Pollutant emissions and combustion efficiency assessment of engines using biodiesel

This paper evaluates the biodiesel produced by a biodiesel plant located in the Mexican Centre for Cleaner Production (CMP + L by its acronym in Spanish) of the National Polytechnic Institute of Mexico. Pollutant emissions from two types of engines were studied: a low power monocylinder engine and a 30-kW electric generator diesel engine. The tests were performed with the following blends: B5, B10, B15, B20, B30, B40, and B50. Parameters such as carbon monoxide, nitrogen oxide, hydrocarbons, and combustion efficiency were analyzed, as well as sulfur dioxide, oxygen, and combustion temperatures. It was demonstrated that NOx increases as the percentage of biodiesel increases, while CO decreases slightly using the monocylinder engine. In the case of the electric generator diesel engine, the B5 mixture had the highest trend for NOx and the lowest trend for CO. Likewise, combustion efficiency was found to be severely affected by the biodiesel blends, i.e., from B5 to B20. An analytical study and experimental thermography tests of the combustion process with biodiesel blends were carried out, and the technical problems of operation when incorporating biodiesel blends are presented.