From the different methods available for the enzymatic synthesis of monoglycerides, glycerolysis reactions seem to be more advantageous than the other reactions due to its high yield and productivity. In addition, glycerolysis route has additional relevance in the present worldwide context, due to the sharply increase on the glycerol supplied in the market as a primary by-product from biodiesel plants. Therefore, converting glycerol into value-added products provides an alternative for glycerol disposal and for its surplus problems. Previous work carried out in our lab has identified that Burkholderia cepacia lipase (Lipase PS-Amano) is a potential enzyme source to produce monoglycerides from the glycerolysis of babassu oil.
Pursing our interested in developing a feasible enzymatic process an attempted was made to perform the process under continuous mode. For this, packet bed reactor (PBRs) configuration was selected based on its suitability to mediate typical lipase catalyzed reactions. Prior to the continuous experiments, the optimization of molar ratio glycerol to oil (15:1) and reaction temperature (50°C) was carried out batchwise via response surface methodology.
The reactor was packed with 6.70g of lipase PS immobilized on SiO2-PVA and feeding with substrate at a flow volumetric rate of 0.028 mL/min. The inert atmosphere was guaranteed by sparking N2 in the feed medium storage. The PBR operated continuously for 22 days and monoglycerides concentration were between 25 and 29%wt. The biocatalyst stability was found to be high and during the first 16 days no significant decrease on the initial lipase activity was observed.
Keywords: glycerolysis, lipase, babassu