Alibro
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The trouble with bio diesel is where it comes from. In many cases forests are cut down to grow crops to produce the veg oil so it ends up being a net contributor to green house gases as the forests held more carbon the the crops ever will.Someone is giving incorrect figures there. It's technically impossible for hydrogen to take up the same space as diesel and give the same amount of energy. Hydrogen at 700 bar of pressure (about the practical limits of container design) holds just 1.4kWhr of energy per litre of volume, but diesel holds over 10kWhr for the same 1 litre, and doesn't need a pressure vessel to contain it.
Add to this the under 40% efficiency of an ICE engine, and it doesn't take a mathematician to work out that hydrogen won't be a practical or green alternative to diesel. It's actually much more green to use vegetable sourced bio diesel in the engine, which again doesn't need to be stored in a pressure vessel at stupid high pressures.
Unfortunately the only way to reach carbon release targets is to stop burning stuff which means change and for many folk change is something they are scared of or just refuse to contemplate.
Having said that here is a slightly different look at the same system
If we can find a way to make the locally and economically then for this type of use case then maybe hydrogen has a place. It would certainly be better than dieseasel.