Monel or Inconel for caustic solution

[jiang1976]

We are designing a caustic tower. The caustic solution has ~10% NaOH, ~10%Na2S, ~5% Na2CO3, ~50ppmw Cl, and ~20ppmW NaClO3. It also has about 4% (CH3SNa + CH3SH). The design temperature is 190DegC.

We are trying to use Ni alloy for this tower. But we still worry about the effects of Chlorides and sulfides. Do you know the resistance of Ni alloy to chlorides and sulfides in the solution mentioned above?

If Monel or Inconel are suitable for the corresponding service, which one is the best? alloy 400, alloy 600, alloy 625?

 

[metengr]

Go here for corrosion information and alloy selection

http://www.specialmetals.com/index.php

 

[strider6]

this is a good reference for selecting materials in caustic soda service.

Corrosion in Caustic Solutions

http://www.hghouston.com/naoh.html

hoep this help u.
S.

http://www.corrosionist.com

 

[MJCronin]

jiang..

You are asking people in an engineering bulletin board about material selection for a caustic tower...??

Isn't this a multi-million dollar decision ?

One of your choices is Ni ??

Pure nickel is about three or four times the cost of your other choices.. Do you really want to trust us..??

How big will this tower be ?

-MJC