Purification engineering of mono-diacylglycerol using creaming demulsification technique in 20 kg-scale

Abstract

Glycerolysis is the easiest, cheapest, and most widely used method for producing monodiacylglycerol (MDAG). The crude MDAG resulting from chemical glycerolysis still contains a glycerol residue of more than 7.5% so it needs to be purified. Purification with a simple method using a creaming demulsification technique (CDT) on a laboratory scale has been proven to produce MDAG with a glycerol content of less than 1%. This study was aimed to apply CDT on a scale of 20 kg and determine the process conditions that need to be adjusted so that the results are not different from the laboratory scale. Through trial and error method, the process condition adjustment was done iteratively to produce MDAG glycerol content after purification of less than 1.5%. The initial content of crude MDAG was 12.48%, application of CDT on a scale of 20 kg produces pure MDAG with a glycerol residue content of 3.07% (without adjusting the process conditions) and was 1.15% (with adjusting the process conditions). The adjustments meant include: increasing the operating temperature from 65 to 70°C, changing the type of stirrer from a propeller into a 2-level impeller, applying the nozzle for electrolyte mixing, providing longer skim and cream separation opportunities (applying repeated settling), using 1.5 times more hot water for washing, the washing technique was set twice, the first washing using nozzle without stirring and the second using nozzle with stirring. The adjustments were able to increase the purity of the MDAG produced and has met the European Union and FAO/ WHO standards.