This study is focused on the use of biodiesel in a liquid fuel heating boiler of 26.7 kW. The
influence of biodiesel/diesel mixtures, air flow rate, and input pressure on a combustion
process for heating purposes was analyzed. The study is divided into two parts. The first
one deals with the characteristics of biodiesel as a heating fuel and the analysis of its
properties and preparation method. The biodiesel was produced from sunflower oil in a
pilot plant of 250 L/charge and was characterized according to standard norms. It was
found that biodiesel is not acceptable as fuel for internal combustion engines (ester content
of 92%). The second one deals with the effect of the operating variables on the combustion
parameters in the boiler. The tests were conducted on experimental facilities and the
generated emissions were analyzed. It was found that increasing the input burner pressure
involves a decrease in CO and O2 and an increase of CO2 in the fumes, as well as an increase
in the combustion process yield. Likewise, a greater air flow rate gives rise to a
decrease in the latter parameter. Moreover, CO emissions were slightly higher when biodiesel
content was increased in the mixture, and therefore the combustion yield decreased.