Extraction and characterisation of corrosion inhibitor developed from avocado Exocarp and Mesocarp oil for mild steel in H2SO4

Abstract

Corrosion of mild steel in acidic environments poses significant challenges to various industries in Nigeria, particularly in the oil and gas sector. This study investigated the extraction and characterization of corrosion inhibitors developed from avocado (Persea americana) exocarp and mesocarp oil for protecting mild steel in H₂SO₄ acid environment. The research addressed the growing need for sustainable, eco-friendly and non-toxic alternatives to synthetic corrosion inhibitors. Avocado exocarp and mesocarp were separately processed and extracted using distilled water and ethanol as solvents. The corrosion inhibition performance was evaluated using weight loss measurements over 72 hours of immersion in H₂SO₄ solution. Results showed that both extracts effectively inhibited mild steel corrosion, with the exocarp extract demonstrating superior performance. The exocarp extract achieved a maximum inhibition efficiency of 94.2%, while the mesocarp extract showed 88.33% efficiency. The weight loss analysis revealed that uninhibited mild steel samples lost 0.6g after 72 hours, while samples treated with exocarp and mesocarp extracts lost only 0.04g and 0.07g, respectively. The study demonstrates that avocado exocarp and mesocarp oil extracts serve as effective green corrosion inhibitors for mild steel in acidic media, with the exocarp extract showing notably higher inhibition efficiency. These findings contribute to the development of sustainable corrosion protection solutions using agricultural waste products.