ARS | Publication request: Fuel Properties and Nitrogen Oxides Emissions Levels of Biodiesel Produced from Animal Fats

Submitted to: Journal of the American Oil Chemists' Society
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: July 7, 2005
Publication Date: August 1, 2005
Citation: Wyatt, V.T., Hess, M.A., Dunn, R.O., Foglia, T.A., Haas, M.J., Marmer, W.N. 2005. Fuel properties and nitrogen oxides emissions levels of biodiesel produced from animal fats. Journal of the American Oil Chemists' Society. 82(8):585-591.

Interpretive Summary: Biodiesel is a renewable and biodegradable diesel fuel made from vegetable oils and animal fats that runs in any conventional, unmodified diesel engine. Additional advantages to using biodiesel are that it improves engine lubricity and reduces engine emissions such as carbon monoxide and particulates. Unfortunately, when used directly or as a blend in petroleum diesel, it increases nitrogen oxides (NOx) emissions, the level of which depends on the source of the biodiesel. Accordingly, there is a need to address the elevated levels of this primary pollutant to further advance and expand the use of this renewable fuel. In this study we produced biodiesel fuels from the animal fats lard, chicken fat, and beef tallow and determined their nitrogen oxides (NOx) emissions in a simple test engine. Biodiesel produced from animal fats had lower NOx emission levels than did vegetable oil-based biodiesel. In fact, NOx emission levels for tallow-based biodiesel gave the same values as did petroleum diesel. This result should further the use of this readily available and renewable fat as a biodiesel feedstock.

Technical Abstract: Fatty acid methyl esters of lard, beef tallow, and chicken fat were prepared by base-catalyzed transesterifcation for use as biodiesel fuels. Selected biodiesel fuel properties for the esters were compared to each other and to soy-based biodiesel and petrodiesel. Nitrogen oxide (NOx) emission tests were conducted with the fat-derived esters as 20 vol% blends in petroleum diesel. The data indicated that all three animal fat-based biodiesel fuels had lower NOx emission levels than did the soy-based biodiesel.