Zero-emission cogeneration device for the production of hydrogen, electric energy, and thermal energy

Abstract

A system for the production of hydrogen and heat energy through spontaneous electrochemical redox reactions is described, which is composed of at least one reactor (1) consisting of a feed line (2) that introduces the reaction material into the reaction cell (6); at least one discharge body (12) for the hydroxide produced during the reaction, in which the pH is converted to the desired value by introducing an acidic solution through a dosing line (13); at least one water injection line (3) that supplies water to the reaction cell (6); at least one cathode body (5) made of a porous material containing gaseous oxygen; at least one filling line (4) that allows the oxygen to be replenished at the cathode body (5); at least one porous material filter (7) for separating the hydrogen from the solid residues produced in the reaction; and at least one exhaust line (8) for releasing the hydrogen. The system is configured to perform the process of producing hydrogen and heat energy through redox reactions between the material used as anode, the material used as cathode and the material used as electrolyte.

Description

Technical Field

[0001] According to the preamble of each independent claim, the present invention relates to the implementation of an integrated system of reactors in which a metal (preferably aluminum) and oxygen undergo a redox reaction in an aqueous environment, producing hydrogen and heat, and an integrated device designed to recover the heat energy generated by the reaction. The resulting system is intended for use in all sectors requiring the replacement of fossil fuel-based energy sources with zero-emission energy. Due to its availability and high energy density, aluminum can play a crucial role in the energy transition. Background Technology

[0002] It is known in the art that under certain conditions, some metals such as zinc, aluminum, and silicon react with water to form their respective hydroxides, and pure hydrogen is generated from the water through a phenomenon known as hydrolysis. Many patents and publications illustrate this principle in different ways, but they all suffer from two main problems: catalysts made of rare earth elements or aluminum alloys containing these elements are expensive, or the aluminum is pulverized to prevent passivation during the reaction, which in turn hinders the completion of the reaction. Handling aluminum powder is extremely dangerous due to its flammable properties. Various hydrogen generators have been developed in the past. The following patent documents constitute a comprehensive catalogue of prior art devices and methods for generating hydrogen by reacting aluminum or aluminum alloys with water.

[0003] US Patent 909,536, published by GF Brindley et al., claims protection for various components of the reactive metal used to generate hydrogen. These components include any flake or powdered metal that is capable of forming hydroxides when in contact with a suitable hydroxide solution. Specifically, aluminum reacts with a high concentration of sodium hydroxide in an aqueous solution, releasing hydrogen and producing sodium aluminate.

[0004] US Patent 2,721,789, published by QC Gill on October 25, 1955, discloses the structure of a hydrogen generator for reacting water with dry aluminum particles and sodium hydroxide flakes. The reaction releases hydrogen gas and produces sodium aluminate.

[0005] US Patent 3,957,483, published by M. Suzuki on May 18, 1976, claims protection for a magnesium plate on which powdered elements such as iron, zinc, chromium, aluminum, and manganese are deposited, which are always in contact with an aqueous solution of sodium hydroxide to form hydrogen.

[0006] U.S. Patent 3,975,913, published by DC Erickson on August 24, 1976, discloses a hydrogen generator in which molten aluminum is allowed to react with water. The generator is maintained at a high temperature to keep the metal in a molten state.

[0007] US Patent 4,730,601, published on March 15, 1988, by HD Hubele et al., describes an apparatus comprising a reaction tank for reacting a reactive fuel composition with water. The fuel composition consists of magnesium and aluminum in a molar ratio of 1:2, and a second portion consists of lithium hydride, magnesium, and aluminum in equimolar ratios.

[0008] US Patent 4,752,463, published on June 21, 1988 by K. Nagira et al., discloses an alloy that reacts with water to produce hydrogen. The alloy is primarily composed of aluminum and 5% to 50% tin.

[0009] US Patent 5,143,047, published by WW Lee on September 1, 1992, describes an apparatus and method for generating steam and hydrogen. In this apparatus, aluminum powder or an aluminum alloy is allowed to react with water to generate hydrogen. An electrical energy source is used to initiate the reaction. This electrical energy is used to cause an explosion in the aluminum conductor, dispersing molten aluminum sheets into a mixture of water and aluminum powder. A heat exchanger is provided to extract the useful heat.

[0010] US Patent 2021 / 0276865 A1, filed by Laurene Meroueh of MIT, claims protection for the use of a specially prepared alloy in a reactor containing 50% aluminum and smaller proportions of gallium, bismuth, indium, and other elements for hydrogen production from water at ambient temperature and pressure. Gallium and the other elements act as catalysts because, although they are part of the fuel, they do not participate in the reaction but rather allow it to proceed completely, while preventing the aluminum from passivating upon contact with oxygen in the water.

[0011] Over the past century, many other methods for producing hydrogen from water have been studied, including reactions involving magnesium, sodium, potassium, lithium, calcium, iron, zinc, or steel.

[0012] Despite the undeniable advantages of existing hydrogen production methods, the reaction of ordinary aluminum with water at room temperature and pressure to release hydrogen and heat without external energy or catalysts has never been provided, observed, or disclosed by existing inventors or researchers.

[0013] A successful energy transition requires abundant and low-cost resources, such as recycled aluminum, or secondary aluminum, collected from selective waste. As mentioned earlier, this form of reactant has never been the subject of patents, nor has a technology been developed to address the main known problem limiting its use: the formation of an Al2O3 surface layer that prevents reaction with water itself. Summary of the Invention

[0014] The primary objective of this invention is to overcome the widely recognized shortcomings of known technologies, and to achieve this objective, this patent describes and claims a system and a series of processes based on previously neglected methods: namely, electrochemical methods. As widely described, although different methods were employed, the previously used methods were entirely chemical. Aluminum was treated as a reactant, chopped, crushed, or alloyed with other rare earth elements, and regardless of the pretreatment used, the reaction water could also be pretreated by adding alkali metal salts or heating or vaporizing. Even when these measures were partially implemented, they either failed to solve the problem or were too costly to implement.

[0015] In its chemical properties, aluminum has the ability to oxidize by losing electrons. In fact, in an anodic-cathode electrochemical system in an aqueous electrolyte (known as a metal-air battery), the reaction is as follows: Anode reaction:

[0016] Cathode reaction:

[0017] This creates a potential difference that increases the system's energy, namely, polarized aluminum. The aluminum is no longer passivated, but instead interacts with the potential generated by oxygen reduction. The ionic reaction produces aluminum hydroxide and hydrogen gas, as shown below: +calories Unlike existing technologies, hydroxide ions are not provided by the dissociation of strong bases, but are generated during the reaction through the reduction of oxygen present in the material or component that serves as the cathode.

[0018] In addition to the purely electrochemical properties mentioned earlier, aluminum also has a high energy density, and besides producing hydrogen, it also serves as an important source of continuously released heat energy during this reaction process.

[0019] In addition to producing and processing hydrogen from water splitting, the system of the present invention also describes and claims the conversion of heat into electrical energy through the use of a heat exchanger that powers a steam turbine operating in a Rankine cycle.

[0020] This invention includes a system for generating hydrogen and thermal energy via a spontaneous electrochemical redox reaction according to claim 1, and a method for generating hydrogen and thermal energy via a redox reaction according to claim 8. Specific embodiments are the subject of the dependent claims and their content should be considered part of this specification. Attached Figure Description

[0021] exist Figure 1 The diagram schematically illustrates a system for carrying out the method claimed herein. It is a reactor 1, into which aluminum scrap is introduced via a feed system 2 and water is introduced via a water injection line 3. The material settles in a reaction tank 6, contacting a cathode 5 and a grid 16 to separate hydroxides during the reaction; the hydroxides, due to their powdery consistency, fall into an exhaust 12. The cathode 5 is made of an oxygen-rich porous material, to which oxygen or an oxygen-rich material is supplied via a line 4. The heat generated by the reaction is transferred to a separate hydraulic circuit equipped with a heat exchanger 9, which powers a steam turbine 10, which in turn supplies power to a generator 11. Hydrogen produced by the water splitting reaction in reactor 1 passes through a sponge filter 7 located at the top of reactor 1 and is directed to a storage location or user location via an exhaust line 8. The hydroxide formed during the aluminum-water reaction in reactor 1's reaction tank 6, due to its alkaline nature, falls through grid 16 into neutralization chamber 12, where it is neutralized by contact with an acidic solution introduced via pipeline 13. The progress of the neutralization reaction is monitored by pH sensor 14, and once the desired pH value is reached, the hydroxide is safely discharged through discharge pipeline 15.

Claims

1. A system for generating hydrogen and thermal energy through a spontaneous electrochemical redox reaction, the system comprising: At least one reactor (1) includes a feed line (2) for introducing reaction materials into a reaction tank (6), in which all elements involved in the reaction come into contact with each other; At least one discharge body (12) is provided, wherein the hydroxide produced by the reaction enters the at least one discharge body (12) under gravity through a grid (16), wherein the pH is adjusted to a desired value by introducing an acidic solution from a feed line (13), a pH sensor (14) is provided for reading the instantaneous pH value, and a discharge line (15) is provided for discharging the hydroxide once the desired pH value is reached. At least one water injection line (3) is used to introduce water into the reaction tank (6). At least one cathode (5) is made of a porous material containing oxygen; At least one refueling line (4) allows for reoxygenation at the cathode body (5) after oxygen depletion; At least one porous material filter (7) is used to separate hydrogen from the solid residues produced in the reaction; and At least one exhaust line (8) is used for hydrogen escaping.

2. The system for generating hydrogen and heat energy according to claim 1 further includes a heat exchanger (9) capable of transferring the heat energy generated by the reaction in the reactor (1) to an external circuit connected to a steam turbine (10), which is then connected to a generator (11).

3. The system for generating hydrogen and heat energy according to claim 1, wherein, The material (2) is uncut and unpulverized recycled aluminum.

4. The system for generating hydrogen and heat energy according to claim 1, wherein, It has a body that serves as a reaction tank (6) and is in contact with the cathode body (5), with material introduced from the feed line (2) serving as the anode and water introduced from the water injection line (3) serving as the electrolyte.

5. The system for generating hydrogen and heat energy according to claim 1, wherein, The cathode (5) is adapted to be supplied with oxygen or oxygen-containing material by the filling pipeline (4).

6. The system for generating hydrogen and heat energy according to claim 1, wherein, The discharge body (12) serves as a neutralization chamber and supplies an acidic aqueous solution via the injection line (13). The solution is introduced manually or automatically according to the desired pH value read from the sensor (14), and the neutralized hydroxide is discharged from the discharge line (15).

7. The system for generating hydrogen and heat energy according to claim 1, wherein, The porous material filter (7) can be made of a sponge or other material suitable for separating hydrogen from the solid residues produced in the reaction, and the filtered hydrogen is delivered to the user through an exhaust line (8).

8. A method for generating hydrogen and thermal energy through a redox reaction between a material used as an anode, a material used as a cathode, and a material used as an electrolyte, comprising: The metal used as the anode is introduced into the reaction tank (6) of the reactor (1) through the feed line (2); Water, which is used as an electrolyte, is introduced into the reaction tank (6) from the water injection line (3) to immerse the heat exchanger (9). Oxygen or oxygen-rich material is introduced into the cathode body (5) through the injection line (4); The reaction begins in the reaction tank (6), and hydrogen gas passes through a porous material filter (7) and is discharged through an exhaust line (8); The heat energy generated by the reaction is transferred through the heat exchanger (9), the Rankine cycle is realized by the steam turbine (10), and the work is converted and used by the generator (11); When the reaction in the reaction tank (6) ends, aluminum hydroxide falls completely into the discharge body (12) through the grid (16); The pH value of the hydroxide contained in the emission body (12) is read by sensor (14); The acidic solution is introduced into the discharge body (12) through the injection line (13); The pH value is read by the sensor (14), and an acidic solution is introduced from the infeed line (13) until the desired pH value is achieved; and Aluminum hydroxide and water are discharged from the discharge line (15).

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