Corrosion Inhibition Assessment of Okra Mucilage in a Corrosive Environment

Abstract

Abstract Corrosion is an undesirable phenomenon that engenders challenges across multiple industries with the petroleum sector among the mentioned. Organic corrosion inhibitors deployment has received a lot of traction. However, these inhibitors pose detrimental environmental effects. Hence, the study evaluated the corrosion inhibition potential of okra extracts on mild steel in different corrosive and temperature conditions. Sieved (mucilage) and non-sieved samples of okra extracts were prepared to evaluate the effect of unblended particles on the inhibition efficiency of okra. The corrosion inhibition efficiency of different concentrations of okra mucilage (0–1250 ppm) was determined at 25°C in acidic and non-acidic environments. Additionally, the optimum okra mucilage concentration was selected and subsequent corrosion tests for temperatures (40–70°C) were performed. The okra mucilage was characterized using Field Emission Scanning Electron Microscope (FESEM), and Fourier Transform Infrared Spectroscopy (FTIR). Similarly, the surface morphology of the mild steel samples was identified using Scanning Electron Microscope (SEM) and FESEM. Gravimetric analysis was conducted to determine the corrosion rate of mild steel and the inhibition efficiency of okra extracts. Corrosion rate decreased with okra mucilage concentration. Maximum corrosion rates of 0.7946 mm/year and 0.9242 mm/year were achieved for 500 ppm of okra mucilage and non-sieved okra extract, respectively. Additionally, okra mucilage and non-sieved okra extract yielded remarkable inhibition efficiencies at elevated temperatures. Okra mucilage recorded 49% and 62% inhibition efficiencies at 25 and 70°C, respectively for 833 ppm of the inhibitor. However, the inhibition efficiency of non-sieved okra extracts was slightly reduced at elevated temperatures (from 62% at 25°C to 61% at 70°C) for 1250 ppm of the inhibitor. The study unraveled the potential of okra mucilage as a green corrosion inhibitor, which can be applied in pilot studies as a corrosion mitigation strategy.