%0 Journal Article %T Sunflower Methyl Ester as an Engine Fuel: Performance Evaluation and Emissions Analysis %A Bjorn S. Santos %A Sergio C. Capareda %A Jewel A. Capunitan %J ISRN Renewable Energy %D 2013 %R 10.1155/2013/352024 %X Biodiesel from sunflower oil offers a potential as an alternative to petroleum-based diesel fuel and must be evaluated in terms of the resulting engine performance and exhaust emissions. Two diesel engines rated at 14.2£¿kW (small) and 60£¿kW (large) were operated on pure sunflower methyl ester (SFME) and its blends with a reference diesel (REFDIESEL). Results showed that less power and torque were delivered by both the small and large engines when ran on pure SFME than on REFDIESEL, while brake-specific fuel consumption (BSFC) was found to be higher in pure SFME. Blends of SFME with REFDIESEL (B5 and B20) showed negligible power loss and similar BSFC with the REFDIESEL. Higher concentrations of nitrogen oxides ( ), carbon dioxide (CO2), and total hydrocarbons (THC) in the exhaust emissions were observed for both pure SFME and SFME-REFDIESEL fuel blends. Comparison with soybean methyl ester indicates similar engine performance. Thus, blends of SFME with diesel may be used as a supplemental fuel for steady-state nonroad diesel engines to take advantage of the lubricity of biodiesel as well as contributing to the goal of lowering the dependence to petroleum diesel. 1. Introduction Biodiesel is an alternative fuel deemed to augment, if not to replace, petroleum diesel supply in the current world¡¯s energy situation. It is a mixture of monoalkyl esters of long chain fatty acids (FAME) derived from a renewable lipid feedstock, such as vegetable oil or animal fat [1¨C3]. With growing concern over possible scarcity in petroleum fuel reserves as well as increasing awareness on global environmental issues, the use of biodiesel either solely or blended with petroleum diesel has been investigated and promoted among energy producers and end-users [1, 2, 4, 5]. Biodiesel can be produced from the transesterification of any triglyceride feedstock, which includes oil-bearing crops, animal fats, and algal lipids [6]. These feedstock materials are rather extremely viscous, and converting them into esters achieves the purpose of lowering their viscosity [7]. Various sources have been identified and used as biodiesel feedstock, including edible oils, nonedible oils, wild oils, used cooking oils, and animal fats [5]. Soybean oil has been the major source in the United States, with approximately 244£¿M lbs consumed in November 2012 [8]. However, soybean oil alone cannot satisfy the necessary feedstock quantity for biodiesel production since it accounts only for 13.5% of the total production, owing to its use in the food industry as well, and thus, there is a need to look for %U http://www.hindawi.com/journals/isrn.renewable.energy/2013/352024/