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Material Selection for Tank holding 40 weight% NaOH at 250 degrees

Material Selection for Tank holding 40 weight% NaOH at 250 degrees

Material Selection for Tank holding 40 weight% NaOH at 250 degrees

(OP)
Hello,

I am currently having trouble finding information on material selection for a tank, which will hold caustic NaOH solution (40 weight%) at 250 degrees celsuis.
Can anyone help me with ideas or locations of where information can be obtained?

Many thanks

DSymes

RE: Material Selection for Tank holding 40 weight% NaOH at 250 degrees

http://www.outokumpu.com/applications/documents/start.asp

You might want to check this as a source.  I am not sure that the data will go hot enough.
How high of a pressure is this?  This isn't a tank, it is a pressure vessel.
At this temp you are into fairly exotic materials.

I could talk to you about heat exchanger alloys, but the vessel will be another issue.

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Plymouth Tube

RE: Material Selection for Tank holding 40 weight% NaOH at 250 degrees

(OP)
The pressure will be approx 42 atm.
My idea was to have a holding tank of NaOH 40 weight% solution and pump it through a heat exchanger to a vessel where the solution would leach a ceramic core out of a single crystal alloy.
Another method could use an autoclave to achieve this, but what I am not sure about is the materials I could use for vessel and pipes that will be non-corrosive to NaOH at these temperatures and pressures?

DSymes

RE: Material Selection for Tank holding 40 weight% NaOH at 250 degrees

Have a look at this document from NIDI. It seems that one candidate materials for you could be the Alloy 625. At page 6 is reported that it can withstand caustic up to 320°C.


Alloy Selection for Caustic Soda Service
http://www.corrosionsource.com/technicallibrary/nidi/literature/pdf/10019.pdf

or also at this @ pag 28
http://www.specialmetals.com/documents/SM%20Aqueous%20Corrosion%20Book.pdf
hope this help u

S

Corrosion Prevention & Corrosion Control
 

RE: Material Selection for Tank holding 40 weight% NaOH at 250 degrees

DSymes,

You are probably up into temperatures where nickel (pure nickel - Ni 100) is the only workable material.

The temperature exceeds the capability of plastics like Teflon for a lining of a steel vessel.   Nickel lining on steel might be considered?   How large is reactor vessel?

RE: Material Selection for Tank holding 40 weight% NaOH at 250 degrees

(OP)
at this stage the reactor vessel is about 80 cubic meters.
Thank you for your time

DSymes

RE: Material Selection for Tank holding 40 weight% NaOH at 250 degrees

For heat exchanger tubing, the super-ferritic stainless E-Brite might be a good bet.  But you can't use it for structure.

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Plymouth Tube

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