The article describes the types, properties and efficiency of reagents (CaO, tetraethoxytitanium), which chemically bind water and dehydrate ethanol. The composition and properties of the absolutized ethanol were studied using the infrared spectroscopy, mass spectroscopy and gas-liquid chromatography. The octane number of gasoline with the addition of absolutized ethanol together with the combustion activator (diethyl ether) was measured as well. It has been shown that the content of even very small amounts (up to 2 %) of the combustion activator in absolutized ethanol results in the increase of the octane number and improves running abilities of gasoline.

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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 %).

Traditional methods of biofuel production using vegetable oils and aliphatic alcohols have a number of disadvantages. A new method of transesterification of vegetable oils with alkyl acetates because they act as promoters of diesel fuel combustion. A method of improving both technology of alcoholysis and esterolysis by modifying the temperature range is proposed. Chemical and technological bases of two-stage process of vegetable oil transesterification are developed. In the first stage, the oils are treated with glycerol  in order to convert tri-acyl-glyceros of oil into mono-acyl-glycerols. The second stage is alcoholysis of mono-acyl-glycerols with ethanol  or esterolysis of mono-acyl-glycerols with ethyl acetate. The temperature range of the transesterification process is improved using heat-transfer solvents. Comparison of material balances of technologies of one- and two-stage ways of ethanolysis and esterolysis showed a significant increase in the selectivity of the process, yield and quality of biofuels. Analysis of the obtained biofuels and mixtures, which contain 20 % of biofuels and 80% of diesel fuel showed  the best physical, chemical and operational characteristics. Therefore, the  blended fuels are promising area of ​​biofuel technology.

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