Comparative Study of the Inhibitor Efficiency of Maize Husk Polar Extract in H2SO4 and HCL Acid Environment for Corrosion Control of Mild Steel

This research work investigated the comparative study of the inhibitor efficiency of Maize Husk Polar Extract (MHPE) green inhibitor to monitor and control corrosion on mild steel in 1.5M of HCl and 1.5M of H2SO4, using gravimetric analysis, Fourier Transform Infrared Spectroscopy (FTIR). The extract was found to efficiently inhibit the corrosion process in 1.5M of HCl and 1.5M of H2SO4 as the inhibitor efficiency increased with increase in the concentration MHPE. The maximum inhibition efficiency of MHPE was 93.6% in 1.5m of HCl at 384 hours. However, in 1.5M of H2SO4, the maximum inhibition efficiency was 96% at 48 hours in 5ml/litre further increase in inhibitor concentration drastically reduced the efficiency to 28.3% at 25ml/litre for 48hrs. Phytochemical analysis revealed the presence of alkaloid flavonoids, phenolics, phytates, saponins, terpenoids anthocyanins, steroids and tannins. The FTIR of MHPE and the corrosion product shows the variation of the peak numbers and the nature of shift indicates the interaction among the functional groups of extract in the corrosion inhibition process. It also confirmed the presence of C-O functional group as the most dominant in the entire corrosion product. The isotherm parameters were evaluated using Langmuir isotherm model, Temkin isotherm model, Frumkin isotherm model and Flory-Huggins isotherm model and it was observed that Langmuir model gave the best fit with the experimental data because the values of the degree of correlation was found to be about unity which shows a very good fit for the experimental data. Also the adsorption process was physiosorption due to the fact that all the values of (G are less than -40KJ/mol. The study clearly shows that by the efficiency of MHPE, gotten from the two media, MHPE is suitable for corrosion control in oil pipelines during pigging, acidizing of reservoirs, hydraulic fracturing and hydro-testing.