Hydrogen home heating

[Ian ParkinParticipant @ianparkin39383]

So do hydrogen powered vehicles always use a fuel cell or can you use it as a fuel source in a ic engine?

the hydrogen filling station in sheffield sells it at £10 per kilo and most cars/vans can load 5 kg so is that as a pressurised gas or liquid?

[Michael GilliganParticipant @michaelgilligan61133]

Interesting graphic, here: **LINK**

https://www.researchgate.net/figure/olume-of-4-kg-hydrogen-compacted-in-different-ways-with-size-relative-to-the-size-of-a_fig1_46710927

‘though I haven’t yet read the paper

MichaelG.

.

P.S. __ I have no idea how they handle it, but this mentions pressures of 350 and 700 bar being available 

https://www.itm-power.com/h2-stations/rotherham-wind-hydrogen-station

Edited By Michael Gilligan on 18/05/2021 23:12:54

[not done it yetParticipant @notdoneityet]

is that as a pressurised gas or liquid?

The answer is just before you posted (probably keying in).

[Paul KempParticipant @paulkemp46892]

Posted by Ian Parkin on 18/05/2021 22:12:22:

So do hydrogen powered vehicles always use a fuel cell or can you use it as a fuel source in a ic engine?

the hydrogen filling station in sheffield sells it at £10 per kilo and most cars/vans can load 5 kg so is that as a pressurised gas or liquid?

Its gas at 350 bar, currently standard pressures for h2 in gaseous form is 350 and 700 bar. On current efficiencies the price of h2 needs to drop quite a bit to be competitive with derv.

Ballard HC wave marine fuel cell is quoted at 58% efficient, not found one yet that is much over 60%.

H2 can be used in an IC engine but usually as a mix with another pilot fuel.

Hydrogen in a PEM fuel cell is the only current technology that is truly zero emission. There is another fuel solution requiring a solid oxide fuel cell that is very low emission but not zero.

Fact is if you want to be green you need to dig deep in your pocket! Economies of scale may well bring prices down and the next generation solid state batteries may well improve EV capability but there is going to be at least 20 years of financial pain for the man on the street while the investors cream their profits off the top. The green revolution requires not only a change in attitudes but a change in lifestyle too.

[Paul LousickParticipant @paullousick59116]

Hydrogen is the universe's most abundant element, but here on Earth it doesn't appear pure in nature, and requires energy to separate. The most common technique is to extract hydrogen from water, which is two parts hydrogen and one part oxygen (hence H2O). Doing this is fairly simple. You can use heat and chemical reactions to release hydrogen from organic materials such as fossil fuels.

But this is enormously polluting. Worldwide hydrogen production is responsible for CO2 emissions equivalent to that of the UK and Indonesia combined. (The hydrogen is mostly used in the oil refining industry and to produce ammonia fertilisers.)

There is a cleaner way of getting hydrogen: a strong electrical current passed through a tank of water splits the molecule into its two constituent elements. This is called electrolysis. Hydrogen atoms form hydrogen molecules (H2) and oxygen molecules pair up too. Each can then be bottled and stored. If the electricity is generated from renewable sources such as solar or wind, production of hydrogen in this way emits no greenhouse gasses.

This is how we come to all the different shades of hydrogen:

• brown hydrogen is produced using coal where the emissions are released to the air
• grey hydrogen is produced from natural gas where the associated emissions are released to the air
• blue hydrogen is produced from natural gas, where the emissions are captured using carbon capture and storage
• green hydrogen is produced from electrolysis powered by renewable electricity.

[Paul LousickParticipant @paullousick59116]

Energy companies, here in Australia are planning on making hydrogen on a commercial basis from solar and wind power. Electric vehicles are not common on our roads because of the long distances travelled and lack of charging stations outside of the capital cities. (they are not green as they are still fuelled from coal fired power stations).

Solar panels on houses are now causing a new problem. Older panels that have to be replaced cannot be recycled and go to landfill.

Excess power generated from the panels during the day is fed back into the supply grid and compensates for that used during the night. The problem is that there is now too much power generated during the daylight hours and is overloading the national grid. Some houses are fitted with batteries but this is an expensive option. The manufacture and disposal of batteries is another problem.

The development of hydrogen producers for home use with solar panels could possibly be a solution.

Paul.

[not done it yetParticipant @notdoneityet]

The problem is that there is now too much power generated during the daylight hours and is overloading the national grid.

There is a simple solution to that – turn off some of the solar farms. Happens with wind generation, in the UK, at any the time when it is extremely windy, particularly at night.

The other solution is to store that excess of energy in a different form – batteries, pumped storage, hydrogen generation, liquid ammonia to list a few alternatives.

[Michael GilliganParticipant @michaelgilligan61133]

Manchester had an interesting ‘Hydraulic Power’ main:

**LINK**

https://en.wikipedia.org/wiki/Manchester_Hydraulic_Power

… which seems a concept worth re-visiting if we need to smooth the peaks of energy availability.

MichaelG.

[David ColwillParticipant @davidcolwill19261]

Don't worry.

Fusion is only 5 years away

[pgk pgkParticipant @pgkpgk17461]

Posted by Michael Gilligan on 19/05/2021 08:35:58:

Manchester had an interesting ‘Hydraulic Power’ main:

**LINK**

https://en.wikipedia.org/wiki/Manchester_Hydraulic_Power

… which seems a concept worth re-visiting if we need to smooth the peaks of energy availability.

MichaelG.

Not the only city with hydraulic power…but Paris unique in compressed air power..
http://www.douglas-self.com/MUSEUM/POWER/airnetwork/airnetwork.htm

Also fascinating that paris had a pneumatic mail system
https://www.cix.co.uk/~mhayhurst/jdhayhurst/pneumatic/book1.html

pgk

[pgk pgkParticipant @pgkpgk17461]

Posted by David Colwill on 19/05/2021 08:46:16:

Don't worry.

Fusion is only 5 years away

A tad optimistic
" . ITER will begin operations with low-power hydrogen reactions in 2025. But from 2035, it will run on a 50:50 mix of deuterium and tritium. "
https://www.nature.com/articles/d41586-021-00408-1

..so if they did get it working circa 2035+ a few it'd still be (at least) another 10 years for a network of new fusion plants>

A close fit to the "fusion is only 30yrs away and always will be"

pgk

[Bob WorsleyParticipant @bobworsley31976]

Somewhere I was reading about sealing at high pressures, hydraulics probably, but as a side comment it was stated that sealing hydrogen is near impossible. The problem seems to be that the molecule size of hydrogen is so small that no type of non-metallic sealing ring will keep it in, things like O rings. You have to use a metal to metal seal. The article also said that over about 250 bar metal to metal seals, like BSP, start to leak, you have to use O rings to seal.

Is this correct? It was long a go and just remembered the conclusions, perhaps incorrectly.

So how was the old coal gas piped if 50% hydrogen? It must have been in a mix with something to make the molecule larger? I can remember as a child the bubbles coming to the surface after rain all along the gas pipelines where we lived, all mud in those days, no hard surface. Of course the gas pressure was very low, not like what is needed in a car application.

[JourneymanParticipant @journeyman]

Posted by pgk pgk on 19/05/2021 09:44:55:

A close fit to the "fusion is only 30yrs away and always will be"

They have always had Fusion Reactors in Star Trek so it must come to be

John

[HillclimberParticipant @hillclimber]

Just a little thought. It is not, apparently, a binary choice between natural gas and hydrogen in our boilers.

I understand that it is possible to blend in up to 10% hydrogen without affecting the boiler. Seen at a macro-level, that provides a significant emissions reduction for unconverted boilers.

Never let the good be the enemy of the perfect.

Cheers, Colin

[Neil LickfoldParticipant @neillickfold44316]

When I hear about Hydrogen gas supplies, I think of the Hindenburg .

[SillyOldDufferModerator @sillyoldduffer]

Posted by Hillclimber on 19/05/2021 10:24:21:

…

Never let the good be the enemy of the perfect.

Cheers, Colin

+1 to that!

There are plenty of ways Green Power can be used fruitfully, and many of the objections assume Hydrogen and other renewables must somehow be crowbarred into 20th century technologies. That's just one of many options.

A few posts mention it's difficult to seal Hydrogen, which is true. But they ignore that this old problem is well understood, that Hydrogen has been massively used on an industrial scale for well over a century, and it was the main component of the Coal Gas pumped into UK homes since Queen Victoria was a teeny bopper. Yes Hydrogen leaks a bit, but not enough to matter. Actually, everything leaks a little – there are no perfect technologies.

Dare I suggest old men shouldn't be allowed to influence the future? Long lives give us confidence, but we may not realise just how horribly dated our experiences are. Time marches on. Mankind has to keep all options open. The answer probably isn't in old-methods, future energy needs new thinking. Imagination, rather than a grey drizzle of negative objections. The older I get the more I hate change – perhaps mother nature is telling me to get out of the way?

Extending the availability of Natural Gas by supplementing it with electrolytic Hydrogen isn't difficult. True it doesn't solve the big problem in the long run, but it helps for a time, which is all that can be expected of any technology. Plenty of other ways of using electrolytic Hydrogen too – about 20% of the world's natural gas is used to make Hydrogen for fertilizer, without which we will all starve.

Or renewable energy could be used to store heat by melting common salt, and recovered as steam to drive turbines. Many options are more practical than bulldozing Hydrogen into fuelling Internal combustion engines designed to run on petrol! If the answer to fuelling cars is Hydrogen, IC engines as we know them are off the agenda.

I think it's a mistake to see the future in terms of Coal, Oil, Gas, Nuclear, Hydrogen, or any other favourite fuel. Better to think about how energy can be supplied and used in the round. All sources of energy are fair game. Quite likely the answers will change the world as much as canals zapped pack-horses, railways zapped canals, and then internal combustion zapped railways, dog carts, and horse-drawn everything. 2020 is nothing like 1920 and 1920 was nothing like 1820. I'm sure 2120 will be different again.

Dave

[Ron ColvinParticipant @roncolvin83430]

Posted by Hillclimber on 19/05/2021 10:24:21:

Never let the good be the enemy of the perfect.

Cheers, Colin

Should not that be, "never let the perfect be the enemy of the good"?, or is there a jocular reference that is making a whoosh sound as it passes over my head.

[Howard LewisParticipant @howardlewis46836]

Hydrogen sounds like a nice clean fuel. When burned, it returns to the water from which it was derived.

No particulates, because no carbon!

A delight for any politician who does not thoroughly understand the subject, but wants to jump on the bandwagon!

But not without some disadvantages.

Very little in life is ALL advantages.

1 ) Requires energy to electrolyse from water.

From hydrocarbon fuel, liberates Carbon Dioxide, so not a "green" process.

(Sea water entering a battery liberates Chlorine from the salt within the sea water, Sodium Chloride )

2 ) To store Hydrogen in liquid form requires high pressures. Many years ago, someone converted a Hillman Imp to run on Hydrogen. The gas cylinders were so heavy and large that there was only space for the driver left.

Look at a picture of a road tanker transporting Hydrogen.

3 ) Hydrogen is quite explosive, when mixed with air. There have been numerous examples of explosions resulting from it being produced when Lead acid batteries are charged. In some cases the injuries have put people in hospital. It most certainly blows the cells out of the battery casing! (Seen it happen! )

Recently, two houses have been demolished by what seems to be a gas explosion. Gas containing some Hydrogen.

4 ) Hydrogen when burned may well produce temperatures high enough to oxidise the Nitrogen in the combustion air.

Exactly the problem that we have with almost every form of combustion today

5 ) Hydrogen does not have the energy density of hyrdocarbon fuels ( No carbon to burn, so less energy from combustion ).

JCB have just exhibited a Hydrogen fuelled 3CX, and are enthusiastic about the fuel, but have not mentioned how the fuel is stored, it's capacity compared to the gas oil that powers the machine normally.

If Hydrogen is to be used as the power source for road vehicles, infrastrucure needs to provided.for refuelling.

Probably neither quick or economic to install.

This all sounds sceptical, but euphoria is contagious without thought.

Howard    EMOJIS, I hate'em!

 

Edited By Howard Lewis on 19/05/2021 12:14:52

[Robert Atkinson 2Participant @robertatkinson2]

Howard Lewis said:

5 ) Hydrogen does not have the energy density of hyrdocarbon fuels ( No carbon to burn, so less energy from combustion ).

Not true. It has one of the highest energy densities (W/g) of any fuel. The real problem is H2 is very light so that gram has a lot of volume, even when liquified.

Robert G8rPI.

[MacolmParticipant @macolm]

Hydrogen cannot be liquified except at cryogenic temperatures. The critical temperature is -240C, so only 33 degrees from absolute zero. The boiling point at one atmosphere is -253C, so unless pressurised AND cooled, it can only be liquified for temperatures within 20C of absolute zero.

Practicable bulk storage has of necessity to use very high pressures, and thus energy per overall unit weight is less than for petroleum fuels.

[not done it yetParticipant @notdoneityet]

Not true

Correct, but (from the net) “up to 800 bar, so that hydrogen can be reach a volumetric density of 36 kg/m3, almost half as much in its liquid form at normal boiling point.”

800 bar is about double the usual pressure used. Work it out – petrol is around 700-750kg in the same volume.🙁

On second thoughts, don’t bother – the energy content of hydrogen is not even in the same ball park as petrol or diesel on a volume basis.

[MacolmParticipant @macolm]

Neither is it on a weight basis if you include the mass of the storage container. Remember that the configuration of even 400 bar storage is likely to be an assembly of small diameter tubes to fit the space, rather than a single container which would necessarily be either spherical or large diameter cylindrical. Fancy any of this under the seats of your car?

[V8EngParticipant @v8eng]

Edited By V8Eng on 19/05/2021 15:00:44

Edited By V8Eng on 19/05/2021 15:01:54

[Neil WyattModerator @neilwyatt]

Posted by Howard Lewis on 19/05/2021 12:13:53:

3 ) Hydrogen is quite explosive, when mixed with air. There have been numerous examples of explosions resulting from it being produced when Lead acid batteries are charged. In some cases the injuries have put people in hospital. It most certainly blows the cells out of the battery casing! (Seen it happen! )

Recently, two houses have been demolished by what seems to be a gas explosion. Gas containing some Hydrogen.

Paper Tiger Howard

Houses flooded by water! Water containing some hydrogen!

Hydrogen poses similar risks to natural gas (methane) except that, being lighter, it is even more likely to disperse in the event of a leak.

Like methane it is odourless, so a scent marker will need to be added, just as we do for natural gas.

One problem is that the smaller molecules will escape more easily through porosity. Probably not enough to cause significant explosion risks, but increasing system losses.

Neil

[Neil WyattModerator @neilwyatt]

Posted by old mart on 18/05/2021 20:07:38:

The hydrogen would have to be compressed to get a worthwhile ammount in a vehicle, maybe even to liquid form. Petrol is bad enough around a crashed vehicle the hydrogen might be worse. If the hydrogen was kept as a refrigerated liquid, there would have to be constant venting, and using a garage to park in would cause additional problems.

This page is very interesting:

so-just-how-dangerous-is-hydrogen-fuel/

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