Hydrogen fuels rockets, but what about power for daily life? We're getting closer

Hydrogen fuels rockets, but what about power for daily life? We're getting closer
NASA has launched all of its space shuttle missions using hydrogen as fuel. Credit: NASA, CC BY

Hydrogen is the first element on the periodic table. In its pure form hydrogen is a light, colourless gas, but forms a liquid at very low temperatures.

Have you ever watched a space shuttle launch? The used to thrust these enormous structures away from Earth's gravitational pull is hydrogen.

Hydrogen also holds potential as a source of for our daily activities – driving, heating our houses, and maybe more.

This month the federal coalition government opened public consultation on a national strategy. Labor has also pledged to set aside funding to develop clean hydrogen. The COAG Energy Ministers meeting in December 2018 indicated strong support for a hydrogen economy.

But is Australia ready to explore this competitive, low-carbon energy alternative for residential, commercial, industrial and transport sectors?

There are two key aspects to assessing our readiness for a hydrogen economy—technological advancement (can we actually do it?) and societal acceptance (will we use it?).

Is the technology mature enough?

The hydrogen economy cycle consists of three key steps:

  • hydrogen production
  • hydrogen storage and delivery
  • hydrogen consumption – converting the chemical energy of hydrogen into other forms of energy.

Hydrogen production

For hydrogen to become a major future fuel, water electrolysis is likely the best method of production. In this process, electricity is used to split water molecules into hydrogen (H₂) and oxygen (O₂).

This technology becomes commercially feasible when electricity is produced at relatively low costs by such as solar and wind. Costs may drop further in the near future as the production technology becomes more efficient.

How hydrogen is created and used as a power source.
Hydrogen storage and delivery

Effective storage and delivery are vital for the safe and efficient handling of large amounts of hydrogen.

Because it is very light, hydrogen has conventionally been compressed at high pressure, or liquefied and stored at an extremely low temperature of -253℃. Taking these steps requires an extra energy investment, so efficiency drops by up to 40%. But current hydrogen storage and delivery still rests on these two technologies – compression and liquefaction – as they are proven and supported by well-established infrastructure and experience.

Another option being explored (but needing further development) is to combine hydrogen with other elements, and then release it when required for use.

Currently, most hydrogen fuel cell cars use carbon-fibre reinforced tanks to store highly compressed hydrogen gas. The cost of tanks will need to lower to make this option more economic (currently over a few thousands of US dollars per unit).

Using hydrogen as a fuel

There are two main ways to convert the chemical energy in hydrogen into usable energy (electrical energy or heat energy). Both of these approaches produce water as the by-product.

A primitive and straightforward way of using hydrogen is to burn it to generate heat – just like you use natural gas for cooking and heating in your home.

A trial planned for South Australia aims to generate hydrogen using renewable electricity, and then inject it into the local gas distribution network. This way of "blending" gases can avoid the cost of building costly delivery infrastructure, but will incur expenditures associated with modifications to existing pipelines. Extensive study and testing of this activity are required.

When used in hydrogen fuel cells, energy is produced when hydrogen reacts with oxygen. This is the technology used by NASA and other operators in space missions, and by car manufacturers in . It's the most advanced method for hydrogen use at the moment.

It works, but will we accept it?

Safety considerations

As a fuel, hydrogen has some properties that make it safer to use than the fuels more commonly used today, such as diesel and petrol.

Turn up the sound for this hydrogen-fuelled launch.

Hydrogen is non-toxic. It is also much lighter than air, allowing for rapid dispersal in case of a leak. This contrasts with the buildup of flammable gases in the case of diesel and petrol leaks, which can cause explosions.

However, hydrogen does burn easily in air, and ignites more readily than gasoline or natural gas. This is why hydrogen cars have such robust carbon fibre tanks – to prevent leakages.

Where hydrogen is used in commercial settings as a fuel, strict regulations and effective measures have been established to prevent and detect leaks, and to vent hydrogen. Household applications of hydrogen fuel would also need to address this issue.

Impact on the environment

From an environmental perspective, the ideal cycle in a involves:

  • hydrogen production through using electrolysis to split water
  • hydrogen consumption via reacting it with oxygen in a fuel cell, producing water as a byproduct.

If the electricity for electrolysis is generated from renewable sources, this whole value chain has minimal environment impact and is sustainable.

Moving closer to a hydrogen economy

Cheap electricity from renewable energy resources is the key in making large-scale via electrolysis a reality in Australia. Internationally it's already clear – for example, in Germany and Texas – that renewable hydrogen is cost competitive in niche applications, although not yet for industrial-scale supply.

Techniques for storage and delivery need to be improved in terms of cost and efficiency, and manufacturing of hydrogen fuel cells requires advancement.

Hydrogen is a desirable source of energy, since it can be produced in large quantities and stored for a long time without loss of capacity. Because it's so light, it's an economical way to transport energy produced by renewables over large distances (including across oceans).

Underpinned by advanced technologies, with strong support by governments, and commitment from many multinational energy and automobile companies, hydrogen fuel links renewable energy with end-users in a clean and sustainable way.

Let's see if hydrogen takes off.


Explore further

Emissions-free hydrogen production edges closer with new pilot site in Denmark

Provided by The Conversation

This article is republished from The Conversation under a Creative Commons license. Read the original article.The Conversation

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Mar 11, 2019
Unique Proven Fountain of Youth Technology
https://www.prlog...ogy.html

Mar 11, 2019
The problem is you can't store it. It leaks out of anything you try to put it into. So you either burn it right now or it's subject to dissipation.

Mar 11, 2019
Hydrogen may have its uses for mass storage..but for driving it makes absolutely no sense.

The chain:
Energy production -> transmission -> charging a battery -> discharging it -> running a motor
is about three times more efficient than the chain:
energy production -> H2 production -> H2 compression -> transport -> reconversion into power -> runnnig a motor

And no. This is not open to be brought down to battery electric vehicle levels by more efficient processes, because the energy losses in creation/compression or storage and reconversion into power of H2 are set a hard lower bound by the laws of physics..

I.e. instead of having to build x extra powerplants to run an BEV sector you'd have to build 3x powerplants to run a H2 automotive sector.

I think mass storage could be made tight (enough)...but hundreds of millions of cars in deteriorating states of repair over the years? No way. And - leaking - H2 is a greenhouse gas (not nearly as bad as CO2, but still).

Mar 11, 2019
This is where Robots are needed. Sea water is abundant. Let them keep making H2 and releasing them in containers into sea. Let whichever country needs it, use it and pay for it. Let all countries get into the act. The containers must float and not explode. O2 that is released into air as byproduct is good too ! Make it a No Limit Affair. Let Robots keep on making them. Let countries keep on using them !

Mar 11, 2019
And - leaking - H2 is a greenhouse gas (not nearly as bad as CO2, but still).
Not to mention it has this tendency to explode when exposed to the atmosphere, see Hindenburg. Think of that happening in your car after a fender-bender.

Mar 11, 2019
It says, "Techniques for storage and delivery need to be improved in terms of cost and efficiency".
Why? Let them keep floating. Whichever Ship is nearby, let it collect them. It must be a Forever affair. When 1 container finds another, let them join together automatically !

Mar 11, 2019
This is where Robots are needed. Sea water is abundant. Let them keep making H2 and releasing them in containers into sea. Let whichever country needs it, use it and pay for it. Let all countries get into the act. The containers must float and not explode. O2 that is released into air as byproduct is good too ! Make it a No Limit Affair. Let Robots keep on making them. Let countries keep on using them !

There must be a safety valve on them that would sense and release all of their content in case of Tornadoes, Hurricanes and Tsunamis and restart the process of filling up all over again !

Mar 12, 2019
"combine hydrogen with other elements"

Combine 4 hydrogen atoms with one oxygen and one carbon. Voila - methanol, an eminently practical liquid fuel that will run (in the form of M85) in most any car built in the last 20 years with only a firmware update. A clean-sheet-of-paper engine would be even better; check out a dozen different categories of racing engines.
The carbon needed could easily come right out of the air - one pathway is CO2 + 3H2 = CH3OH + H2O
There's already a commercial plant running in Iceland.

H2 on its own is far too difficult to store.

Mar 12, 2019
It is also much lighter than air, allowing for rapid dispersal in case of a leak. This contrasts with the buildup of flammable gases in the case of diesel and petrol leaks, which can cause explosions.


Hydrogen loses its buoyancy once it is dispersed in air, which it does indeed do rapidly, but that means you've got a cloud of hydrogen mixed with air that does not rise up and away just as rapidly. In contrast, diesel doesn't cause explosions unless heated to a boil because it hardly evaporates - it's closer to cooking oil.

Hydrogen leaking creates a large explosion hazard - and these accidents keep happening every now and again in powerplants where pressurized hydrogen is used as the coolant in high performance generators. You'd think it would just safely lift away, but especially with pinhole leaks it mixes with air rapidly and starts to collect up, even outdoors if there's little wind.

Mar 12, 2019
This technology becomes commercially feasible when electricity is produced at relatively low costs by renewable sources such as solar and wind.


Aka. never. Take for the sake of argument, a round-trip efficiency of 25% from electricity to electricity. If the payback time of your solar panel or wind turbine is 10 years, turning it into hydrogen and back, while selling the electricity at the same market prices, is going to grow that payback to 40 years and more because you have to pay for the hydrogen infrastructure as well.

Longer than the lifespan of the devices, which means it never pays back. You only get your money back if you sell the resulting power at a higher price.

Another option being explored (but needing further development) is to combine hydrogen with other elements, and then release it when required for use.


Like carbon, make it a hydrocarbon, like gasoline or diesel. Those are more valuable than the electricity and fetch a better price.

Mar 12, 2019
Not to mention it has this tendency to explode when exposed to the atmosphere, see Hindenburg. Think of that happening in your car after a fender-bender.

Sorta.
Yes, Hydrogen is a lot more flammable than gasoline (over a wider range of ratio to oxygen) but it escapes upwards. Unless it is caught in some sort of overhead containment the danger from escaping/burning/exploding H2 is a lot less than dangers posed by pooling gasoline and gasoline vapors.
(What happens when H2 is contained could be seen at Fukushima. The intense heat created H2 which in turn was caught under the ceiling and eventually exploded. The buildings were designed with just that in mind to have lighter built top portions)

Here's a neat side-by-side comparison of what happens when a H2 car burns down and a gasoline car burns down
https://www.youtu...zEAs34r0

I guess I'd rather sit in the H2 car (though I most definitely would MUCH rather sit in a battery electric vehicle).

Mar 12, 2019
Combine 4 hydrogen atoms with one oxygen and one carbon. Voila - methanol

True, but that makes the entire chain even more inefficient (because that 'combine' action takes power you're not getting back out. Conversion/reconversion always has losses).
And now you're again burning stuff in piston engines...which , again, has an atrociously low efficiency.

So yeah...you can do all sorts of stuff. But you always have to think about: Does it make sense? Methanol does not, unless really long-term storage is the main thing you're looking for (e.g. storing excess renewable power from PV powerplants in summer for use in winter).

Plus: When you burn hydrocarbons, like methanol, you get all sorts of stuff besides CO2 and H2O. Combustion also lets the nitrogen in the air come along and play (resulting in toxic NOx)

Mar 12, 2019
The carbon needed could easily come right out of the air - one pathway is CO2 + 3H2 = CH3OH + H2O

Just looking at the chemical formula doesn't give you the whole picture. You have to look at how hard it is to crack the bonds of each. Cracking CO2 is extremely hard. It's a very stable molecule (stable for hundreds of years in the atmosphere). Carbon is also pretty dilute in the air at 410ppm (note that 'dilute' does most definitely not equate to 'not problematic' in this case). To fuel a reactor that produces appreciable amounts of methanol from ambient CO2 you'd have to process HUGE quantities of air.

So, no. The carbon could not come 'easily' out of the air. Carbon for methanol synthesis often comes from industrial processes where carbon (often as carbon monoxide) is already produced in concentrated form.

Mar 12, 2019
Yes, Hydrogen is a lot more flammable than gasoline (over a wider range of ratio to oxygen) but it escapes upwards.


Except when it's mixed in air, because the density difference isn't so great anymore. Buoyancy is a bulk effect - individual hydrogen molecules don't just shoot up towards the sky.

Here's a neat side-by-side comparison of what happens when a H2 car burns down and a gasoline car burns down


That's a nice propaganda video, but in a real car crash the hydrogen tanks don't vent neatly out of a tube cut through the trunk lid. In the video, the gasoline car was lit from the bottom, whereas the hydrogen car was deliberately vented. In a real situation, the hydrogen tanks and fuel lines would also be on the bottom of the car, and the flame would burn there.

Of course, they won't do that test because the glue in the composite tank starts to come loose above 90C and the very high pressure tanks soon rupture, sending the whole thing up

Mar 12, 2019
Here's a neat video that shows what happens to pressure cylinders containing flammable gasses in a real car crash. A CNG bus in Sweden tries to drive into an underpass that is too low for the vehicle and the gas tanks on the roof of the car get crushed. The result is an instant explosion:

https://www.youtu...CEA_JWbk

If that was hydrogen, the tanks would have been at a higher pressure, leading to a more rapid dispersal of the gas, and the resulting explosion would have been much more violent - because hydrogen burns a whole lot faster.

Mar 12, 2019
Here's a USAF training video of what happens with liquid hydrogen:

https://www.youtu...JK5kU_UQ

You can see how the cloud of mixed gases does not go straight up - it follows the contours of the ground, and once ignited it all goes in a pop.

One of the concerns of spillage is that liquid hydrogen is so cold that it condenses oxygen out of air, and forms a mixture capable of detonation. They tested it, and found that clouds of evaporating hydrogen don't detonate in free air - the just combust very rapidly. What happens inside a building, like a parking garage for example, was not investigated.

They found that the hydrogen cloud that forms from a pipeline leak remains close to the ground for 600 ft (200m) from the point of release before it diffuses up.

Mar 12, 2019
One of the main factors limiting the adoption of propane vehicles around here is the fact that they aren't permitted in parkades. Hydrogen will certainly be no better. It may have some application for industrial energy storage, but will be outrun on the road by the development of electric cars.

Oil companies love to be seen researching hydrogen as a green fuel, especially as it has no chance whatsoever of displacing their current business model.

Mar 12, 2019
This is where Robots are needed. Sea water is abundant. Let them keep making H2 and releasing them in containers into sea. Let whichever country needs it, use it and pay for it. Let all countries get into the act. The containers must float and not explode. O2 that is released into air as byproduct is good too ! Make it a No Limit Affair. Let Robots keep on making them. Let countries keep on using them !

There must be a safety valve on them that would sense and release all of their content in case of Tornadoes, Hurricanes and Tsunamis and restart the process of filling up all over again !

Ocean Floating Solar Technology
https://cleantech...atkraft/

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