Diesel powered vehicles are increasingly present in the current freight and leisure transportation scenario. To face the new market needs and restricted legal emission limits, the demand for new technologies is one of the greatest challenges of the diesel development.
The Legislation in both developed and developing countries is being continuously revised, in order to reduce the emissions and particulate matter of the engines. Another relevant fact is that many countries currently have similar or even identical emission limits. Both facts drive to new technologies research opportunities.
Non-fossil fuels, called biofuels, are becoming increasingly an economically viable option. Their molecular chain has less carbon and more oxygen, therefore they have different physical properties compared to the regular diesel.
Cummins Brazil Technical Center Lab conducted a study aiming to understand the differences in the behavior of gaseous emissions and torque level when the engine is working with two different blends of soybean biodiesel fuels: Petrobras commercial S50 (5% soybean blend and maximum 50ppm sulfur level) and reference B20 soybean biodiesel (20% soybean blend and 80% S50). The engine used in this work was the Cummins ISL 8.9 liters rated power of 400 hp. Tests with different command injection parameters (injection start, pressure and separation of the pre-injection) were made in order to investigate the performance potentials for both fuels.
The results show that B20 biodiesel, in comparison to S50, presents particulate matter reduction and worse NOx values and degradation in torque output. These results are discussed here as a function of injection parameters, trace of apparent heat release rate and other parameters of engine performance.