Corrosion protection issues in the top of atmospheric and vacuum distillation towers – experts, please answer!
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Regarding the corrosion protection issue at the top of atmospheric and vacuum distillation towers, the \"one removal and four injections\" process is generally used for such purposes. If material-based corrosion protection is employed, what type of material should be used to resist corrosion caused by hydrosulfuric acid and hydrochloric acid? ? ? ? ? ? ? ? ? ? ? ? ? ? ?
Carbon steel towers definitely won’t work; glass-lined towers and equipment should be used instead.
For glass-lined tower connections and caps, polypropylene pipes can be used as weather tubes above the caps.
It might not be appropriate to discuss this issue in the context of atmospheric and vacuum distillation towers; epoxy-coated materials could perhaps be used for oil and gas pipelines, but what about air-cooled heat exchangers? Using enamel isn’t very practical either; it doesn’t have that high a heat exchange capacity
Why not use process anti-corrosion? Neutralizing corrosion inhibitors solve the problem very simply.
For the atmospheric pressure tower top system, the tower vessels are generally lined with 316L stainless steel. The vaporization line is made of carbon steel thick-walled pipes. The air coolers are constructed from 09Cr2AlMoRE material, while the water coolers consist of carbon steel tube bundles protected by a coating. In the tower top system, process anti-corrosion measures are essential and cannot be replaced, unless titanium or duplex steel is used throughout
The corrosive agents at the top of atmospheric and vacuum distillation towers include hydrogen sulfide and hydrochloric acid; the materials used are typically 06Cr13 stainless steel composite plates or 2205 duplex stainless steel composite plates, with our choice being the former. After years of use, corrosion-induced thinning, severe pitting corrosion, and serious corrosion in the welds occurred. Later, we applied the TT-300 phenol red anti-corrosion coating to protect the tower top head, and inspections during maintenance showed that the anti-corrosion effect was very good. Later, when replacing the vapor line pipelines, this coating was also used for internal anti-corrosion, with very good results. This coating features heat resistance up to 200°C, as well as resistance to corrosion by hydrochloric acid or chloride ions, hydrogen sulfide, organic solvents, and various types of gasoline.
I’ve heard of this coating for the first time; it seems that technology never stops advancing.