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I'm not against using Hydrogen but the problem is always what are they producing Hydrogen with and how is it more efficient energetically and emission wise?

pantalaimon 5y ago
Most Hydrogen is produced from Methane by steam reforming https://en.wikipedia.org/wiki/Steam_reforming https://en.wikipedia.org/wiki/Steam_reforming
- ncmncm 5y ago
  That will change, obviously.
gopalv 5y ago
> what are they producing Hydrogen with and how is it more efficient energetically and emission wise? Even if it is just Blue hydrogen being burnt here, the splitter plants can have some carbon capture in it which would be impossible to install on a moving train (beats diesel and also direct LNG burning). That said, with trains there's no real argument against electrification. The wheels have been electrically driven for a few decades now. It's not like they need to come up with motors or work out batteries.
ncmncm 5y ago
Hydrogen can be produced electrically from water. A positively stupendous amount of electrolysis equipment will need to be built out, but there will be demand for as much as can be produced. Burning hydrogen produces mainly water. Burned in an engine, it also produces nitrous oxides, so probably some ammonia would be dissolved in to scavenge that. Liquid hydrogen takes up a lot more room than kerosene. The insulated liquid-hydrogen tank is quite a lot bigger than the kerosene tank -- maybe it is a whole other car -- but so what? Room on a train is cheap. What matters is weight. The tank is light, and the weight of LH2 needed to go the same distance is much less. The difference is weight that doesn't itself need to be transported. Furthermore, the LH2 can be produced and banked on-site at the railyard, and during peak-production hours, so cheaply. So, a win all around. Not as big a win as LH2-powered aircraft, but better, and much easier to retrofit.
- Nick87633 5y ago
  Just because the tank is light, doesn't mean that a completed fuel carriage will be much lighter than any other car.
  - aurizon 5y ago
    A tanker that holds 80,000 pounds of kerosine will hold about 8000 pounds of LH2 in the same dimensionality. 0.07 = density of LH2, Density of water 1.0, kerosine 0.7 +/- varies with grade. So it take 10 times the cubeage plus Dewar grade insulation. At a permeant depot they will have a super refrigerator to condense boil off into LH2. They are trying to get a viable clathrate hydrate to hold a higher density form of bound but not reacted Hydrogen
    - ncmncm 5y ago
      The measure of fuel you need to carry is not weight, but energy content. It takes a much smaller weight of LH2 to match the energy content of diesel. So, correspondingly less than 10x volume. It is this better "gravimetric energy density" that makes LH2 an attractive fuel in many cases. You end up needing only about 2-3x tankage space, including the insulation. Better gravimetric energy density doesn't make so much difference for a train, so its other advantages -- production on-site, zero emissions, carbon-neutral -- are more important. At the trainyard, the LH2 would be banked in an underground tank where insulation is easy. It is not necessary to refrigerate it after it is liquified. It will gradually boil off, so you just make more anytime the level goes down, whether from boil-off or pumping out to a locomotive tank.
      - aurizon 5y ago
        There is truth in that energy density. but it is still cheaper energetically to chill boil off to liquid back to the tank that to make new hot hydrogen you then chill to liquid back to the tank. The end game of clathrate storage will solve many of these problems.
        5y ago

pantalaimon 5y ago

Most Hydrogen is produced from Methane by steam reforming https://en.wikipedia.org/wiki/Steam_reforming https://en.wikipedia.org/wiki/Steam_reforming

ncmncm 5y ago
That will change, obviously.

gopalv 5y ago

> what are they producing Hydrogen with and how is it more efficient energetically and emission wise? Even if it is just Blue hydrogen being burnt here, the splitter plants can have some carbon capture in it which would be impossible to install on a moving train (beats diesel and also direct LNG burning). That said, with trains there's no real argument against electrification. The wheels have been electrically driven for a few decades now. It's not like they need to come up with motors or work out batteries.

ncmncm 5y ago

Hydrogen can be produced electrically from water. A positively stupendous amount of electrolysis equipment will need to be built out, but there will be demand for as much as can be produced. Burning hydrogen produces mainly water. Burned in an engine, it also produces nitrous oxides, so probably some ammonia would be dissolved in to scavenge that. Liquid hydrogen takes up a lot more room than kerosene. The insulated liquid-hydrogen tank is quite a lot bigger than the kerosene tank -- maybe it is a whole other car -- but so what? Room on a train is cheap. What matters is weight. The tank is light, and the weight of LH2 needed to go the same distance is much less. The difference is weight that doesn't itself need to be transported. Furthermore, the LH2 can be produced and banked on-site at the railyard, and during peak-production hours, so cheaply. So, a win all around. Not as big a win as LH2-powered aircraft, but better, and much easier to retrofit.

Nick87633 5y ago
Just because the tank is light, doesn't mean that a completed fuel carriage will be much lighter than any other car.
- aurizon 5y ago
  A tanker that holds 80,000 pounds of kerosine will hold about 8000 pounds of LH2 in the same dimensionality. 0.07 = density of LH2, Density of water 1.0, kerosine 0.7 +/- varies with grade. So it take 10 times the cubeage plus Dewar grade insulation. At a permeant depot they will have a super refrigerator to condense boil off into LH2. They are trying to get a viable clathrate hydrate to hold a higher density form of bound but not reacted Hydrogen
  - ncmncm 5y ago
    The measure of fuel you need to carry is not weight, but energy content. It takes a much smaller weight of LH2 to match the energy content of diesel. So, correspondingly less than 10x volume. It is this better "gravimetric energy density" that makes LH2 an attractive fuel in many cases. You end up needing only about 2-3x tankage space, including the insulation. Better gravimetric energy density doesn't make so much difference for a train, so its other advantages -- production on-site, zero emissions, carbon-neutral -- are more important. At the trainyard, the LH2 would be banked in an underground tank where insulation is easy. It is not necessary to refrigerate it after it is liquified. It will gradually boil off, so you just make more anytime the level goes down, whether from boil-off or pumping out to a locomotive tank.
    - aurizon 5y ago
      There is truth in that energy density. but it is still cheaper energetically to chill boil off to liquid back to the tank that to make new hot hydrogen you then chill to liquid back to the tank. The end game of clathrate storage will solve many of these problems.
      - 5y ago