Acetone reacts with Carbon steel????

[koshyeng]

Do Acetone reacts with carbon steel to for mesityloxide? When we switch our storage tanks after few days, mesityloxide content will be high and gradually reduces when diluted with recovered acetone from columns.

Have you guys experienced this poblem before? If yes is there nay kind of inert coating you applied for carbon steel tanks?

Koshy

 

[ash9144]

I don't believe carbon steel causes MO or DAA formation. My experience has always been that their formation is due to reduced pH. Maybe a dissolved oxygen issue, but that's a guess.

 

[koshyeng]

ash9144,

We maintain a pH aroung 6.5-7.5 using ion exchange resin and the tank is blanketed with N2 and water content in aceotne is 2500 ppm. Our distillation column also runs in vacuum so I dun see any reason for presence of dissolved oxygen. Could it be due to water in acetone?

Appreciate your comments

 

[dcasto]

Well, Fe3O8 is a wonderfull catalyst.

 

[ash9144]

What levels of MO are you seeing? How are you keeping your acetone dry? I guess could be iron. You could take a sample of low MO acetone in glass bottle then test later to see if it is similar to material in tank.

 

[koshyeng]

Normal concnetration of MO in Acetone is 50 ppm but when you let acetone sit in the tank for a week during shutdowns, conc increases to 300 ppm. Acetone is blanketed by nitrogen.

During normal operations, MO is less because it is well dispersed in the acetone. Since MO gravity is higher than acetone, during shutdowns, it will settle in the bottom and when we collect sample from the pump outlet, it gives high reading. This level increases our reaction time. After couple of batches, MO comes back to normal.( due to dilution)

 

[25362]

To dcasto, please give some information or a link on Fe₃O₈. The common black oxide is Fe₃O₄.