PSI - Issue 68

M. Hadj Meliani et al. / Procedia Structural Integrity 68 (2025) 292–296 M. H. Meliani et al. / Structural Integrity Procedia 00 (2025) 000–000

293

2

Nomenclature CP

Calotropis procera

X52

grade minimum yield strength, which is 52,000 psi (pounds per square inch)

IE

Inhibition Efficiency (%)

1. Introduction The rising global demand for natural gas has led Algeria to ramp up production, intensifying stress on its extensive pipeline infrastructure. With over 24,000 kilometers of pipelines dedicated to transporting crude oil and gas, Algeria’s national oil and gas corporation, Sonatrach™, faces significant challenges from corrosion a persistent issue that incurs substantial economic losses annually. Corrosion of pipeline materials, especially carbon steel, is a critical issue that compromises the safety and efficiency of oil and gas operations, particularly in high-temperature environments [1, 2]. Corrosion leads to substantial economic losses globally. According to the World Corrosion Organization, approximately a quarter of annual steel production, roughly 150 million tons is destroyed by corrosion each year. To combat this, corrosion inhibitors have been adopted as protective measures. When added to an acidic environment, these inhibitors shield the metal by covering active corrosion sites, forming a protective layer through physical or chemical adsorption, thereby minimizing corrosion to safer levels. Both organic and inorganic compounds serve as corrosion inhibitors, with the performance of organic inhibitors largely dependent on their molecular structure. Organic compounds containing heteroatoms like nitrogen (N), oxygen (O), sulfur (S), phosphorus (P), and those with aromatic rings or conjugated π-electron systems, have shown effective corrosion inhibition properties [2,4]. However, synthetic inhibitors, both organic and inorganic, tend to be toxic, costly, and hazardous to both human health and the environment, underscoring the need for safer alternatives. As a result, there has been a shift toward green inhibitors that are non-toxic, eco-friendly, and economically sustainable. These concerns have spurred interest in developing ecofriendly alternatives, with natural plant-based extracts emerging as promising candidates for corrosion inhibition. These natural inhibitors are selected for their biodegradability, cost-effectiveness, efficiency, and minimal environmental impact, making them a promising replacement for synthetic options [3, 5]. This study examines the corrosion inhibition potential of various locally sourced plant extracts on carbon steel, with a focus on their practical application in Algeria's oil and gas infrastructure. To assess the effectiveness of these natural extracts, electrochemical methods such as potentiodynamic polarization and electrochemical impedance spectroscopy (EIS) are employed under simulated conditions reflecting the high temperatures typical of southern Algeria’s climate. By investigating the protective capabilities of these plant-based inhibitors, this research aims to offer a sustainable solution for corrosion control in pipelines, advancing the adoption of environmentally friendly technology within Algeria’s petroleum sector and reducing reliance on toxic chemical inhibitors. 2. Materials and methods 2.1. Sample preparation 2.1.1. steel preparation A bulk X52 metal sheet with the following composition was utilized in this study: C (0.22%), Mn (1.22%), P (-%), Si (0.24%), Cr (0.16%), Ni (0.14%), Mo (0.06%), S (0.04%), Cu (0.19%), Ti (0.04%), Nb < (0.05%), Al (0.32%), and Fe (balance) [5]. The metal samples for electrochemical and weight loss testing were cut to ensure a contact area of precisely 1 cm². 2.1.2. Extract Preparation Leaves of Calotropis procera were collected from southern Algeria. The collected leaves were rinsed and then dried thoroughly. After drying, the leaves were ground, and a cold extraction was performed using oilfield water. The resulting mixture was filtered and stored in a light resistant bottle at 4°C.