A viable pathway for hydrogen as fuel
vox.com
vox.com
"Johnson boasts that his electrolyzer can produce hydrogen at about three or four times the rate of electrolyzers with similar footprints, using about a third the electrical current. That represents a stepwise drop in costs."
Three or four times? Current efficiencies are 65-70% for larger plants.[1] There's a theoretical maximum here; it takes a known amount of energy to break down water into oxygen and hydrogen. This isn't magic or perpetual motion. Electrolysis is energetically uphill. You can get most of the energy back recombining oxygen and hydrogen in a fuel cell or by combustion.
The "with similar footprints" is very suspicious. His demo unit is small. Little electrolyzers are known to be inefficient. Industrial units are bigger and more efficient.
As an emissions control measure, it might work out.
[1] https://en.wikipedia.org/wiki/Electrolysis_of_water#Industri...
It's a way to preserve energy during surplus. As a gardener I'm constantly balancing inputs and outputs. A huge tomato harvest eaten raw off the vine is the most efficient use.
But during a huge glut, I cannot eat the tomatoes fast enough so I start freezing tomatoes and produce sauce.
I trade energy, and human time and labor to extend the shelf life of the tomato.
In this sense, from my naive perspective, A hydride fluid battery if cheap enough to build/install would be a great way to store surplus energy from solar / wind / etc.
At the same time, there are less and less applications which cannot be powered by electricity directly, having only a fraction of losses compared to the equivalent hydrogen chain. So as long we do not have more than 100% reneweable electricity generation, we should be very concerned about the efficiency of our energy usage.
Open fuel cells storage can be much cheaper than battery based storage. You can store energy for a long period, paying by the maximum power, not storage capacity.
That said, molten salt cells look way more promising than hydrogen.
It doesn't matter how good hydrogen becomes. Battery tech will continue to improve faster than hydrogen tech. H2 will never catch up.
Those interested in the topic should acquaint themselves with the policy context and the state-of-the-art.
[1] https://energy.gov/eere/fuelcells/doe-technical-targets-hydr...
[2] https://www.nrel.gov/docs/fy14osti/60528.pdf
The DOE goal for cost of distributed / dispensed hydrogen is $4/kgH2. Cost of centralized production is estimated at half that even with electrolysis. I find it suspicious that there aren't any specific production cost estimates cited; just vague comparisons to unspecified existing technologies.
Also, methane is a far better source of hydrogen than water (less energy required to break down the molecule for the yield of twice as much hydrogen). Steam-methane reforming (95% of industrial hydrogen production) gets you hydrogen from both methane and water, but is a huge CO2 emitter (9-10 kgCO2/kgH2).
I'm personally a big proponent of thermal decomposition of methane [3]. Theoretical energy consumption is only 1.29 kWh/kgH2. if you can use a non-emitting source of energy, there's no CO2 emission. Carbon falls out as a solid and capture and sequestration is free. If you can make a valuable carbon (e.g. graphene) along the way, then you're set and there's no way electrolysis will ever be competitive.
True, directly using that electric energy from wind or solar is definitely the best option.
However, that is not always possible, since there is no place to consume, transport or store that electric energy.
Furthermore, scrapping all ICE vehicles for BEVs is most likely the end goal. But replacing the worldwide fleet of vehicles will take decades.
HyTech seems to be on to something for these two scenarios.
If for instance you can capture some of the excess solar and wind energy in a metal hydride for some hours, weeks, or even months, you will on a larger scale reduce the load of the electric grid.
And if some of that Hydrogen can be burnt instead of Diesel, the car or truck in your driveway is both cleaner and less dependant on fossil fuels.
SMRs can be easily scaled up to meet all H2 demand, and they are easily fitted with carbon capture technology (since it's a single large emission point). Then you have zero-emission H2 in quantities as large as oil and gas today.
I'm entirely convinced it will be the future, and that we'll never be able to scale pure BEVs beyond 10-15% of all cars in any large country, simply due to electricity production and distribution constraints.
Would impurities in the source methane be a problem for this case?
Not as snarky as might sound. Given infinite fusion energy via the real thing or solar panels, truly pure synthetic fuel opens up some interesting ideas WRT catalysts and efficient burn designs to squeek out another percent or two of performance. Inherently zero (not low, but ZERO) sulfur diesel is interesting, for example. And no one says the carbon thats added has to come from underground; go harvest some trees that sucked the carbon right out of the air, then when you put it back in the air after a couple months of storage, nothing bad happened.
If that's the case, it's equally true for H2 from renewables, no?
And I don't think it's true. LPG vehicles today are common enough, and they've solved very similar transport and distribution problems.
If cars ever run on hydrogen in significant numbers, they'll actually be running on ammonia.
But if HyTech is to be believed, some of these problems are solved. Probably their most significant claim, is hydride storage at ordinary temperature / pressure with safe, practical, cost effectiveness in recovering that stored energy.
The idea of injecting small amounts of hydrogen into a combustion engine to improve fuel economy is not new, but congrats if they can bring that concept to market. That would be a win, but is not the same as hydrogen as a primary fuel.
Does it make the battery in your mobile phone useless?
At some level of inefficiency, an energy solution can indeed become useless at scale.
There are a few developed countries I can think of that have vast renewable capacity but the distances between the optimum location for renewables make it impractical at present.
Also modern nuclear plants are an option if you want to produce vast amounts of electricity with a smaller carbon footprint than coal/gas.
Hydrogen produced by direct, catalytic hydrolysis from sunlight, in water, is taken up by microbes in the water that absorb CO2 and excrete hydrocarbons -- oil -- that floats to the surface, and is directly usable in existing fuel tanks and engines, no further processing needed.
What about methanol? We can convert hydrogen to hydrocarbon. Liquid is dense, much less dangerous, less acidic, less leaky, and our current trillion-dollar infrastructure already uses it as a substantial additive.
>To date, most hydride fluids have been less energy dense than compressed hydrogen, and far short of fossil fuels. They weigh too much for the energy they provide. Johnson thinks he’s cracked both problems. He won’t reveal the details of the hydrides involved, but he’s got the power-to-weight ratio high enough to beat lithium-ion batteries (which are very heavy) and the hydride bond weak enough that it can be broken using only the redirected waste heat from the engine (no added heat or pressure required).
https://www.bizjournals.com/sacramento/stories/1999/03/08/st...
> There are four main sources for the commercial production of hydrogen: natural gas, oil, coal, and electrolysis; which account for 48%, 30% 18% and 4% of the world’s hydrogen production respectively.