Existing technologies for the synthesis of active additives to motor fuels are quite complicated. Therefore,improvement of the technology of biodiesel fuel synthesis in order to increase the cetane number and andimprovement of other diesel fuel characteristics with combustion activators is an urgent problem. Raw materialsfor the biodiesel production are vegetable oils methanol and ethanol with the alkaline or acid catalyst usage. Theuse of ethyl esters of long-chain fatty acids of rapeseed oil as biodiesel has a number of advantages comparedwith the methyl ester use [2]. Thus, biodiesel fuel was synthesized by transesterification of rapeseed oil withabsolute ethanol (99.9 %), which was dehydrated with calcium oxide (95 %) freshly prepared, using sodiumethoxide as a catalyst [3]. In order to achieve a high degree of mixing of a heterogeneous system, which consistsof natural oil and ethyl alcohol, a specially synthesized non-ionic emulsifier was used as a reagent. Thetechnological features of this type of a rapeseed oil transesterification process were studied and the maincharacteristics of the new diesel fuels such as fractional composition and molecular mass were estimated usingthe chromatographic method and mass spectrometry. The yield of biodiesel from rapeseed oil increases from 85 -90 % to 95 – 98 % without waste fraction of glycerol (10 – 15 %).