CA2091495C - Method for generating electric energy from biological raw materials - Google Patents
Method for generating electric energy from biological raw materialsInfo
- Publication number
- CA2091495C CA2091495C CA002091495A CA2091495A CA2091495C CA 2091495 C CA2091495 C CA 2091495C CA 002091495 A CA002091495 A CA 002091495A CA 2091495 A CA2091495 A CA 2091495A CA 2091495 C CA2091495 C CA 2091495C
- Authority
- CA
- Canada
- Prior art keywords
- combustible gas
- hydrogen
- biological raw
- fuel cell
- raw materials
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Fee Related
Links
Classifications
-
- 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
-
- 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
- H01M8/0662—Treatment of gaseous reactants or gaseous residues, e.g. cleaning
-
- 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
- H01M8/10—Fuel cells with solid electrolytes
- H01M8/12—Fuel cells with solid electrolytes operating at high temperature, e.g. with stabilised ZrO2 electrolyte
- H01M2008/1293—Fuel cells with solid oxide electrolytes
-
- 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
- H01M8/14—Fuel cells with fused electrolytes
- H01M2008/147—Fuel cells with molten carbonates
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M2300/00—Electrolytes
- H01M2300/0002—Aqueous electrolytes
- H01M2300/0005—Acid electrolytes
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M2300/00—Electrolytes
- H01M2300/0002—Aqueous electrolytes
- H01M2300/0005—Acid electrolytes
- H01M2300/0008—Phosphoric acid-based
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M2300/00—Electrolytes
- H01M2300/0002—Aqueous electrolytes
- H01M2300/0005—Acid electrolytes
- H01M2300/0011—Sulfuric acid-based
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M2300/00—Electrolytes
- H01M2300/0017—Non-aqueous electrolytes
- H01M2300/0048—Molten electrolytes used at high temperature
- H01M2300/0051—Carbonates
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M2300/00—Electrolytes
- H01M2300/0017—Non-aqueous electrolytes
- H01M2300/0065—Solid electrolytes
- H01M2300/0068—Solid electrolytes inorganic
- H01M2300/0071—Oxides
- H01M2300/0074—Ion conductive at high temperature
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M4/00—Electrodes
- H01M4/86—Inert electrodes with catalytic activity, e.g. for fuel cells
- H01M4/90—Selection of catalytic material
- H01M4/9016—Oxides, hydroxides or oxygenated metallic salts
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M4/00—Electrodes
- H01M4/86—Inert electrodes with catalytic activity, e.g. for fuel cells
- H01M4/90—Selection of catalytic material
- H01M4/92—Metals of platinum group
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M4/00—Electrodes
- H01M4/86—Inert electrodes with catalytic activity, e.g. for fuel cells
- H01M4/90—Selection of catalytic material
- H01M4/92—Metals of platinum group
- H01M4/921—Alloys or mixtures with metallic elements
-
- 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
-
- 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
- Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
- Y02P70/00—Climate change mitigation technologies in the production process for final industrial or consumer products
- Y02P70/50—Manufacturing or production processes characterised by the final manufactured product
Landscapes
- Chemical Kinetics & Catalysis (AREA)
- Life Sciences & Earth Sciences (AREA)
- Manufacturing & Machinery (AREA)
- Sustainable Development (AREA)
- Sustainable Energy (AREA)
- Chemical & Material Sciences (AREA)
- General Chemical & Material Sciences (AREA)
- Electrochemistry (AREA)
- Engineering & Computer Science (AREA)
- Fuel Cell (AREA)
- Treatments Of Macromolecular Shaped Articles (AREA)
- Preparation Of Compounds By Using Micro-Organisms (AREA)
- Physical Or Chemical Processes And Apparatus (AREA)
- Saccharide Compounds (AREA)
- Electrical Discharge Machining, Electrochemical Machining, And Combined Machining (AREA)
- Processes Of Treating Macromolecular Substances (AREA)
- Developing Agents For Electrophotography (AREA)
- Inert Electrodes (AREA)
- Processing Of Solid Wastes (AREA)
- Crystals, And After-Treatments Of Crystals (AREA)
- Inorganic Compounds Of Heavy Metals (AREA)
Abstract
A method of generating electric energy from biological raw materials. A biological raw material is used which is substantially free from sulphur of natural origin. A combustion gas is generated from biological raw materials in an oxidation reactor by partial oxidation. An oxygen/biological raw material proportion of ingredients and a gas phase temperature are maintained which ensure a combustible gas virtually free of nitrogen oxides. After removing suspended matter from the combustible gas in a separator, the combustible gas is converted into electric energy in fuel cells having a porous anode, a porous cathode and a suitable electrolyte.
Description
~~~14~~
METHOD OF GENERATING ELECTRIC ENERGY FROM BIOLOGICAL
RAW MATERIALS
SPECIFICATION
Field of the Invention My present invention relates to a method of generating electric energy from biological raw materials and, more particu-larly, to a method involving gasification of the raw material and fuel/cell utilization of gas.
Background of the Invention "Biological Raw Materials" generally refer to so-called regenerative raw materials, i.e. raw materials which are biolog-ically recoverable with a production rate that approximately corresponds with the consumption rate as opposed to fossil raw materials the formation of which takes considerably more time than their consumption.
A biological raw material may for instance be supplied as a fine powder with a substantially still undamaged cell struc-ture or with disintegrated structure. Bioloctical raw materials can also be obtained as so-called biological organic waste.
Biological raw materials substantially contain the elements car-bon, hydrogen, oxygen and nitrogen.
Directly converting hydrogen into electric energy by means of fuel cells is well known. As compared with thermal heat i 18853 ?~9L~~~
engines, fuel cells offer the advantage of not being subjected to the principal thermodynamic restrictions of the efficiency re-sulting from the Carnot cycle. Fuel cells are theoretically able to convert combustion heat from the reaction of hydrogen with oxygen to water practically completely into electric energy.
Therefore, clearly higher efficiency values can be obtained in practice with fuel cells than with thermal heat engines without any particular difficulties. This, however, takes for granted that the catalysts of fuel cells will not be poisoned by cata-lytic poison which may be contained in the hydrogen gas fed to the fuel cell.
Molecular hydrogen as raw material is not naturally available but must be extracted from hydrogenous raw materials.
Generating hydrogen from water by means of normal electrolysis consumes more current than can be generated with hydrogen, and is for that reason, of course, out of the question. The catalytic separation of water into hydrogen and oxygen is very slow and yields only small quantities with high expenditure of energy, thus offering no advantage for commercial utilization.
Generating so-called synthesis gas which substantially contains hydrogen and carbon monoxide, from coal and the instal-lations required for this generation have been well known for a long time. This process is called coal gasification. The carbon monoxide in the synthesis gas can be converted into hydrogen and carbon dioxide by adding steam at elevated temperatures in a so called water shift reaction.
METHOD OF GENERATING ELECTRIC ENERGY FROM BIOLOGICAL
RAW MATERIALS
SPECIFICATION
Field of the Invention My present invention relates to a method of generating electric energy from biological raw materials and, more particu-larly, to a method involving gasification of the raw material and fuel/cell utilization of gas.
Background of the Invention "Biological Raw Materials" generally refer to so-called regenerative raw materials, i.e. raw materials which are biolog-ically recoverable with a production rate that approximately corresponds with the consumption rate as opposed to fossil raw materials the formation of which takes considerably more time than their consumption.
A biological raw material may for instance be supplied as a fine powder with a substantially still undamaged cell struc-ture or with disintegrated structure. Bioloctical raw materials can also be obtained as so-called biological organic waste.
Biological raw materials substantially contain the elements car-bon, hydrogen, oxygen and nitrogen.
Directly converting hydrogen into electric energy by means of fuel cells is well known. As compared with thermal heat i 18853 ?~9L~~~
engines, fuel cells offer the advantage of not being subjected to the principal thermodynamic restrictions of the efficiency re-sulting from the Carnot cycle. Fuel cells are theoretically able to convert combustion heat from the reaction of hydrogen with oxygen to water practically completely into electric energy.
Therefore, clearly higher efficiency values can be obtained in practice with fuel cells than with thermal heat engines without any particular difficulties. This, however, takes for granted that the catalysts of fuel cells will not be poisoned by cata-lytic poison which may be contained in the hydrogen gas fed to the fuel cell.
Molecular hydrogen as raw material is not naturally available but must be extracted from hydrogenous raw materials.
Generating hydrogen from water by means of normal electrolysis consumes more current than can be generated with hydrogen, and is for that reason, of course, out of the question. The catalytic separation of water into hydrogen and oxygen is very slow and yields only small quantities with high expenditure of energy, thus offering no advantage for commercial utilization.
Generating so-called synthesis gas which substantially contains hydrogen and carbon monoxide, from coal and the instal-lations required for this generation have been well known for a long time. This process is called coal gasification. The carbon monoxide in the synthesis gas can be converted into hydrogen and carbon dioxide by adding steam at elevated temperatures in a so called water shift reaction.
2~91~~ i Using synthesis gas to operate fuel cells is basically possible, but considerable disadvantages have been obvious in practice. Firstly, coal usually contains sulphur of natural origin which is entrained in the synthesis gas as gaseous sulphur compounds. Sulphur compounds are as a rule high-grade catalytic poisons which may irreversibly deactivate the catalyst of a fuel cell and thus the fuel cell itself. Sulphur-containing gases are undesirable emissions as environmental hazards. Secondly, gener-ating synthesis gas from coal is altogether especially expensive l0 because of the accumulated costs resulting from e.g. underground mining, coal gasification and the necessary desulphurization.
Obiects of the Invention The principal object of the invention is to provide an improved method of generating electric energy which processes cheap raw materials, achieves a high efficiency, operates reli-ably and permanently, and evidences an especially low emission of harmful substances.
Another object of the invention is to provide an im-proved method of generating electrical energy whereby the draw-backs of earlier systems are avoided.
Obiects of the Invention The principal object of the invention is to provide an improved method of generating electric energy which processes cheap raw materials, achieves a high efficiency, operates reli-ably and permanently, and evidences an especially low emission of harmful substances.
Another object of the invention is to provide an im-proved method of generating electrical energy whereby the draw-backs of earlier systems are avoided.
~p~~495 summary of the Invention These objects are achieved according to the invention in a method of generating electric energy from biological raw materials consisting at least predominantly of perennial C4 reed plants substantially free of naturally occurring sulphur and including essentially the elements carbon, hydrogen, oxygen and nitrogen, comprising the steps of:
(a) generating a combustible gas which contains carbon monoxide and hydrogen from the biological raw materials with 'a gasification agent substantially containing steam by partial oxidation in an oxidation reactor, (b) a combustible gas is generated which contains car-bon monoxide and hydrogen from the biological raw materials with an oxygenous gasification agent (oxygen, atmospheric air or an-other oxygen-containing agent) by partial oxidation in an oxida-tion reactor, (c) removing suspended matter from the combustible gas discharged from the oxidation reactor in a separator, (d) converting the transformed combustible gas into electrical energy in a fuel cell having a porous anode, a porous cathode and an acidic electrolyte containing phosphoric acid, and (e) converting the transformed combustible gas free from suspended matter into electric energy in a fuel cell having a porous anode, a porous cathode and an electrolyte consisting of a molten carbonate.
A
(a) generating a combustible gas which contains carbon monoxide and hydrogen from the biological raw materials with 'a gasification agent substantially containing steam by partial oxidation in an oxidation reactor, (b) a combustible gas is generated which contains car-bon monoxide and hydrogen from the biological raw materials with an oxygenous gasification agent (oxygen, atmospheric air or an-other oxygen-containing agent) by partial oxidation in an oxida-tion reactor, (c) removing suspended matter from the combustible gas discharged from the oxidation reactor in a separator, (d) converting the transformed combustible gas into electrical energy in a fuel cell having a porous anode, a porous cathode and an acidic electrolyte containing phosphoric acid, and (e) converting the transformed combustible gas free from suspended matter into electric energy in a fuel cell having a porous anode, a porous cathode and an electrolyte consisting of a molten carbonate.
A
Sufficiently free from sulphur of natural origin means that the sulphur content is so low that the catalyst of the fuel cell will not be poisoned nor will sulphur be emitted in inadmissible quantities.
If the sulphur content is higher, the biological raw material can be desulphurized by interposing a conventional de-sulphurization stage in the process.
In an oxidation reactor, the biological raw material is treated with oxygen at a concentration higher than that of the ambient atmosphere and/or atmospheric oxygen and/or steam at an elevated temperature which results in a partial oxidation of the biological raw material into a combustible gas containing hydro-gen and carbon monoxide.
The proportion of oxygen and biological raw material, and the gas phase temperature in the oxidation reactor are then selected in such a way that, because of the thermodynamics, for one thing, the oxidation of the biological raw material does not go beyond the reaction product hydrogen or transform the hydrogen to water, and for another thing, the nitrogen of natural origin and/or the atmospheric nitrogen is not oxidized into nitrogen oxides in the oxidation reactor.
When steam is used in the gasification agent, the com-bustible gas may contain carbon dioxide aside from carbon monox-ide. It is a matter of course that the deviations from the ther-mal equilibrium occurring in continuous operation are to be taken ~,~ ",s-..
;.
y-::
2~~1~~j into consideration in the manner known in materials processing, when dimensioning the ingredients proportion of oxygen and raw material and the gas phase temperature.
Suspended matter means particles the size and density of which permits them to be entrained in a combustible gas stream. Suspended matter may originate from nonburned raw mate-rials but may also be ash particles.
The anode refers to the possibly catalytically active electrode of the fuel cell over which the combustible gas passes and is oxidized with electron emission. The cathode refers to the possibly catalytically active electrode or fuel cell over which a combw.stion agent passes and is reduced with electron take up. The combustion agent must contain carbon dioxide for con-s version into oxygen and carbonate ions at the cathode. Porous refers to an electrode structure which on the one hand ensures a contact of all three phases (combustible gas or combustion agent, electrode or catalyst and electrolyte), but on the other hand prevents the electrolyte from flooding into a combustible gas compartment or combustion agent gas compartment, for instance by the action of capillary forces. Therefore, the term "porous"
also includes grid structures having suitable mesh widths.
The invention is based on the knowledge that a combus-tible gas resulting from partial oxidation of biological raw materials can be converted into electric energy in fuel cells with especially high efficiency, provided that the process for generating the combustible gas will be adapted just to this _.__ r~:
2~9~~~J
purpose of the combustible gas.
The use of raw materials which are sufficiently free of sulphur of natural origin ensures without any other measures that on the one hand the fuel cells can be operated permanently and reliably without poisoning the catalysts, and that on the other hand, the entire process does not release any disturbing sulphu-rous emissions.
The adaptation of the oxidation reactor's operating parameters to the relatively high nitrogen content of biological raw materials guarantees that in effect no disturbing nitrogen oxides will be released despite the high nitrogen portion. Ni-trogen oxides just as sulphurous emissions are undesirable for environmenta~ protection reasons.
Removing suspended matter, which may increasingly accu-mulate during the partial oxidation of raw materials, from the combustible gas ensures on the one hand that the pores of fuel cell electrodes cannot be clogged to an interfering degree with the result of reduced specific faces and thus decreased current density, and on the other hand the troublefree run of the entire process without any particle emission.
Suspended matter may be separated by using conventional means, for instance by a cyclone filter.
Fuel cells having an electrolyte made of a carbonate melt are characterized by a particularly high efficiency and a high specific performance because of the comparatively high oper-ating temperature. Another advantage of this type of fuel cell :.' 2~~~~~
in combination with conversion of combustible gas from raw mate-rials into electric energy is the fact that carbon monoxide not only does not interfere with the catalysis, but is even processed for generating electric energy just like hydrogen. Carbon monoxide and carbonate ions react at the anode with electron emission to carbon dioxide.
The combination of the features of the invention achieves a considerable synergistic effect, namely generating electric energy from very cheap and regenerative raw material with a particularly high efficiency and high reliability, with virtually no emission of sulphur compounds, nitrogen oxides and particles.
End products of the method according to the invention are appreciat~ly harmless water and, in conventional generation of electric energy, unavoidable carbon dioxide. Heat is addition-ally generated and may be recuperated for use in the process especially with application of the allothermal method.
Methods for thermal partial oxidation of biological raw materials into a service gas are in principle known. As yet no operation with direct conversion into electric energy or any special measures required for such operation are known.
In a preferred embodiment of the method according to the invention, the carbonate melt is substantially compounded from alkali metal carbonates and alkali metal aluminates, and the carbonate melt has pasty (viscous) flow properties at the~operat-ing temperature of the fuel cell.
_ g _ Alkali metal carbonates in melted condition provide excellent ion conductivity and melting temperatures which are comparatively low. The melting temperature of an eutectic mixture consisting of lithium, sodium and potassium carbonates is especially low.
Adding alkali aluminates has two effects: To begin with, a pasty composition can be produced at the operating tem-perature of the fuel cell since powder from alkali metal alumi-nates will not be melted. An electrolyte having a pasty consis-tency permits keeping the requirements to be met by the pore structure of the electrodes relatively low without endangering the electrolyte retention. Secondly, alkali metal aluminates act probably as carbon dioxide buffers.
In an especially advantageous and environmentally ac-ceptable embodiment of the method according to the invention, carbon dioxide is extracted from the combustible waste gas escap-ing on the anode side in a recycler and added to the combustion agent flowing to the cathode side.
A fuel cell with an electrolyte consisting of carbonate melt develops on the anode side carbon dioxide from oxidation of hydrogen as well as from oxidation of carbon monoxide. On the other hand, carbon dioxide is required in the combustion agent on the cathode side in order to permit generating carbonate ions with oxygen. If, for instance, the combustion agent is to be compounded with air, adding carbon dioxide is required. The carbon dioxide required can be processed by recycling the carbon dioxide from the combustible waste gas. This recycling results in an optimal material balance, saving the otherwise necessary carbon dioxide source, and in a lowest possible total emission of carbon dioxide of the process. A carbon dioxide cycle neutral for the environment involving regenerative biological raw materi-als, especially C4 plants, can be arranged.
A method for generating electric energy from biological raw materials, independently of the previously described combin-ation of steps, can be characterized by the following:
(a) use of biological raw materials consisting at least predominantly of perennial C4 reed plants substantially free of naturally occurring sulphur and including essentially the elements carbon, hydrogen, oxygen and nitrogen, (b) generating a combustible gas containing carbon monoxide and hydrogen from biological raw materials with an oxygen-containing gasification agent by partial oxidation in an oxidation reactor, (c) adjusting and maintaining an oxygen/biological raw material proportion of ingredients and a gas phase temperature which ensure a combustible gas virtually free of nitrogen oxide in the oxidation reactor, (d) removing suspended matter from the combustible gas extracted form the oxidation reactor in a separator, (e) converting the transformed combustible gas into electrical energy in a fuel cell having a porous anode, a porous cathode and an acidic electrolyte containing phosphoric acid, and (f) converting the transformed combustible gas free of suspended matter into electric energy in fuel cells having a porous anode, a porous cathode and an acidic electrolyte.
This method provides substantially all properties and advantages of the method with an electrolyte consisting of a carbonate melt. The difference from the latter, however, is that the fuel cell can be operated at a comparatively low temperature.
Altogether, the efficiency with an acidic electrolyte is somewhat lower as compared with an electrolyte consisting of a carbonate melt. But this is compensated by the better controllability of eventual electrode corrosion effects because of the comparatively low operating temperature.
In this respect, special reliability is achieved be-cause, for instance, sintering of the suppoYting frame of the electrode pore structures is avoidable. Sulphuric acid or phos-phoric acid are preferred as electrolytes. Both acids, especial-ly phosphoric acid, have a relatively high boiling point with only small water additions, thus enabling operation of the fuel cells at high temperatures, e.g. 160'C.
However, the operating temperature of fuel cells with acidic electrolytes is altogether still so low that a special catalytic activity of the electrodes can assist in the conversion of the combustible gas into electric energy.
Compounds or alloys of gold and platinum can form the catalysts. Most other metals cannot resist corrosive attacks of sulphuric acid and especially of phosphoric acid. The catalytic activity of platinum as a rule exceeds the catalytic activity of gold. Platinum catalysts can be poisoned by carbon monoxide.
The combustible gas is for this reason treated with acidic electrolytes in a water shift reactor by adding steam and heat in order to,convert carbon monoxide into hydrogen and carbon dioxide. This ensures also the optimum utilization of the gross calorific value of combustible gas.
In another embodiment of the method with acidic elec-trolytes according to the invention, the fuel cell is operated at a temperature >130'C using a platinum-rhodium catalyst. Specific carbon monoxide quantities in the combustible gas can be tolerat-ed under these conditions. In another embodiment form of the method with acidic electrolytes according to the invention, the fuel cell is operated at a temperature <130°C using a platinum catalyst with molybdenum or tungsten oxides. This embodiment is also characterized by tolerating carbon monoxide in the combustible gas.
In the methods according to the invention, C4 plants are advantageously used as biological raw materials. Typical for this genus are perennial C4 reed plants. C4 plants can be grown fast and inexpensively with virtually no sulphur present.
As far as the partial oxidation in the oxidation reac-for is concerned, the method according to this aspect of the in-vention can operate in various embodiments.
In one embodiment, to which a particular importance is to be attributed, partial oxidation is realized with supply of externally generated heat and a gasification agent substantially containing steam. This method is an allothermal gasification.
Allothermal gasification requires the supply of externally gener-' ~' .~. . - 12 -r~i y.'%~v' ated heat since the reaction of biological raw material with steam into combustible gas is altogether endothermal. The heat for partial oxidation can thereby preferably be generated by combusting biological raw material or by combustible gas.
The heat for partial oxidation will advantageously be supplied to the oxidation reactor by means of a normal heat transfer gas through a heat exchanger.
In another embodiment of the method according to the invention, the partial oxidation is carried out without supply of externally generated heat with a gasification agent which sub-stantially contains steam and molecular oxygen or air. This method is an autothermal gasification. Thereby exothermal oxida-tion reactions occur with the molecular oxygen portion in the gasification agent which generate "in situ" the heat required for the endothermal reaction of steam and biological raw material.
An autothermal or allothermal gasification is in prin-ciple known from the technical journal "Stahl and Eisen", volume 110, 1990, No. 8, pages 131 to 138, but in another context. The so-far known autothermal or allothermal gasification relates to the generation of a service gas from coal, and the literature mentioned does not give any indication as to how a combustible gas can be autothermally or allothermally generated from biologi-cal raw materials as this term is used here.
Another aspect of the invention is a method for gener-ating electric energy from biological raw materials wherein the combination of the following features is realized:
~~t (a) Use of biological raw materials which are suffi-ciently free of sulphur of natural origin, (b) generating a combustible gas containing carbon dioxide and hydrogen from biological raw materials with an oxyge-nous gasification agent by partial oxidation in an oxidation reactor, (c) adjusting and maintaining an oxygen/biological raw material proportion of ingredients and a gas phase temperature which ensure a combustible gas virtually free of nitrogen oxide in the oxidation reactor, (dj removing suspended matter from the combustible gas extracted from the oxidation reactor in a separator, (e) converting the transformed combustible gas into electrical energy in a fuel cell having a porous anode, a porous cathode and an acidic electrolyte containing phosphoric acid, and (f) converting the combustible gas now free of suspend-ed matter into electric energy in fuel cells having a porous anode, a porous cathode and a solid electrolyte whereby the fuel cells are operated at a minimum of 800°C.
This combination of features too permits generation of combustible gas autothermally or allothermally.
Due to the exceptionally high operating temperature of fuel cells having a solid electrolyte made of a metal oxide, the catalytic effect of electrodes is not only nonessential but very high reaction rates of the combustible gas are provided on the anode and of a combustion agent on the cathode since the thermal energy of gases substantially exceeds the activating energy of _the-heterogeneous dissociation reactions.
~r High reaction rates permit high specific electric pow-ers of fuel cells.
In a preferred embodiment of the invention, fuel cells are therefore operated at a minimum of 1000°C (min. 1000°C), and preferably at min. 1200°C. Operating temperatures within this range may be obtained without any difficulties provided that the thermal expansion coefficients of the anode, cathode and electro-lyte materials can be matched or adapted to each other in the usual way. This, of course requires selection of materials of anode and cathode which are sufficiently corrosion-resistant.
High ion conductivity of electrolytes is achievable by using a mixture of zirconium oxide and calcium oxide or a mixture of zirconium oxide and yttrium oxide for the electrolyte. High ion conductivity together with high reaction rates on electrodes ensure a particularly high performance of fuel cells. In further formation, a ceramic metal, preferably of zirconium oxides with nickel or cobalt will be used here advantageously as anode mate-rial, and LaNi03 or doped indium oxide as cathode material.
In order to reduce carbon monoxide, which can possibly be disturbing in combustible gas, the latter can be treated in a water-shift reactor with supply of steam and heat for converting carbon monoxide into hydrogen and carbon dioxide.
A possibly disturbing hydrocarbon content of the com-bustion gas can be reduced by conducting the combustible gas immediately before conversion into electric energy through a reformer having a catalyst, preferably a transition metal catalyst, and most preferred a nickel catalyst, whereby the cata lyst is operated at the same temperature level as the fuel cell.
Exceptionally high fuel cell performances are obtained by using fuel cells, the cathode, electrolyte and anode of which are deposited in a thin-film mode in layers onto a porous, inert backing. Due to the minor layer thickness of the electrolyte, the inside resistance of fuel cells is very low. It is under-stood that the porosity of the backing is an open porosity in~
order to permit gas supply to the directly-attached electrode.
Fuel cells having electrolytes of a metal oxide are known as such in the art but are almost exclusively used in aero-space operations, whereby hydrogen carried along acts as combus-tible gas, the hydrogen having been previously produced and stored by conventional means.
Perennial C9 reed plants are used as biological raw materials with this aspect of the invention. C9 plants can be grown rapidly with minor costs and virtually no presence of sulphur.
Concerning partial oxidation in the oxidation reactor, the method according to the invention functions in various em-bodiment forms. In one embodiment, partial oxidation is carried out with a supply of externally-generated heat and a gasification agent substantially containing steam. This method is, as noted, ' an allothermal gasification. Thereby the heat required for par-tial oxidation can be generated preferably by combustion of bio-2~9~.~~
logical raw material or by combustible gas. The heat for partial oxidation is advantageously supplied to the oxidation reactor by means of a normal heat transfer gas through a heat exchanger.
In another embodiment of the method according to the in-vention, the partial oxidation is performed without supply of externally generated heat by means of a gasification agent sub-stantially containing steam and molecular oxygen or air respec-tively in an autothermal gasification as previously described.
Thereby exothermal oxidation reactions occur with the molecular oxygen portion in the gasification agent which generate "in situ"
the heat required for endothermal reaction of steam and biologi-cal raw material.
In another embodiment of the method according to this aspect of the invention, the partial oxidation of biological raw materials in the oxidation reactor is carried out thermally, e.g.
by means of air as gasification agent. Air as gasification agent may be used without any difficulties provided that the thermody-namical requirements concerning the oxygen to biological raw material proportion of ingredients are met. Air is always avail-able and cheap.
Brief Description of the Drawincr The above and other objects, features, and advantages will become more readily apparent from the following, reference being made to the accompanying drawing in which:
FIG. 1 is a flow diagram of an installation for carry-ing out the method according to the invention with an electrolyte consisting of a carbonate melt;
FIG. 2 is a diagram of an installation for the method according to the invention with an electrolyte containing phos-phoric acid; and FIG. 3 is a diagram of an installation for the method according to the invention with a "solid oxide" fuel cell.
Specific Description and Examples According to FIG. 1, a dissected (comminutedj and dried biological raw material 1 is made of plants, especially of C4 plants. The biological raw material 1 is delivered into a reac-tion space 4 of an oxidation reactor 2 through a pipe 3. Air 5 is supplied as gasification agent from a gasification agent sup-ply means.
Oxidation of biological raw material in the reaction space 4 of oxidation reactor 2 is controlled or regulated re-spectively by means of the air supplied and a heat supply so that only a partial oxidation of biological raw material 1 into hydro-gen and carbon monoxide takes place, and practically no nitrogen ~~~~.~9a oxides are generated. To achieve this, conventional sensors and actuators (not shown) can be adapted.
Partially or completely oxidized, solid biological raw material 1 is taken from ash discharge line 6.
Hydrogen and carbon monoxide are drawn from combustion gas collecting line 7 as combustible gas and supplied to separa-tor 8.
In separator 8 suspended matter is removed from combus-tible gas, and separately discharged through suspended matter collecting line 9.
The combustible gas now free of suspended matter is then delivered to an anode 11 in a fuel cell 12. Air derivprl from air supply means 22 is first enriched with carbon dioxide and then supplied to a cathode 12 of fuel cell 10 as a combustion agent.
An electrolyte 14 consisting of a mixture of alkali metal carbonates and alkali metal aluminates is enclosed between anode 11 and cathode 12, and maintained at a temperature of ap-prox. 650°C. Anode 11 and cathode 12 have open pores 13 which enable electrolyte 14 to contact combustible gas and combustion agent respectively, but safely enclose the pastous electrolyte.
Carbon monoxide and oxygen react with absorption of electrons from the cathode at cathode 122 into carbonate ions which are dissolved in the electrolyte. The carbonate ions mi-grate to anode 11 and react with hydrogen of the combustible gas into water and carbon dioxide, and with the carbon monoxide of the combustible gas into carbon dioxide with electron emission to anode 11.
The direct voltage generated between negative anode il and positive cathode 12 is led to a power inverter and voltage transformer 18, and transformed into a normal mains voltage.
A carbon dioxide recycler 17 feeds the combustible waste gas generated at the anode side to an exhaust 16. At the same time carbon dioxide is extracted from combustible waste gas in carbon dioxide recycler 17. The combustible waste gas gener-ated at the cathode side is delivered directly to exhaust 16.
In the method according to FIG. 2, the biological raw material 1 is converted into combustible gas and freed of sus-pended matter according to FIG. 1, and reference can be made, therefore, to the description associated with FIG. 1. Reference units having the same number in both Figures correspond with each other.
The further method using an acidic electrolyte will now ' be described in detail:
At first the combustible gas freed of suspended matter is supplied to a water shift reactor 20~, to which an addition steam in sufficient quantity from a superheated steam source 19' is supplied at the temperature required so that carbon monoxide of the combustible gas is converted into hydrogen and carbon dioxide in a water shift reaction.
A combustible gas with hydrogen and carbon dioxide as main constituents is generated from which excess steam and/or . ,;.
N ~ ~ ~ ~ ~ a7 water resulting from the water shift reaction is removed in a water separator 21'. The combustible gas so treated and freed of water is then supplied to an anode 11' of a fuel cell 10'.
Air is taken from air supply means 22' and as combus-tible agent supplied to a cathode 12' of fuel cell 10~. An elec-trolyte 14' of phosphorous acid with approx. 10~ water maintained at a temperature of approx. 150°C is enclosed between anode 11' and cathode 12'. Anode 11' and cathode 12' have open pores 13' which enable electrolyte 14' to contact combustible gas and com-bustion agent respectively, but securely enclose electrolyte 14' due to suitably matched surface tensions.
At anode 11', hydrogen of combustible gas is dissolved as protons in electrolyte 14' with emission of electrons to anode 11'. The protons migrate to cathode 12' and react with oxygen of the combustion agent to water with absorption of electrons from cathode 12'.
Anode 11' and cathode 12' have a catalytically-active platinum surface. Rhodium is additionally alloyed to platinum at least at anode 11'.
ThA uirect voltage produced between negative anode 11' and positive cathode 12' is led to a power inverter and voltage transformer 18, and transformed into normal mains voltage.
The combustible waste gas escaping from the anode side, which virtually contains nothing but carbon dioxide from the water shift reaction as well as the combustion agent waste gas escaping form the cathode side, containing only water aside from s~
air constituents, can be blown out through an exhaust 16' without any difficulties.
Material balances of the partial oxidation of the bio-logical raw materials into combustible gas of an embodiment exam-s ple of the invention with allothermal gasification are given as follows:
One biological raw material is used at a time and con-tains 29.4 mol % carbon, 48.3 mol % hydrogen, 21.9 mol % oxygen, 3.0 mol % nitrogen and 0.3 mol % sulphur.
The allothermal gasification always takes place at 750°C but at different pressures, namely at 40 bar, at 10 bar and at 2 bar.
The allothermal gasification at 40 bar resulted in a combustible gas with 47 percent by volume hydrogen, 11.6 percent by volume carbon. monoxide, 28.3 percent by volume carbon dioxide and 12.7 % methane. The net gas quantity amounted to 1.27 m3/kg biological raw material (normal pressure).
The allothermal gasification at 10 bar resulted in a combustible gas with 57.6 percent by volume hydrogen, 15.8 per-cent by volume carbon monoxide, 22.8 percent by volume carbon dioxide and 3.6 percent by volume methane. The net gas quantity amounted to 1.67 m3/kg biological raw material (normal pressure).
The allothermal gasification at 2 bar resulted in a combustible gas with 61.4 percent by volume hydrogen, 17.6 per-cent by volume carbon monoxide, 20.7 percent by volume carbon t >, 2~9I~
dioxide and 0.3 percent by volume methane. The net gas quantity amounted to 1.84 m3/kg biological raw material (normal pressure).
The gas analyses were conducted in thermal equilibrium.
In all cases, the combustible gas was virtually free of nitrogen oxides. Sulphur oxides could be detected only in minor quanti-ties which did not influence the performance of the fuel cell even in prolonged operation. To operate a fuel cell with an elec-trolyte containing phosphoric acid, a comparatively simple water shift reactor was required with allothermal gasification, since the combustible gas escaping form the oxidation reactor already contained relatively little carbon monoxide and relatively much carbon dioxide. Probably the water shift reactor may be disp-ensed with entirely in the embodiment form of the invention with allothermal gasification and electrolyte containing phosphoric acid. It is understood that heat released within the scope of the invention can be suitably regenerated in the method according to the invention.
In the embodiment shown in FIG. 3, the gasification functions as described with reference to FIGS. 1 and 2.
The combustible gas freed of suspended matter in the already described manner is then supplied to a water shift reac-for 20 " to which in addition steam from a superheated steam source 19 " at the temperature required is delivered in suffi-cient quantity.
A combustible gas with hydrogen and carbon dioxide as main constituents is generated from which excess steam and/or ' ;
2~9~.~~~
water resulting from the water shift reaction is removed in a water separator 21 " . The combustible gas thus treated and freed of water is at first conducted through a conventional carbon dioxide separator 23 " and then through a reformer 24 " having a nickel catalyst 25 " .
Since the reformer 24 " is structurally combined with the fuel cell 10 " , the temperature of catalyst 25 " is in effect equal to the temperature of fuel cell 10 " , i.e. approx. 1000°C.
The combustible gas streaming out of reformer 24 " and freed of carbon residues streams then over anode 11 " of fuel cell 10 " .
Air is taken from supply means 22 " and fed to fuel cell 10 " as a combustion agent for cathode 12 " .
Anode 11' may for instance consist of a ceramic metal with zirconium oxides and cobalt. LaNi03 may be used as cathode material. Zirconium oxide and yttrium oxide are present in elec-trolyte 14 " in the embodiment example. Anode 11 " and cathode 12 " have perforations 13 " as pores enabling electrolyte 14 " to contact combustible gas and combustion agent respectively. Hy-drogen of combustible gas is burned to water at anode 11 " under reaction of oxygen ions from electrolyte 14 " .
The oxygen ions are obtained from the combustion agent at cathode 12 " and transported by electrolyte 14 " to the anode.
The direct voltage applied between negative anode 11 " and posi-tive cathode 12 " is led to an inverter and voltage transformer 18 " and converted into normal mains voltage. The combustible waste gas escaping from the anode side contains in effect only -x-~:
2~9I~9a water, and the combustion agent waste gas escaping from the ca-thode side essentially contains nitrogen. Both can be blown off through an exhaust 16 " without any difficulties.
If the sulphur content is higher, the biological raw material can be desulphurized by interposing a conventional de-sulphurization stage in the process.
In an oxidation reactor, the biological raw material is treated with oxygen at a concentration higher than that of the ambient atmosphere and/or atmospheric oxygen and/or steam at an elevated temperature which results in a partial oxidation of the biological raw material into a combustible gas containing hydro-gen and carbon monoxide.
The proportion of oxygen and biological raw material, and the gas phase temperature in the oxidation reactor are then selected in such a way that, because of the thermodynamics, for one thing, the oxidation of the biological raw material does not go beyond the reaction product hydrogen or transform the hydrogen to water, and for another thing, the nitrogen of natural origin and/or the atmospheric nitrogen is not oxidized into nitrogen oxides in the oxidation reactor.
When steam is used in the gasification agent, the com-bustible gas may contain carbon dioxide aside from carbon monox-ide. It is a matter of course that the deviations from the ther-mal equilibrium occurring in continuous operation are to be taken ~,~ ",s-..
;.
y-::
2~~1~~j into consideration in the manner known in materials processing, when dimensioning the ingredients proportion of oxygen and raw material and the gas phase temperature.
Suspended matter means particles the size and density of which permits them to be entrained in a combustible gas stream. Suspended matter may originate from nonburned raw mate-rials but may also be ash particles.
The anode refers to the possibly catalytically active electrode of the fuel cell over which the combustible gas passes and is oxidized with electron emission. The cathode refers to the possibly catalytically active electrode or fuel cell over which a combw.stion agent passes and is reduced with electron take up. The combustion agent must contain carbon dioxide for con-s version into oxygen and carbonate ions at the cathode. Porous refers to an electrode structure which on the one hand ensures a contact of all three phases (combustible gas or combustion agent, electrode or catalyst and electrolyte), but on the other hand prevents the electrolyte from flooding into a combustible gas compartment or combustion agent gas compartment, for instance by the action of capillary forces. Therefore, the term "porous"
also includes grid structures having suitable mesh widths.
The invention is based on the knowledge that a combus-tible gas resulting from partial oxidation of biological raw materials can be converted into electric energy in fuel cells with especially high efficiency, provided that the process for generating the combustible gas will be adapted just to this _.__ r~:
2~9~~~J
purpose of the combustible gas.
The use of raw materials which are sufficiently free of sulphur of natural origin ensures without any other measures that on the one hand the fuel cells can be operated permanently and reliably without poisoning the catalysts, and that on the other hand, the entire process does not release any disturbing sulphu-rous emissions.
The adaptation of the oxidation reactor's operating parameters to the relatively high nitrogen content of biological raw materials guarantees that in effect no disturbing nitrogen oxides will be released despite the high nitrogen portion. Ni-trogen oxides just as sulphurous emissions are undesirable for environmenta~ protection reasons.
Removing suspended matter, which may increasingly accu-mulate during the partial oxidation of raw materials, from the combustible gas ensures on the one hand that the pores of fuel cell electrodes cannot be clogged to an interfering degree with the result of reduced specific faces and thus decreased current density, and on the other hand the troublefree run of the entire process without any particle emission.
Suspended matter may be separated by using conventional means, for instance by a cyclone filter.
Fuel cells having an electrolyte made of a carbonate melt are characterized by a particularly high efficiency and a high specific performance because of the comparatively high oper-ating temperature. Another advantage of this type of fuel cell :.' 2~~~~~
in combination with conversion of combustible gas from raw mate-rials into electric energy is the fact that carbon monoxide not only does not interfere with the catalysis, but is even processed for generating electric energy just like hydrogen. Carbon monoxide and carbonate ions react at the anode with electron emission to carbon dioxide.
The combination of the features of the invention achieves a considerable synergistic effect, namely generating electric energy from very cheap and regenerative raw material with a particularly high efficiency and high reliability, with virtually no emission of sulphur compounds, nitrogen oxides and particles.
End products of the method according to the invention are appreciat~ly harmless water and, in conventional generation of electric energy, unavoidable carbon dioxide. Heat is addition-ally generated and may be recuperated for use in the process especially with application of the allothermal method.
Methods for thermal partial oxidation of biological raw materials into a service gas are in principle known. As yet no operation with direct conversion into electric energy or any special measures required for such operation are known.
In a preferred embodiment of the method according to the invention, the carbonate melt is substantially compounded from alkali metal carbonates and alkali metal aluminates, and the carbonate melt has pasty (viscous) flow properties at the~operat-ing temperature of the fuel cell.
_ g _ Alkali metal carbonates in melted condition provide excellent ion conductivity and melting temperatures which are comparatively low. The melting temperature of an eutectic mixture consisting of lithium, sodium and potassium carbonates is especially low.
Adding alkali aluminates has two effects: To begin with, a pasty composition can be produced at the operating tem-perature of the fuel cell since powder from alkali metal alumi-nates will not be melted. An electrolyte having a pasty consis-tency permits keeping the requirements to be met by the pore structure of the electrodes relatively low without endangering the electrolyte retention. Secondly, alkali metal aluminates act probably as carbon dioxide buffers.
In an especially advantageous and environmentally ac-ceptable embodiment of the method according to the invention, carbon dioxide is extracted from the combustible waste gas escap-ing on the anode side in a recycler and added to the combustion agent flowing to the cathode side.
A fuel cell with an electrolyte consisting of carbonate melt develops on the anode side carbon dioxide from oxidation of hydrogen as well as from oxidation of carbon monoxide. On the other hand, carbon dioxide is required in the combustion agent on the cathode side in order to permit generating carbonate ions with oxygen. If, for instance, the combustion agent is to be compounded with air, adding carbon dioxide is required. The carbon dioxide required can be processed by recycling the carbon dioxide from the combustible waste gas. This recycling results in an optimal material balance, saving the otherwise necessary carbon dioxide source, and in a lowest possible total emission of carbon dioxide of the process. A carbon dioxide cycle neutral for the environment involving regenerative biological raw materi-als, especially C4 plants, can be arranged.
A method for generating electric energy from biological raw materials, independently of the previously described combin-ation of steps, can be characterized by the following:
(a) use of biological raw materials consisting at least predominantly of perennial C4 reed plants substantially free of naturally occurring sulphur and including essentially the elements carbon, hydrogen, oxygen and nitrogen, (b) generating a combustible gas containing carbon monoxide and hydrogen from biological raw materials with an oxygen-containing gasification agent by partial oxidation in an oxidation reactor, (c) adjusting and maintaining an oxygen/biological raw material proportion of ingredients and a gas phase temperature which ensure a combustible gas virtually free of nitrogen oxide in the oxidation reactor, (d) removing suspended matter from the combustible gas extracted form the oxidation reactor in a separator, (e) converting the transformed combustible gas into electrical energy in a fuel cell having a porous anode, a porous cathode and an acidic electrolyte containing phosphoric acid, and (f) converting the transformed combustible gas free of suspended matter into electric energy in fuel cells having a porous anode, a porous cathode and an acidic electrolyte.
This method provides substantially all properties and advantages of the method with an electrolyte consisting of a carbonate melt. The difference from the latter, however, is that the fuel cell can be operated at a comparatively low temperature.
Altogether, the efficiency with an acidic electrolyte is somewhat lower as compared with an electrolyte consisting of a carbonate melt. But this is compensated by the better controllability of eventual electrode corrosion effects because of the comparatively low operating temperature.
In this respect, special reliability is achieved be-cause, for instance, sintering of the suppoYting frame of the electrode pore structures is avoidable. Sulphuric acid or phos-phoric acid are preferred as electrolytes. Both acids, especial-ly phosphoric acid, have a relatively high boiling point with only small water additions, thus enabling operation of the fuel cells at high temperatures, e.g. 160'C.
However, the operating temperature of fuel cells with acidic electrolytes is altogether still so low that a special catalytic activity of the electrodes can assist in the conversion of the combustible gas into electric energy.
Compounds or alloys of gold and platinum can form the catalysts. Most other metals cannot resist corrosive attacks of sulphuric acid and especially of phosphoric acid. The catalytic activity of platinum as a rule exceeds the catalytic activity of gold. Platinum catalysts can be poisoned by carbon monoxide.
The combustible gas is for this reason treated with acidic electrolytes in a water shift reactor by adding steam and heat in order to,convert carbon monoxide into hydrogen and carbon dioxide. This ensures also the optimum utilization of the gross calorific value of combustible gas.
In another embodiment of the method with acidic elec-trolytes according to the invention, the fuel cell is operated at a temperature >130'C using a platinum-rhodium catalyst. Specific carbon monoxide quantities in the combustible gas can be tolerat-ed under these conditions. In another embodiment form of the method with acidic electrolytes according to the invention, the fuel cell is operated at a temperature <130°C using a platinum catalyst with molybdenum or tungsten oxides. This embodiment is also characterized by tolerating carbon monoxide in the combustible gas.
In the methods according to the invention, C4 plants are advantageously used as biological raw materials. Typical for this genus are perennial C4 reed plants. C4 plants can be grown fast and inexpensively with virtually no sulphur present.
As far as the partial oxidation in the oxidation reac-for is concerned, the method according to this aspect of the in-vention can operate in various embodiments.
In one embodiment, to which a particular importance is to be attributed, partial oxidation is realized with supply of externally generated heat and a gasification agent substantially containing steam. This method is an allothermal gasification.
Allothermal gasification requires the supply of externally gener-' ~' .~. . - 12 -r~i y.'%~v' ated heat since the reaction of biological raw material with steam into combustible gas is altogether endothermal. The heat for partial oxidation can thereby preferably be generated by combusting biological raw material or by combustible gas.
The heat for partial oxidation will advantageously be supplied to the oxidation reactor by means of a normal heat transfer gas through a heat exchanger.
In another embodiment of the method according to the invention, the partial oxidation is carried out without supply of externally generated heat with a gasification agent which sub-stantially contains steam and molecular oxygen or air. This method is an autothermal gasification. Thereby exothermal oxida-tion reactions occur with the molecular oxygen portion in the gasification agent which generate "in situ" the heat required for the endothermal reaction of steam and biological raw material.
An autothermal or allothermal gasification is in prin-ciple known from the technical journal "Stahl and Eisen", volume 110, 1990, No. 8, pages 131 to 138, but in another context. The so-far known autothermal or allothermal gasification relates to the generation of a service gas from coal, and the literature mentioned does not give any indication as to how a combustible gas can be autothermally or allothermally generated from biologi-cal raw materials as this term is used here.
Another aspect of the invention is a method for gener-ating electric energy from biological raw materials wherein the combination of the following features is realized:
~~t (a) Use of biological raw materials which are suffi-ciently free of sulphur of natural origin, (b) generating a combustible gas containing carbon dioxide and hydrogen from biological raw materials with an oxyge-nous gasification agent by partial oxidation in an oxidation reactor, (c) adjusting and maintaining an oxygen/biological raw material proportion of ingredients and a gas phase temperature which ensure a combustible gas virtually free of nitrogen oxide in the oxidation reactor, (dj removing suspended matter from the combustible gas extracted from the oxidation reactor in a separator, (e) converting the transformed combustible gas into electrical energy in a fuel cell having a porous anode, a porous cathode and an acidic electrolyte containing phosphoric acid, and (f) converting the combustible gas now free of suspend-ed matter into electric energy in fuel cells having a porous anode, a porous cathode and a solid electrolyte whereby the fuel cells are operated at a minimum of 800°C.
This combination of features too permits generation of combustible gas autothermally or allothermally.
Due to the exceptionally high operating temperature of fuel cells having a solid electrolyte made of a metal oxide, the catalytic effect of electrodes is not only nonessential but very high reaction rates of the combustible gas are provided on the anode and of a combustion agent on the cathode since the thermal energy of gases substantially exceeds the activating energy of _the-heterogeneous dissociation reactions.
~r High reaction rates permit high specific electric pow-ers of fuel cells.
In a preferred embodiment of the invention, fuel cells are therefore operated at a minimum of 1000°C (min. 1000°C), and preferably at min. 1200°C. Operating temperatures within this range may be obtained without any difficulties provided that the thermal expansion coefficients of the anode, cathode and electro-lyte materials can be matched or adapted to each other in the usual way. This, of course requires selection of materials of anode and cathode which are sufficiently corrosion-resistant.
High ion conductivity of electrolytes is achievable by using a mixture of zirconium oxide and calcium oxide or a mixture of zirconium oxide and yttrium oxide for the electrolyte. High ion conductivity together with high reaction rates on electrodes ensure a particularly high performance of fuel cells. In further formation, a ceramic metal, preferably of zirconium oxides with nickel or cobalt will be used here advantageously as anode mate-rial, and LaNi03 or doped indium oxide as cathode material.
In order to reduce carbon monoxide, which can possibly be disturbing in combustible gas, the latter can be treated in a water-shift reactor with supply of steam and heat for converting carbon monoxide into hydrogen and carbon dioxide.
A possibly disturbing hydrocarbon content of the com-bustion gas can be reduced by conducting the combustible gas immediately before conversion into electric energy through a reformer having a catalyst, preferably a transition metal catalyst, and most preferred a nickel catalyst, whereby the cata lyst is operated at the same temperature level as the fuel cell.
Exceptionally high fuel cell performances are obtained by using fuel cells, the cathode, electrolyte and anode of which are deposited in a thin-film mode in layers onto a porous, inert backing. Due to the minor layer thickness of the electrolyte, the inside resistance of fuel cells is very low. It is under-stood that the porosity of the backing is an open porosity in~
order to permit gas supply to the directly-attached electrode.
Fuel cells having electrolytes of a metal oxide are known as such in the art but are almost exclusively used in aero-space operations, whereby hydrogen carried along acts as combus-tible gas, the hydrogen having been previously produced and stored by conventional means.
Perennial C9 reed plants are used as biological raw materials with this aspect of the invention. C9 plants can be grown rapidly with minor costs and virtually no presence of sulphur.
Concerning partial oxidation in the oxidation reactor, the method according to the invention functions in various em-bodiment forms. In one embodiment, partial oxidation is carried out with a supply of externally-generated heat and a gasification agent substantially containing steam. This method is, as noted, ' an allothermal gasification. Thereby the heat required for par-tial oxidation can be generated preferably by combustion of bio-2~9~.~~
logical raw material or by combustible gas. The heat for partial oxidation is advantageously supplied to the oxidation reactor by means of a normal heat transfer gas through a heat exchanger.
In another embodiment of the method according to the in-vention, the partial oxidation is performed without supply of externally generated heat by means of a gasification agent sub-stantially containing steam and molecular oxygen or air respec-tively in an autothermal gasification as previously described.
Thereby exothermal oxidation reactions occur with the molecular oxygen portion in the gasification agent which generate "in situ"
the heat required for endothermal reaction of steam and biologi-cal raw material.
In another embodiment of the method according to this aspect of the invention, the partial oxidation of biological raw materials in the oxidation reactor is carried out thermally, e.g.
by means of air as gasification agent. Air as gasification agent may be used without any difficulties provided that the thermody-namical requirements concerning the oxygen to biological raw material proportion of ingredients are met. Air is always avail-able and cheap.
Brief Description of the Drawincr The above and other objects, features, and advantages will become more readily apparent from the following, reference being made to the accompanying drawing in which:
FIG. 1 is a flow diagram of an installation for carry-ing out the method according to the invention with an electrolyte consisting of a carbonate melt;
FIG. 2 is a diagram of an installation for the method according to the invention with an electrolyte containing phos-phoric acid; and FIG. 3 is a diagram of an installation for the method according to the invention with a "solid oxide" fuel cell.
Specific Description and Examples According to FIG. 1, a dissected (comminutedj and dried biological raw material 1 is made of plants, especially of C4 plants. The biological raw material 1 is delivered into a reac-tion space 4 of an oxidation reactor 2 through a pipe 3. Air 5 is supplied as gasification agent from a gasification agent sup-ply means.
Oxidation of biological raw material in the reaction space 4 of oxidation reactor 2 is controlled or regulated re-spectively by means of the air supplied and a heat supply so that only a partial oxidation of biological raw material 1 into hydro-gen and carbon monoxide takes place, and practically no nitrogen ~~~~.~9a oxides are generated. To achieve this, conventional sensors and actuators (not shown) can be adapted.
Partially or completely oxidized, solid biological raw material 1 is taken from ash discharge line 6.
Hydrogen and carbon monoxide are drawn from combustion gas collecting line 7 as combustible gas and supplied to separa-tor 8.
In separator 8 suspended matter is removed from combus-tible gas, and separately discharged through suspended matter collecting line 9.
The combustible gas now free of suspended matter is then delivered to an anode 11 in a fuel cell 12. Air derivprl from air supply means 22 is first enriched with carbon dioxide and then supplied to a cathode 12 of fuel cell 10 as a combustion agent.
An electrolyte 14 consisting of a mixture of alkali metal carbonates and alkali metal aluminates is enclosed between anode 11 and cathode 12, and maintained at a temperature of ap-prox. 650°C. Anode 11 and cathode 12 have open pores 13 which enable electrolyte 14 to contact combustible gas and combustion agent respectively, but safely enclose the pastous electrolyte.
Carbon monoxide and oxygen react with absorption of electrons from the cathode at cathode 122 into carbonate ions which are dissolved in the electrolyte. The carbonate ions mi-grate to anode 11 and react with hydrogen of the combustible gas into water and carbon dioxide, and with the carbon monoxide of the combustible gas into carbon dioxide with electron emission to anode 11.
The direct voltage generated between negative anode il and positive cathode 12 is led to a power inverter and voltage transformer 18, and transformed into a normal mains voltage.
A carbon dioxide recycler 17 feeds the combustible waste gas generated at the anode side to an exhaust 16. At the same time carbon dioxide is extracted from combustible waste gas in carbon dioxide recycler 17. The combustible waste gas gener-ated at the cathode side is delivered directly to exhaust 16.
In the method according to FIG. 2, the biological raw material 1 is converted into combustible gas and freed of sus-pended matter according to FIG. 1, and reference can be made, therefore, to the description associated with FIG. 1. Reference units having the same number in both Figures correspond with each other.
The further method using an acidic electrolyte will now ' be described in detail:
At first the combustible gas freed of suspended matter is supplied to a water shift reactor 20~, to which an addition steam in sufficient quantity from a superheated steam source 19' is supplied at the temperature required so that carbon monoxide of the combustible gas is converted into hydrogen and carbon dioxide in a water shift reaction.
A combustible gas with hydrogen and carbon dioxide as main constituents is generated from which excess steam and/or . ,;.
N ~ ~ ~ ~ ~ a7 water resulting from the water shift reaction is removed in a water separator 21'. The combustible gas so treated and freed of water is then supplied to an anode 11' of a fuel cell 10'.
Air is taken from air supply means 22' and as combus-tible agent supplied to a cathode 12' of fuel cell 10~. An elec-trolyte 14' of phosphorous acid with approx. 10~ water maintained at a temperature of approx. 150°C is enclosed between anode 11' and cathode 12'. Anode 11' and cathode 12' have open pores 13' which enable electrolyte 14' to contact combustible gas and com-bustion agent respectively, but securely enclose electrolyte 14' due to suitably matched surface tensions.
At anode 11', hydrogen of combustible gas is dissolved as protons in electrolyte 14' with emission of electrons to anode 11'. The protons migrate to cathode 12' and react with oxygen of the combustion agent to water with absorption of electrons from cathode 12'.
Anode 11' and cathode 12' have a catalytically-active platinum surface. Rhodium is additionally alloyed to platinum at least at anode 11'.
ThA uirect voltage produced between negative anode 11' and positive cathode 12' is led to a power inverter and voltage transformer 18, and transformed into normal mains voltage.
The combustible waste gas escaping from the anode side, which virtually contains nothing but carbon dioxide from the water shift reaction as well as the combustion agent waste gas escaping form the cathode side, containing only water aside from s~
air constituents, can be blown out through an exhaust 16' without any difficulties.
Material balances of the partial oxidation of the bio-logical raw materials into combustible gas of an embodiment exam-s ple of the invention with allothermal gasification are given as follows:
One biological raw material is used at a time and con-tains 29.4 mol % carbon, 48.3 mol % hydrogen, 21.9 mol % oxygen, 3.0 mol % nitrogen and 0.3 mol % sulphur.
The allothermal gasification always takes place at 750°C but at different pressures, namely at 40 bar, at 10 bar and at 2 bar.
The allothermal gasification at 40 bar resulted in a combustible gas with 47 percent by volume hydrogen, 11.6 percent by volume carbon. monoxide, 28.3 percent by volume carbon dioxide and 12.7 % methane. The net gas quantity amounted to 1.27 m3/kg biological raw material (normal pressure).
The allothermal gasification at 10 bar resulted in a combustible gas with 57.6 percent by volume hydrogen, 15.8 per-cent by volume carbon monoxide, 22.8 percent by volume carbon dioxide and 3.6 percent by volume methane. The net gas quantity amounted to 1.67 m3/kg biological raw material (normal pressure).
The allothermal gasification at 2 bar resulted in a combustible gas with 61.4 percent by volume hydrogen, 17.6 per-cent by volume carbon monoxide, 20.7 percent by volume carbon t >, 2~9I~
dioxide and 0.3 percent by volume methane. The net gas quantity amounted to 1.84 m3/kg biological raw material (normal pressure).
The gas analyses were conducted in thermal equilibrium.
In all cases, the combustible gas was virtually free of nitrogen oxides. Sulphur oxides could be detected only in minor quanti-ties which did not influence the performance of the fuel cell even in prolonged operation. To operate a fuel cell with an elec-trolyte containing phosphoric acid, a comparatively simple water shift reactor was required with allothermal gasification, since the combustible gas escaping form the oxidation reactor already contained relatively little carbon monoxide and relatively much carbon dioxide. Probably the water shift reactor may be disp-ensed with entirely in the embodiment form of the invention with allothermal gasification and electrolyte containing phosphoric acid. It is understood that heat released within the scope of the invention can be suitably regenerated in the method according to the invention.
In the embodiment shown in FIG. 3, the gasification functions as described with reference to FIGS. 1 and 2.
The combustible gas freed of suspended matter in the already described manner is then supplied to a water shift reac-for 20 " to which in addition steam from a superheated steam source 19 " at the temperature required is delivered in suffi-cient quantity.
A combustible gas with hydrogen and carbon dioxide as main constituents is generated from which excess steam and/or ' ;
2~9~.~~~
water resulting from the water shift reaction is removed in a water separator 21 " . The combustible gas thus treated and freed of water is at first conducted through a conventional carbon dioxide separator 23 " and then through a reformer 24 " having a nickel catalyst 25 " .
Since the reformer 24 " is structurally combined with the fuel cell 10 " , the temperature of catalyst 25 " is in effect equal to the temperature of fuel cell 10 " , i.e. approx. 1000°C.
The combustible gas streaming out of reformer 24 " and freed of carbon residues streams then over anode 11 " of fuel cell 10 " .
Air is taken from supply means 22 " and fed to fuel cell 10 " as a combustion agent for cathode 12 " .
Anode 11' may for instance consist of a ceramic metal with zirconium oxides and cobalt. LaNi03 may be used as cathode material. Zirconium oxide and yttrium oxide are present in elec-trolyte 14 " in the embodiment example. Anode 11 " and cathode 12 " have perforations 13 " as pores enabling electrolyte 14 " to contact combustible gas and combustion agent respectively. Hy-drogen of combustible gas is burned to water at anode 11 " under reaction of oxygen ions from electrolyte 14 " .
The oxygen ions are obtained from the combustion agent at cathode 12 " and transported by electrolyte 14 " to the anode.
The direct voltage applied between negative anode 11 " and posi-tive cathode 12 " is led to an inverter and voltage transformer 18 " and converted into normal mains voltage. The combustible waste gas escaping from the anode side contains in effect only -x-~:
2~9I~9a water, and the combustion agent waste gas escaping from the ca-thode side essentially contains nitrogen. Both can be blown off through an exhaust 16 " without any difficulties.
Claims (12)
1. Process of generating electrical energy from biological raw materials consisting at least predominantly of C4 perennial reed plants substantially free of naturally occurring sulfur and including essentially the elements carbon, hydrogen, oxygen and nitrogen, comprising the steps of:
(a) generating a combustible gas containing carbon monoxide and hydrogen from the biological raw materials in an oxidation reactor in an allothermic reaction with a gasification agent substantially containing steam, (b) discharging the combustible gas from the oxidation reactor and removing suspended matter from the combustible gas in a separator, (c) transforming the combustible gas free from suspended matter in a water-shift reactor into a transformed combustible gas consisting of hydrogen and carbon dioxide by adding steam and heat, and (d) converting the transformed combustible gas into electrical energy in a fuel cell having a porous anode, a porous cathode and an acidic electrolyte containing phosphoric acid, whereby the heat for the gasification reaction is supplied to the oxidation reactor by way of a heat transfer gas through a heat exchanger, and the oxygen/biological raw material proportion of ingredients and the gas phase temperature in the oxidation reactor is adjusted to ensure a combustible gas virtually free of nitrogen oxide.
(a) generating a combustible gas containing carbon monoxide and hydrogen from the biological raw materials in an oxidation reactor in an allothermic reaction with a gasification agent substantially containing steam, (b) discharging the combustible gas from the oxidation reactor and removing suspended matter from the combustible gas in a separator, (c) transforming the combustible gas free from suspended matter in a water-shift reactor into a transformed combustible gas consisting of hydrogen and carbon dioxide by adding steam and heat, and (d) converting the transformed combustible gas into electrical energy in a fuel cell having a porous anode, a porous cathode and an acidic electrolyte containing phosphoric acid, whereby the heat for the gasification reaction is supplied to the oxidation reactor by way of a heat transfer gas through a heat exchanger, and the oxygen/biological raw material proportion of ingredients and the gas phase temperature in the oxidation reactor is adjusted to ensure a combustible gas virtually free of nitrogen oxide.
2. Process of generating electrical energy from biological raw materials consisting at least predominantly of C4 perennial reed plants substantially free of naturally occurring sulfur and including essentially the elements carbon, hydrogen, oxygen and nitrogen, comprising the steps of:
(a) generating a combustible gas containing carbon monoxide and hydrogen from the biological raw materials in an oxidation reactor in an allothermic reaction with a gasification agent substantially containing steam, (b) discharging the combustible gas from the oxidation reactor and removing suspended matter from the combustible gas in a separator, (c) transforming the combustible gas free from suspended matter in a water-shift reactor into a transformed combustible gas consisting of hydrogen and carbon dioxide by adding steam and heat, and (d) converting the transformed combustible gas into electrical energy in a fuel cell having a porous anode, a porous cathode and an electrolyte consisting of a carbonate melt.
(a) generating a combustible gas containing carbon monoxide and hydrogen from the biological raw materials in an oxidation reactor in an allothermic reaction with a gasification agent substantially containing steam, (b) discharging the combustible gas from the oxidation reactor and removing suspended matter from the combustible gas in a separator, (c) transforming the combustible gas free from suspended matter in a water-shift reactor into a transformed combustible gas consisting of hydrogen and carbon dioxide by adding steam and heat, and (d) converting the transformed combustible gas into electrical energy in a fuel cell having a porous anode, a porous cathode and an electrolyte consisting of a carbonate melt.
3. Process of generating electrical energy from biological raw materials consisting at least predominantly of C4 perennial reed plants substantially free of naturally occurring sulfur and including essentially the elements carbon, hydrogen, oxygen and nitrogen, comprising the steps of:
(a) generating a combustible gas containing carbon monoxide and hydrogen from the biological raw materials in an oxidation reactor in an allothermic reaction with a gasification agent substantially containing steam, (b) discharging the combustible gas from the oxidation reactor and removing suspended matter from the combustible gas in a separator, (c) transforming the combustible gas free from suspended matter in a water-shift reactor into a transformed combustible gas consisting of hydrogen and carbon dioxide by adding steam and heat, and (d) converting the transformed combustible gas into electrical energy in a fuel cell having a porous anode, a porous cathode and a solid electrolyte made of a metal oxide, whereby the fuel cell is operated at a temperature of at least 800°C.
(a) generating a combustible gas containing carbon monoxide and hydrogen from the biological raw materials in an oxidation reactor in an allothermic reaction with a gasification agent substantially containing steam, (b) discharging the combustible gas from the oxidation reactor and removing suspended matter from the combustible gas in a separator, (c) transforming the combustible gas free from suspended matter in a water-shift reactor into a transformed combustible gas consisting of hydrogen and carbon dioxide by adding steam and heat, and (d) converting the transformed combustible gas into electrical energy in a fuel cell having a porous anode, a porous cathode and a solid electrolyte made of a metal oxide, whereby the fuel cell is operated at a temperature of at least 800°C.
4. Process according to claim 1, wherein the fuel cell is operated at a temperature of above 130'C and a platinum/rhodium catalyst is used.
5. Process according to claim 1, wherein the fuel cell is operated at a temperature below 130°C and a platinum catalyst with molybdenum or tungsten oxide is used.
6. Process according to claim 2, wherein the carbonate melt consists essentially of alkali metal carbonates and alkali metal alluminates, the carbonate melt having a pasty flow property at an operating temperature of the fuel cell.
7. Process according to claim 3, wherein the fuel cell is operated at a temperature of at least 1000°C.
8. Process according to claim 7, wherein the fuel cell is operated at a temperature of at least 1200°C.
9. Process according to one of claims 3 to 8, wherein the electrolyte is selected from the group of a mixture of zirconium oxide and calcium oxide and a mixture of zirconium oxide and yttrium oxide.
10. Process according to one of claims 3 to 9, wherein a ceramic metal is used as the anode.
11. Process according to claim 10, wherein zirconium oxide with nickel or cobalt is used as the anode.
12. Process according to one of claims 3 to 11, wherein LaNIO3 or indium oxide is used as the cathode.
Applications Claiming Priority (6)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| DEP4207975.6-45 | 1992-03-13 | ||
| DE4207975 | 1992-03-13 | ||
| DEP4227485.0-45 | 1992-08-20 | ||
| DE4227485 | 1992-08-20 | ||
| DEP4235017.4-45 | 1992-10-16 | ||
| DE4235017 | 1992-10-16 |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CA2091495A1 CA2091495A1 (en) | 1993-09-14 |
| CA2091495C true CA2091495C (en) | 1999-11-30 |
Family
ID=27203517
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA002091495A Expired - Fee Related CA2091495C (en) | 1992-03-13 | 1993-03-11 | Method for generating electric energy from biological raw materials |
Country Status (18)
| Country | Link |
|---|---|
| US (1) | US5645951A (en) |
| EP (1) | EP0564796B1 (en) |
| JP (1) | JPH0696790A (en) |
| KR (1) | KR930020198A (en) |
| CN (1) | CN1076553A (en) |
| AT (1) | ATE189082T1 (en) |
| BR (1) | BR9301155A (en) |
| CA (1) | CA2091495C (en) |
| DE (1) | DE59309933D1 (en) |
| DK (1) | DK0564796T3 (en) |
| ES (1) | ES2143994T3 (en) |
| FI (1) | FI931113L (en) |
| GR (1) | GR3033282T3 (en) |
| IL (1) | IL104858A (en) |
| NO (1) | NO930889L (en) |
| PL (1) | PL298018A1 (en) |
| PT (1) | PT564796E (en) |
| UA (1) | UA42670C2 (en) |
Families Citing this family (24)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE4328379C2 (en) * | 1993-08-24 | 2001-11-29 | Binsmaier Geb Gallin Ast | Modular power plant for the generation of electrical energy from solar energy |
| DE4341438C2 (en) * | 1993-12-04 | 2000-07-13 | Binsmaier Hannelore | Modular power plant for the production of mainly hydrogen from solar energy |
| DK0677882T3 (en) * | 1994-04-12 | 2000-06-13 | Binsmaier Hannelore | Process for producing electrical energy from regenerative biomass |
| DE4430750C2 (en) * | 1994-08-30 | 1996-11-21 | Binsmaier Hannelore | Process for generating electrical energy from bio-raw materials and device for carrying out the process |
| WO1996007210A1 (en) * | 1994-08-30 | 1996-03-07 | Binsmaier, Hannelore | Method of generating electrical energy from regenerative biomass |
| NL1008832C2 (en) * | 1998-04-07 | 1999-10-08 | Univ Delft Tech | A method of converting a carbon-containing material, a method of operating a fuel cell and a method of operating a fuel cell stack. |
| DE19900116C2 (en) * | 1999-01-05 | 2002-02-14 | Univ Muenchen Tech | Device for generating fuel gas by allothermic gasification of biomass |
| US6571747B1 (en) | 1999-03-26 | 2003-06-03 | Michael Prestel | Method and device for producing energy or methanol |
| AU7062200A (en) * | 1999-08-19 | 2001-03-13 | Manufacturing And Technology Conversion International, Inc. | Gas turbine with indirectly heated steam reforming system |
| EP1216287B1 (en) | 1999-08-19 | 2005-11-23 | Manufacturing And Technology Conversion International, Inc. | System integration of a steam reformer and fuel cell |
| JP2001126742A (en) * | 1999-10-27 | 2001-05-11 | Sanyo Electric Co Ltd | Fuel cell generator |
| EP1375628A3 (en) * | 2000-01-21 | 2004-12-08 | Integrated Environmental Technologies, Llc. | Methods and apparatus for treating waste |
| US6835354B2 (en) * | 2000-04-05 | 2004-12-28 | Hyradix, Inc. | Integrated reactor |
| DE10025033A1 (en) * | 2000-05-20 | 2001-11-29 | Dmc2 Degussa Metals Catalysts | Process for generating electrical energy using a fuel cell |
| EP1849200A2 (en) * | 2005-02-16 | 2007-10-31 | 3M Innovative Properties Company | Fuel cell catalyst |
| US20090320368A1 (en) * | 2006-03-31 | 2009-12-31 | Castaldi Marco J | Methods and Systems for Gasifying a Process Stream |
| US7906251B2 (en) * | 2006-04-20 | 2011-03-15 | 3M Innovative Properties Company | Oxygen-reducing catalyst layer |
| US7740902B2 (en) * | 2006-04-20 | 2010-06-22 | 3M Innovative Properties Company | Method for making oxygen-reducing catalyst layers |
| KR100821037B1 (en) * | 2006-11-03 | 2008-04-08 | 삼성에스디아이 주식회사 | Reformer for fuel cell and fuel cell employing the same |
| CN100459267C (en) * | 2007-07-03 | 2009-02-04 | 山东省科学院能源研究所 | Biomass hydrogen energy electric generation method |
| DE102009032524B3 (en) * | 2009-07-10 | 2011-02-03 | Highterm Research Gmbh | Reactor for producing a product gas by allothermic gasification of carbonaceous feedstocks |
| CN102249424A (en) * | 2011-04-02 | 2011-11-23 | 大连民族学院 | Proton exchange membrane-free microbiological fuel cell sewage treatment system and application method thereof |
| CA3005628C (en) * | 2015-11-17 | 2021-05-25 | Fuelcell Energy, Inc. | Fuel cell system having enhanced co2 capture |
| CN113036195B (en) * | 2021-03-05 | 2022-08-09 | 广东工业大学 | Electrolyte of biomass flow fuel cell, preparation method of electrolyte and biomass flow fuel cell |
Family Cites Families (21)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| FR1340155A (en) * | 1958-06-27 | 1963-10-18 | Process for producing hydrogen and other gases along with electrical energy from carbonaceous bodies, water and air | |
| GB1102726A (en) * | 1964-06-10 | 1968-02-07 | Engelhard Ind Inc | Improvements in or relating to fuel cells |
| FR1458408A (en) * | 1964-09-08 | 1966-03-04 | Texas Instruments Inc | Method and device for converting chemical energy to both electrical energy and thermal energy |
| US3393100A (en) * | 1965-10-01 | 1968-07-16 | Gen Electric | Process of generating electrical energy utilizing a fuel containing carbon monoxide and a fuel cell electrode structure therefor, comprising a carbon-monoxide resistant electrode body |
| US4090978A (en) * | 1976-12-28 | 1978-05-23 | Uop Inc. | Electrocatalysts and a method for the preparation thereof |
| US4128700A (en) * | 1977-11-26 | 1978-12-05 | United Technologies Corp. | Fuel cell power plant and method for operating the same |
| DE3018039A1 (en) * | 1980-05-10 | 1981-11-26 | Karl Otto Paul Chilliwack British Columbia Fischer | METHOD FOR THE PROCESSING OF CONIFIERS, ESPECIALLY LOW-WOOD CONIFERES FOR THE EXTRACTION OF ENERGY CARRIERS AND ROSES |
| JPS5869291A (en) * | 1981-07-08 | 1983-04-25 | Okutama Kogyo Kk | Gasification of solid fuel and gas producer |
| US4522894A (en) * | 1982-09-30 | 1985-06-11 | Engelhard Corporation | Fuel cell electric power production |
| JPS5968478A (en) * | 1982-10-08 | 1984-04-18 | サカイ鉄工有限会社 | Parking apparatus |
| US5141823A (en) * | 1984-03-03 | 1992-08-25 | Vickers Shipbuilding And Engineering Limited | Electrical generating plant |
| JPH0650643B2 (en) * | 1986-04-09 | 1994-06-29 | 株式会社日立製作所 | Method for manufacturing electrolyte plate for molten carbonate fuel cell |
| US4847172A (en) * | 1988-02-22 | 1989-07-11 | Westinghouse Electric Corp. | Low resistance fuel electrodes |
| NL8801492A (en) * | 1988-06-10 | 1990-01-02 | Kinetics Technology | PROCESS FOR CONVERTING FUEL TO ELECTRICITY. |
| JPH02117072A (en) * | 1988-10-26 | 1990-05-01 | Toyo Eng Corp | Fuel cell power generation system |
| JPH02172159A (en) * | 1988-12-24 | 1990-07-03 | Ishikawajima Harima Heavy Ind Co Ltd | Molten carbonate fuel cell power generation method and device |
| JP2926259B2 (en) * | 1989-06-09 | 1999-07-28 | 大阪瓦斯株式会社 | Solid electrolyte fuel cell |
| US4921765A (en) * | 1989-06-26 | 1990-05-01 | The United States Of America As Represented By The United States Department Of Energy | Combined goal gasifier and fuel cell system and method |
| US4983471A (en) * | 1989-12-28 | 1991-01-08 | Westinghouse Electric Corp. | Electrochemical cell apparatus having axially distributed entry of a fuel-spent fuel mixture transverse to the cell lengths |
| JP3108079B2 (en) * | 1990-07-05 | 2000-11-13 | 電源開発株式会社 | Fuel cell, carbon dioxide fixed combined power generation method |
| US5198310A (en) * | 1991-09-11 | 1993-03-30 | Institute Of Gas Technology | Thermal management in fuel cell system by feed gas conditioning |
-
1993
- 1993-02-25 IL IL10485893A patent/IL104858A/en not_active IP Right Cessation
- 1993-02-25 AT AT93102898T patent/ATE189082T1/en not_active IP Right Cessation
- 1993-02-25 EP EP93102898A patent/EP0564796B1/en not_active Expired - Lifetime
- 1993-02-25 ES ES93102898T patent/ES2143994T3/en not_active Expired - Lifetime
- 1993-02-25 PT PT93102898T patent/PT564796E/en unknown
- 1993-02-25 DE DE59309933T patent/DE59309933D1/en not_active Expired - Fee Related
- 1993-02-25 DK DK93102898T patent/DK0564796T3/en active
- 1993-03-10 JP JP5049068A patent/JPH0696790A/en not_active Ceased
- 1993-03-10 PL PL29801893A patent/PL298018A1/en unknown
- 1993-03-11 NO NO93930889A patent/NO930889L/en unknown
- 1993-03-11 CA CA002091495A patent/CA2091495C/en not_active Expired - Fee Related
- 1993-03-12 BR BR9301155A patent/BR9301155A/en not_active IP Right Cessation
- 1993-03-12 KR KR1019930003717A patent/KR930020198A/en not_active Ceased
- 1993-03-12 CN CN93102253A patent/CN1076553A/en not_active Withdrawn
- 1993-03-12 FI FI931113A patent/FI931113L/en not_active Application Discontinuation
- 1993-03-15 UA UA93002414A patent/UA42670C2/en unknown
-
1996
- 1996-04-02 US US08/630,884 patent/US5645951A/en not_active Expired - Lifetime
-
2000
- 2000-04-19 GR GR20000400967T patent/GR3033282T3/en not_active IP Right Cessation
Also Published As
| Publication number | Publication date |
|---|---|
| PL298018A1 (en) | 1993-11-02 |
| KR930020198A (en) | 1993-10-19 |
| UA42670C2 (en) | 2001-11-15 |
| US5645951A (en) | 1997-07-08 |
| IL104858A (en) | 1996-01-31 |
| FI931113A0 (en) | 1993-03-12 |
| DE59309933D1 (en) | 2000-02-24 |
| JPH0696790A (en) | 1994-04-08 |
| CA2091495A1 (en) | 1993-09-14 |
| DK0564796T3 (en) | 2000-07-10 |
| ES2143994T3 (en) | 2000-06-01 |
| BR9301155A (en) | 1993-09-21 |
| IL104858A0 (en) | 1993-06-10 |
| FI931113A7 (en) | 1993-09-14 |
| PT564796E (en) | 2000-07-31 |
| EP0564796B1 (en) | 2000-01-19 |
| FI931113L (en) | 1993-09-14 |
| GR3033282T3 (en) | 2000-09-29 |
| CN1076553A (en) | 1993-09-22 |
| NO930889L (en) | 1993-09-14 |
| NO930889D0 (en) | 1993-03-11 |
| ATE189082T1 (en) | 2000-02-15 |
| EP0564796A1 (en) | 1993-10-13 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CA2091495C (en) | Method for generating electric energy from biological raw materials | |
| US4925745A (en) | Sulfur tolerant molten carbonate fuel cell anode and process | |
| US4532192A (en) | Fuel cell system | |
| US4454207A (en) | Steam reforming of fuel to hydrogen in fuel cells | |
| US5308456A (en) | Molten carbonate fuel cell sulfur scrubber and method using same | |
| US20150299871A1 (en) | Partial oxidation of methane (pom) assisted solid oxide co-electrolysis | |
| CN105762386A (en) | Integration Of Reforming/water Splitting And Electrochemical Systems For Power Generation With Integrated Carbon Capture | |
| WO2000028610A1 (en) | Process and system for converting carbonaceous feedstocks into energy without greenhouse gas emissions | |
| IE60292B1 (en) | Dual compartment anode structure | |
| US20150080483A1 (en) | Power station-based methanation system | |
| US7981563B2 (en) | Direct carbon fuel cell with pre-wetted carbon particles | |
| WO1995006334A1 (en) | Modular power plant for the generation of electrical energy from solar energy | |
| EP2800188A1 (en) | Combined generation system and method for collecting carbon dioxide for combined generation system | |
| JP2560232B2 (en) | Solid oxide fuel cell and carbon direct oxidation electrode for the fuel cell | |
| US20250073695A1 (en) | Methods and systems for utilizing carbon dioxide in flue gas | |
| RU2107359C1 (en) | Process of generation of electric energy from biomaterials (versions) | |
| JP7666869B2 (en) | Carbon Dioxide Treatment Equipment | |
| US5071718A (en) | Use of sulfur containing fuel in molten carbonate fuel cells | |
| JP2005108509A (en) | Fuel cell power generation system | |
| CA2453854C (en) | Integrated biomass gasification and fuel cell system | |
| JP4467924B2 (en) | Fuel cell power generation system | |
| EP0284553B1 (en) | Use of sulfur containing fuel in molten carbonate fuel cells | |
| JP4467925B2 (en) | Control method for fuel cell power generation system, control program for realizing the control method, and recording medium recording the control program | |
| JPH01143155A (en) | Fuel cell power generator | |
| JPH0326913B2 (en) |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| EEER | Examination request | ||
| MKLA | Lapsed |