Study of Garlic Extract as an Inhibitor on Carbon Steel Corrosion in NaCl Solution

• Main Author: Yudi Hastuti, Rani
• Format: Final Project
• Language: Indonesia
• Subjects: Kimia
• Online Access: https://digilib.itb.ac.id/gdl/view/38071
• Institution: Institut Teknologi Bandung

Carbon steel is a material that used as pipe line of oil and gas transport system. But this carbon steel pipes is easily corroded by the environment. To inhibit corrosion in this pipe, people use corrosion inhibitor. There are some types of corrosion inhibitor, but biodegradable corrosion inhibitor is preferable. In this study, garlic crude extract was used as “green” corrosión inhibitor. Garlic crude extract was obtained by maceration and extraction methods. This methods give 20.1440 gram of garlic crude extract (%rendement = 5.04%). This garlic crude extract was characterized by FTIR spectroscopy and UV-Vis spectrophotometry. Based on FTIR spectroscopy, garlic crude extract has some functional groups such as S=O, S=C, C=C (alkene), C-H (alkane) and O-H. UV-Vis spectrophotometry shows some absorption peaks at wavelength 226.5, 267.5, and 438.5 nm. Inhibition performance of garlic crude extract was measured by EIS (Electrochemical Impedance Spectroscopy) in 0.5 and 1% w/v NaCl solution saturated with CO2. The EIS measurement was done by varieting concentrations (0, 5, 10, 20, 40, 60, 80, 100, 120, 150, and 200 ppm) and temperatures (25, 45, and 55 °C). The highest inhibition efficiency (% EI) is 83.32% in condition of 0.5% NaCl solution saturated with CO2, 45 °C, and 200 ppm garlic crude extract. Based on Tafel extrapolation, garlic crude extract is a mix-type corrosión inhibitor.