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Pitting problem in 316L reactor

I work for a chemical plant in Dalton, GA we produce Dioctyl Maleate which is made by loading the reactor with Maleic Anhydride and 2-Ethyl Hexanol and Methane Sulfonic Acid as a catalyst. The reactor is then heated to 170 C. We are noticing a problem inside the reactor the coils and walls are getting pitted. The product also has to be filtered due to remove a green substance. Is there a passivation technique I should use or what could be done to eliminate this problem.

Thank you,

Mark Jager
- Dalton, Georgia, USA
2006

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Some pitting of stainless steel would not be unusual with this chemical process. However, good passivation would help to prevent it. I assume that the tank is 316L stainless steel. There are a number of ways to passivate the tank prior to use, but once you have the pits formed it is quite difficult to remove them and start over with a passive layer. The degree of difficulty depends on the size and shape of the tank, etc. Removal of the pits by grinding or with electricity can be necessary depending on the severity. Please call me if you need help.

Lee Kremer
Stellar Solutions, Inc.

McHenry, Illinois

2006