Effect of Ethoxlate Chain Length on the Pour Point Depressant of Middle Distillate Fuel Oil

A series of ethoxylated laurates, C12En (n=7, 9, and 14) surfactants were prepared by reacting lauric acid with polyethylene glycol of different molecular weights 300, 400, and 600. The chemical structures of these prepared surfactants were confirmed by high performance liquid chromatography (HPLC) and proton nuclear magnetic resonance (NMR) analysis. The surface tension of the synthesized surfactants was measured at 25 degrees C, critical micelle concentration (CMC) and hydrophobic lipophilic balance (HLB) were calculated. The additives prepared were added to improve oils properties as pour point depressant and improve viscosity or storage stability. They were added at different concentration to meet the performance requirements. It was found that the ethoxylate laurate, C12En, n=14 (C) is more effective as pour point depressant and improve viscosity than ethoxylated laurate, C12En, n=7 (A) as pour point depressant and viscosity improver were determined. Storage stability of the treated middle distillate fuel was tested in terms of pour point depression for 28 days. The obtained data were used to explain the discrepancy of these ethoxylate laurate as pour point depressants.