Validation of a Novel Method for Ethyl Lactate Separation Using Langmuir Hinshelwood Model

Abstract

In this work, the batch wise esterification of lactic acid and ethanol was carried out using different cation-exchange resins including amberlyst 15, amberlyst 16, dowex 50W8x and amberlyst 36 as catalysts. The Scanning electron microscopy/energy dispersive analysis of X-ray (SEM/EDAX) was used to examine the surface morphology of the resin catalysts before and after the esterification process. The SEM of the commercial resin catalysts showed a clear surface with no crack before esterification . The order of the surface integrity from the SEM morphology of the resin catalysts after the esterification process was amberlyst 36 > dowex 50W8x. Gas chromatography with mass spectrometry (GC-MS) detector was used to analyse the esterification products. Ion 45 on the mass spectra confirmed that the esterification product was in accordance with the library mass spectra of the commercial ethyl lactate solvent. FTIR was used to determine the most adsorbed components on the surface of the catalysts. The rationale of the adsorption strength of the resin catalyst was described and validated using two mechanisms of Langmuir Hinshelwood model.