Assessing the significance of factors in the toxic components forming during diesel engine operation on biofuels
P.Ya. Kantor, S.А. Plotnikov
Section: Ecologization of industry
The article considers environmental problems associated with partial replacement of hydrocarbon diesel fuel with plant components, in particular, rapeseed oil. We analyze factors that change the toxic component composition in exhaust gases when a diesel engine operates on mixed fuel, in particular, specific physicochemical properties of rapeseed oil and changes in the temperature conditions of the engine. Theoretical assessment of the temperature effect on the nitrogen oxides (NOx) and soot forming is carried out. It is shown that direct nitrogen oxidation (Zeldovich mechanism) is practically absent at temperatures typical for the diesel engine working cycle. We assumed that the low-temperature oxidation mechanism with the participation of intermediate products (refined Fenimore mechanism) plays the main role in the NOx forming. Bench tests of mixed fuels were carried out on a D-245.5S2 tractor diesel engine produced by the Minsk Motor Plant (Republic of Belarus). Three series of results were obtained: adjustment, load and speed characteristics. The results of experimental tests of mixed fuels containing up to 55% rapeseed oil are presented. In most cases, the increase in the rapeseed oil content decreases NOx concentration in the exhaust gases. In some modes, a decrease in NOx concentration by more than 2 times was detected. The smoke content of the exhaust gases, mainly due to the presence of free carbon in soot form, also showed a pronounced tendency to decrease with
increasing rapeseed oil content in the mixed fuel.
ISSN 1995-4301
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