TP24-12 Development of a Novel Non-Azole-Containing Cooling Water Treatment Program

Since the introduction of phosphate to replace chromate-based cooling water treatment programs, azoles have been widely used to inhibit corrosion of copper and copper alloy heat exchangers, and to prevent galvanic attack on mild steel components. Some azoles and the films they produce are not stable in the presence of oxidizers, such as sodium hypochlorite, which significantly reduces the level of protection they offer. Moreover, azoles also have a challenging environmental profile. Chemical improvements have been made to this chemical class to enhance their compatibility with halogenation and improve the stability of their protection. More recently, supply chain constraints on azoles have presented unique challenges for the water treatment industry to offer this important component economically. This paper describes the development of a non-azole-containing corrosion and deposit control program for cooling water applications. The chemistries are halogen stable and offer an improved toxicity profile over conventional cooling treatment components. Comprehensive laboratory studies and field applications are presented in the paper.