High Content of CO2 in Gas Pipeline

[sioklian]

Dear all,
I am doing some study on a platform which produces gas. If there is a leak from a gas pipeline (in which the gas is in high content of CO2 (30mol% to 65mol%)), would the gas burn as jet fire? Or it won't burn?
Thanks.
Regards,
SL.

 

[zdas04]

You didn't say what the rest of the analysis was, but if you assume that it is 50% CO2 and 50% Methane (or 65% CO2 and 35% Methane) then you have either 500 BTU/SCF or 352 BTU/SCF. The 500 BTU gas will definately burn and should ignite in about the same conditions that 100% methane would ignite. The 352 BTU gas will require a hotter ignition source, but it will burn. If the other constituents are heavier hydrocarbons then the mix will ignite easier and burn hotter.

The range of values you've provided is not that far from land-fill gas that runs engine-driven compressors just fine.


David Simpson, PE
MuleShoe Engineering

http://www.muleshoe-eng.com

Please see FAQ731-376 for tips on how to make the best use of Eng-Tips Fora.

The harder I work, the luckier I seem

 

[sioklian]

Thanks David for your response. I have two gas lines here:
a) 37% CO2, 49% Methane: estimate 490 BTU/SCF
b) 30% CO2, 16% Methane: estimate 167 BTU/SCF

So, the a) would burn when ignited rather than b). Am I correct to say that?

 

[zdas04]

"A" is close enought to what I calculated (you don't say what the missing 4% is, but 490 BTU/SCF should ignite just fine).

From the BTU content, the missing 54% on "B" must also be inert. "B" would probably burn, but I would think that the ignition temp would be really hot (100% methane has an autoignition temp around 1,000F) and wouldn't be suprised to see that it had to be exposed to 1,500F for a prolonged period to ignite. I'd be reluctant to try to run 167 BTU gas into an engine.

David