Analysis of biodiesel

Authors: Knothe, Gerhard

Submitted to: Encyclopedia of Analytical Chemistry
Publication Type: Book / Chapter
Publication Acceptance Date: 10/21/2016
Publication Date: 3/25/2017
Citation: Knothe, G.H. 2017. Analysis of biodiesel. In: Meyers, R.A., editor. Encyclopedia of Analytical Chemistry. Hoboken, NJ: John Wiley & Sons, Ltd. p. 1-15. doi: 10.1002/9780470027318.a9586.

Interpretive Summary: This article is concerned with methods for analyzing biodiesel, which is a plant-derived alternative to diesel fuel from petroleum. Analytical issues at all stages of the biodiesel production and application chain, from feedstock analysis to storage and use, are discussed.

Technical Abstract: Biodiesel is a biogenic alternative to diesel fuel derived from petroleum. It is produced by a transesterification reaction from materials consisting largely of triacylglycerols such as vegetable and other plant oils, animal fats, used cooking oils, and “alternative” feedstocks such as algal oils. The variety of feedstocks that biodiesel can be derived from entails that biodiesel from different sources can have different properties depending on its composition, especially the fatty acid profile, and that the composition of the feedstock, in this case, especially the presence of extraneous materials, can influence the production process. Moreover, biodiesel is miscible with petrodiesel in all ratios, and blends of these two fuels can also be used to power diesel engines. Consequently, analysis of biodiesel has to deal with a variety of issues including the nature and quality of the feedstock, monitoring the production process, analyzing the biodiesel product for specifications in quality standards, assessing the properties of the biodiesel, and biodiesel-petrodiesel blend level determination. This chapter provides a brief synopsis of these issues and the methods used to analyze them.