Studying optimum conditions to reduce low carbon steel corrosion in cooling towers system of Al-Daura refinery

Abstract

The behaviour of corrosion of low carbon steel in makeup and recirculating water of cooling towers installed in AL-Daura Refinery was studied in the absence and presence of different concentrations of the commercial ku-2050 inhibitor (25 to 2000 ppm) at different pH values (7-8.5) and for different periods of immersion (1 day to 6 weeks) using Weight Loss method under static conditions (velocity=0). Factorial and Taguchi methods were applied to analyse the data by the software Minitab 2021. The analyses aimed at obtaining mathematical expressions to show the correlation of the corrosion rate with the working parameters. Monte Carlo Simulation technique was used to evaluate the effects of random events facing the corrosion process. Sensitivity analysis was utilized to see how corrosion rate variates by the variation in the working parameters in mathematical expression. The inhibitor efficiency results showed the direct increase with increasing in conc. of ku-2050 up to 500 ppm in makeup water while in recirculating water this increase continued up to 800 ppm of ku-2050 inhibitor.