Distillation-crystallization coupling process is a new kind of separation technology based on vapor-liquid equilibrium and solid-liquid equilibrium. The separation of azeotropic systems composed with Acetic acid and N-neptane by distillation-crystallization process (DCC) was studied in this paper. We apply the orthogonal experiment to search for the optimal technique process. The final results demonstrate that the DCC process can purify the heavy and light components over 90 wt% respectively, verifying the advantage of the DCC for the azeotropic systems separation.

The stability of M30 Methanol Gasoline (30% methanol, 70% gasoline, v/v) under low temperature and metal corrosion were studied in this paper. Kinds of co-solvents were added into M30 for enhancing its stability at different low temperature and the influence of co-solvents on the stability was also investigated. Results showed that the more the content of co-solvent was, the lower temperature of phase disengagement was. When the content of co-solvent was 3%, the n-hexanol added has the lowest phase separation temperature (-27 °C) of any straight chain alcohols studied. Obvious corrosion happened with the copper samples in pure methanol, FCC gasoline and M30. For M30, the biggest copper’s corrosion appears in the first 3 h (weight loss rate 0.67 mg/h). In addition, the separation mechanism of methanol from gasoline was also discussed.