Classifications

• • C—CHEMISTRY; METALLURGY
  • C01—INORGANIC CHEMISTRY
  • C01B—NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
  • C01B3/00—Hydrogen; Gaseous mixtures containing hydrogen; Separation of hydrogen from mixtures containing it; Purification of hydrogen
  • C01B3/02—Production of hydrogen or of gaseous mixtures containing a substantial proportion of hydrogen
  • C01B3/32—Production of hydrogen or of gaseous mixtures containing a substantial proportion of hydrogen by reaction of gaseous or liquid organic compounds with gasifying agents, e.g. water, carbon dioxide, air
• • C—CHEMISTRY; METALLURGY
  • C07—ORGANIC CHEMISTRY
  • C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
  • C07C31/00—Saturated compounds having hydroxy or O-metal groups bound to acyclic carbon atoms
  • C07C31/28—Metal alcoholates
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
  • H01M8/00—Fuel cells; Manufacture thereof
  • H01M8/06—Combination of fuel cells with means for production of reactants or for treatment of residues
  • H01M8/0606—Combination of fuel cells with means for production of reactants or for treatment of residues with means for production of gaseous reactants
  • H01M8/0612—Combination of fuel cells with means for production of reactants or for treatment of residues with means for production of gaseous reactants from carbon-containing material
  • H01M8/0643—Gasification of solid fuel
• • C—CHEMISTRY; METALLURGY
  • C01—INORGANIC CHEMISTRY
  • C01B—NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
  • C01B2203/00—Integrated processes for the production of hydrogen or synthesis gas
  • C01B2203/12—Feeding the process for making hydrogen or synthesis gas
  • C01B2203/1205—Composition of the feed
  • C01B2203/1211—Organic compounds or organic mixtures used in the process for making hydrogen or synthesis gas
  • C01B2203/1217—Alcohols
  • C01B2203/1223—Methanol
• • C—CHEMISTRY; METALLURGY
  • C01—INORGANIC CHEMISTRY
  • C01B—NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
  • C01B2203/00—Integrated processes for the production of hydrogen or synthesis gas
  • C01B2203/12—Feeding the process for making hydrogen or synthesis gas
  • C01B2203/1258—Pre-treatment of the feed
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
  • H01M8/00—Fuel cells; Manufacture thereof
  • H01M8/04—Auxiliary arrangements, e.g. for control of pressure or for circulation of fluids
  • H01M8/04082—Arrangements for control of reactant parameters, e.g. pressure or concentration
  • H01M8/04201—Reactant storage and supply, e.g. means for feeding, pipes
  • H01M8/04208—Cartridges, cryogenic media or cryogenic reservoirs
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
  • H01M8/00—Fuel cells; Manufacture thereof
  • H01M8/04—Auxiliary arrangements, e.g. for control of pressure or for circulation of fluids
  • H01M8/04082—Arrangements for control of reactant parameters, e.g. pressure or concentration
  • H01M8/04201—Reactant storage and supply, e.g. means for feeding, pipes
  • H01M8/04216—Reactant storage and supply, e.g. means for feeding, pipes characterised by the choice for a specific material, e.g. carbon, hydride, absorbent
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
  • H01M8/00—Fuel cells; Manufacture thereof
  • H01M8/06—Combination of fuel cells with means for production of reactants or for treatment of residues
  • H01M8/0606—Combination of fuel cells with means for production of reactants or for treatment of residues with means for production of gaseous reactants
  • H01M8/065—Combination of fuel cells with means for production of reactants or for treatment of residues with means for production of gaseous reactants by dissolution of metals or alloys; by dehydriding metallic substances
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
  • Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
  • Y02E60/00—Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
  • Y02E60/30—Hydrogen technology
  • Y02E60/50—Fuel cells

Definitions

• Fuel cells have developed as a method of generating electricity from chemicals. Some early development focused on using hydrogen as a clean fuel source for producing power. Work has been done on the storage and generation of hydrogen for use in fuel cells and is disclosed in US 6,057,051, US 6,267,229, US 6,251,349, US 6,459,231, and US 6,514,478. Hydrogen is a high energy, low pollution fuel, however, the storage of this fuel is cumbersome, both from an energy density and safety point of view. [0002] The difficulty of storing hydrogen has led to looking at the generation of hydrogen from more useful fuels. Liquid fuels containing a relatively high amount of hydrogen that can be generated through reforming have received significant attention.
• Reforming of a fuel is expensive, and adds significantly to the complexity and size of a unit using fuel cells for power generation. Reformers and methods of reforming liquid fuels have been developed, as shown in US 4,716,859, US 6,238,815, and US 6,277,330. Therefore, there is significant interest in fuel cells that can use a hydrogen rich fuel that can be processed directly over a fuel cell electrode. This separates the fuel cells into two general categories: an indirect or reformer fuel cell wherein a fuel, usually an organic fuel, is reformed and processed to produce a hydrogen rich, and substantially carbon monoxide (CO) free feed stream to the fuel cell; and a direct oxidation fuel cell wherein an organic fuel is directly fed to the fuel cell and oxidized without any chemical reforming. Direct oxidation fuel cells can use either a liquid feed design or a vapor feed design, and preferably the fuels, after oxidation in the fuel cell, yield clean combustion products like water and carbon dioxide (CO 2 ).
• direct oxidation fuel cells can use either a liquid feed design
• the present invention is a solid fuel for use in a fuel cell.
• the solid fuel comprises a solid oxygenate that is selected from metal oxygenates, gelled oxygenates, and frozen oxygenates.
• the invention particularly includes as a solid fuel a mixture of an oxygenate, such as methanol or acetaldehyde, and a polymer, such as an acrylic polymer in amounts necessary to produce a solid gel.
• the invention comprises the addition of a metal or metal compound wherein the metal is selected from the group consisting of alkali metals, alkaline earth metals, and mixtures thereof.
• the preferred metal compounds include magnesium compounds such as magnesium hydroxide, magnesium oxide, magnesium methoxide, magnesium hydride, and mixtures thereof.
• a preferred metal is magnesium.
• the metal compounds enhance the behavior of the oxygenates, and provide for a material to adsorb carbon dioxide generated at the anode.
• the invention comprises the addition of an oxidizing agent.
• the oxidizing agent is selected from the group consisting of sodium percarbonate, carbamide hydrogen peroxide, organic peroxides, calcium peroxide, magnesium peroxide, and mixtures thereof.
• the addition of oxidizing agents enhances the power density of the fuel in a direct methanol fuel cell.
• Figure 1 shows the stability of several chemical compounds and mixtures
• Figure 2 shows a comparison of DMFC liquid and solid fuel
• Figures 3 and 4 show comparisons of current against cell potential for different compositions of solid fuels and liquid methanol
• Figures 5 and 6 show comparisons of current against cell potential for different compositions of solid fuels;
• Figure 7 shows a comparison of solid acetaldehyde fuel and solid methanol fuel;
• Figure 8 shows the effect of additional oxidant added to methanol for a direct methanol fuel cell;
• Figure 9 shows the I-V (current- voltage) curves for different hydrogen peroxide with methanol for a direct methanol fuel cell;
• Figure 10 shows the voltage and amperage for a fuel cell with magnesium and solid methanol with a pulse of sulfuric acid;
• Figure 11 shows the voltage, amperage and power density for magnesium and solid methanol in a fuel cell with a pulse of sulfuric acid
• Figure 12 shows the power density and the pressure for magnesium and solid methanol in a fuel cell with a pulse of sulfuric acid.
• the present invention comprises a new fuel for use in a fuel cell.
• the new fuels are solid fuels and are not restricted to the type of fuel cells they can be used in, and can include proton exchange membrane (PEM) fuel cells, solid oxide fuel cells (SOFC), phosphoric acid fuel cells (PAFC), direct methanol fuel cells (DMFC), molten carbonate fuel cells (MCFC), and alkaline fuel cells (AFC).
• PEM proton exchange membrane
• SOFC solid oxide fuel cells
• PAFC phosphoric acid fuel cells
• DMFC direct methanol fuel cells
• MCFC molten carbonate fuel cells
• AFC alkaline fuel cells
• What is needed is a fuel that is easier to handle and readily generates a gaseous component for use in a fuel cell.
• the solid fuel provides greater energy density and ease of handling.
• a solid fuel allows for convenient loading, removal, and replacement into a fuel cell.
• a solid fuel reduces risk of leaks and spills, as can occur with liquid or gaseous fuels.
• a solid fuel allows for lighter containers than would be available for gaseous fuels.
• the fuel can be any solid chemical that generates an appropriate fuel, such as an oxygenate or hydrogen for direct oxidation at the fuel cell anode.
• the fuel is comprised of a mixture of fuel components, and the fuel components are any chemical compounds that are added to the fuel mixture.
• An oxygenate is a hydrocarbon compound that has been altered with the addition of at least one oxygen atom to the hydrocarbon compound.
• Oxygenates include, but are not limited to, alcohols, diols, triols, aldehydes, ethers, ketones, diketones, esters, carbonates, dicarbonates, oxalates, organic acids, sugars, and mixtures thereof.
• a gaseous oxygenate such as methanol is produced for reaction in the fuel cell.
• One preferred group of oxygenates is metal alkoxides, that react with water to generate an oxygenate in a vapor phase for reaction at the anode of the fuel cell.
• Preferred metal oxygenates include metal alkoxides.
• Appropriate metals include, but are not limited to, alkali and alkaline earth metals, and are selected from lithium (Li), sodium (Na), potassium (K), beryllium (Be), magnesium (Mg), and calcium (Ca).
• Other appropriate metals include rubidium (Rb), cesium (Cs), strontium (Sr), barium (Ba), and aluminum (Al).
• the oxygenate produced for use in the fuel cell preferably has a boiling point of less than 100°C.
• oxygenates include low molecular weight alcohols, aldehydes, organic acids, and ethers.
• Alkali alkoxides and in particular alkali methoxides and ethoxides, are very reactive and pyrophoric materials. Adding water produces a vigorous reaction and heat sufficient to vaporize the alcohol generated from the reaction.
• a particular alkoxide studied was lithium methoxide (LiOCH 3 ). Lithium methoxide reacts with water to generate lithium hydroxide and methanol, with sufficient heat to generate the methanol in the vapor phase, as shown in equation 1.
• the fuel should be sealed in a container that is moisture impermeable to prevent consumption of the fuel through exposure to the atmosphere.
• the fuel container is opened when in use, but sealed against the anode forming a compartment closed to the atmosphere. This is to prevent loss of fuel, as well as to prevent excess moisture affecting the fuel. The fuel consumption is therefore controlled by moisture allowed into the compartment.
• Additional compositions were studied, showing similar results in weight losses and gains in Figure 1, and are listed in Table 1. Some of the test fuels included a small amount of catalyst, MnO 2 , to facilitate the decomposition of an exothermic reactant. The exothermic reactant generates heat to vaporize the fuel.
• the carbon dioxide is a waste gas that must be disposed of in some manner.
• the carbon dioxide reacts with the fuel waste product, such as a metal hydroxide, and forms a solid.
• a preferred fuel will contain components that absorb, or react with the waste gases from the fuel cell.
• Fuel components may include but are not limited to, metal oxides and metal hydroxides.
• the waste gases are reacted to form a solid product, or are absorbed onto a solid.
• the primary waste gases for a direct methanol fuel cell are carbon dioxide and water. The water will react with the fuel to form more oxygenate in the vapor phase.
• the metal When the fuel is metal alkoxide, where the metal is an alkali or alkaline earth metal, the metal will form a hydroxide reacting with water to give up the alcohol. The metal hydroxide will subsequently react with the carbon dioxide generated at the anode and remove the carbon dioxide from the gas phase to form a carbonate solid product.
• Other preferred fuels included gelled oxygenates and frozen oxygenates.
• the gelled oxygenates are oxygenates that have a polymer added to form a solid.
• One example of a gelled oxygenate comprises a mixture of 5 wt. % of CarbopolTM 981 polymer and 95 wt. % of methanol.
• Carbopol 981 is an acrylic polymer made by B.F. Goodrich of Akron, Ohio.
• the oxygenate in the solid fuel comprises at least 30% by weight of the fuel, and preferably at least 50% by weight.
• the fuel comprises additional compounds for absorbing waste gases from the anode.
• Additional fuel components for gelled and frozen oxygenates include metals, metal oxides, metal hydroxides, or metal hydrides.
• the metals, metal oxides, metal hydroxides, and metal hydrides comprise alkali or alkaline earth metals.
• the additional components provide heat to vaporize the oxygenates and provide components for removing anode waste gases through absorption or reaction to form solid waste products.
• Additional materials added to the solid oxygenates include hydroreactive materials for generating heat upon the addition of water.
• the materials contribute additional fuel, such as hydrogen, and/or peroxide for adsorption of carbon dioxide.
• Preferred materials include metal hydrides, such as lithium hydride, magnesium hydride, sodium hydride, potassium hydride, aluminum hydride, and mixtures thereof.
• Solid fuels can be formed by using selected chemicals to polymerize an organic solution to gel the organic compound.
• the polymerizing chemicals comprise at least 3% by weight of the solid fuel.
• Chemicals for forming the gel include, but are not limited to, acrylic acid/acrylic amide based polymers, copolymers of polyols, ethylene/acrylic acid copolymers with amine emulsifiers, carboxyl vinyl polymers, polyacrylic acid polymers, olefin-maleic anhydride copolymers, and copolymers of oligomers containing OH groups with formaldehyde.
• the copolymers of oligomers containing OH groups include high melting point alcohols, i.e.
• a study of a particular gelled fuel was done to demonstrate the use of a gelled fuel.
• the fuel comprised methanol, calcium oxide (CaO), and Carbopol 981 polymer with a ratio of 32:56:5 respectively.
• the fuel was loaded into a DMFC and the fuel cell was run.
• the fuel cell generated an I-V curve for comparison with an aqueous methanol fuel at different temperatures, and at ambient pressure.
• Figure 2 shows the results of the I-V curve for comparison with a liquid fuel.
• the composition of fuel can be adjusted to compensate for additional water generated or absorbed by the fuel, and additional heat necessary to ensure vaporization of the fuel when exposed to moisture. Additional heat can be generated by using chemicals that have very exothermic reactions upon addition of water or an appropriate chemical that generates heat upon decomposition. Examples of appropriate chemicals include, but are not limited to, organic peroxides, and carbamide hydrogen peroxide.
• the fuel composition can also be adjusted by using a combination of the above mentioned fuels, for example, mixing a metal hydride with a metal oxygenate to form a fuel that will generate hydrogen and an alcohol for reaction at the fuel cell anode. Alternate mixtures might include additional metal hydroxides for more rapid reaction of carbon dioxide generated at the anode.
• the tests involved using magnesium compounds either alone, as in the case of magnesium methoxide (Mg(OCH 3 ) 2 ), or as a mixture with solid methanol.
• the solid methanol comprised a mixture of methanol and Carbopol 981.
• Figures 3-6 show the results of tests using magnesium or various magnesium compounds with solid methanol in fuel cells.
• the magnesium compounds include, but are not limited to, magnesium hydroxide (Mg(OH) 2 ), magnesium oxide (MgO), magnesium methoxide (Mg(OCH 3 ) 2 ), and magnesium hydride (MgH 2 ).
• the figures present the I- V, or current vs. potential, curves measured for various compositions.
• Alternate oxidants include, but are not limited to, sodium percarbonate, carbamide hydrogen peroxide, organic peroxides, such as tert-butyl hydroperoxide (TBHP), tert-pentyl hydroperoxide, etc., and alkaline earth metal peroxides such as magnesium peroxide and calcium peroxide.
• TBHP tert-butyl hydroperoxide
• alkaline earth metal peroxides such as magnesium peroxide and calcium peroxide.
• a strong liquid oxidizing agent can be held in a separate and sealed compartment for controlled addition to a solid fuel when the fuel is placed in fluid communication with the anode compartment of the fuel cell.
• Another aspect with the addition of compounds such as peroxides, is the heat release when the peroxide reacts, or decomposes.
• the heat release facilitates the vaporization of methanol, or other organic compound that reacts at the anode of the fuel cell in a gaseous phase.
• the decomposition of the peroxide can be facilitated by the addition of a small amount of catalyst.
• the catalyst for the decomposition of the oxidizer is a compound comprising one or more metals selected from calcium (Ca), scandium (Sc), titanium (Ti), vanadium (V), chromium (Cr), manganese (Mn), iron (Fe), cobalt (Co), nickel (Ni), copper (Cu), zinc (Zn), strontium (Sr), yttrium (Y), zirconium (Zr), niobium (Nb), molybdenum (Mo), technetium (Tc), ruthenium (Ru), rhodium (Rh), palladium (Pd), silver (Ag), cadmium (Cd), barium (Ba), lanthanum (La), hafnium (Hf), tantalum (Ta), tungsten (W), rhenium (Re), osmium (Os), iridium (Ir), platinum (Pt), gold (Au), and mercury (Hg).
• metals selected from calcium (C
• the catalyst can include oxides of the metal, sulfides and other sulfur compounds of the metal and sols comprising the metal.
• Preferred catalysts comprise one or more metals from vanadium, iron, cobalt, ruthenium, copper, nickel, manganese, molybdenum, platinum, gold, silver, palladium, rhodium, rhenium, osmium, and indium, with the more preferred catalyst comprising iron, cobalt, nickel and manganese.
• a more preferred compound is manganese oxide (MnO 2 ).

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• 2004
  • 2004-11-05 WO PCT/US2004/037099 patent/WO2006052243A1/en active Application Filing
  • 2004-11-05 CA CA002586465A patent/CA2586465A1/en not_active Abandoned
  • 2004-11-05 JP JP2007540292A patent/JP2008519418A/ja not_active Withdrawn
  • 2004-11-05 MX MX2007005077A patent/MX2007005077A/es unknown
  • 2004-11-05 EP EP04800852A patent/EP1807898A1/en not_active Withdrawn
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  • 2004-11-05 BR BRPI0419137-4A patent/BRPI0419137A/pt not_active IP Right Cessation
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• 2007
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