Optimization of Cooling System Passivation in Petrochemical Facilities

A combination of laboratory experimental studies and the results of real-world plant experience is being used to optimize NOVA Chemicals’ corporate cooling water program.  All aspects of the program are being considered, including passivation treatments for individual bundles, system pre-film solutions, and long-term cooling water chemistries.  The aim of the optimization plan is to select that combination of passivation, pre-film, and cooling water solutions that provides the most cost-effective protection of the system within defined performance targets that the vendor must.
This paper will present an overview of the cooling water optimization program, as well as discuss the results of electrochemical laboratory studies designed to provide an understanding of how each part of the program functions.  The focus in this paper will be on the passivation and protection of C-steel heat exchangers in nitrite, polyphosphate, and orthophosphate passivation solutions and their compatibility with a phosphate-based cooling water program.