乙醇和柴油的相容性研究

Miscibility of ethanol-diesel fuels

以相分离温度及其变化幅度为指标考察了乙醇和柴油的相容性.结果表明,直馏和加氢柴油馏分油及所有市售柴油与乙醇的相分离曲线随乙醇含量增大呈先上升后下降的变化规律,馏分油在乙醇含量为5%～20%范围内,相分离温度升高25～40℃,调合柴油在乙醇含量为10%～20%时,相分离温度升高10～15℃,且在乙醇含量约50%时相分离温度都达到最高值;芳烃含量较高的催化裂化柴油相分离温度随乙醇含量增加呈单调升高的趋势,但整体升高幅度小于15℃.柴油的烃族组成和50%馏出温度对乙醇与柴油的相容性有较大影响.加入助溶剂后乙醇和柴油的低温稳定时间明显延长.

The miscibility of ethanol in nineteen diesel fuels was studied based on the value of phase separation temperature （PST/C） and its changing range. The experimental results indicate that the PST curves of straight-run, hydrogenated diesel oil and all product diesel fuel show the ,same shape of first rising then dropping with the content of ethanol increasing. The increase range of PST is from 25 to 40℃ when the extent of ethanol content in distillate is from 5 % to 20 %. The increase range of PST is from 10 to 15℃ when the extent of ethanol content in blended diesel is from 10% to 20%. Moreover, the PST of distillate and blended diesel are both up to peak when the content of ethanol is about 50 %. The PST of catalytic cracked diesel oil with high content of aromatic hydrocarbon rises monotonously with the content of ethanol increas- ing, But the global increased range is under 15℃. Aromatic contents and 50 % distillate temperatures have much effect on the miscibility of ethanol in diesel fuel. The results show that adding cosolvent can prolong the stable time evidently.