| The high solidifying point (SP) and cold filter plugging point (CFPP) of Nanyang dieseloil resulted in a poor low temperature flow property. It brought in great difficulties to its usein winter. In this paper, a series of pour point depressants for Nanyang diesel oil weredesigned and synthesized, based on the analyses of Nanyang diesel oil physical properties andthe mechanism of pour point depressant.In this paper, the sensitivity of Nanyang diesel oil, Qilu diesel oil and Xinjiang diesel oilto the domestic and foreign PPDs was researched. The test results of CFPP showed t hat theQilu diesel oil had good sensitivity to the PPDs in current market, but the Nanyang diesel oilhad poor sensitivty to PPDs. The group composition, carbon distribution, the content of wax,as well as distillation range of the three kinds of diesel o il were studied. It was found thatNanyang diesel possessed the characteristics of higher saturated hydrocarbon content, themuch higher wax content, and the relatively lower aromatic hydrocarbon content, also theconcentrated distribution of n-alkane, which may be the main factors affecting the sensitivityof Nanyang diesel to PPDs.According to the characteristics of Nanyang diesel, copolymers of fumarate and vinylacetate were designed and synthetized under the optimized reaction conditions: the molarratio of dihexadecyl fumarate to vinyl acetate to was1∶8, reaction temperature was75℃,reaction time was7h, the amount of BPO was0.8%. The molecular structures of copolymerswere characterized by FTIR spectroscopy and the molecular weights were got by gelpermeation chromatography. The crystal wax dispersant BR, which had the structurecharacteristics of surfactant, was designed and synthetized under the optimized reactionconditions: the molar ratio of benzotriazote to cetyl bromide was1∶0.9, reaction temperature was80℃, reaction time was4h. The molecular structures of BR were characterized by FTIRspectroscopy. The evaluation results showed that the synthetized dihexadecyl fumarate-vinylacetate copolymer had good sensitivity to Nanyang diesel oil, it could lower the cold filterplugging point by9℃in the dosage of800ppm; When compounded with BR, it could lowerthe cold filter plugging point by11℃. Moerover, the cold filter plugging point can be loweredby14℃when the copolymer compounded with BR and Span80, showing obviouslysynergistic effect.The viscosity-temperature curves, rheological curves and DSC curves of diesel oil withand without PPD were investigated, the fuction mechanism of pour point depressant waspreliminarily deduced. The possible fuction mechanism of PPD wasnucleation-co-crystallization mechanism. |
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