Abstract: Preventing equipment corrosion is particularly important for the safe and stable operation of sulfuric acid alkylation units. The corrosion problems in a 200 kt/a SINOALKY sulfuric acid alkylation unit were investigated, and it was found that four types of corrosion problems are relatively prominent: Sulfuric acid corrosion, alkali corrosion, H₂S+HCl+H₂O corrosion, and circulating water corrosion. The mechanism of several main corrosion problems is briefly expounded, and the main factors affecting the corrosion rate of the unit are analyzed in detail, including the concentration, temperature and flow rate of sulfuric acid, the impurity content in raw materials, sulfuric acid esters and sulfates. Five corrosion protection measures are proposed: correctly selecting equipment materials, strictly controlling the concentration, temperature and flow rate of sulfuric acid, reducing the impurity content in raw materials, applying cathodic protection and online corrosion monitoring measures, and strengthening daily anti-corrosion management. It has good guiding and reference significance for the anti-corrosion work of similar units.

Key words: alkylation, sulfuric acid, corrosion, influencing factors, concentration, material, measures