Abstract:

The corrosion of the ketobenzene dewaxing unit often occurs in the solvent recovery system. The temperature and pH values of the corrosive medium in the solvent recovery system were tested to study the corrosion law. It is found that there are small molecule organic acids in the circulating solvent, and the corrosion of the solvent system may be caused by small molecule organic acids; the corrosion rate of the deketone tower bottom drainage increases with the increase of temperature, and the corrosion rate of the circulating solvent increases first and then decreases with the increase of temperature, and the corrosion product is iron oxide, which is easy to be washed away. The corrosion rate of the deketone tower bottom drainage decreases first, then increases, and then decreases with the increase of pH value. For the corrosion of small molecule organic acid, it is suggested that the pH value can be controlled at 6～9 to control the corrosion of solvent system.

摘要：

酮苯脱蜡装置的腐蚀常发生于溶剂回收系统，针对溶剂回收系统的腐蚀介质进行了温度、pH值的相关试验，研究腐蚀规律。研究发现：循环溶剂中存在小分子有机酸，溶剂系统的腐蚀可能是由小分子有机酸导致；脱酮塔底排水的腐蚀速率随温度升高而增大，循环溶剂的腐蚀速率则随温度升高呈现先增大后减小的趋势，且腐蚀产物为铁的氧化物，易被冲刷带走；脱酮塔底排水的腐蚀速率随pH值的增大呈现出先减小后增大再减小的趋势。针对小分子有机酸的腐蚀，建议可将pH值控制在6～9,以控制溶剂系统的腐蚀程度。