Corrosion inhibition of pipeline steel in 0.5 m h2so4 solution using seed pericarp of <i>Chrysophyllum albidum</i>

Abstract

The corrosion inhibitory characteristics of Chrysophyllum albidum seed pericarp extract was studied on pipeline steel corrosion in sulphuric acidic environment using gravimetric and electrochemical techniques at varied temperatures (30, 40 and 60^OC). Fourier transformed infra red spectroscopy (FTIR) and Scanning Electron Microscope (SEM) were used to study metal’s surface film and surface morphology respectively. The phyto-constituents were identified using standard functional group analysis. The results obtained showed that corrosion inhibition efficiency increased with increase in extract concentration but decrease with increase in temperature. This is attributed to the identified phytochemical constituents of the extract adsorbed and desorbed on the surface of the pipeline steel. The adsorption data fitted into Langmuir adsorption model better. The data obtained from electrochemical analysis shows that the inhibitor functioned as a mixed type. The kinetics studies revealed that the extract molecules got physically adsorbed spontaneously on pipeline steel, while the thermodynamic data showed an exothermic process.

Keywords: Corrosion Inhibition, Chrysophyllum albidum, Surface coverage, Activation energy, Pipeline steel, Weight loss.