Sulfuric acid dryer

[robot6]

A lot of sulfuric acid plant vessels are brick-lined. The vessel is typically made of carbon steel. Brick lining can crack during transport and installation, and increases the cost of the carbon steel vessel.

On the other hand, 316L and other stainless steels can be found which have minimal corrosion at concentrations of around 93% and beyond. It seems, therefore, that it would be possible to construct the vessel of 316 or better alloy (Incoloy 686) and have something a bit more robust than something that is lined with brick.

Let's consider the air dryer. One can say that there will be areas of liquid which are significantly less than 93%, thus necessitating the brick lining, but is this really true? If your sulfuric acid circulation is high, then should this really be the case? My calculated outlet concentration from one such air dryer is 92.9%. (The inlet gas is guaranteed to have less than 25C dewpoint because of an upstream cooler.)

 

Different alloys have different corrosion resistance at different concentrations, so variable concentration will be your biggest challenge.

https://books.google.ca/books?id=X-...ric acid plant vessels "brick-lined"&f=false

https://www.neonickel.com/wp-conten...ess-Steels-in-Concentrated-Sulphuric-Acid.pdf

"Everyone is entitled to their own opinions, but they are not entitled to their own facts."

 

[robot6]

Ironic_metallurgist! Thank you for the references! Always nice to get more reading material.

But inherent in your answer is that theoretically it's possible to forego brick lining, it seems.

 

[robot6]

Here's a page from the second edition. I forgot to look there.

They recommend SX or SARAMET or ZeCor, without a corrosion barrier under the "Alternate materials." Now I have to figure out who will make me a vessel and what the maximum temp of the sulfuric acid should be so I can design the sulfuric acid cooler.

Thanks again!

 

[EdStainless]

The three alloys listed are proprietary compositions based on modifications of A610/611, high Si austenitic stainless alloys.
These high Si alloys have some inherent weldability issues.
They are used for heat exchangers in acid cooling applications. Which alloy you get depends on who you buy your acid plant from.
People don't design and build their own acid equipment, they go to one of the small number of companies in world that specialize in this work and put the responsibility on them.

Here is a very good ref, if you work in sulfuric then you need this book:

https://store.nace.org/ms-1-materials-select-for-hazd-chem-2nd-ed

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P.E. Metallurgy, Plymouth Tube

 

[robot6]

Thanks for the reference! Trying to convince management to purchase...

 

[EdStainless]

There is a whole set of these MS books for various environments, something like $4700 for all of the volumes.

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P.E. Metallurgy, Plymouth Tube

 

[Dhurjati Sen]

It is sad that this forum is frequently used by people to get highlighted in a meeting or in his / her organisation.





DHURJATI SEN