Performance of a Diesel Engine Run with Kerosene–Rapeseed Oil Blends Doped with Ignition Promoters

Abstract

The use of straight vegetable oil in diesel engines leads to undesirable consequences due to the peculiar physicochemical properties of vegetable oils. In this regard, the use of pure and unmodified vegetable oils requires their obligatory dilution with petroleum fuels, usually diesel fuel. However, blends of diesel fuel with vegetable oil have a significantly higher density and viscosity than pure diesel fuels. Therefore, in this article, it was proposed to use blends of vegetable oil with aviation kerosene since kerosene has lower density and viscosity compared to diesel fuel. In addition, kerosene is less prone to coking of injectors, has a higher calorific value, and has a lighter hydrocarbon composition, which makes starting the engine easier. Within the framework of the study, engine tests of a full-size four-cylinder diesel engine, MMZ D-245.12.C, were carried out at maximum load in the range of crankshaft speeds from minimum (1000 min−1) to nominal (2400 min−1). Various blends of kerosene with rapeseed oil with an oil content of 10 to 50% by volume have been tested. Ignition promoters were introduced into the fuel blends to improve their combustion. Commercial ethylhexyl nitrate was used as an ignition promoter. In addition, experimental additives were investigated, which are the FAMEs of vegetable oils oxidized to various concentrations of peroxide compounds. It has been shown that blends of kerosene and rapeseed oil doped with ignition promoters can be successfully used in diesel engines. The engine showed the maximum power and the lowest level of smoke emissions when running on a blend of kerosene and rapeseed oil with the addition of oxidized FAME of olive oil with a peroxide content of 1.1 g OOH/100 g.