ABSTRACT
In.concept,. reversible.hydrides.offer.a.direct.means.of.storing.hydrogen.on-board. fuel.cell.vehicles.and.would.be.compatible.with.a.hydrogen-based.transportation.fuel. infrastructure..A.tank,.or.perhaps.more.accurately.a.storage.system,.containing.an. appropriate.hydride.material.would.remain.fixed.on.a.vehicle.and.could.be.refueled. simply.by.applying.an.overpressure.of.hydrogen.gas..Once.filled,.the.hydrogen.gas. would.remain.at.the.equilibrium.pressure.for.the.particular.hydride.material,.changing.only.with.temperature.changes.induced.in.the.storage.tank..When.hydrogen.was. needed,.it.would.be.released.endothermically,.using.the.waste.heat.from.the.fuel.cell. (or.internal.combustion.engine.[ICE]).to.supply.the.required.energy..This.approach. offers.certain.advantages.over.high-pressure.compressed.gas. tanks.and.cryogenic. liquid. hydrogen. systems-it. is. inherently. stable. with. regard. to. hydrogen. release,. it. can.operate. at. a. low.or.moderate. gas.pressure,. and. it. could. eliminate. some.of. the.energy.costs.of.compression.or.liquefaction..It.also.has.the.potential.to.achieve. volumetric.hydrogen.densities.much.higher.than.those.of.compressed.gas.and.even. liquid.hydrogen.
