Have chunks of hydrogen impregnated aerogel in a holding container with an auto feeding system into a basin of solvent with a vacuum drawn on it. After so long the spent aerogel, still under a vacuum, go to a separate holding container to be recharged later. The sealnt would need to be a material that would dry hard and strong yet when dissolved not form a gel, or a sticky mess when you want to change it out.
A specially designed carburator would be the best but a regular carburator, provided some holes are pluged, would work.