The synthesis of
5-(hydroxymethyl)furfural (HMF) and conversion
to the corresponding HMF-monoesters upon certain treatment are presented
with their properties that are validated in a diesel engine. With
a collection of fatty acids (C8–C18) using cyanuric acid as
a catalyst under mild reaction conditions, the subsequent reduction
of the HMF-monoesters with NaBH4 produced the corresponding
alcohols. After purification, both HMF-monoesters and their alcohol
derivatives were determined for their solubility, cetane index, heat
of combustion, viscosity, and specific gravity. HMF-Capric (1-C10), HMF-Oleic (1-C18:1), HMF-Caprylic-OH
(2-C8), and HMF-Oleic-OH (2-C18:1) were
soluble in a neat diesel fuel. The observed highest cetane index and
heat of combustion of 1-C10 and 1-C18:1 were
evaluated for combustion characteristics in a single-cylinder compression
ignition engine. The diesel fuel containing 3% 1-C10 displayed
comparable properties during burning in terms of thermal efficiency,
cylinder pressure, and heat release rate with respect to the neat
diesel fuel (D100) for all usage engine speeds. In general, all tested
fuels initiated their burning onset with a similar ignition delay
period. The 3% 1-C10-blended diesel fuel emitted slightly
higher smoke opacity but an equivalent nitric oxide level compared
to those of D100. The HMF-Capric (1-C10) synthesized
in this study represents a promising additive for diesel fuel. Blended
fuel lubricity and other unregulated emissions upon broader engine
test cycles are suggested to be accomplished in future work.