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.
