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Comment by mrweasel | Hacker News Reader

It doesn't say anything about the size of the tank, which seems a little weird. Technically you could break that record by adding a bigger tank.

Does anyone know what this means: "It purified 449,100 litres of air on the journey – enough for 33 adults to breathe in a day."

Why is the car purifying air while driving? Is this a side effect of hydrogen powered cars?

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I was curious about this too, basically they're just filtering air as they go and counting it as negative emissions:

https://www.altenergymag.com/story/2021/03/can-fuel-cell-tec...

The car has an HEPA filter which removes dust from the air which is nice but that's not the whole story, as can be expected from marketing.

6.3kg of hydrogen consumed means 50 kg of atmospheric oxygen consumed, which is 170 000 liters of air. So it purified 450 000 liters but it also removed oxygen from that same air, around 38% of it. I would not breathe that exhaust air, it may not be CO2 rich, but it sure is oxygen depleted.

You don't want your fuel cell chemistry to be contaminated. The fuel cell needs oxygen from the air.

That's also why it's so light, since in H2O, 90% of the weight is the oxygen.

> That's also why it's so light, since in H2O, 90% of the weight is the oxygen.

which also makes it unsuitable for moon cars.

Or alternately, you can use a lithium battery with air. But it gains more weight as it is used up.

Anyway, energy density is comparable to gasoline.

https://en.wikipedia.org/wiki/Lithium%E2%80%93air_battery

To make a fuel cell work, you need an external oxygen supply for the chemical reaction. A cleaner oxygen supply with fewer particles make the fuel cell work longer, therefore Hyundai added an air filter which filters out fine particles before passing it on to the fuel cell.

(I'm not an expert, but this is how I understood the process.)

I guess that’s marketing speak for an F150 doing the same journey would have produced that much impure air.

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