Material issues of the solvent regeneration tower
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What is the material used for the solvent regeneration tower in this unit? Is it entirely made of stainless steel, or is it lined with stainless steel? Are there any other materials used? Has the solvent regeneration tower leaked at any point, or have the pipelines at the inlet and outlet of the reboiler leaked?
We have three sets of regeneration units; the first two amine solution regeneration towers were made entirely of stainless steel, while the one installed in 2009 had a stainless steel lining. We replaced the pipelines at the inlet and outlet of the reboiler with stainless steel around 1995.
Won’t leaks occur if stainless steel is used?
The material of the solvent regeneration tower is carbon steel + 321 or 316L, with 316L being the more common choice for cladding. Leaks in the solvent regeneration tower generally occur at the cooler behind the tower top. Especially the solvent used in the catalytic processing unit, due to its CO2 content, causes severe corrosion at the tower top; therefore, the pipelines at the tower top must be made of double-layer 316L material, and the equipment at the tower top as well needs to be made of stainless steel. The solvent regeneration tower in the processing hydrogenation unit is better. If the inlet and outlet pipelines of the reboiler are properly designed, leakage is virtually eliminated; it is best to use a kettle-type reboiler.