H2S corroion of SS at high Temp. reducing environment 1

[swimworm]

We have a high temp. pyrolysis chamber for wastes. The off-gas from the chamber is strongly reducing - contains 10% levels of hydrogen, CO, N2, CO2 and H2O but no oxygen. H2S is contained at about several thousand ppm. The gas temp. is about 1000 deg. centigrade at atmosphereic pressure. What would be the corrosion of CS or SUS-316L steam pipe ? Will the reducing environment prevent the corrosion due to H2S ?

 

[SJones]

Have a look at Section 4 of API RP 571.

Steve Jones
Materials & Corrosion Engineer

http://www.pdo.co.om/pdo/

 

[EdStainless]

Not while there is any water present it won't.
What is the carbon potential? How much nitrogen?
Nitriding, metal dusting and sulfidation are all possible concerns, depending on gas composition.

There was a lot of work done on alloys for coal gasification.
Annual reports by A.O. Schaefer, The Metal Properties Council, "A Program to Discover Materials Suitable for Service Under Hostile Conditions Obtaining in Equipment for the Gassification of Coal and Other Solid Fules", from 1975 through 1981.

In short, Cobalt alloys are the best. Alloys like 310 and 800 will not take the extened exposure. Once the protecive Cr oxide surface is reduced to metal the just come apart.

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Corrosion never sleeps, but it can be managed.

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[swimworm]

Thanks a lot.
To be more specific, the gas comp. is :
H2 15%, CO 15%, CO2 8%, N2 : 45%, H2O 18%, HCL :0.1%. The combustibles are less than in the gas of coal gasification abd Sulfur should be about 0.1% level. There should be trace amount of NH3. It would be appreciated if you provide information on the corrosion study in IGCC.

 

[EdStainless]

Forget IGCC, I am talking about general metal loss of say 0.100"/year.
Go to a local Univ library and find the MPC reports. At slightly lower temps 800 and 310 do great, but all hell breaks loose at higher temp.
The data from this work is summarized in "High-Temperature Corrosion of Engineering Alloys", George Lai, ASM, ISBN 0-87170-411-0

= = = = = = = = = = = = = = = = = = = =
Corrosion never sleeps, but it can be managed.

http://www.trenttube.com/Trent/tech_form.htm