Corrosion Inhibition of Mild Steel Using Terminalia Catappa Leaves Extract (TCLE) in 1M HCl Solution

Abstract The oil and gas industry plays a vital role in driving global economies by meeting the energy demands of nations. However, the industry faces significant challenges in maintaining the integrity and longevity of its infrastructure due to the corrosive environments in which it operates. Conventional corrosion inhibitors typically rely on synthetic chemicals, such as disodium hydrogen phosphate (DSHP), which have raised environmental concerns due to their potential toxicity and ecological impact. As industries increasingly adopt sustainable and eco-friendly practices, there arises a critical need to explore alternative and environmentally friendly corrosion inhibition approaches that offer comparable or superior effectiveness. This research investigates the viability of Terminalia catappa leaf extract (TCLE) as an eco-friendly corrosion inhibitor for mild steel (measuring 3cm x 4cm) in 1M HCl solution. Utilizing the weight loss method over a 14-day period, the study compares the performance of TCLE to DSHP. The green extract was obtained using the maceration technique; Terminalia catappa leaves were blended, soaked in ethanol for 60 hours, filtered, and then concentrated. It was found that TCLE demonstrates an improvement in inhibition efficiency with increasing concentrations but diminishes with prolonged immersion time. A maximal inhibition efficiency of 89.24%, 94.12%, 94.12%, 93.64%, and 96.20% was observed for TCLE at the concentrations of 0.3g/L, 0.6g/L, 0.9g/L, 1.2g/L, and 1.5g/L respectively, markedly contrasting with DSHP’s peak efficiency of 10.57%, 13.25%, 20.25%, 31.65%, and 39.24% at 0.3g/L, 0.6g/L, 0.9g/L, 1.2g/L, and 1.5g/L concentrations respectively. Over time, TCLE’s efficiency demonstrated impressive durability; even after two weeks, it inhibited with a notable 55.68%, 71.19%, 80.33%, 82.55%, and 83.38% efficiency at the concentrations of 0.3g/L, 0.6g/L, 0.9g/L, 1.2g/L, and 1.5g/L respectively. In sharp contrast, DSHP dwindled to 4.16%, 4.43%, 4.43%, 4.71%, and 8.59% efficiency at the concentrations of 0.3g/L, 0.6g/L, 0.9g/L, 1.2g/L, and 1.5g/L respectively by the end of the experiment. In conclusion, this evidence positions Terminalia catappa leaf extract (TCLE) as a promising and environmentally conducive alternative for the corrosion inhibition of mild steel. It demonstrates superior efficiency compared to disodium hydrogen phosphate (DSHP), a conventional synthetic inhibitor. It is recommended that TCLE should be harnessed and upscale for application in the industry‒wide corrosion inhibition strategies.