Tompkins, Brandon T. (2008-12). Emissions comparison between petroleum diesel and biodiesel in a medium-duty diesel engine. Master's Thesis. Thesis uri icon


  • Biofuels have become very important topics over the past decade due to the rise in crude oil prices, fear of running out of crude oil, and environmental impact of emissions. Biodiesel is a biofuel that is made from plant seed oils, waste cooking oils, or animal fats. It has become increasingly popular and is looked at as a diesel replacement. This research characterizes the emissions of the new John Deere PowerTech Plus 4045HF285 in the Advance Engine Research Laboratory at Texas A&M University and compares the emissions of a 100 percent blended feed stock biodiesel to an ultra low sulfur diesel certification fuel. The steady state tests were conducted while holding engine speed constant at three different speeds and three different loads. The gaseous emissions, exhaust gas recirculation, fuel flow rate, and torque were monitored and recorded for 300 points per test. Four tests were performed and the results were averaged per each fuel. Carbon monoxide, carbon dioxide, oxygen, and oxides of nitrogen emissions were analyzed. The biodiesel averaged up to 12% lower torque, 5.4% more fuel, 7.5% less carbon dioxide, 29% more oxygen, and 29% more oxides of nitrogen. Overall the biodiesel produced less torque and carbon dioxide emissions, while emitting more oxygen and oxides of nitrogen.

publication date

  • December 2008