The effects of petroleum refinery wastewater on the rate of corrosion of steel equipment

The present study addresses the mutual relationship between pollution and corrosion in the context of the petroleum refining industry. The rate of galvanic corrosion of steel coupled with copper when immersed in oil refinery wastewater was studied by the weight‐loss technique. The variables studied were: MgCl₂ concentration, the ratio between the cathode area and the anode area of the galvanic couple, and operating temperature. It was found that the rate of galvanic corrosion of steel coupled with copper increased with increasing MgCl₂ up to a certain concentration and then remained almost constant with further increase in concentration. Increasing the cathode/anode area ratio also increased the rate of corrosion. The rate of corrosion increased with temperature at an activation energy of 8.4 kcal/mol, which denotes that galvanic corrosion of steel in MgCl₂ solution is a diffusion‐controlled reaction.