Statistical analysis and optimization of the corrosion inhibition efficiency of a locally made corrosion inhibitor under different operating variables using RSM

Abstract

Corrosive solutions such as hydrochloric acid find huge applications in many manufacturing processes such as pickling, cleaning and acid removal techniques due to effective cleaning procedures and low costs. The utilization of corrosion inhibitors is a significant practical technique to reduce the corrosion of mild steel in corrosive solutions. Organic molecules with hetero atoms such as sulfur, phosphorous, oxygen, and nitrogen are the best corrosion inhibitors. 4-Amino-3-(2-bromo-5-methoxyphenyl)-1H-1,2,4-triazole-5(4H)-thione (ATH) was synthesized by cyclization of 2-bromo-5-methoxybenzohydrazide in the presence of carbon disulfide and hydrazine. ATH was characterized by proton, carbon-13 nuclear magnetic resonance (NMR) and Fourier transform infrared (FT-IR) spectroscopy techniques in addition to carbon, hydrogen and nitrogen elemental analysis (CHN elemental analysis). ATH was investigated as a sustainable inhibitor for mild steel corrosion in acidic medium using corrosion experiments. Response surface method (RSM) was used in obtaining the optimum operating conditions, interactive and main effect of the parameters inhibiting the mild steel corrosion. The coefficient of determination (R2 ) and ANOVA (analysis of variance) proved the RSM method appropriate for the optimization of waste product inhibition on mild steel. The predicted and experimental values from the model are in good agreement. This study suggests that (ATH) is a promising significant corrosion inhibitor.