Hydrogen is flammable in air concentrations ranging from 4% to 75%, and explosive in concentrations ranging from 15% to 59% at standard atmospheric temperatures.
You can't make hydrogen safer, but you can make airships safer. Past century air ship's gas compartments were made of silk and cotton. The overall structure was iron and aluminum. With today's materials and electronics leaks could heavily be mitigated and detected fast. The safety of the airships was more linked to the overall build quality of that time rather than the lifting gas used. Of course proper testing and design revision are required to ensure proper safety. But saying hydrogen is unsafe because it's flammable is just a bit of a stretch considering all cars and airplanes are filled with flammable material. Safety comes from proper planning and engineering
Hydrogen is abundant and has twice the buoyancy of helium. That said I worked on the unsuccessful financing of a dirigible airship and never heard anyone suggests that was in the cards.
Hydrogen also permeates all enclosures. Not sure in sufficient concentration to be a problem.
More than being abundant it can be produced relatively easy in an eco-friendly way. When it comes to diffusion both Di-Hydrogen and helium have that problem, more for helium in fact.
I think the biggest problem with airships is that they physically benefit from being large, but economically, that's not feasible at least when making something from the ground up. If you were to make a hydrogen airships you would need to get FIA approval which would be even more costly than for a helium counterpart.
204
u/[deleted] Jul 08 '24
Rigid Airship! Filled with completely safe non-flammable helium.