*4.2. Effect of Alcohol on Azeotrope*

4.2.1. Azeotropic Temperature of Binary Mixture

Figure 5a shows the azeotropic temperature between NB and water. Initially, an azeotropic plateau occurred, during which the temperature growth rate was approximately 0, azeotropic time was approximately 8 min, and the azeotropic temperature was approximately 97.4 ◦C. As the temperature increased, the balance of the azeotropic ratio between the liquid phase and the gas phase was disturbed, azeotropic plateau period ended, and the temperature gradually increased to the boiling point of water at 100 ◦C. The short azeotropic time was primarily due to the low NB content, which did not allow the same proportion of gas and liquid mixture for a long time, thereby ending the azeotrope process. Furthermore, previous studies have shown that the organic compound content is only related to the azeotropic time.

**Figure 5.** Temperature curves of nitrobenzene (NB)–water (**a**), NB/water/ethanol (**b**), NB/water/ n-butanol (**c**), NB/water/ n-pentanol (**d**), and NB/water/ n-heptanol (**e**).
