Motor de combustão interna dual operando com diesel, biodiesel e gás natural: análises de desempenho e emissões.

Abstract

The gaseous fuel (Natural Gas) has been widely used on diesel engines in the last few years, due to its positive characteristics as far as the level of emissions released in the atmosphere is concerned. Biodiesel has been considered a potential alternative to contribute to reducing pollutant emissions level in the world, as a renewable fuel, its properties are comparable to the one of the diesel fuel which is already widely used in diesel engines. The big challenge is to use the diesel engine which operates in a dual form, using adequate mixtures of diesel, biodiesel and natural gas to obtain the correct proportion of each fuel and maintaining the original characteristics of the engine as well as a good performance. In this sense, the aim of this research is to study the characteristics of the commercial diesel engine emissions, operating with B40, B50, B60 and natural gas. The fuel used in the engine consists of a mixture of 15% diesel and biodiesel (liquid fuel) and 85% natural gas. Experiments were made using 40, to 120 kW, with an interval of 20 kW. The engine was instrumented to obtain the temperature, air, gas, diesel and biodiesel flow rate, the air pressure at the entrance of the engine, the lubricant oil temperature, and the concentration of exhaust gases during each experimental test. The specific cost of the engine operating in dual mode was better than in diesel mode, and the blend of diesel, biodiesel and natural gas with the lowest specific cost was the B50 blend. It was verified that the emission of NOx, NO and CO2 had decreased while the emissions of CO had increased, when compared to the conditions using commercial diesel (B5) as the only fuel.