Improving cold-flow properties of biodiesel through blending with nonedible castor oil methyl ester

Castor oil biodiesel is one of the different types of renewable fuels which can be produced from nonedible source. The unique physical properties of this fuel including low cloud point (CP) and pour point (PP) will bring about opportunities to improve the cold-flow properties of other fuels. Biodiesel was first synthesized from castor, canola, and frying oil with purity of 98.8%, 97.9%, and 98.5%, respectively. Blends of castor biodiesel with other biodiesels and conventional diesel were prepared in six various levels. Kinematic viscosity, specific gravity, CP, and PP of all samples were then evaluated. In addition, maximum acceptable ratio of castor biodiesel in blends of conventional diesel, canola biodiesel, and frying oil biodiesel were obtained and equal to 48, 35, and 50 wt %, respectively. At such condition, an improvement of 6.5, 4.5, and 12.5 degrees C for CP were observed. Moreover, although other properties were in the ranges of ASTM, an enhancement of 7, 7, and 15 degrees C for PP were obtained. (c) 2014 American Institute of Chemical Engineers Environ Prog, 34: 897-902, 2015