Hydrogen domestic gas supply?

biffvernon · Post by **biffvernon** » 10 Apr 2016, 08:41

A plan...

http://www.telegraph.co.uk/news/2016/04 ... le-global/

johnhemming2 · Post by **johnhemming2** » 10 Apr 2016, 09:11

Does anyone know how efficiently gas is converted to hydrogen including ccs?

Post by **adam2** » 10 Apr 2016, 11:24

Very silly idea IMHO.
Production of hydrogen from natural gas needs a lot of complex and energy consuming plant, that also consumes energy.
The resultant hydrogen contains about half the energy of the natural gas feedstock.
CCS has yet to be demonstrated on an industrial scale so the costs in money and energy are not known, but would assuredly be significant.

There are already concerns about our increasing reliance on natural gas imports, and our limited storage, so anything that increases consumption seems unwise.

Better IMO to carry on burning SOME natural gas but to seek to reduce this consumption, for reasons of both energy security and climate change.
Apart from the obvious savings by better insulation and more efficient appliances, there are two ways in which gas consumption can be reduced.

Firstly increase the amount of electricity produced from renewables, largely from wind turbines. Increase renewably generated power until gas burning for base load power has been eliminated. Gas would still be needed for peaks but not for base load.

Secondly, when the above has been achieved, install yet more renewable capacity such that an actual surplus results at times of high wind and low demand. Use this surplus to power electric boilers in premises that also have a gas boiler. Use remote control to substitute electricity for natural gas at times of surplus.

Wind turbines, PV modules and remotely controlled electric boilers are all mature technologies.

biffvernon · Post by **biffvernon** » 10 Apr 2016, 15:40

Just what I thought. (Though we ought to approach these sort of questions from the standpoint that zero-carbon emissions are urgently required.)

Post by **clv101** » 10 Apr 2016, 19:12

Daft idea and article.

"Experts say alternative sources of home heating will need to be found if Britain is to comply with its Climate Change Act, which requires an 80 per cent cut in emissions on 1990 levels by 2050."

How about insulation? Oh yeah, government cut funding. Article doesn't even mention insulation!

"The carbon would then be disposed of using carbon capture and storage technology..."

Which doesn't exist. Let's just use magic?

"A key advantage would be that gas distribution pipe network infrastructure would need minimal modification, because old metal pipes are already being replaced with plastic ones which NGN says are suitable for carrying hydrogen."

I'm dubious about that - hydrogen is much 'leakier' than CH4.

Basically this scheme still using methane, it just attempts to decarbonise it with CCS. Locking us into decades more dependency on gas seems a bad idea.

johnhemming2 · Post by **johnhemming2** » 10 Apr 2016, 19:52

The eternal problem of the Westminster bubble not really being scientifically numerate.

vtsnowedin · Post by **vtsnowedin** » 10 Apr 2016, 20:17

clv101 wrote:
I'm dubious about that - hydrogen is much 'leakier' than CH4.

.

I'm not a plumber but I've done quite a bit of pipe work both on the job and at home with pipes having working pressures up to 150 psi.
In my experience a pipe ether leaks or it does not, with a slow weeping dripper being a rare exception. If your new HDPE gas mains hold for test pressure for Natural gas they will hold for hydrogen just fine.
Your old cast iron lines with oakum and lead joints do need to be replaced but that is true for everything from sewer to water to natural gas.

vtsnowedin · Post by **vtsnowedin** » 10 Apr 2016, 20:20

clv101 wrote:
Basically this scheme still using methane, it just attempts to decarbonise it with CCS. Locking us into decades more dependency on gas seems a bad idea.

Especially when you consider that you probably don't have decades left of Natural gas supply.

johnhemming2 · Post by **johnhemming2** » 10 Apr 2016, 20:24

https://en.wikipedia.org/wiki/Hydrogen_ ... _transport

I would say a score draw.

Post by **clv101** » 10 Apr 2016, 20:27

Point is the H molecule is much smaller than CH4, it happily fits through gaps CH4 won't. He is the same - inflate a rubber balloon with He and it escapes pretty quick (compared with N and O2) which is why foil balloons are used.

vtsnowedin · Post by **vtsnowedin** » 10 Apr 2016, 20:52

clv101 wrote:Point is the H molecule is much smaller than CH4, it happily fits through gaps CH4 won't. He is the same - inflate a rubber balloon with He and it escapes pretty quick (compared with N and O2) which is why foil balloons are used.

In HDPE pipe systems all the joints can be welded and there are no gaps.
The last line I worked on was 24" ID and had pipe walls 30 mm thick.
Not that I think anybody is going to put in a big hydrogen system but if you needed to it could be easily done.

Post by **adam2** » 10 Apr 2016, 21:16

I also doubt that all appliances could be converted to burn hydrogen instead of natural gas.
Common types of gas cooker and central heating boiler could be converted, and have been converted on a trial basis.
But what about specialist industrial furnaces in which the gas is not just a source of heat, but also takes part in a chemical reaction with the materials being heated.
Is a hydrogen flame luminous enough to work the optical flame detector used in industrial boilers ?
And hydrogen certainly wont work in a gas flame light, as favoured for historic buildings.
Incandescent gas lights should be OK and we might see a return of that Victorian curiosity, the self igniting gas light, no pilot light needed.

Anyway the elfansafety will never allow hydrogen ! It should not in fact be inherently any more dangerous than natural gas, but anything new tends to be subjected to stricter standards than established technologies.

(it is sometimes said that neither petrol, nor electricity would be allowed if newly invented)

Post by **clv101** » 10 Apr 2016, 21:16

Not saying it can't be done. I'm saying I'm dubious of the claim in the article "that gas distribution pipe network infrastructure would need minimal modification".

Jonh's Wikipedia link is telling, suggesting hydrogen pipeline transport is proven, and the transport costs are similar to those of CNG. CNG transport is far more costly than our regular gas network so the "minimal modification" claim is probably optimistic.[/i]

woodburner · Post by **woodburner** » 10 Apr 2016, 21:19

How big are the spaces between molecules in HDPE pipe? Thickness will not make much difference if the gaps are large enough fo H2 to get through the gaps. For pipes that meet the requirement https://avt.inl.gov/sites/default/files ... endixc.pdf

biffvernon · Post by **biffvernon** » 10 Apr 2016, 21:31

clv101 wrote: I'm dubious about that - hydrogen is much 'leakier' than CH4.

Completely off topic but does anyone know how this works: if you fill two ordinary party balloons, one with air made of small molecules of N an O2 and the other with larger molecules of CO2 the CO2 filled one deflates within a couple of days while the air filled one takes much longer to go down?

I've always assumed it's something rather more complicated than the size of a molecule. Actually, I don't really know what 'size of a molecule' is. Mass is easy enough. I don't think billiard-ball models of molecules are very helpful.