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In the wet desulfurization process of coke oven gas, the corrosion of desulfurization equipment is a major issue related to safe production. Especially in the case of older equipment, most of these devices are made of carbon steel with internal anti-corrosion coatings. Over time, these internal anti-corrosion coatings wear off, which can lead to corrosion inside the device; this causes the device’s walls to thin out gradually, eventually resulting in leakage problems. In addition to the corrosion of equipment caused by the by-products we are familiar with, there are also other factors that lead to corrosion in the desulfurization systems for coke oven gas. These include inadequate protection of the equipment, poor on-site management, catalyst corrosion, corrosion caused by acidic gases, and chloride ion corrosion. Today, we will discuss the main factors responsible for equipment corrosion in wet desulfurization systems for coke oven gas. 1. Secondary salt corrosion is well-known, so it will not be discussed further here. II. Corrosion of catalysts: For the coke oven gas desulfurization system, the two main sources of corrosion are chemical corrosion and electrochemical corrosion. Chemical corrosion mainly refers to the corrosion caused by by-products and sulfur. Electrochemical corrosion, as the name suggests, occurs when reactive metals come into contact with an electrolyte solution; this leads to the formation of numerous tiny galvanic cells on the metal surface, resulting in galvanic reactions. The more reactive metal loses electrons and gets oxidized, and this type of corrosion is known as electrochemical corrosion. Electrochemical corrosion generally has a greater impact on equipment and is more corrosive than chemical corrosion. In coke oven gas desulfurization systems, when complexed iron catalysts are used, electrochemical corrosion can occur easily if the complexed iron is unstable. The main reason for this is that when the complexed iron is unstable, iron ions are released; these ions combine with alkaline solutions to form iron hydroxide colloids, which adhere to the surface of carbon steel equipment. This creates a galvanic cell effect with carbon, thereby leading to electrochemical corrosion. When the complexed iron catalyst is sufficiently stable, this phenomenon does not occur; therefore, when using such a catalyst, it is necessary to ensure that it has adequate stability. During routine production control and management, the stability of the catalyst should be analyzed regularly, and any deficiencies should be addressed promptly to prevent electrochemical corrosion. III. Corrosion by acidic gases such as CO2 and H2S in the feed gas: During the desulfurization of coke oven gas, in addition to H2S, acidic gases such as CO2 and HCN are often present as well. Although the concentration of such gases in coke oven gas is not very high, their direct contact with desulfurization equipment, particularly the inner walls of the desulfurization tower and its internal components, causes acidic corrosion that can have a significant impact on the equipment. For example, in a wet H2S environment, H2S corrosion of low-strength steel or soft steel leads to oxygen bubbling; the hydrogen that penetrates the steel can cause steel with higher strength or hardness to deform, reducing its toughness and even inducing microcracks within the steel, making it more brittle. IV. Corrosion caused by chloride ions: The source of Cl- in the desulfurization solution is mainly the water used for desulfurization. At present, most coking enterprises do not have excess deionized water available for desulfurization purposes; therefore, recycled water or fire-fighting water is generally used as water to supplement that needed for desulfurization processes. Due to the long-term closed-loop circulation of desulfurization liquid, the Cl- level in the desulfurization liquid of many manufacturers is severely excessive. Due to the small radius of Cl-, which gives it strong penetration ability, it can activate the surface of passivated steel, thereby inducing pitting and stress corrosion; as a result, stainless steel corrodes very rapidly in environments with high Cl- concentrations. Therefore, for desulfurization systems utilizing stainless steel equipment, it is necessary to strictly control the source of make-up water. If there is no demineralized water available for production, it is advisable to cool steam condensate and use it as make-up water for the system. V. Conclusion: The above merely provides a brief discussion on some less common corrosion factors and their preventive measures. In reality, the mechanism of desulfurization-related corrosion is extremely complex, with numerous influencing factors. We must address this issue from various aspects, including engineering design, selection of materials and anti-corrosion measures for equipment, as well as operational management, in order to prevent or minimize corrosion in desulfurization systems and extend the service life of equipment.