Materials selection for C3 Hydrogenation Reactor

[kissjxp]

Guys,
I have some questions on materials selection for a C3 Hydrogenation Reactor.

Design temperature (Normal operating): 250C
Design pressure (Normal operating): 3950 KPa
MDMT: -46C

Maximum operating Temp. for catalyst regeneration: 460C
Maximum design Temp. for catalyst regeneration: 490C
Design pressure for catalyst regeneration: 1000 KPa

The maximum operating temperature during regeneration is 460°C at reactor outlet during burning step. This regeneration step is short. There is no corrosive contaminant in this reactor.

My questions:

1) Can we use Low Temperature Carbon Steel for this case since the regeneration is short? What is the Graphite formation speed in short period of time at a temperature over 427C?

2) How long we can use carbon steel plate short-periodically exposure to a temperature above 427C (the total hours)?

3) Can we use 1.25Cr-0.5Mo at low temperature (-46C)?


Thanks!

 

[stanweld]

Low temperature carbon steels have been used in this service as have Manganese-Moly low alloy steels; e.g., SA-302 and SA-533 with Supplementary Charpy Tests.

 

[kissjxp]

How about the temperature higher than 427C?

 

[stanweld]

My answer was based on the 460 C operating condition during regeneration.

What is the regeneration cycle and time at 460 C?

 

[kissjxp]

12 hours for every year. The expected life is 20 years.

Can I use impact tested A516-70?

Thanks.

 

[stanweld]

No problem.