n-Butane Oxidation Reactor cooled by molten salt 1

[etsen]

Maleic anhydride (MA) is produced by n-butane oxidation in a salt cooled tube bundle reactor. Tubeside: n-butane and air. Shellside: molten salt. I want to know corrosion or other degradations of tubes (15Mo3,low-alloy steel)by the reaction of n-butane and air from tubeside and molten salt from shellside. I searched papers or books about them but found nothing. Could anyone give me some advice for searching or materials or links about them. Thanks a lot.

 

[unclesyd]

You want find much general information about the materials used in the Maleic process as most people like to keep this information out of the public domain.
We had 4 salt cooled reactors with around 22,000 25mm tubes each. Over twenty five years we have had very little problem with the tube proper even with several occasions with contaminated salt. The main problem is the tube to tubesheet seal welds. Leaks on the bottom head have caused several unplanned shutdowns. The leaks are very troublesome as far as locating the offending tube and then making the weld repair. We have plugged some tubes.
At each catalyst change we usually pull several tubes for metallurgical examination. We have never found anything that would cause us to consider retubing.

Huntsman Chemical now owns the process. I understand that they were looking for partners at one time.