STUDY OF DIESEL FUEL STABILITY ON OXYGEN ABSORPTION. II. EFFECT OF TEMPERATURE AND OXYGEN PRESSURE

The effect of temperature and oxygen pressure on oxygen absorption properties of Daqing straight run diesel fuel (SRDF) and Daqing hydrogenated coking diesel fuel (HCDF) was investigated at 293 ∼ 353 K under 0.11 ∼ 0.25MPa(O2) and Cu catalysis in darkness based on the study of diesel fuel stability on oxygen absorption. The experimental results show that the oxygen absorption quantities (OAQs) of diesel fuels increase rapidly with the increasing of temperature or oxygen pressure at given time and oxygen pressure or temperature during the oxygen absorption. The higher the oxygen pressure or the temperature and the longer the time, the greater the OAQ of diesel fuel. The OAQs of diesel fuels change a little at shorter times, while they vary greatly at longer times. Low temperature has a great effect on OAQ of SRDF and high temperature affects clearly OAQ of HCDF. Oxygen pressure gives a evident action on OAQ of SRDF, but it affects a little OAQ of HCDF. At low temperature or high oxygen pressure the OAQ of HCDF is less than that of SRDF, while at high temperature or low oxygen pressure the OAQ of HCDF greater than that of SRDF. The more the types of unstable constituents and the higher their contents in diesel fuel, the easier the oxygen absorption reaction takes place and the more obviously the diesel fuel stability or quality deteriorates.