System and Method of Producing Hydrogen from Superheated Water Vapour

Abstract

The invention can be used in the creation of devices for producing hydrogen as fuel, including at energy-intensive industrial facilities. Disclosed is a system for producing hydrogen from superheated water vapour which includes the following units: a generating unit comprising, arranged coaxially in the direction from the centre to the periphery: a centre electrode, a cathode, a solid oxide electrolyte tube with oxygen ion conductivity sealed at one end, an anode and permanent magnets; an electric power unit that supplies voltage to the cathode, the anode, and the centre electrode; a control unit and a measuring gas unit. The control unit receives data from the measuring gas unit and performs a two-way communication with the electric power unit. The electric power unit, the control unit and the measuring gas unit are combined into a single unit which performs a two-way communication with the generating unit. The measuring gas unit is a system of sensors. Also disclosed is a method for producing hydrogen using this system. The group of inventions makes it possible to simplify the design of the hydrogen production system and to facilitate process adjustment, automation, control, controlled effective feedback, and expansion of the range of energy-efficient means and methods for producing hydrogen. 2 independent and 3 dependent claims, 2 drawings, 1 ex.

Description

Untitled System and Method of Producing Hydrogen from Superheated Water Vapour Technical field The proposed technical solution relates to the field of electrochemical engineering and can be used in the creation of devices for producing hydrogen as fuel, including at energy-intensive industrial facilities. In particular, the proposed technical solution relates to a system and method of producing hydrogen from superheated water vapour. Prior art The industrial production of hydrogen is an integral part of hydrogen power engineering, the first link in the life cycle of hydrogen utilisation. Hydrogen is practically not found on earth in pure form and must be extracted from other compounds using various chemical methods. The electrolysis method of producing hydrogen from water is of great interest due to its simplicity and high purity of the obtained gas components. The electrolysis method of producing hydrogen from water has the following positive qualities: 1) the high purity of the obtained hydrogen – up to 99.99% and higher, 2) the simplicity of the technological process, its continuity, the possibility of most complete automation, the absence of moving parts in the electrolytic cell, 3) the possibility of obtaining valuable by-products: heavy water and oxygen, 4) the generally available and inexhaustible raw material: water, 5) the flexibility of the process and the possibility of obtaining hydrogen directly under pressure, 6) the physical separation of hydrogen and oxygen in the same electrolysis procedure. Thus there is a need for an improvement of means and methods for hydrogen production, particularly electrolysis methods. From Patent RU 2309198, published October 27, 2007, a device for an electrolytic production of hydrogen and oxygen is known, containing technical lines for the supply of water and electrolyte and withdrawal of electrolysis products, an electrolyser including a housing with upper and lower lids made of electrically conductive material, installed on a shaft connected with a rotational drive with channels for supply of electrolyte solution and withdrawal of electrolysis products, short-circuited electrodes, one of which is arranged on the shaft and the other is formed by the inner surface of the housing, wherein the line for withdrawing the electrolysis products comprises a device for discharging the electrolysis products and a separator, connected in series, the line for the supply of water and electrolyte comprising a container for water and electrolyte, a device for regulating the water outlet, valves, a mixer and a heat exchanger, see the patent. The device is equipped with an electromagnetic system, including immovable magnets in the form of disks, installed in parallel above the upper and under the lower lids of the housing, mechanically connected to them by a magnet circuit with an exciter coil and electrically connected to the pulse generator and the voltage converter; on the line for withdrawing the electrolysis products a gas analyser is installed, the inlet of which is connected to the outlet of the device for discharging electrolysis products, and the outlet is connected to the device for regulating the water outlet, wherein the short-circuited electrode arranged on the shaft is cylindrically shaped with radial channels. Also known is an installation for the decomposition of water by electrolysis according to Patent RU 2224051, published February 2, 2004, containing technical lines for the supply of water and electrolyte and withdrawal of electrolysis products, an electrolyser including a housing mounted on a shaft connected with a rotational drive with channels for the supply of electrolyte solution and the withdrawal of electrolysis products, a channel for the withdrawal of electrolyte solution, short-circuited electrodes, one of which is arranged on the shaft, and the other is formed by the inner surface of the housing, and a heat exchanger, as well as upper and lower bearing nodes in which the shaft is vertically arranged. The external circuit for electrolyte solution circulation contains an annular chamber of electrolyte solution with an inner surface in the form of a cochlea, stationarily installed on the upper bearing node, a sensor for the presence of electrolyte solution and an electrolyte solution mixer connected to the supply lines of electrolyte and water and the supply channel of electrolyte solution, wherein the body of the electrolyser is made of electrically conductive material and equipped with lower and upper lids made of electrically conductive material, the electrolyte solution discharge channel being formed in the upper lid of the electrolyser and equipped with a control valve communicating with an annular electrolyte solution chamber, on the inner surface of the housing of which at least one guiding groove is provided, and on the water supply line a water outlet regulation valve is arranged, a discharge line for the electrolysis products equipped with a device for withdrawing the electrolysis products, a heat exchanger is arranged in the external circuit for electrolyte solution circulation, and the sensor for the presence of electrolyte solution is connected to the water outlet regulation apparatus and the rotational drive of the shaft. The disadvantages of the known device include the complexity of construction and low productivity. The solutions according to RU Patent 2675862, published December 25, 2018, relating to a method of decomposition of water into oxygen and hydrogen and a device for its realization, can be considered the most pertinent prior art. The method is carried out by applying electric and magnetic fields to water flowing through inter-electrode cavities. Herein a constant pulsed electric field is applied to arranged coaxially tubular insulated hydrogen electrodes of negative potential and insulated oxygen electrodes of positive potential, separated by inter-electrode cavities having inlet and outlet water apertures, the spaces of which are connected to the spaces of hydrogen and oxygen electrodes through gas apertures. Thus water flowing between the electrodes is decomposed into hydrogen and oxygen ions under the influence of the electric and magnetic fields, and hydrogen ions are drawn through the apertures of the hydrogen electrode by a negative static field formed by a negative current-conducting isolated hydrogen surface into the oxygen electrode; correspondingly, oxygen ions are drawn through the apertures of the oxygen electrode by a positive static field formed by a positive isolated current-conducting surface into the oxygen electrode, in which the hydrogen and oxygen ions are neutralised by the negative and positive neutralising surfaces respectively, and exit through each of its apertures as atoms for further use. The disadvantages of the known solutions include the complexity of design of the device, high energy consumption for hydrogen production, and the impossibility to regulate the process of hydrogen production. The aim of the proposed inventions is to eliminate the disadvantages of the prior art, to simplify the construction of the system and method for producing hydrogen, to facilitate process adjustment, automation and control, to obtain controlled effective feedback, and to expand the range of energy-efficient means and methods of hydrogen production. List of figures FIG. 1 shows a schematic diagram of the system for producing hydrogen from superheated water vapour.FIG. 2 shows an exterior view of the experimental / research apparatus in assembled form. Disclosure of the invention The technical result of the group of inventions is the simplification of the construction of the system and the method for producing hydrogen, the facilitation of process adjustment, automation, control, the obtainment of controlled effective feedback, the increase of the scalability and efficiency of gas-tight separation of anode and cathode gas spaces, mass and heat transfers, the expansion of the range of energy-efficient means and methods of hydrogen production. A method of producing hydrogen from superheated water vapour and a system for its realization are proposed to solve the set technical task and achieve the technical result. The proposed system for producing hydrogen (H2) from superheated water vapour includes the following units:- a generating unit (1) comprising, arranged coaxially from the centre to the periphery: a centre electrode (8), a cathode (7), a solid oxide electrolyte tube with oxygen ion conductivity (5) sealed at one end, an anode (6) and permanent magnets (9);- an electric power unit (2) supplying voltage to the cathode, anode and centre electrode;- a control unit (3);- a measuring gas unit (4),wherein the control unit receives data from the measuring gas unit and performs a two-way communication with the electric power unit. In a particular embodiment of the system, the units (2), (3) and (4) are combined into a single unit that communicates bilaterally with the generating unit (1). The proposed method for producing hydrogen (H2) from superheated water vapour includes the following steps:- superheated (500-950°C) water (H2O) vapour is fed through the centre electrode (8) into a tube of solid oxide electrolyte with oxygen ion conductivity (5);- the superheated water vapour impinges on the cathode (7);- a pulse voltage is applied between the cathode (7) and the centre electrode (8) using the electric power unit (2), resulting in partial decomposition of the water vapour into oxygen ions and hydrogen ions;- part of the water vapour, impinging on the cathode (7), loses the oxygen ion;- caused by the potential difference between the cathode (7) and anode (6), oxygen ions pass through the tube of solid oxide electrolyte with oxygen ion conductivity (5) and exit on the other side as pure oxygen, which enters the measuring gas unit (4);- hydrogen remaining in the solid oxide electrolyte tube with oxygen ion conductivity (5) enters the measuring gas unit (4);- oxygen and hydrogen from the measuring gas unit (4) further enter an external storage system (11);wherein the characteristics of the pulse voltage between the cathode (7) and the centre electrode (8) and the voltage between the cathode (7) and the anode (6) are set by the control unit (3), and in order to stabilize the characteristics of the pulse voltage between the cathode (7) and the centre electrode (8), a permanent magnetic field is created around the tube of solid oxide electrolyte with oxygen ion conductivity (5) by means of permanent magnets (9). Detailed description of the proposed invention and embodiments thereof The solid oxide electrolyte with oxygen ion conductivity (5) is a solid-body ion-conducting membrane. Oxygen ion conductivity is caused by a disruption of the crystal lattice when an impurity is introduced into it and occurs in a temperature range of 500-950°C. Variants of materials for solid oxide electrolyte (5) are zirconium oxide stabilized with yttrium oxide (YSZ); zirconium oxide stabilized with scandium oxide (ScSZ); lanthanum gallate (LSGM); cerium oxide alloyed with gadolinium (GDC), etc. The solid oxide electrolyte tube with oxygen ion conductivity (5) is sealed at one end to form a bottom needed to increase the effective surface area of the solid ion-conducting membrane and to increase the structural strength of the generating unit (1). To stabilize the pulse voltage characteristics, a constant magnetic field is created between the cathode (7) and the centre electrode (8) by permanent magnets (9). Variants of materials for the permanent magnets (9) are neodymium-iron-boron, samarium-cobalt, alnico (YuNDK, based on an Al-Ni-Co-Fe alloy), ceramics (magnetically hard barium or strontium ferrites), etc. The electric power unit (2) supplies the centre electrode (8) with unipolar positive pulses with a frequency in the range of 40 Hz – 1.5 MHz, with a relative duration in the range of 10-90, with a current up to 50 A and with a voltage in the range of 10-50 V. The electric power unit (2) supplies the cathode (7) and anode (6) with a constant voltage in the range of 5-20 V and with a current up to 100 A. The electric power unit (2) measures and transmits data on the actual mode of operation to the control unit (3): voltage, current, resonant frequency, etc. Variants of materials for the cathode (7), the anode (6), the centre electrode (8) are platinum, palladium, gold, nickel sponge coated with platinum, silicon carbide, graphite, graphene, platinum and nickel-based metal ceramics (nickel cermet); metal / metal ceramics (lanthanum chromite), lanthanum strontium manganite, etc. The measuring gas unit (4) measures and transmits to the control unit (3) the temperature of the hydrogen and oxygen gases, the partial pressure of the hydrogen and oxygen gases, the quantity of the hydrogen and oxygen gases over a time interval, the relative humidity of the hydrogen and oxygen gases (the water vapour residue), etc. A system of sensors is used as measuring gas unit. On the basis of the received data from the measuring gas unit (4) and the electric power unit (2) the control (processor) unit (3) analyses and controls the energy efficiency of the system as a whole, carrying out a controlled effective feedback. The control unit (3) transmits data on the scheduled mode of operation to the power unit (2): voltage, current, pulse characteristics (frequency, relative pulse duration), etc.  The coaxial arrangement of the elements of the generating unit (1) increases the scalability and efficiency of the gas-tight separation of the anode and cathode, gas spaces as well as mass and heat transfers. The combination of the initial resonant pulse electrolysis of water vapour and electrolysis of water vapour through a solid ion-transmitting membrane (5) facilitates a significant reduction of energy costs for the water vapour electrolysis. The heating of the solid membrane (5) to operating temperature is achieved by the heat of the superheated steam. Superheated water vapour is obtained by utilizing heat from solar collectors or heat generating / heat releasing plants: thermal power plants, waste incinerators, blast furnaces, etc. Since the water vapour is fed into the system under the pressure created by heating, this allows the creation of effective filters which cleanse hydrogen from water vapour residues and also facilitate the hydrogen supply into the external storage system (11). The high scalability of the proposed system / method makes it possible to create miniaturized solutions, to create high-output solutions, and to create both industrial solutions and solutions for private use. The originality of the proposed solution lies: 1) in the coaxial combination arrangement of the above solutions, 2) in the use of permanent magnets to stabilize the characteristics of the resonant pulse voltage, 3) in the use of a control (processor) unit to obtain controlled effective feedback. Implementation of the invention The proposed system and method are currently implemented in a LANEMATEC HYDX EHG-01experimental / research hydrogen generation apparatus with an output of 0.02-0.05 m3 / hour. The external view of the experimental / research apparatus in assembled form is shown in Fig. 2. The apparatus corresponds to the drawing given in the application (Fig. 1) and includes a unit (10) for generating superheated steam, a generating unit comprising, in coaxial arrangement, a tube of zirconium oxide stabilized with yttrium oxide and sealed at one end, an anode, a cathode, a centre electrode of graphite and neodymium-iron-boron permanent magnets, an electric power unit, a control unit (computer), a measuring gas unit system of sensors. From the unit (10) for generating superheated stem, water vapour superheated to a temperature of about 700°C is fed through the centre electrode into a tube of solid oxide electrolyte with oxygen ion conductivity; the superheated water vapour impinges on the cathode; a pulse voltage is applied between the cathode and the centre electrode by means of an electric power unit, resulting in partial decomposition of the water vapour into oxygen ions and hydrogen ions; part of the water vapour, impinging on the cathode, loses an oxygen ion; oxygen ions under the action of the potential difference between the cathode and the anode pass through the tube of solid oxide electrolyte with oxygen ion conductivity and exit on the other side as pure oxygen, which enters the measuring gas unit; hydrogen remaining in the tube of solid oxide electrolyte with oxygen ion conductivity enters the measuring gas unit; oxygen and hydrogen from the measuring gas unit further enter the external storage system (11). The characteristics of the pulse voltage between the cathode and the centre electrode and the voltage between the cathode and the anode are set by the computer (the control unit), and to stabilize the characteristics of the pulse voltage between the cathode and the centre electrode, a permanent magnetic field is created around the solid oxide electrolyte tube with oxygen ion conductivity by means of permanent magnets. The tests carried out on the LANEMATEC HYDX EHG-01 experimental / research apparatus confirmed the workability of the apparatus and its industrial applicability. This system and method provide an increase in energy efficiency by 5-12 times due to the reduction of electric power consumption for electrolysis. Up to 0.5-1 kWh per m3 H2 (water-alkaline low-temperature electrolysis: 5.0-6.0 kWh per m3 H2). The system and method use superheated water vapour obtained by using excess cheap / free heat: in thermal power plant installations, in high-temperature nuclear gas-cooled reactor (HTGR) installations, in waste incinerator installations, in blast furnace installations, etc. or using solar energy. Technically, this efficiency is provided due to a more efficient decomposition of superheated water vapour (into oxygen ions and hydrogen ions) by a pulse voltage and due to a more efficient operation of solid oxide electrolyte with oxygen ion conductivity, the operating temperature of which (500-950°C) is maintained by the temperature of superheated vapour, and the heating of which does not require electric energy. This system and method provide a high technological efficiency: a 10-20 times decrease in volume-mass characteristics; a 4-8 times increase in total productivity by current density: 2-2.5 A / cm2 (water-alkaline low-temperature electrolysis; current density 0.3-0.5 A / cm2); scaling (increase in total productivity) by simple arrangement of additional modules; high temperatures making electrolysis less critical to water purity; high temperatures increasing the total productivity by increasing the speed of the process; more efficient filtration of hydrogen and more efficient feeding of hydrogen into the storage system (11) due to the pressure of the superheated steam. Also, a full automation and adjustability of the hydrogen production process, its quality and quantity, are achieved.

Claims

1. System for producing hydrogen from superheated water vapour , comprising the following units: -     a generating unit comprising, arranged coaxially in the direction from the centre to the periphery, a centre electrode, a cathode, a solid oxide electrolyte tube with oxygen ion conductivity sealed at one end, an anode and permanent magnets; -     an electric power unit that supplies voltage to the cathode, the anode, and the centre electrode; -     a control unit; -     a measuring gas unit ; wherein the control unit receives data from the measuring gas unit and also performs a two-way communication with the electric power unit .

2. System according to claim 1, characterized in that the electric power unit, the control unit and the measuring gas unit are combined into a single unit facilitating two-way communication with the generating unit.

3. System according to claim 1 or 2, characterized in that the measuring gas unit is a system of sensors.

4. Method of producing hydrogen from superheated water vapour using the system according to claim 1, comprising the following steps: -           superheated water vapour at a temperature of 500-950°C is fed through the centre electrode into a tube of solid oxide electrolyte with oxygen ion conductivity; -           the superheated water vapour impinges on the cathode ; -           a pulse voltage is applied between the cathode and the centre electrode using an electric power unit for a partial decomposition of the water vapour into oxygen ions and hydrogen ions; -           part of the water vapour, impinging on the cathode, loses the oxygen ion; -           caused by the potential difference between the cathode and anode , oxygen ions pass through the tube of solid oxide electrolyte with oxygen ion conductivity and exit on the other side as pure oxygen, which enters the measuring gas unit; -           hydrogen remaining in the solid oxide electrolyte tube with oxygen ion conductivity is also fed into the measuring gas unit; -           oxygen and hydrogen from the measuring gas unit are further fed into an external storage system; wherein the characteristics of the pulse voltage between the cathode and the centre electrode and the voltage between the cathode and the anode are set by the control unit, and in order to stabilize the characteristics of the pulse voltage between the cathode and the centre electrode, a permanent magnetic field is created around the tube of solid oxide electrolyte with oxygen ion conductivity by means of permanent magnets.

5. Method according to claim 4, characterized in that the measuring gas unit is a system of sensors.

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