Kinetics of lipase-catalysed methyl gallate production in the presence of deep eutectic solvent |
| |
Authors: | Ceren Ülger |
| |
Institution: | Department of Chemical Engineering, Ankara University Faculty of Engineering, Ankara, Turkey |
| |
Abstract: | Production of methyl gallate (MG), which is an important phenolic acid ester for pharmaceutical industry, was carried out by Novozym 435-catalysed transesterification of propyl gallate (PG) with methanol in a deep eutectic solvent. Reaction parameters governing substrate molar ratio, enzyme concentration, temperature and agitation rate were investigated batch-wise in choline chloride:glycerol-water binary mixture. The results were evaluated in terms of conversion of PG, yield of MG and hydrolysis of PG to gallic acid. 10% (w/w) of water was found to be favourable in the reaction medium for low hydrolysis percent. The highest conversion (17.4%) and yield (60.4%) but the lowest hydrolysis (2%) after 120?h of transesterification were found at PG/methanol molar ratio of 1:6, enzyme concentration of 40?g/L, 50?°C and 200?rpm. A kinetic model based on the Ping-Pong Bi–Bi mechanism for transesterification of PG was proposed with the assumption that there were no internal and external mass transfer resistances. |
| |
Keywords: | Choline chloride deep eutectic solvent methyl gallate Novozym 435 propyl gallate transesterification |
|
|