421–426 of 426 posts
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The total amount isn't as much a problem as is the activation energy. Hydrogen will explode when you look at it cross eyed. For gasoline you will have to do some work.
Hydrogen does not explode unless mixed with oxygen or other comburents.
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Yes. Gasoline has a relatively narrow ignition range, it has much less rigorous sealing requirements, and it burns with a flame that's visible in daylight. The problem is that we can't easily make gasoline with solar panels and water.
Actually it is possible to make gasoline with solar panels, water and carbon dioxide from the air. Making synthetic gasoline was already possible before WWII and that was used a lot by Germany. It is true that making hydrogen is easier, because making gasoline requires additional steps and equipment, but due to the large disadvantages of storing and handling hydrogen, making gasoline is nonetheless preferable and it…
Fun fact: methanol has a similar "invisible fire" risk, which is the origin of the "Don't let the invisible fire burn my friend" joke in Talladega Nights.
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An electric semi's battery weight alone makes them not viable imo. I think it's a good idea to ignore the endless Tesla sales hype and brand reinforcement and focus on the basic logic and physics. Musk is as fake as his hair imo and spends most of his time being very misleading while aggressively selling theoretical future projects. I grew up in the UK with electric milk floats, a practical use of EV's for short, qui…
Why would you think a semi's battery weight would make it not viable? If you calculate what the batteries would weight and subtract the weight of the engine, transmission and of course fuel in a full tank, you get to about 2 tons more for the battery powered semi, if not less. That is a small reduction of the maximum load capacity.
Also for an 18 wheeler just the amount of tires on the road requires tremendous torque to create a rolling load and sustain it. Freightliner are working hard to make E trucks viable but the acid test is fleet buyers and maintenance, it's a ruthlessly efficiency first market. https://freightliner.com/electric-trucks/
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I have no clue about batteries or hydrogen tanks. But I'm always amused to think that posters on HN give more credence to their back-of-the-napkin calculations over opinions of, say, folks at Toshiba, Volvo or Daimler.
Smart engineers chose Hydrogen as the first stage fuel fuel the Space Shuttle, and it turned out to be a terrible choice. H2 offered the highest ISP, ie energy per fuel mass, and originally they wanted the Shuttle to be a single stage to orbit vehicle. But Hydrogen also added larger, much heavier tanks and engines didn’t have enough thrust for that. So they had to add large Solid Rocket Boosters to get off the pad. A…
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Hydrogen does not explode unless mixed with oxygen or other comburents.
Fortunately there isn't any free oxygen in the atmosphere. Oh, wait.
That's why it can flame out when pierced but not explode.
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Animal droppings are not our primary source of methane. Not sure if that was meant to be sarcastic. Electrolysis is expensive and energy inefficient. It is unlikely to be a primary source of hydrogen unless there is some breakthrough. If the limiting factor is clean electricity production, it makes sense to use it more efficiently with a BEV than it does to use it inefficiently with a HFCV.
The comment I was replying to said two odd, incorrect things: 1) water is our primary source of hydrogen (it isn't), and 2) that people were researching animal droppings as a source of hydrogen. Though people are looking for biogas to be a replacement for fossil-natural gas, there won't be enoug my for that, and certainly using it for steam methane reformation to hydrogen would be a poor use for biogas. Hydrogen is a…