Diesel Fluidity Improving Agent Performance Evaluation And Mechanistic Studies

The text mainly evaluated the capability of new kind diesel fuel low-temperature flow improver (for short DFI), and discussed the action mechanism of DFI. It was composed of the following parts: (l)Gas chromatography was used in the analysis of n-paraffin content of 0# diesel oils which were obtained from Dalian and Jinxi Petrochemistry Filiale. Through the compares of chromatograms and the results of adding DFI, it proved that the content and distribution of higher number n-paraffin was the great factor of influencing itself low temperature character and DFI using effect. (2)Different series of DFI were tested by molecular weight apparatus. The molecular weight distribution of DFI having better effect on the disesl oils was 12000-50000. And there was a well corresponding relation between the molecular weight and the effect of it depressing CFPP. (3)The shapes of wax crystals in diesel oil with or without DFI were observed by using polarizing microscope at different temperatures, dosages and composing mol. Through it we found that wax crystals in diesel oil with DFI became shorter and smaller, were prevented from connecting each other to form network. But the dosage was not the more the better, it had an optimum point. Each component of polymers existed an optimum proportion. Under it, the effect of depressing CFPP was the best. And photomicrography was a finer method than macroscopical measurement, that could evaluate the effect of DFI. (4) Experiment datum showed that, good DFI should meet following terms that the carbon number of long alkyl matched equal carbon number of wax in diesel oil, especially higher carbon number; Crystal temperature of DFI in oil matched of wax; Polarity group or surface active group shoud be right introduced into DFI. Our experiment results accorded crystal together theory, and explained the action mechanism of DFI.