There is little "surplus" H developed in oil refinery process because it is refluxed back into feed streams. And guess what, oil refining is by an almost insane percentage majority the primary source of hydrogen. Cryo refrigeration extraction USES MORE ENERGY IN EXTRACTION than the product contains.
Proponents of any idea, concept, product, or process manage to amplify (their) enthusiasm and somehow neglect or diminish negative or points counter to their enthusiasm. Human nature.
To manufacture, store, transport, and dispense such a gas reveals hidden costs that never seem to get included in many discussions. To divert billions of cubic feet of H from refinery process drastically reduces refined product outflow. Sixty to eighty percent. A typical refinery has a Hydrogen Plant, Gas Oil Straight run Hydrotreater, Lube Oil Hydrotreater, Cat Gas and Cat Feed Hydrotreater. These are not vessels, they are entire plant units consisting of columns, heaters, vessels and miles of piping.
Extract hydrogen from the process and much of the remains will consist of carbon. Carbon just itching to combine with a pair of oxygen atoms.
Rather than Dick & Jane this I'll encourage folks to look up the latent percentage content of hydrogen in the atmosphere. Hint: Don't hold your breath.
Hydrogen power is still a toy locomotive energy because of the stuff mentioned above. The realization of emissions benefits is actually ludicrous when compared to methane based natural gas. Uncurl your upper lip. Divert that energy into actually finding out the energy, money, and effort emissions needed to extract hydrogen. It comes at a heavy price.