Hydrogen generation system using stabilized borohydrides for hydrogen storage
First Claim
1. A method of generating hydrogen in a fuel supply system combined with a hydrogen consuming device, said method comprising the steps of:
- storing a slurry of lithium and/or sodium borohydride particles in water in a fuel supply storage vessel, said water containing sufficient dissolved hydroxide ion to inhibit chemical reaction with said borohydride at ambient storage temperatures of said slurry, said slurry comprising, by weight, about 1.6 to 2.5 parts of water per 1 part of lithium borohydride, or 1 to 1.5 parts of water per 1 part of sodium borohydride;
conveying a portion of said slurry to the inlet of an axial flow-through reactor upon demand for hydrogen from said hydrogen consuming device, said reactor having a reaction zone;
reacting said borohydride particles and water in said reaction zone at a temperature above approximately 90°
C. to produce reaction products comprising hydrogen gas and solid by-products while mixing said borohydride particles and solid by-products in said reaction zone to expose unreacted borohydride particle surfaces for reaction with said water, and conveying the mixed materials through said reaction zone, said mixing and conveying using two rotating augers, the rate of conveying of said slurry to said reactor being controlled so as to retain a hydrogen gas volume in said reaction zone;
removing said reaction products from said reactor; and
conveying said hydrogen gas to said hydrogen consuming device or to a hydrogen buffer container for said device.
12 Assignments
0 Petitions
Accused Products
Abstract
A method is provided that generates hydrogen to power a hydrogen consuming device. Hydrogen is stored on-board a motorized vehicle, or the like, in a stabilized slurry of alkali metal borohydride particles and water. Upon demand from the hydrogen consuming device, such as a fuel cell, a portion of the slurry is conveyed to a reactor where borohydride particles are heated so that they hydrolyze to produce hydrogen gas and solid-phase by-products. The reactor includes a mixing element therein where the slurry is mixed and ground to expose unreacted borohydride particles from the solid reaction products. A separate grinding mechanism can be used to further crush and grind by-product particles for reaction efficiency and product transport. The solid-phase by-products are then stored in a by-products storage vessel whereas hydrogen gas is delivered to either a hydrogen buffer container for temporary storage or to the hydrogen consuming device.
29 Citations
18 Claims
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1. A method of generating hydrogen in a fuel supply system combined with a hydrogen consuming device, said method comprising the steps of:
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storing a slurry of lithium and/or sodium borohydride particles in water in a fuel supply storage vessel, said water containing sufficient dissolved hydroxide ion to inhibit chemical reaction with said borohydride at ambient storage temperatures of said slurry, said slurry comprising, by weight, about 1.6 to 2.5 parts of water per 1 part of lithium borohydride, or 1 to 1.5 parts of water per 1 part of sodium borohydride;
conveying a portion of said slurry to the inlet of an axial flow-through reactor upon demand for hydrogen from said hydrogen consuming device, said reactor having a reaction zone;
reacting said borohydride particles and water in said reaction zone at a temperature above approximately 90°
C. to produce reaction products comprising hydrogen gas and solid by-products while mixing said borohydride particles and solid by-products in said reaction zone to expose unreacted borohydride particle surfaces for reaction with said water, and conveying the mixed materials through said reaction zone, said mixing and conveying using two rotating augers, the rate of conveying of said slurry to said reactor being controlled so as to retain a hydrogen gas volume in said reaction zone;
removing said reaction products from said reactor; and
conveying said hydrogen gas to said hydrogen consuming device or to a hydrogen buffer container for said device. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9)
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10. A method of generating hydrogen in a fuel supply system combined with a hydrogen consuming device, said method comprising the steps of:
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storing a slurry of lithium and/or sodium borohydride particles in water in a fuel supply storage vessel, said water containing sufficient dissolved hydroxide ion to inhibit chemical reaction with said borohydride at ambient storage temperatures of said slurry, said slurry comprising, by weight, about 1.6 to 2.5 parts of water per 1 part of lithium borohydride, or 1 to 1.5 parts of water per 1 part of sodium borohydride;
conveying a portion of said slurry to the inlet of an axial flow-through reactor upon demand for hydrogen from said hydrogen consuming device, said reactor having a reaction zone and a grinding zone downstream from said reaction zone;
reacting said borohydride particles and water in said reaction zone at a temperature above approximately 90°
C. to produce reaction products comprising hydrogen gas and solid by-products while mixing said borohydride particles and solid by-products in said reaction zone to expose unreacted borohydride particle surfaces for reaction with said water, and conveying the mixed materials through said reaction zone, said mixing and conveying using two rotating augers, the rate of conveying of said slurry to said reactor being controlled so as to retain a gas volume in said reaction zone at least as large as the volume of said mixed materials in said reactor;
grinding said solid by-products to a storable particle size in said grinding zone, and conveying them to a by-products storage vessel; and
conveying said hydrogen gas to said hydrogen consuming device or to a hydrogen buffer container for said device. - View Dependent Claims (11, 12, 13, 14)
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15. A method of generating hydrogen in a fuel supply system combined with a hydrogen consuming device, said method comprising the steps of:
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storing a slurry of lithium and/or sodium borohydride particles in water in a fuel supply storage vessel, said water containing sufficient dissolved hydroxide ion to inhibit chemical reaction with said borohydride at ambient storage temperatures of said slurry, said slurry comprising, by weight, about 1.6 to 2.5 parts of water per 1 part of lithium borohydride, or 1 to 1.5 parts of water per 1 part of sodium borohydride;
conveying a portion of said slurry to an axial flow-through reactor upon demand for hydrogen from said hydrogen consuming device, said reactor having a reaction zone and a gas separation zone;
reacting said borohydride particles and water in said reaction zone at a temperature above approximately 90°
C. to produce reaction products comprising hydrogen gas and solid by-products while mixing said borohydride particles and solid by-products in said reaction zone to expose unreacted borohydride particle surfaces for reaction with said water, and conveying the mixed materials through said reaction zone, said mixing and conveying using two rotating augers, the rate of conveying of said slurry to said reactor being controlled so as to retain a gas volume in said reaction zone at least as large as the volume of said mixed materials in said reactor;
separating said hydrogen from said solid by-products in said separation zone and conveying said hydrogen gas from said separation zone to said slurry stored in said fuel supply storage vessel to condense any water vapor in said gas; and
conveying said hydrogen gas from said fuel supply storage vessel to said hydrogen consuming device or to a hydrogen buffer container for said device. - View Dependent Claims (16, 17, 18)
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Specification