The Study of Mixing Purple Sweet Potato and Turmeric Extract as Green Corrosion Inhibitor for API-5L in NaCl 3,5% Environment

Green inhibitors have become a major option for corrosion prevention since people are more aware of environmental damage. It is true that chemical inhibitors are more powerful at preventing corrosion, but its side effects are very harmful to the environment. Purple sweet potato (Ipomoea batatas L) in single use has been proven as an active inhibitor for certain applications. To improve this property, purple sweet potato is used as a mixed with other plants that contain antioxidant agents, such as ginger, melinjo, turmeric, jeera, etc. This paper discussed the effect of applying mixed extract of purple sweet potato with turmeric (Curcuma longa) as a green inhibitor to corrosion rate of API 5L steel in a 3.5% NaCl environment. Turmeric extract contains curcumin and kaempferol antioxidants while purple sweet potato extract contains antocyanin antioxidants. Corrosion rates were analyzed based on weight loss and polarization methods. The results showed the highest inhibitor efficiency was 82.54% achieved by 16 ml of turmeric mixed with 2 ml of purple sweet potato, and the optimum inhibitor efficiency was 74.2% achieved by 8 ml of turmeric mixed with 6 ml of purple sweet potato.

DNA Inhibition of Hydrogen Ion-Induced Corrosion of Mild Steel Used for Pipelines in Oil and Gas Industries

Corrosion of mild steel via chemical reaction in a corrosive environment is a problematic occurrence that is very common in oil and gas industries. Corrosion constitutes a huge part of the total costs in the production of oil and gas. Corrosion inhibitors have found interest in the scientific domain because they are mainly understood by their chemical complexes and formulations. Their utilization in small amount on metal surface used in oil and gas industries can help shield the metal from corrosion devoid of any significant alteration in the concentration of the corrosive media in the environment. An effort was made to study the possibility of using calf thymus gland DNA (CTGDNA) inhibitor in chlorine induced mild steel for possible usage in piping in oil and gas industry. The SEM micrograph shows that the adsorption of the CTGDNA biomacromolecules coat on the mild steel surfaces functions as a protection against HCl corrosive solution. Electrochemical study and weight loss analysis showed that the inhibitor efficiency (70.48 and 72%, respectively) of the tested DNA (CTGDNA) in HCl acidic corrosion environment for the mild steel was high at 1.5 M of HCl. The inhibitor efficiency decreased with increasing HCl concentrations. The open circuit potential (OPC) revealed that the mild steels got corroded until the end of the immersion. The intensities of XRD peak substantiate the existence of corrosion products of FeCl2.

Use of a Metallic Complex Derived from Curcuma Longa as Green Corrosion Inhibitor for Carbon Steel in Sulfuric Acid

A tin-containing metallic complex derived from Curcuma longa, bis[1,7-bis(4-hydroxy-3-methoxyphenyl)-1,6-heptadiene-3,5-dionato-κO,κO ′ ]bis(butyl), has been obtained and used as a green corrosion inhibitor for carbon steel in 0.5 M sulfuric acid by using weight loss, electrochemical techniques, and the Density Functional Theory. It was found that the obtained metallic complex greatly decreases the steel corrosion rate by adsorption according to a Frumkin model in a weak, physical type of adsorption. Inhibitor efficiency increased with its concentration, and it acted as a mixed type of inhibitor. Results were supported by quantum-chemical research in order to examine the relationship between structural and electronic properties and the inhibitor efficiency.

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.