Development of environmental friendly corrosion inhibitor from the extract of areca flower for mild steel in acidic media

One of the industries that play a role in supporting the development of the country is the oil and gas industry. In addition, this industry has an influence on the country's economy, so it must be operated as efficiently as possible so as not to produce substantial costs and not have a significant impact on the country's economy. The oil and gas industry is equipped with good supporting equipment that plays an important role in the success of the production process. The most important equipment for the continuity of production is the pipe. Generally, this pipe is made of mild steel and the material commonly used for pipes in the oil and gas industry is API 5L. Corrosion is one of the challenges found in pipes in the oil and gas industry. This is due to aggressive ions such as Cl^- and also the fluid contained in the pipe. The aggressive ions that exist can cause corrosion in the form of pitting corrosion. Corrosion that occurs in pipes in the oil and gas industry must be addressed as efficiently as possible with effective results. Inhibitors are one solution that can provide effective results in reducing corrosion rates. Corrosion rate can be reduced by 99 % or more if the concentration of the inhibitor is appropriately added. Generally, inhibitors that are often used are inorganic inhibitors, where these inhibitors contain chemical compounds that are harmful to the environment and health. So, currently there are many developed environmentally friendly inhibitors, namely inhibitors produced from plants and fruits. Environmentally friendly inhibitors do not have an impact on environmental pollution because the material from these inhibitors has organic properties. Until now, there have been many studies on environmentally friendly inhibitors carried out on API 5L steel. However, there have been no studies on inhibitors obtained from Areca Flower extract as environmentally friendly inhibitors. Thus, this study was conducted in order to determine the effect of adding environmentally friendly inhibitors on the corrosion behavior of API 5L steel pipes in aggressive environments, namely HCl media. Areca flower extract has been investigated as a green corrosion inhibitor on API 5L Grade B in 1 M HCl acidic solution using Linear polarization and Electrochemical Impedance Spectroscopy (EIS). Additions of 4 ml, 8 ml, 12 ml, 16 ml, and 20 ml of corrosion inhibitors increase the efficiency of the inhibitors. Optimum inhibition efficiency occurs with the addition at a concentration of 20 ml is 96.6 % on Electrochemical Impedance Spectroscopy (EIS) testing. Polyphenolic and flavonoid compounds contained in the areca flower inhibit corrosion by physical adsorption, to form a monolayer which can inhibit corrosion. Adsorption occurs spontaneously in accordance with Langmuir isothermal adsorption. The polarization showed that the areca flower extract acts through mixed-type inhibition. The value of the free energy of -7.026 kJ/mol of adsorption indicated that the adsorption of inhibitor molecules was typical of physical adsorption.