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I checked out the Toyota Mirai - it does indeed use hydrogen gas cylinders from what I can tell. So this research is targeting simply the ability to transport hydrogen.

Ironically, the ships that carry all that ammonia to Asia almost certainly used fossil fuels and who knows what the carbon footprint around building the membranes for the hydrogen transfer is like

And shipping is the most egregiously polluting transportation in existence. Something like 10 to 30% of emissions come from 6000 ships in service. Folks claim its ok because it settles into the ocean quickly - ok for everybody but the ocean.

This is just false - shipping contributes only 2-3% of global emissions (see e.g. http://theconversation.com/the-shipping-sector-is-finally-on...).

> Something like 10 to 30% of emissions come from 6000 ships in service.

Some 10% to 30% of sulfur emissions come from those ships. They do that because they move in the open ocean where nobody cares about a short lived pollutant.

Sulfur moves quickly into the ocean where it not only non-toxic, but also beneficial to life. (Sulfates - what it will settle down into - is widely used as fertilizer on land.)

Just like CO2 is good for plants therefore buringnoilmis great formthe environment?

Well, there is certainly some amount where the wrong kind of life takes over. It is way over what cargo ships throw around, but people have been polluting some parts of the ocean with too much sulfates.

this is from some horribly irresponsible clickbait newsy reporting a couple of years ago. It's only a very specific subtype of emissions, not 'emissions' in general.

Nitrogen oxides and sulfur oxides. How is that irresponsible? The conversation has turned to CO2 because of global warming, but these are still damaging. And CO2 isn't strictly a pollutant at all. I stand by those statistics.

Here's a fun little exercise with the Toyota Mirai.

Read the spec sheet, and read the wikipedia article. They claim the thing can hold 5 kg of H2, at 10,000 psi.

Look into how big the tanks are.

The math will show that at that pressure, taking up that much space, you can fit no more than about 3.7 kg of H2 in there.

The difference between the diesel emissions and mileage scandal and the Mirai is that they actually made the math work with the former, as well as large enough scale for people to care.

The spec sheet at [0] claims:

Hydrogen storage is "Approx. 5.0 kg"

122.4L of volume (60L front, 62.4L rear)

pressure is between 70 MPa and 87.5MPa

Doing the math shows:

density of hydrogen at 70MPa equals 36.69 g/L [1]

122.4L at 36.69 g/L equals 4.49kg [2]

density of hydrogen at 87.5MPa equals 45.96 g/L [3]

122.4L at 45.96 g/L equals equals 5.63kg [4]

So the amount is somewhere between 4.5kg and 5.63kg, depending upon the final pressure after filling. Which seems to line up squarely with "Approx. 5.0kg".

[0] - https://pressroom.toyota.com/releases/2016+toyota+mirai+fuel...

[1] - http://www.wolframalpha.com/input/?i=density+of+hydrogen+at+...

[2] - http://www.wolframalpha.com/input/?i=122.4L+at+36.69+grams%2...

[3] - http://www.wolframalpha.com/input/?i=density+of+hydrogen+at+...

[4] - http://www.wolframalpha.com/input/?i=122.4L+at+45.96+g%2FL

I am highly skeptical of using Wolfram Alpha like this. It steadfastly refuses to explain how it got its answer or what sources it used. These are high pressures and large densities. Are these results of an ideal gas law calculation? Are they results from the van der Waals equation? Are they extrapolated from actual experimental data? If so, what experiment? What are the error bars? Are they talking about pure Hydrogen-1 or are they talking about the isotopic mix found in sea water? (The latter is a small correction, but it’s still something that they should explain on the site.)

If you hover over the "Variation with temperature at constant pressure" chart you get a "sources" link, which references

National Institute of Standards and Technology, NIST Reference Fluid Thermodynamic and Transport Properties Database (REFPROP)

https://www.nist.gov/srd/refprop

I.e. these are standard reference curves at a fixed temperature.

If you click the link on "Hydrogen" you get a page for molecular hydrogen, H2, so not an isotopic mix. Whether that's the right input for this calculation is beyond my technical knowledge, but Wolfram is displaying its parameters quite straightforwardly.

To my reading it looks like a quite well-explained calculation, though I can see why you might think otherwise if you hadn't spotted the somewhat-hidden "sources" link.

At least Wolfram Alpha agrees with Toyota data.

Surely van der Waals should provide a better model here, as we're having pretty dense gas which is far from ideal. So I'd assume it should be van der Waals model; not sure what Wolfram Alpha actually does.

The data I found for the internal volume of the tanks says they're about 122 litres.

When I do the math with that volume, 10.000 psi, and 25 degrees, I get about 3400 moles, which is actually over 5 kg. But certainly 25 is an ideal temperature, so claiming 5 kg seems reasonable.

Can you show your working?

> So the input for this technology is imaginary.

They proposed one use, which would be to use it as storage for solar/wind power. Perhaps their plan is that when there's excess output from renewables, they'll use electrolysis to generate hydrogen gas from water?

That is exactly the plan. With renewables you have to deploy far more than you need due to capacity factor, so to average 100kW on solar you need to deploy between 300kW and 400kW of capacity. So during the course of the day you will be generating significantly more or significantly less power than required.

Batteries and hydro will help for short term storage of excess power (ie: overnight, during cloud passage) but for long term storage (eg for transport by sea) you need something with higher energy density. For export especially you need high energy density since shipping charged batteries across the planet is going to be extremely inefficient.

The breakthrough this membrane represents is an increase in the “well to wheels” efficiency of the hydrogen economy (which is lower overall than the “pure electric” economy involving BEVs). Having said that, the “well to wheels” efficiency of H2 using Ammonia as a transport medium is under 20%, so it’s really only useful when there is plentiful cheap energy which nobody else has a better use for.

Other uses for plentiful cheap electricity could be (for example) chilling or heating large volumes of water or other thermal mass for air conditioning and industrial processes. If you have large tanks of water you can spend energy chilling (or heating) them when electricity is cheap, then use the chilled water to cool whatever it is you have that is getting too hot (and vice versa for hot water storage).

But if people are willing to pay enough for hydrogen at point of use, there will be an economic case for producing ammonia in Australia to be converted to hydrogen in Japan resulting in 1kWh in Japan costing about the same as 4kWh in Australia.

”Australia does not have huge deposits of hydrogen”

Australia has plenty of sunlight, though, much more than they need. In the long term, if/when we live of renewables, they hope to export the energy in it.

The traditional solution is a cable, but Australia is fairly distant from the possible export markets.

That, I think, is where this comes in. Australia has access to oceans that have the hydrogen, and air contains the necessary nitrogen.

I would think they envision producing ammonia at scale, shipping it in tankers to a densely populated country or a country that has less sunlight, converting it back to electricity in a power station there, and feeding the result into the grid.

Doable? Yes. Economically viable? Who knows. That doesn’t only depend on this process, but also on the question how easily other countries can get their power cheaper.

It might help to note that in 2009, Australia imported 900,000 tonnes of urea. Gonna take a long time before they meet that demand.

Australia's an energy importer, big time. Sure, bargeloads of coal go out to places like Saudi Arabia, but tankerloads of oil and LNG come in.

If you want to export your energy cheaply, look at Aluminum (sorry Aussies, Aluminium to you) instead. It's safe, made from local ingredients, and stable. That's why gulf petrostates are putting huge aluminum smelters in- much cheaper to make the aluminum with their natural gas than compress and store the stuff.

I live 20min from the largest aluminium smelter in Oz. :) It's the largest energy consumer in the state and every time there's fears about electricity blackouts they make the news because of the worry about their potlines getting killed.

We're also a bit LNG exporter... so I'm curious, as what you're saying they're doing in the gulf should apply here too. When they use LNG for smelting, are they using it to generate electricity or burning it direct for heating?

What I never understood was why they didn't tap into Portland's geothermals for a ready source of steam to run a local electricity generating turbine.

These days they would have to be worried about a bushfire hitting Loy Yang. It was a close call in 2009 when they could have lost the mine and plant.

There's a gas powerstation at Mortlake and talks of building another for Alcoa as it could feed straight off the Otway Basin gas fields. I see a few wind farms have popped up, no doubt due to the areas reputation for being constantly windy.

Gotta watch the "L". Gulf Alumino-states take natural gas and generate captive electricity without a liquefaction step.

There's an equivalent amount of electrical energy to make an aluminum can as a gallon of gasoline (err.. 4L of petrol?).

Gotcha! That makes sense, thanks.

>So let's take two flows and compare them to this technology's flows:

>NG -> pipeline -> CNG -> CNG Engine (simple, if not all that widespread)

>e- -> grid -> EV charger -> battery -> EV motor (same)

>vs.

>Aussie coal -> CO2 + H2 -> NH3 -> H2 -> H2 tank -> Fuel Cell -> EV motor

>or

>Aussie PV -> H2 -> NH3 -> H2 -> H2 tank -> Fuel Cell -> EV motor

There is still one dark horse in the competition:

https://phys.org/news/2017-06-ammonia-on-demand-alternative-...

On my memory, there were countless claims of "direct" ammonia production, and all came to be uneconomical or being outright scams. But in last few years, there were numerous works on catalytic production with some merit to them.

This.

The comparative advantage nations have over each other in energy in a post-fossil fuel world will be much reduced. That is, Saudi Arabia has a huge advantage over Japan in terms of cheap fossil fuel energy, so Japan imports a lot from them. Though Saudi Arabia likely has an advantage over Japan in renewable resources, its not as dramatic as their fossil fuel advantage, so Japan would invest in their own energy resources and import less of them.

Because of this there will likely be much less international energy traded in general.

> university-sponsored snake oil

It's coming out of the CSIRO, which while not the greatest at commercialisation, have a pretty solid track record of not spinning bullshit. The car spinning looks like it's coming from auto industry wingnuts.

>Urea is inoffensive little white pellets.

Except it became one of the most controlled substances around out of a sudden.

You're thinking of ammonium nitrate. Urea is not a powerful oxidizer so it is not useful in making explosives.

Yes, totally mistook it for urea nitrate.

Maybe the scientists involve did think twice before embarking on such an endeavor?

You seem to be dismissively implying that because scientists are experts that they have obviously considered this. Which isn't true at all. Scientists are typically much more motivated by the pursuit of knowledge than strict commercial value.