CH4 w/ H2 Blend 2

You need a STEM brain, or a brain STEM, I can't remember which.
(Entropy and time have had their way with my brain.)


"Everyone is entitled to their own opinions, but they are not entitled to their own facts."

 

[1503-44]

Blending, pipeline transmission and molecular separation at destination.

https://www.pipeline-journal.net/news/fraunhofer-ikts-spearheads-development-co2-free-energy-supply

 

[moltenmetal]

Anyone who thinks we'll blend gases just to pump them, and then separate them again at destination, needs to give their head a very vigorous shaking.

Fraunhofer has really gone nuts this past while. First that useless overhyped "powerpaste" stuff- MgH2 used to make H2, with perhaps a cycle efficiency from electricity to electricity again in the single digits- and now THIS...

Yeah, you CAN separate H2 from methane using membranes. It's expensive and lossy to fight entropy needlessly this way though. And you end up losing a lot of your H2 in the methane (from which it was MADE, so obviously it's worth MORE than the methane) and you also get methane in your hydrogen- not something that makes fuelcells happy because they have to vent anode tailgas to get rid of it.

 

[1503-44]

I did not read that they propose to use this for making fuel cells. Their stated intent is use "in the transportation and distribution of hydrogen as an energy source". Nothing about making fuel cells.

 

[rb1957]

ok, so if they burn H2, I hope they collect the water vapour ... a much more significant GHG than CO2.

and if they're messing with CH4, I hope none of this is escaping ... also a much more significant GHG than CO2.

another day in paradise, or is paradise one day closer ?

 

[1503-44]

Pipelines and the oilfield in general began reducing methane emissions a long time ago. Progress has not been as fast as desired by many, which was also hindered by the previous government's "relaxation" of prior regulations.

Have you tried reducing your own water vapor, CH4 and CO2 emissions?

 

[moltenmetal]

Water vapour IS a powerful GHG, but it is in rapid PHYSICAL equilibrium with water liquid in the oceans and biosphere. Water vapour emissions are NOT of concern from a global warming perspective. However, as we warm the planet, we shift the equilibrium from water liquid to water vapour in the atmosphere, which is a powerful feedback...

Yes, methane leakage is a big problem.

But here's the problem folks: people are talking about adding 20% H2 to methane and keeping it there for burning- which you can do. The gas distribution and fuel burning infrastructure can tolerate 10% easily but maxes out around 20% by volume.

Sadly, a 20% mixture of H2 in methane has 14% less energy content than pure methane...

The reduction in GHG emissions, assuming the hydrogen is electrolytic and made from electricity as pure as the driven snow, is therefore what- 6%? At most?

Great business if your customers are idiots- and pay per unit volume. Rather like adding water to gasoline...

 

[1503-44]

94% is better than 0. Profit is not the motive. Its more of a continued existence sort of thing. It may get to the point where methane disappears from the pipeline entirely some day and they still want to have something inside to move around.

 

[EdStainless]

Merchant gas has a min heat capacity, as they add Hydrogen they will just add less air.
Like they had to when they took the butane and ethane out of gas.

= = = = = = = = = = = = = = = = = = = =
P.E. Metallurgy, consulting work welcomed

 

[1503-44]

I've never seen air being added. The problem is in fact usually the opposite in that gas from the well heads contain more Btu's than the average pipeline blend and the excess heavier HCs contributing to the higher Btu contents being removed. That also saves them from condensing in the pipeline as temperatures cool. What is left is pretty much methane with very small quantities <5% of ethane, butane plus a few other limited impurities normally yielding around 1050 Btu/cf. Pure CH4 has only 980 Btu/lbm, so you can see that nobody is purposely adding air to lower the Btu content, all that is needed is to remove the richer heavier compounds, which are sold separately. Neither is anyone adding air to a heavier blend just so they can transport that air cross country only to sell the gas at a lesser volumetric price, since gas you know is bought and sold by Btu content.

BTW Adding H2 to methane reduces the volumetric energy content. A 30% H2 blend into methane results in a CF having 863 Btu, 80% that of pipeline quality methane. Adding air will drop it a bit more, so no point in that.

Table 3-1. Typical Pipeline Gas Specifications

Characteristic Specification
Water content 4–7 lbm H2O/MMscf of gas
Hydrogen sulfide content 0.25–1.0 grain/100 scf
Gross heating value 950–1200 Btu/scf
Hydrocarbon dewpoint 14–40 °F at specified pressure
Mercaptans content 0.25–1.0 grain/100 scf
Total sulfur content 0.5–20 grain/100 scf
Carbon dioxide content 2–4 mol%
Oxygen content 0.01 mol% (max)
Nitrogen content 4–5 mol%
Total inerts content (N2 + CO2) 4–5 mol%
Sand, dust, gums, and free liquid None
Typical delivery temperature Ambient
Typical delivery pressure 400–1200 psig

 

The problem is in fact usually the opposite in that gas from the well heads contain more Btu's than the average pipeline blend and the excess heavier HCs contributing to the higher Btu contents being removed.

Not to mention those heavier HCs are more valuable when separated.

"Everyone is entitled to their own opinions, but they are not entitled to their own facts."

 

[1503-44]

"richer heavier compounds" Yes, "richer" has a double meaning when it comes to petroleum products.

 

[1503-44]

Ireland is in.

https://www.pipeline-journal.net/news/hydrogen-energy-supply-tested-gas-networks-ireland

Rest of zEU is in

https://gasforclimate2050.eu/news-item/european-hydrogen-backbone-grows-to-40000-km/