Effects of biodiesel made from swine and chicken fat residues on carbon monoxide, carbon dioxide, and nitrogen oxide emissions

ABSTRACTThe effects of two alternative sources of animal fat-derived biodiesel feedstock on CO2, CO, NOx tailpipe emissions as well as fuel consumption were investigated. Biodiesel blends were produced from chicken and swine fat waste (FW-1) or floating fat (FW-2) collected from slaughterhouse wastewater treatment processes. Tests were conducted in an unmodified stationary diesel engine operating under idling conditions in attempt to simulate slow traffic in urban areas. Significant reductions in CO (up to 47% for B100; FW-2) and NOx (up to 20% for B5; FW-2 or B100; FW-1) were attained when using biodiesel fuels at the expense of 5% increase in fuel consumption. Principal component analysis (PCA) was performed to elucidate possible associations among gas (CO2, CO, and NOx) emissions, cetane number and iodine index with different sources of feedstock typically employed in the biodiesel industry. NOx, cetane number and iodine index were inversely proportional to CO2 and biodiesel concentration. High NOx emi...