(264b) Biodiesel Production by Utilizing by Products From Fish Oil Concentration

Due to the health-promoting properties of polyunsaturated fatty acids (PUFA) shown in numerous medical studies, omega 3 concentrates based on fish oil are enjoying increasing popularity in the food industry. According their occurrence in natural fish oils, concentrates with high concentrations of PUFAs of Eicosapentaenoic acid (EPA) and Docosahexaenoic acid (DHA) are used. The applications range from nutritional supplements and food supplements up to pharmaceutical preparations. For large scale industrial production, high-quality fish oils with concentrations about 30% in total in EPA/DHA are commonly used for the production of EPA/DHA ethyl ester and triglyceride concentrates. For concentration to desired EPA/DHA amounts the fish oil is transesterified to ethyl esters. Adjacent to the transesterification the EPA and DHA esters are concentrated by molecular distillation. During the concentration step more than 60% of the starting ethyl ester amount forms the so called ethyl ester light fraction which is low in content EPA and DHA. Due to the low content of poly unsaturated fatty acids, this light fraction is usually thermal utilized. However, since the quantities of high-quality fish oils are limited, there is consequently an increasing trend also using fish oils with considerably lower concentrations of these omega-3-fatty-acids. Naturally by converting fish oils which are low in EPA/DHA content also the amount of ethyl ester light fraction will increase. Therefore a further upgrade of this light fraction to higher value products is important to improve the overall economics.

Target of the ongoing research is the evaluation and necessary treatment of ethyl ester light fraction for utilization as alternative fuel. Therefore fish oil with lower content of polyunsaturated fatty acids was transesterified to ethyl ester. By molecular distillation this ester was used to produce marketable ethyl ester concentrates. The resulting ethyl ester light fraction with low contents of PUFAs was evaluated for its ability to produce biodiesel according ASTM standard. Compared to conventional methyl ester several parameter of the light fraction has to be improved to fulfil the ASTM standard. Especially the quality parameters of free glycerine, carbon residue and atmospheric residue are standard parameters out of specification. By utilizing this side stream, a renewable fuel could be generated, offering also the opportunity to recover remaining PUFAs in the light fraction.