Is There a Safer Way to Store Hydrogen in Cars?

[bobbobwhite]

It seems to me that the only way this technology will become positively pervasive is if the car also has an H generating unit along with the power unit thus making it totally self contained. The car could then be used to generate home electric power when not driven, with the excess sold back to the hard wire electricity provider thus giving many drivers a profit motive to switch to cars having this new tech.

Storing H in big tanks within the car is questionable, as out of the tens of millions of Ford Pintos and Chevy PU trucks made in the 70's, a few blew up due to gas tank impact explosions and created a huge public outcry. Will the same thing occur with H tanks in testing and render this new tech unsafe for cars before it even gets out of the gate? I fear it will(or should) and wonder:

is there a process under research that produces H immediately before combustion thus making a holding tank unnecessary? Thanks for informed responses.

 

[Q_Goest]

Hydrogen can be stored in a number of ways:

- As a cryogenic liquid: Problems include pressure rise in tank due to heating over time and subsequent venting. Hydrogen vented into an enclosed space such as a garage is simply not permissible due to fire and explosion hazard. Liquid storage isn’t taken very seriously except potentially for bus fleets or similar, well controlled and regularly used vehicles.

- As a gas: Biggest issue is how to safely handle pressure to 750 bar +. Vehicle impact is a potential concern, but simply filling the tank is just as great a concern. Connection must be purged to eliminate air, generally with helium, and connection must be redundantly sealed against leakage both internal and external. Also, hoses must have break away just like gas station fuel hoses to prevent loss of product if connection remains hooked to vehicle when car drives away. These safety issues have all been addressed, but there is tremendous concern about putting these systems into the hands of the general public.

- Carbon based hydrogen storage: Carbon of various types such as nanotubes can adsorb hydrogen. Heating releases. Systems then can run at much lower pressure, say 100 psi +/-.

- Liquid carriers: Similar to carbon systems, but storage is at essentially 0 psig. Liquid is heated to release hydrogen, then returned to separate liquid storage tank to be exchanged during the next fill.

There has also been some work done on “on board” hydrogen reformers. They would take gasoline from a tank and convert it to hydrogen for use in a fuel cell. Not sure how far this idea has gotten. A few years ago it looked fairly promising but I believe the economics of this just didn’t pan out. Maybe something technology has to address.

Right now, the best chance for starting up a hydrogen economy is through government subsidized projects and niche markets such as electric powered fork lifts.

 

[dst]

I heard there was a microbe-driven process for creating hydrogen, and it looked promising at the time I saw it. Any word on that?