CORROSION INHIBITION STUDY OF COCOA POD EXTRACTS ON CARBON STEEL IN ACIDIC ENVIRONMENT

Abstract

The research studied the inhibitory effect of crude cocoa pod extract and ashed cocoa pod extract on the corrosion of API5L steel in 0.5 M H2SO4 and 1.0 M H2SO4 using potentiodynamic polarization method at room temperature. The cocoa pod extracts were characterized using Atomic Absorption Spectroscopy (AAS) and Fourier Transform Infrared Spectroscopy (FTIR). Cocoa pod extract concentrations of 0.25 – 5v/v% were used for the study. The potentiodynamic results showed that crude and ashed cocoa pod extract possessed good inhibitory properties in both 0.5 M H2SO4 and 1.0 M H2SO4. Optimum inhibition efficiencies of 90.8% and 95.5% were attained at 0.5 M H2S04 and 1.0 M H2SO4 respectively with 2v/v% crude cocoa pod extract concentration. Ashed cocoa pod extract exhibited maximum inhibition efficiencies of 97% and 99% in 0.5 M H2SO4 and 1.0 M H2SO4 respectively with 3.5v/v% ashed cocoa pod extract concentration. The good inhibitory properties of ashed and crude cocoa pod extracts were attributed to the presence of aromatic and phenolic functional groups present in the extracts. The elemental composition of the extract confirms the effectiveness and eco-friendliness of crude and ashed cocoa pod extract