01194-2

Chemical Papers 74 (10) 3597–3604 (2020)