Feasibility of sending hydrogen thru the NG infrastructure.

[microhenry]

I'm rather skeptical of the "hydrogen economy" hype.
As an EE, I'm out of my area of expertise. I've be told
that because hydrogen is smaller and more viscose
than NG, it's impractical to send thru the NG infrastructure.

 

[DrillerNic]

I do know that hydrogen can diffuse through steel (often causing a failure mode called Hydrogen Induced Cracking), so that may be a problem for the existing storage and transportation infrastructure.

The other point is that unless hydrogen is extracted from water using electricy generated from renewable sources (wind etc), the best source of hydrogen is natural gas, so we're back to square one in terms of any concerns about non renewable resources and global warming.

 

[DickRussell]

Aside from the material handling aspect of hydrogen, one rarely hears any government body that promotes the "hydrogen economy" ever talk about the ultimate source of energy needed to produce the hydrogen. Sure, hydrogen might lead to automobiles that produce no CO2, but hydrogen can't be thought of as a fuel, but merely a medium for transferring energy from an ultimate source to the automobile. If the hydrogen is to come from electrolysis of water, the energy needed upstream is far greater than the energy delivered at the automobile engine, due to inefficiency, compression, etc. If it comes from extraction from natural gas, there still is an energy cost, plus the matter of what to do with the carbon in the methane. Is our government ignorant of thermodynamics, or are they trying to pull a fast one on us to promote some new industry?

 

[Guidoo]

Microhenry wrote that he heard that "hydrogen is smaller and more viscose than NG". Viscosity of hydrogen at 0 °C is slightly lower than viscosity of natural gas or methane. Natural Gas (Groningen) has a viscosity of 0.011 mPas, where hydrogen has a viscosity of 0.0084 mPas.

 

[dwedel]

Is Drillernic still here? Isn't hydrogen cracking only an issue during the welding process when the steel is at elevated temps?

I have heard of the compressers we use for NG being used for Hydrogen in industrial processes. Not sure if it would work to send hydrogen down the lines. There have been oil pipes changed over to NG service, so I imagine, if it NG pipes need to be changed to Hydrogen, it could be made to work. Not sure about the expense or if the old pipes with dressers in them would work well.

Personally I think hydrogen has too low of a fuel value to do much with. However, I haven't done any research on the posibilities.

dwedel
Hotrod Big Engines!

 

[DrillerNic]

dwedel- I've seen consideration of HIC during the design of low temperature well tubulars and flowlines. The reservoir fluid was very high in H2S (we had to wear BA sets while drilling in reservoir- ****ing awful), and as H2S hinders the recombination of atomic hydrogen to molecular hydrogen you could get atomic hydrogen entering the metal. The flowlines were full sour service spec- as well as the ususal NACE MR 0175 requirements, there were very tight tolerances on the amount of Manganese in the steel (MnS inclusions are where the atomic hydrogen often recombines to form H2 in the metal), and various alloying elements to control the shape of these inclusions as well.

However, this was for reservoir fluids with water, as well as H2S present.....for a transmission pipeline, you'd hope that the water and anything like H2S would be removed, so perhaps any atomic hydrgoen would recombine to H2 rather than enter the line pipe metal: that's what metallurgists are for- to answer these type of questions!

 

[dwedel]

Drillernic,

Thanks for the explanation. Yes, we have H2S slam valves for a reason. Not that our customers appreciate them, but our operators and safety folks sure do!

dwedel
Hotrod Big Engines!