Does the tannin desulfurization solution, with a pH of around 12, easily cause equipment corrosion?

Tannin desulfurization is too specialized; I’m not aware of its corrosion effects. You can refer to this for information on the corrosion caused by NaOH and its preventive measures. 　　1. Corrosion analysis of NaOH 　　NaOH is a highly corrosive medium in chlor-alkali production. At room temperature, a dilute alkaline solution with a mass concentration of ≤30% (m/m), hereafter referred to as concentration, can form an insoluble passivation film on the steel surface, thereby granting it good corrosion resistance. However, the corrosion resistance of steel decreases as the concentration of the alkaline solution and the temperature increase. When the concentration of the alkaline solution exceeds 30%, the protective properties of the passivation film decrease as the concentration rises; if the temperature also increases (>80°C), ordinary steel will suffer severe corrosion. There are two types of corrosion damage caused by NaOH to steel equipment: uniform corrosion and local corrosion. Local corrosion, which can be caused by various factors, is the more significant type; it can lead to sudden failure of the equipment, posing a serious threat. Steel becomes brittle when corroded by high temperatures and concentrated alkalis; if stress (either applied stress or residual stress) is present at the same time, stress corrosion of varying degrees occurs, which accelerates the degradation of the material. This phenomenon is generally referred to as \"alkali embrittlement\". According to available information, 15%–48% NaOH does not suffer from \"alkali embrittlement\" at temperatures below 82°C, whereas 50% NaOH experiences alkali embrittlement at 52°C. “\"Alkali embrittlement\" can cause cracks to appear in the heated areas on both sides of the welds in equipment, leading to alkali leakage; once leakage occurs, it is difficult to carry out repair welding. 　　2. Protective measures The NaOH production system should select appropriate materials based on the concentration and temperature of the alkaline solution. With a NaOH concentration of 30%–33% and a temperature of 85–95°C, this constitutes a stress-corrosion environment; therefore, for the custom-made equipment and pipes in this system, ultra-low carbon austenitic stainless steels are the best choice, with 00Cr18Ni10, 0Cr18Ni9, and 00Cr17Ni14Mo2 being common options ； Materials such as Ni can be used when the NaOH concentration is 30%~33%, the temperature is 50°C, or the temperature is >85°C. This system can also use non-metallic materials such as polypropylene (PPH), chlorinated polyvinyl chloride (CPVC), and fiber-reinforced polyvinyl chloride (FRP/PVC), but the disadvantages are short lifespan and poor reliability. To prevent \"alkali embrittlement\" in steel equipment, reasonable structural design and manufacturing processes should be employed. While strictly controlling the quality of the materials, it is also necessary to improve the quality of manufacturing; appropriate heat treatment should be carried out after welding (for low-carbon and low-alloy steels, annealing at 600–650°C is used), and thorough inspection of welds is required to eliminate external and residual stresses.