Fractionation of fatty acid methyl esters via urea inclusion and its application to improve the low-temperature performance of biodiesel

Biodiesel is viewed as the alternative to petroleum diesel, but its poor low-temperature performance constrains utilization. Cloud point (CP), onset temperature of thermal crystallization, appropriately shows performance. The effective way reduce CP remove saturated fatty acid methyl esters (FAMEs). Compared current methods, this work describes an extraordinary approach fractionating FAMEs by forming solid urea inclusion compounds (UICs). Urea fractionation reduces CPs removing high melting-point linear FAME components. in study was performed under various processing conditions: mass ratios and solvents FAMEs, solvents, from feedstocks, temperatures. Supersaturation solution driving force, it significantly affects yield, composition, CP, separation efficiency, selectivity. Through a single process, except palm oil resulted reduction ranging 20 42 oC with yield 77–80% depending on compositions. could reach low -17 46% after twice fractionation. According model prediction, cetane number decreased about 0.7–2 still higher than minimum biodiesel requirement. Oxidation stability according proposed model, can be mitigated adding antioxidants. Emission evaluation indicated hydrocarbons, carbon monoxide, particulate matter. However, increasing emission nitrogen oxides.