Examining the Corrosion Behaviour of Carbon Steel Pipelines with Bio-Corrosion Inhibitors in Sub-Sea Environments

Abstract This paper embarks on an extensive investigation into the corrosion behavior of carbon steel pipelines across aqueous environments. It aims to evaluate the effectiveness of bio-corrosion inhibitors, specifically focusing on beetroot powder doped with NaNO2, in bolstering the durability of these pipelines. The study encompasses a multifaceted analysis, including quantification of corrosion rates, and assessment of the inhibitor's impact on pipelines in various sub-sea fluid conditions. The combination of beetroot with NaNO2 presents a promising avenue for corrosion inhibition, aligning with sustainability goals and offering a potential solution to enhance pipeline longevity. The research methodology employs immersion experiments with carbon steel samples to scrutinize their response across seawater environments. Bio-corrosion inhibitors are rigorously tested in aqueous samples using a wet immersion technique, wherein a solution of beetroot powder doped with NaNO2 is prepared. Experiments are meticulously conducted utilizing a 4 wt./volume % NaCl solution, with the churned beetroot powder doped with NaNO2 at varying loadings, typically ranging between 18% to 64%. The resulting inhibitor doped samples were tested through FTIR analysis and microscopic analysis, in order to understand the changes in the corrosion environment, and finally the corrosion measurement calculations, corrosion rate calculations and inhibition efficiencies were calculated. The experimental findings unveil a substantial reduction in corrosion rates, particularly notable in seawater conditions (NaCl solution), where the combination of beetroot powder and NaNO2 demonstrates superior effectiveness. Visual observations compliments the significant decrease in corrosion by 47.2 wt.% with the utilization of the bio-corrosion inhibitor blend. This innovative approach not only offers a practical and environmentally friendly strategy for corrosion prevention in pipelines but also underscores the potential of organic inhibitors in mitigating corrosion challenges. This study contributes novel insights into the efficacy of bio-corrosion inhibitors, shedding light on the synergistic effects of beetroot powder with NaNO2 in combating corrosion in carbon steel pipelines. The presence of organic compounds in beetroot, coupled with the corrosion inhibition properties of NaNO2, enhances the protective capabilities against corrosion, thus showcasing the potential of natural substances in corrosion management. Understanding the performance of bio-corrosion inhibitors across diverse environmental conditions is pivotal in devising tailored strategies to optimize pipeline durability and ensure reliable operation in varying contexts.