Pipeline material for gas phase CO2 transport

[new2co2]

Hi all,

What material would you pick for a CO2 pipeline, where the pipeline is no longer than 10 miles, and the CO2 is in the gas phase (for example at 17 psia and ambient temperature, around 6 tons/hr of CO2)?

I want to avoid the need for a compressor at the inlet, and use some plastic or composite pipe with large diameter, but I cannot find the right composite to use. PVC, for example, is disallowed because of its potential "brittle shattering" failure mode when pressurized.

I can use carbon or stainless steel of course, but for uncompressed CO2 the diameter (and price!) would be crazy.

Any ideas?
Thanks!

 

[SJones]

I would pick the material that demonstrated the lowest life cycle cost. There are at least two other options that could be incorporated into a life cycle cost analysis: HDPE as per API 15LE; GRP as per ISO 14692.

Steve Jones
Materials & Corrosion Engineer

http://www.linkedin.com/pub/8/83b/b04

 

[Montemayor]

new2co2:

When you don't tell us the source or original state of the CO2, one is left to ponder and guess - sometimes guess wrong. That's why getting the right, correct recommendation is your (the OP's) responsibility. Having done this one before, I'm left with only the guess that you are dealing with a liquified CO2 source (-8 oF, 250 psig) that you are vaporizing at the stated rate of 6 tons/hr. I find it hard to conceive that you could generate CO2 (& probably water-saturated) at that rate and at that low a pressure. Now, why you are limiting yourself to a mere 17 psia is still another thing to ponder. This stated pressure is so low for a 10-mile long gas pipeline that one HAS to ask the obvious question: just exactly where do you mean that the CO2 pressure is 17 psia - at the inlet or at the end?

Before one can take this as a serious gas pipeline proposal, you have to know what are the inlet and outlet condtions on the pipeline. You haven't furnished (or identified) either.

If my original guess that the CO2 is dry, then a carbon steel pipe will do just fine - as far as material of construction. But the BIG factor is the DIAMETER of the pipe that you will need -- and that all depends on the pressure drop constraints on the pipe run. With only 17 psia (2 psig) you are going to need a very big pipeline.

 

[new2co2]

Hi Montemayor,

Thanks for the reply, and I understand your doubts... but I reiterate:
inlet conditions: 17psia, 90 F
outlet conditions: 14.5 psia, 90 F
My initial back-of-the-envelope calculations when I was assuming PVC came out to about a 24" pipe.
If no cheap plastic or composite works, then I agree I would need to switch to carbon steel (the CO2 is dry), but then I'd also need to compress it to have an affordable pipe diameter. I'm trying to see if there is a way to avoid the expensive compressor + steel.

 

[new2co2]

SJones:

Thanks for your input. I agree that the way to choose is by comparing life cycle costs of the entire system (including compressors, fans, as required).

I'll check out HDPE and GRP; they look promising but available diameters look small.

 

[SJones]

You'll get 24-inch GRP and HDPE - keep looking.

Steve Jones
Materials & Corrosion Engineer

http://www.linkedin.com/pub/8/83b/b04