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316L stainless steel and duplex steels (such as S32205) are widely used in distillation towers, but their selection should be based on the specific operating conditions. Here are more practical application examples: 1. Use of 316L stainless steel in distillation towers in the fine chemical industry. A pharmaceutical intermediate manufacturer used 316L as the material for the columns in its chlorobenzene solvent recovery towers to process organic phases containing trace amounts of hydrochloric acid, and no significant corrosion was observed over two years of operation. In acetone-water azeotropic distillation systems, 316L is used to manufacture trays and downcomers due to its smooth surface and ease of cleaning, which reduces the risk of material residue and coking. As materials for the packing compression ring and support plate, they can withstand the weight of the packing as well as operational vibrations over a long period in DN800 packing towers, ensuring good structural stability. 2. Application examples of duplex steel (S32205) in highly corrosive environments: In the distillation tower of a coastal petrochemical plant, used for crude oil pretreatment and desalination, the high-temperature section at the bottom of the tower (>120°C) utilized duplex steel to manufacture the tower body and the reboiler connection sections, thereby effectively resisting wet H₂S corrosion containing chlorides and sulfides. In an aromatic hydrocarbon extraction unit, the shell of the overhead condenser in the benzene/toluene separation tower was prone to frequent leaks when made of 316L steel; by using 2205 duplex steel, the equipment’s service life was extended from 18 months to over 6 years. In the dehydration distillation columns of natural gas liquids (NGL) recovery units, duplex steel is used to manufacture feed distributors and gas-liquid separation components, as its high strength allows for thinner wall thicknesses, thereby improving heat transfer efficiency.