Biodiesel and ULSD Fueled Compression Ignition Engines Operating with Multiple Fuel Injections

Abstract

Biodiesel offers an inherent life-cycle carbon dioxide emissions reduction compared to conventional diesel, along with renewability, making it an attractive alternative fuel from the prospective of greenhouse gas emissions and dependence on foreign oil. However, biodiesel comes with an economic disadvantage due to its high upfront cost and higher fuel consumption. In addition, a misconception exists that biodiesel produces higher emission of nitrogen oxides than conventional diesel. As a result, biodiesel has struggled to gain mainstream acceptance, thus, denying its potential contributions to the fight against climate change. Multiple fuel injections have had great success at providing benefits in both emissions and fuel consumption with conventional diesel fueled compression ignition engines. Moreover, biodiesel fueled compression ignition engines employing multiple injections have shown to be just as affective, if not more so, than conventional diesel. To contribute to the limited amount of literature on multiple fuel injections with biodiesel and gain a fundamental understanding of multiple injections overall, experimentation was conducted to compare combustion between soybean biodiesel and ULSD when a single pilot injection is employed. The results of testing showed that soybean biodiesel largely produced reduced amounts of partial products of combustion, nitrogen oxides, and particulate matter relative to ULSD, with further potential benefits to be had with more complex injection strategies. This effort lays the groundwork for additional work with biodiesel and multiple fuel injections that will hopefully play a part in the proliferation of biodiesel use in the future.