Electrochemical Techniques for Hydrocarbon Leak Detection in Cooling Water Systems

摘要

Open recirculating cooling water systems are commonly used in petroleum industries, mainly in oilrefineries. Heat exchangers are often applied to cool or condense process fluids. The chemicaltreatment used in cooling water system is essential to prevent corrosion, scaling, fouling andmicrobiological growth. When tubes fail due to corrosion, the cooling water can be contaminated withhydrocarbons. This contamination may cause corrosion, fouling and microbiological growth. The mainpurpose of this study is to evaluate electrochemical techniques for quick detection of hydrocarbonleaks in cooling water systems. To this purpose, synthetic cooling water with and without inhibitors,dispersant and biocide was prepared, based on the historical parameters of a refinery cooling watersystem. Diesel was injected in order to simulate hydrocarbon leak. The electrochemical tests werecarried out on carbon steel and brass electrodes that are materials commonly used in heat exchangersof cooling water systems. The results showed that electrochemical impedance spectroscopy and linearpolarization resistance tests carried out on brass electrodes were able to detect diesel leak in syntheticcooling water.