Is reducing energy losses critical for the success of hydrogen in the gas grid?

[chemisttree]

Does 20% hydrogen cause only 20% of the hydrogen embrittlement in those cast iron distribution lines? Wouldn’t this idea only hasten end of life for susceptible metal components throughout the distribution network?

 

[mfb]

which is around 7 per cent of the annual CO2 tonnage churned out by the burning of fossil fuel around the world.

These 7% are offset by our food production which binds as much CO2 as we exhale again. The burning of fossil fuels is not balanced.

 

[member 656954]

Apologies. I should not have implied more than was warranted. Are you saying that is your active profession?

LOL, your comment did seem a little direct, @anorlunda, but I take your point regards opinion. And yes, this is my active profession.

 

[member 656954]

Does 20% hydrogen cause only 20% of the hydrogen embrittlement in those cast iron distribution lines? Wouldn’t this idea only hasten end of life for susceptible metal components throughout the distribution network?

The embrittlement is not as linear as that, as it depends on pressure and structural irregularities, but hydrogen will increase the failure rate over non-hydrogen in operation. NREL released this excellent summary of hydrogen in gas pipeline distribution studies, including a conclusion that hydrogen concentrations up to 28% may safely be used with properly serviced existing domestic appliances.

 

[tech99]

Can I thank everyone for the replies and discussion on Hydrogen Injection which has turned out to be a complex issue. I was hoping it would avoid building new electricity stations to supply electric cars, because there are issues about the technology and also the effect on habitats.

 

[Genava]

These 7% are offset by our food production which binds as much CO2 as we exhale again. The burning of fossil fuels is not balanced.

Thank you. That's the difference between someone understanding the basics about the carbon cycle and someone who doesn't.

 

[bigfooted]

The embrittlement is not as linear as that, as it depends on pressure and structural irregularities, but hydrogen will increase the failure rate over non-hydrogen in operation. NREL released this excellent summary of hydrogen in gas pipeline distribution studies, including a conclusion that hydrogen concentrations up to 28% may safely be used with properly serviced existing domestic appliances.

Domestic boilers have to be tested under extreme conditions (well, more extreme than what they would encounter in their lifetime) before they are released on the market. One of the tests is a light-back safety test where a mixture of 23% H2 +77% CH4 (mole-fraction) is used. So all domestic boilers on the European market passed this test. Very old or very different appliances (certain gas turbines) are the limiting factor for widening the fuel flexibility of the gas network, and they may need to be banned when changing the gas composition on the network.

That's why I think the 'electrify everything' trend is a better investment than gas+hydrogen, because the moment we have a price on carbon is the moment the exodus from gas for domestic use starts in earnest.

Well, a lot of electricity comes from gas or coal power plants, so unless you exempt power plants from carbon tax, the electricity price will also go up. Also, a complete switch from gas to electric is not possible without upgrading the entire network up to the fuse box and this will certainly have an impact on the electricity price.
Anyway, if we want to decarbonize, we need to get rid of natural gas completely and adding hydrogen to the gas network is a nice intermediate solution: the gas lines do not need to be replaced (at least not in the UK and in the Netherlands, don't have information about other countries) and many appliances can handle the larger hydrogen concentrations. With this experience, the next step will be to switch to 100% hydrogen on the gas lines, as proposed in e.g. the H21 Leeds city gate project as well as the Hy4Heat program in the UK. Hydrogen production technologies will be more mature and hydrogen prices will drop when more hydrogen will be available.
All in all I think the 'electrify everything' trend might not be a better investment than a combined electric + hydrogen network.

 

[member 656954]

hydrogen prices will drop when more hydrogen will be available

Do you happen to have any articles or studies that predict this, @bigfooted? I'm struggling to find any that don't cost out to be at least the gas price...or more.

 

[gmax137]

With this experience, the next step will be to switch to 100% hydrogen on the gas lines, as proposed in e.g. the H21 Leeds city gate project as well as the Hy4Heat program in the UK. Hydrogen production technologies will be more mature and hydrogen prices will drop when more hydrogen will be available.

Where is this hydrogen coming from? How much are we talking about?

Please Check my arithmetic:

google says UK natural gas consumption is about 7.6 billion ft3 per day
at 1000 Btu/ft3
and 3413000 Btu/MW-hr
I get
93,000 MW
That's a lot of windmills.

 

[member 656954]

Where is this hydrogen coming from? How much are we talking about?

That is the big question, @gmax137. With efficiency losses, creating hydrogen from renewable sources is more than "a lot of windmills".

The UK generated 75.2 TWh of electricity from gas in Q1 2019, while renewable electricity (RE) generation was 31.1 TWh in the same period, but solar and wind was only 23.6% of that. Gas accounted for 41.5% of total generation in the period (coal was only 3.5%, a record low), which shows how large the generation gap is, and that does not account for the efficiency loss creating the hydrogen. It is also not all energy used in the UK - just electricity!

Still RE is increasing, year-on-year, and was up 9.2% on the same period in 2018, but we clearly have a long way to go.

 

[Rive]

...we clearly have a long way to go.

Not really. Not clearly, at least. The whole Hydrogen generation came from the idea of taking the surplus RE as 'free'. Just this 'free' alone is a serious misconception, but it gets even worse when it is paired with the 'long way to go'.
It is a known problem that with the improving penetration of intermittent RE the grid is more and more strained, and system operators are more and more frequently forced to reject taking in more wind, even if it costs them money (look up 'curtailment'). This also means that above a point the new wind capacity is actually reducing the capacity factor of the whole installed capacity, messing up any investment/return calculations.
Hard to say where is actually the point when new capacity is no longer advantageous anymore, but California and Germany already clearly closing to that point.

 

[member 656954]

Not really. Not clearly, at least.

Not sure you're saying what I think you are saying, @Rive. RE provided about 11.0% of total UK energy consumption in 2018, and for me, at least, 89% is a long way to go

I understand the rest of your post (including curtailment), and agree with it. The hydrogen economy concept makes no sense to me.

 

[Nik_2213]

I'm old enough to remember 'Town Gas', which was a very nasty CO + H2 mix. IIRC, there was an art to crafting joints and connections that so-slippery H2 would not get through in quantity. Then I used H2 for GC instruments, again met that so-slippery molecule. Ninja-fu Helium was worse for containment, but essentially harmless...

As a ~20% blend, H2 may be some-what more dangerous than pure methane. The 'Flash-over' danger will be less than that infamous ~50% Town Gas mix, but explosion shock fronts would be faster than pure methane. Will ~20% allow catalytic ignition ? I missed being able to wave a 'Cerium' ceramic-coated wand over burner to light it...

 

[reiver]

I work in renewable energy for a company that is testing this approach - issues such as grid connections for offshore wind farms are part of the reason for interest - it is one of the trickiest elements to ensure that there is a grid connection available with the capacity that you need and that you have permisison to connect to it.

Another reason for interest is ctually exploring the concept using in-house utilities knowledge of cost bases and network infrastructure - in Europe, many of the transmission networks are owned by companies also involved in generation). The view is largely of what utilities can do to avoid curtailment.

The 20% H2 value is largely predicated on the modern domestic boilers needing no change to be able to burn this fuel, so adding the 20% H2 would not require any significant infrastructural changes (and these would incur significant costs).

RE would always focus on electricity generation and the way that RE is going, merchant price is becoming the mechanism i.e. if there is low demand for electricity, it can't be sold and you don't get paid for curtailment for power that hasn't been sold already (curtailment tends to be agreeing to come off grid having contractually promised/agreed to provide power - CCGTs (gas plants) get paid for curtailment in the same manner). But if the wind is blowing anyway, is there a way to sell the excess potential electricity? This electricity has low marginal cost so is the "free" electricity that everyone is talking about. So these H2 trials are more to see that it can be done and if there are any unexpected problems and to do so at very low cost.

[Moderator: paragraph breaks added for readability.]

 

[Christopher L]

At least here in the USA, many (most?) gas pipes are steel. Using Hydrogen in them brings up the problem of making the steel pipes brittle, leading to fractures... and a pure Hydrogen flame is invisible! (no incandescent Carbon to generate visible light.)

https://scholar.google.com/scholar?...+in+steel&hl=en&as_sdt=0&as_vis=1&oi=scholart

Not saying it can't be done, just that there are a lot 'unmentioned circumstances.'

Cheers,
Tom

"H2S plays a multiple role in increasing hydrogen permeation of passivated steel in slightly acidic environments. It increases the rates of iron corrosion and proton discharge and poisons the hydrogen evolution reaction on the depassivated surface, thereby permitting a large fraction of hydrogen atoms to enter the metal."

The Role of  H 2 S  in the Corrosion and Hydrogen Embrittlement of Steel
B. J. Berkowitz and H. H. Horowitz

© 1982 ECS - The Electrochemical Society
Journal of The Electrochemical Society, Volume 129, Number 3

https://iopscience.iop.org/article/10.1149/1.2123882/meta

 

[Dragrath]

Has anyone accounted for the losses of hydrogen? I ask as independent research has reported natural gas lines already leak more than officially reported
https://www.sciencedaily.com/releases/2019/06/190606183254.htm
which already at least in the US was much higher than was officially reported
https://www.reuters.com/article/us-...larger-than-epa-estimates-study-idUSKBN1JH2TP
Given that escape is even easier for Hydrogen I'm skeptical this would really do much.

 

[member 656954]

There have been studies of this. NREL released an extensive review of blended H2 and NG in 2013, and noted:

"Extending this calculation to the larger pipeline network suggests that use of a 20% hydrogen blend within the approximately 415,000 miles of PE pipes in the United States would result in a gas loss of about 43 million ft3/yr, with about 60% of the losses being hydrogen and 40% being natural gas (Appendix A)."​

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And a recent IRENA report noted:

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"Currently, significant energy losses occur in hydrogen production, transport and conversion. Reducing these losses is critical for the reduction of the hydrogen supply cost."​