A general kinetic model which describes the
combustion characteristics of aliphatic hydrocarbons at any
given temperature, involving the variations of conversion,
carbon number and combustion time was developed for the
combustion of aliphatic hydrocarbons. A combustion
quality tester (CQT) was designed, fabricated, and then used
to carry out combustion experiments on CNG. Data was
sourced from coherent works from the internet, for certain
experiments that could not be carried out due to required
equipment sophistication. Experimental data on CNG
combustion were curve-fitted using the derived kinetic
models to ascertain their goodness of fit. It was found that
the curves fitted well at 97.5%, 97.9%, 97.6% and 98.7%
goodness of fit for combustion temperatures of 385K, 390K,
395K and 400K respectively. The models agree vehemently
with experimental data, and show that reaction rate of the
fuel increases with temperature, and the overall reaction
rate with temperature is an inverse function of combustion
time. Next, ignition quality tester (IQT) was used to
investigate pressure and temperature effects on ignition
delay, effect of fuel additive (2-EHN) on cetane number and
ignition delay, and also measurement of cetane number
according to ASTM D6890 standards. Test was conducted
under steady state conditions at constant pressure and
temperature of 145psi and 828K respectively for cetane
number experiments. Data were curve-fitted at 98.18%,
99.64%, 99.43% 99.82% and 99.19% goodness of fit for
cetane number-%additive vol., cetane number-ignition
delay, ignition delay-%additive vol., ignition delay-pressure
and ignition delay-temperature experiments. Data agreed
well with derived models. Ignition delay time of the fuel
gives an inverse function with temperature, pressure, cetane
number and percentage vol. additive concentration. Fuel
additive (2-EHN) has a profound impact on cetane number
and increases it up to about 8 points beyond which there is
no appreciable increase no matter the volume of additive
added. The present research finding can find use in
combustion laboratories and automotive industries, to
correlate certain variable parameters instead of habitually
resorting to experiments.