Electrochemical engine

An electrochemical engine for a vehicle, comprising:

• a storage tank containing hydrogen-retention material which reversibly takes-up and stores hydrogen at a hydrogen-storage temperature and releases it upon heating to a release temperature, a fuel cell stack using the released hydrogen to produce electricity and heat by-product, a radiator, a primary coolant flow circuit through said radiator, fuel cell stack and storage tank, a coolant-distribution valve in said primary coolant flow circuit intermediate said fuel cell stack and said storage tank, and a bypass coolant flow line from said coolant-distribution valve to said radiator, wherein said coolant-distribution valve is operable to direct heated coolant from said fuel cell stack to either or both said storage tank or said radiator, whereby the heat by-product of said fuel cell stack is transferred via said primary coolant flow circuit to said storage tank for heating said hydrogen-retention material to the release temperature to release hydrogen gas for fueling said fuel cell stack, and said electrochemical engine further comprising a heat generator within a superheater coolant flow loop having a bypass valve intermediate said storage tank and said radiator operable to keep coolant within said superheater coolant flow loop and a pump to circulate the coolant, wherein said superheater coolant flow loop extends from said coolant-distribution valve, through said storage tank, said bypass valve, said pump, said heat generator, and back to said coolant-distribution valve, and wherein said heat generator operates to heat the coolant in said superheater coolant flow loop and said pump circulates the heated coolant through said storage tank to further release hydrogen from said hydrogen-retention material.

A method for controlling the operation of an electrochemical engine having a fuel cell stack and first and second storage tanks containing hydrogen-retention material, comprising the steps of:

• pumping coolant through said fuel cell stack to generate heated coolant;
• monitoring the demand for power from said fuel cell stack and hence the demand for hydrogen in said fuel cell stack;
• if hydrogen gas is demanded by said fuel cell stack, directing the heated coolant through said first and second storage tanks to heat said hydrogen-retention material to a hydrogen release temperature;
• monitoring the pressure in said storage tanks to see if hydrogen releasable at the release temperature is depleted;
• if hydrogen releasable at the release temperature is depleted, delivering by-product hydrogen from said fuel cell stack to said heat generator;
• actuating a bypass valve to isolate a first superheater coolant loop comprising said heat generator, said first storage tank, and a pump;
• heating coolant in said first superheater coolant loop by said heat generator;
• pumping the superheated coolant through said first storage tank to heat said hydrogen-retention material to a superheated release temperature to release the balance of stored hydrogen in said first storage tank;
• upon depletion of hydrogen stored in said first storage tank, actuating said bypass valve to isolate a second superheater coolant loop comprising said heat generator, said second storage tank, and said pump;
• heating coolant in said second superheater coolant loop by said heat generator;
• pumping the superheated coolant through said second storage tank to heat said hydrogen-retention material to the superheated release temperature to release the balance of stored hydrogen in said second storage tank.