Effect of selected green corrosion inhibitors on SO2 removal during carbon steel corrosion in aqueous solutions of ammonia and histidine

To understand the feasibility of using carbon steel in the flue gas desulfurization process, the corrosion protection of carbon steel was investigated by adding four green corrosion inhibitors (12-aminolauric acid; 4-carboxyphenylboronic acid; 1,2,3-benzotriazole; and L-methionine) to an ammonia solution con-taining histidine as the SO2 absorbent. The effects of the corrosion inhibitors on the corrosion rates of car-bon steel and SO2 absorption performance were investigated. We observed that 1,2,3-benzotriazole was the most effective corrosion inhibitor, reducing the corrosion rate by 73 % and increasing the SO2 absorp-tion loading by 8.3 % compared to other corrosion inhibitors. Scanning electron microscopy/energy dis-persive X-ray spectroscopy and X-ray diffraction studies were conducted to understand the corrosion inhibition behavior of 1,2,3-benzotriazole. The formation of the Fen-(SO2-BTA)m complex and its subse-quent adsorption on the carbon steel surface blocked active sites and inhibited corrosion. This study demonstrated the feasibility of effectively using carbon steel under harsh environmental conditions such as in desulfurization.CO 2023 The Korean Society of Industrial and Engineering Chemistry. Published by Elsevier B.V. All rights reserved.

Automated summary

The feasibility of using carbon steel in the flue gas desulfurization process was investigated through corrosion protection experiments. The study found that 1,2,3-benzotriazole was the most effective corrosion inhibitor, significantly reducing the corrosion rate and enhancing SO2 absorption loading.