Rheology and MT-DSC studies of the flow properties of ethyl and methyl babassu biodiesel and blends

• DOI: 10.1007/s10973-011-1394-z
• Publication Date: 2011-02-26T10:46:12Z
• Authors: N. A. Santos; R. Rosenhaim; M. B. Dantas; T. C. Bicudo; E. H. S. Cavalcanti; A. K. Barro; I. M. G. Santos; A. G. Souza
• Keywords: Pour point; Shear thinning

Biodiesel is an increasingly attractive alterna- tive to diesel fuel. The main component of Babassu bio- diesel is lauric acid (C12:0), which is a saturated fatty acid with a high melting point. Controlling flow properties, such as viscosity and the cold filter plugging point, is critical because viscosity affects atomization, and crystal forma- tion resulting from decreases in temperature can negatively affect engine starting and performance. To evaluate its flow characteristics more fully, the rheological properties of babassu biodiesel were analyzed, taking into account variations in temperature. The crystallization temperature was determined by modulated temperature differential scanning calorimetry (MT-DSC). The curve of biodiesel viscosity as a function of the biodiesel refrigeration tem- perature contained an inflection point (corresponding to a steep increase in viscosity) that was coincident with both the transition from a Newtonian-type flow to a pseudo- plastic-type flow and the crystallization temperature obtained by MT-DSC, indicating that the appearance of crystals in the biodiesel increased its viscosity. The rheo- logical properties of fatty acid methyl and ethyl mixtures (FAME and FAEE) with metropolitan diesel were also evaluated; a higher FAME percentage reduced viscosity in blends up to B100.