Effects of Biodiesel Blending with Fossil Fuel on Flow Properties of Biodiesel Produced From Non-Edible Oils

The cold flow properties of biodiesel from various feedstocks have been a challenge in adapting the use of biodiesel in diesel engines, especially in cold regions. The use of cold flow improvers for biodiesel helps using biodiesel in a wide range of temperature conditions. In this study, cold flow properties of biodiesel produced from non-edible feedstocks such as croton megalocarpus, jatropha curcas, and moringa oleifera oils were investigated. The evaluated properties were kinematic viscosity, cloud point, and pour point. Different transesterification methods were used to produce biodiesel from these feedstocks due to their difference in the level of free fatty acids (FFA). Croton and moringa oils were found with FFA levels of 1.68% and 0.6%, respectively; thus, one-step transesterification method was chosen for their methyl esters conversion. Jatropha oil was found with FFA level of 8.14% making a two-step acid-base transesterification method to be employed for its methyl esters conversion. The effect of water in the two-step acid-base transesterification process was also investigated for jatropha biodiesel production. The presence of water after acid pretreatment process of jatropha oil was found to reduce both product and methyl esters yield, the best option was to preheat the pretreated jatropha oil to 110 degrees C for 10 min to evaporate water that remain during gravity separation of methanol-water phase. Blending of biodiesels from these three feedstocks with kerosene improved their cold flow properties. The reduction of cloud and pour points from -4 degrees C and -9 degrees C to -11 degrees C and -15 degrees C, respectively, of croton biodiesel was observed when blended with 20% kerosene while cloud and pour points reduction from 1 degrees C and -2 degrees C to -7 degrees C and -12 degrees C, respectively, of jatropha biodiesel was observed when blended with 20% kerosene. Similarly, the reduction of cloud and pour points from 10 degrees C and 3 degrees C to -3 degrees C and -7 degrees C, respectively, of moringa biodiesel was observed when blended with 20% kerosene.