Enzymatic hydrolysis of oil in a spray column

Free enzyme lipolase 100 T from Thermomyces lanuginosus has been investigated as a hydrolyzing catalyst in a spray extraction column. The aqueous buffer (pH 7.0) enzyme solution as continuous phase (batch-wise) and the oil as dispersed phase have been used. Various operating parameters which affect the drop size in a spray column, i.e. nozzle diameter, oil flow rate, etc. have been studied. Using the optimized flow rate and nozzle diameter, the effect of various other operating parameters such as concentration of enzyme, enzyme solution height (oil residence time) on the hydrolysis reaction has been evaluated. The highest conversion is obtained for the optimum flow rate of 3.8 ml/min and the nozzle diameter of 0.75 mm. The experimental result showed that the extent of hydrolysis of castor oil is 0.16% in a column reactor due to drop coalescing is almost equal to the hydrolysis due to drop residence time of 1 min in the column. It was also observed that the enzyme activity does not show any appreciable change up to a maximum of 44 passes in the spray column. The contributions of various hydrodynamic phenomena, such as drop formation, rise and coalesce of drops, to the overall hydrolysis rate have been estimated and discussed. Experimental data obtained for the spray column have been compared with that of an agitated batch reactor.