Why does Hydrogen run counter to Joule-Thomson principles for gases?
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11/12/2015
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Virendra Kapoor, Petroleum Refining Consultants, vkkapoor9@yahoo.com
It does not run counter to Joule - Thomson rule. Its inversion temperature is very low much much lower than inversion temperature. All gases above their inversion temperature get cooled on expansion. I hope it answers your question.
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10/12/2015
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Morgan Rodwell, Fluor Canada Limited, morgan.rodwell@fluor.com
This is because the Joule-Thompson coefficient is temperature dependent for all gases. For some gases, the curve takes the JT coefficient negative at normal temperatures. H2 and He have JT coefficients below zero for temperatures above cryogenic. For nitrogen, the JT coefficient is only negative above 600 K, so it is rare you experience that in any industrial process.
The reason for this is that at low mole weights, the ratios of key properties end up "strange"
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10/12/2015
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keith bowers, B and B Consulting, kebowers47@gmail.com
Do you want the very technical theoretical answer or just Accept it!! There are also a very few (3 known in the world I think) very high pressure gas deposits that exhibit similar behavior --at the temperatures and 28000 psi pressure in the reservoir, everything is vapor and the formation rock is DRY. If your reduce the pressure, natural gas liquids will form, wetting the source rock and 40% of the NGL is forever lost and unrecoverable. One has to 'cycle' the gas--lowering the pressure in surface facilities, extracting the NGL, re-compress the now 'dry gas' and re-inject it into the formation in such a pattern as to 'sweep' the rich gas to the producing well(s) This reverse JT behavior is called "retro-grade" behavior. Mother Nature is strange sometimes.
One formation in Uzbekistan has a gas cap, oil layer, and salt water bottom layer. The gas is being cycled and some 70,000 B/D of NGL recovered, some 100,000 B/D of oil is being produced, some 1 Billion SCFD of pipeline quality natural gas produced, and some 200,000 B/D of sterilized and filtered saline formation water injected to slowly squeeze the oil layer higher to keep the gas cap pressure stable. This operation should run at least another 20 years just like it is.
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