GB1597113A

GB1597113A - Method and apparatus for producing hydrogen and oxygen gases

Info

Publication number: GB1597113A
Application number: GB14153/77A
Authority: GB
Original assignee: BLUE WOOD HYDROTHON Ltd
Current assignee: BLUE WOOD HYDROTHON Ltd
Priority date: 1978-05-30
Filing date: 1978-05-30
Publication date: 1981-09-03

Description

(54) IMPROVED METHOD AND APPARATUS FOR PRODUCING HYDROGEN AND OXYGEN GASES (71) We, BLUE WOOD SYDROTHON LIMITED, a company organised under the laws of the Channel Islands, of 11, Clos du Petit Bois, Rue Cauchez, Saint Martin, Guernsey, Channel Islands, do hereby declare the invention, for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement:- This invention relates to the production of gases which can be utilised primarily but not necessarily as a fuel.

To electrically decompose water it is necessary to pass direct current between a pair of electrodes which are immersed in a suitable electrolyte. It is normal in such electrolysis to place some form of gas barrier between the two electrodes in order to prevent the gases evolved during the electrolysis from forming an explosive mixture. However provided suitable precautions are taken it has been found that the gases can be allowed to mix and can be fed into a storage tank for subsequent use. Because the gases when mixed form an explosive mixture, it is possible for the mixture to be utilised for instance as a fuel for an internal combustion engine. In such circumstances it is desirable that the gases should also be mixed with a certain proportion of air in order to control the explosive force which results when the gases are ignited.

According to one aspect of the present invention, a method of producing a gas mixture comprising hydrogen and oxygen includes the steps of passing air through an electrochemical cell in which the hydrogen and oxygen are produced electrochemically, in such a manner that the air flows past at least one electrode of the cell, and thereby entraining the gases formed in the electrochemical cell with the incoming air.

One of the difficulties encountered with electrolysis is that bubbles of gas are liable to remain on the electrodes during the electrolysis thus effectively limiting the area of electrode which is in contact with the electrolyte and preventing optimum current flow between the electrodes. Because in accordance with the present invention the gases evolved during the electrolysis are mixed with air, then it is possible for air to be passed through the cell while the electrolysis is in progress. The passage of air through the cell can be directed past the electrodes so as to entrain in the passage of air any bubbles of gas remaining on the electrodes.

Also according to the invention an electrochemical cell comprises an aqueous electrolyte container, a cathode electrode and an anode electrode in the container, means for supplying air to the container so as to flow past at least one electrode, and means for removal from the container of the mixture of hydrogen, oxygen and air produced in operation.

A suitable electrolysis cell for the generation of hydrogen and oxygen is a closed cell with an electrode assembly of aluminium plates having a tube running down the centre. The alternate aluminium plates are connected to respective terminals which in turn are connected to a source of electrical current, the said electrode assembly being suspened in an aqueous solution of caustic soda in the closed cell. Air passed down the said tube passes through the caustic solution in the cell and removes the gases from the aluminium plates, and the resulting mixture of air, H2 and O2 is taken off the top of the cell and fed into a storage tank or other apparatus for use. The electrodes serve to produce hydrogen and oxygen gases by the application of electrical current to the plates of the said assembly.Hydrogen and oxygen gases formed on the plates are taken off by means of the stream of air pumped through the centre of the said assembly and are led out of the cell forming a mixture of hydrogen and oxygen gases for use, e.g. as a fuel gas for heating or cooking, in such manner as may be needed or collected under pressure and stored in a suitable container.

The invention is illustrated, by way of example only, in the accompanying drawings, in which: Figure 1 shows an electrochemical cell pertinent to the practice of the invention, Figure 2 diagrammatically illustrates one construction of apparatus in accordance with the invention, and Figure 3 diagrammatically illustrates apparatus in accordance wih the invention for propelling a motor vehicle.

Figure 1 shows schematically an arrangement for the construction of the gas cell. In a vessel 20, oxygen electrodes 22 and hydrogen electrodes 23 are surrounded by an aqueous electrolyte 25, the cell having two sets of electrodes shown in section. Air is fed in from a pump through a plastics air inlet tube 26 to the bottom of the vessel 20 and into the electrolyte 25 by the opening 24 of the inlet tube 26. The gases hydrogen and oxygen produced by electrolysis in the cell are removed from the vessel 20 by means of a tube 28. The electrodes 22 and 23 are insulated from each other by means of insulating spacers 21. The inlet tube 26 is composed of plastics material to further insulate the electrodes. One set of electrodes 22 is connected to a positive terminal 4 and the other set of electrodes 23 is connected to a negative terminal 5.These terminals respectively are in turn connected to a source of direct current supply of high ampereage, but low voltage, such as a 12 volt storage battery.

The electrodes 22, 23 are perforated aluminium discs alternately connected to respective terminal posts 8 by leads 9, and the electrolyte is an aqueous caustic soda solution. The terminal posts also supply an electric heating element 6 in the bottom of the container for heating the electrolyte, particularly to assist starting up by bringing the cell quickly to an efficient operating temperature, and the bottom end of the tube 26 carries a deflector plate 10 to deflect the incoming air away from the heating element.

The container is airtight and is made of non-corrodible material e.g. plastics. In operation, electrolysis produces hydrogen and oxygen gases at the electrode discs and these gases are carried out of the cell through a tube 28 by the air flow through the cell. The air flow also agitates the electrolyte and prevents bubbles of the hydrogen and oxygen from adhering to the electrodes.

Figure 2 shows schematically a gas producing system. A cell 20 as in Figure 1 has inlet tube 26 connected to an air pump 27 which forces air through the electrolyte in cell 20. The purpose of the air passing through the electrolyte is to remove the gases formed on the electrodes in the cell 20 by means of the direct current applied to the terminals 4 and 5. The gases produced in cell 20 are then drawn off through tube 28 into a storage tank 31 for use as desired. The cell is energised by a low-voltage high-current battery 1, e.g. a motor vehicle battery. The battery may be charged by a wind generator 2 through a cut-out 3, and is connected through a switch 7 to the air pumps 27, and cell terminals 4, 5. The storage tank 31 has a pressure gauge 11, a safety valve, and an outlet pipe with a control valve 12.

The apparatus may also include currentlimiting and/or controlling means for controlling the intensity of the electrolytic reaction; a drier for drying the gas mixture produced in the cell; and means for automatically replenishing the water in the cell. The battery may be omitted if the generator can produce power at an appropriate voltage and current.

The gas mixture produced can be used for numerous purposes, e.g. for heating, lighting, or cooking, or for work such as welding, or cutting. It can also be used in an internal or external combustion engine for propelling a vehicle, a boat, or machinery e.g. a lawn mower.

Figure 3 shows very schematically an arrangement for propelling a car. The car is generally conventional with a battery 1 (which may however be of greater capacity than is normal in a petrol-engined car), and an internal combustion engine 32 with a carburettor 33 and a generator (not shown) for recharging the battery. Conventional control and safety devices for the electrical system of the car are also provided. The battery energises an electrolytic cell 20 of the construction shown in Figure 1, a first pump 34 which takes in air from the atmosphere and supplies it to the cell 20, and a second pump which pumps the combustible gas mixture from the cell to the carburettor for burning in the engine. The mixture is fed at a relatively low pressure, and can thus be fed directly into the carburettor without any special measures to control the pressure.

WHAT WE CLAIM IS 1. A method of producing a gas mixture comprising hydrogen and oxygen which includes the steps of passing air through an electrochemical cell in which the hydrogen and oxygen are produced electrochemically, in such a manner that the air flows past at least one electrode of the cell, and thereby entraining the gases formed in the electrochemical cell with the incoming air.

2. A method as claimed in claim 1 in which the cell contains electrodes of respective different electrical polarities immersed in an aqueous electrolyte whereby the hydrogen and oxygen are liberated by electrolysis at respective electrodes.

3. A method as claimed in claim 2 in which the air is passed through the electrolyte.

4. A method as claimed in claim 2 or 3 in which the electrolyte is heated.

5. A method for producing by electrolysis of an aqueous liquid a combustible mixture of air, hydrogen and oxygen, comprising: electrolysing the aqueous liquid into

**WARNING** end of DESC field may overlap start of CLMS **.

Claims

**WARNING** start of CLMS field may overlap end of DESC **. construction of apparatus in accordance with the invention, and Figure 3 diagrammatically illustrates apparatus in accordance wih the invention for propelling a motor vehicle. Figure 1 shows schematically an arrangement for the construction of the gas cell. In a vessel 20, oxygen electrodes 22 and hydrogen electrodes 23 are surrounded by an aqueous electrolyte 25, the cell having two sets of electrodes shown in section. Air is fed in from a pump through a plastics air inlet tube 26 to the bottom of the vessel 20 and into the electrolyte 25 by the opening 24 of the inlet tube 26. The gases hydrogen and oxygen produced by electrolysis in the cell are removed from the vessel 20 by means of a tube 28. The electrodes 22 and 23 are insulated from each other by means of insulating spacers 21. The inlet tube 26 is composed of plastics material to further insulate the electrodes. One set of electrodes 22 is connected to a positive terminal 4 and the other set of electrodes 23 is connected to a negative terminal 5.These terminals respectively are in turn connected to a source of direct current supply of high ampereage, but low voltage, such as a 12 volt storage battery. The electrodes 22, 23 are perforated aluminium discs alternately connected to respective terminal posts 8 by leads 9, and the electrolyte is an aqueous caustic soda solution. The terminal posts also supply an electric heating element 6 in the bottom of the container for heating the electrolyte, particularly to assist starting up by bringing the cell quickly to an efficient operating temperature, and the bottom end of the tube 26 carries a deflector plate 10 to deflect the incoming air away from the heating element. The container is airtight and is made of non-corrodible material e.g. plastics. In operation, electrolysis produces hydrogen and oxygen gases at the electrode discs and these gases are carried out of the cell through a tube 28 by the air flow through the cell. The air flow also agitates the electrolyte and prevents bubbles of the hydrogen and oxygen from adhering to the electrodes. Figure 2 shows schematically a gas producing system. A cell 20 as in Figure 1 has inlet tube 26 connected to an air pump 27 which forces air through the electrolyte in cell 20. The purpose of the air passing through the electrolyte is to remove the gases formed on the electrodes in the cell 20 by means of the direct current applied to the terminals 4 and 5. The gases produced in cell 20 are then drawn off through tube 28 into a storage tank 31 for use as desired. The cell is energised by a low-voltage high-current battery 1, e.g. a motor vehicle battery. The battery may be charged by a wind generator 2 through a cut-out 3, and is connected through a switch 7 to the air pumps 27, and cell terminals 4, 5. The storage tank 31 has a pressure gauge 11, a safety valve, and an outlet pipe with a control valve 12. The apparatus may also include currentlimiting and/or controlling means for controlling the intensity of the electrolytic reaction; a drier for drying the gas mixture produced in the cell; and means for automatically replenishing the water in the cell. The battery may be omitted if the generator can produce power at an appropriate voltage and current. The gas mixture produced can be used for numerous purposes, e.g. for heating, lighting, or cooking, or for work such as welding, or cutting. It can also be used in an internal or external combustion engine for propelling a vehicle, a boat, or machinery e.g. a lawn mower. Figure 3 shows very schematically an arrangement for propelling a car. The car is generally conventional with a battery 1 (which may however be of greater capacity than is normal in a petrol-engined car), and an internal combustion engine 32 with a carburettor 33 and a generator (not shown) for recharging the battery. Conventional control and safety devices for the electrical system of the car are also provided. The battery energises an electrolytic cell 20 of the construction shown in Figure 1, a first pump 34 which takes in air from the atmosphere and supplies it to the cell 20, and a second pump which pumps the combustible gas mixture from the cell to the carburettor for burning in the engine. The mixture is fed at a relatively low pressure, and can thus be fed directly into the carburettor without any special measures to control the pressure. WHAT WE CLAIM IS

1. A method of producing a gas mixture comprising hydrogen and oxygen which includes the steps of passing air through an electrochemical cell in which the hydrogen and oxygen are produced electrochemically, in such a manner that the air flows past at least one electrode of the cell, and thereby entraining the gases formed in the electrochemical cell with the incoming air.

4. A method as claimed in claim 2 or 3 in which the electrolyte is heated.

hydrogen and oxygen in an electrolytic cell having a gas-tight casing, a substantially central tubular post mounted in the casing and having an air inlet at its upper end, and a plurality of electrodes supported on the post and axially spaced therealong, alternate electrodes being connected to a first electrical terminal and to a second electrical terminal respectively connected to a respective poles of a current source and being mutually insulated, the post having an air outlet below the electrodes out of which flows air from the air inlet into the cell and over the electrodes; and a source of air under pressure connected to the said air inlet forcing a flow of air through the aqueous liquid contained in the cell in operation thereof; the cell having in its upper region a common outlet exhausting the combustible mixture comprising air forced through the cell and hydrogen and oxygen produced by electrolysis of said liquid in said cell.

6. A method as claimed in any preceding claim in which the air is supplied by a pump.

7. A method of operating an internal combustion engine, comprising producing a gas mixture as set forth in any of the preceding claims, supplying the gas mixture to the engine by way of a carburettor of the engine, and burning the gas mixture in the engine.

8. A method as claimed in claim 7 in which the gas mixture is supplied to the carburettor by a pump.

9. A method as claimed in claim 7 or 8 in which the engine is a propulsion engine of a vehicle.

10. An electrochemical cell which comprises an aqueous electrolyte container, a cathode electrode and an anode electrode in the container, means for supplying air to the container so as to flow past at least one electrode, and means for removal from the container of the mixture of hydrogen, oxygen and air produced in operation.

11. Apparatus for producing by electrolysis of an aqueous liquid a combustible mixture of air, hydrogen and oxygen, comprising: an electrolytic cell having a gas-tight casing, a substantially central tubular post mounted in the casing and having an air inlet at its upper end and a plurality of electrodes supported on the post and axially spaced therealong, alternate electrodes being connected to a first electrical terminal and to a second electrical terminal respectively for connection to respective poles of a current source and being mutually insulated, the post having an air outlet below the electrodes for flow of air from the air inlet into the cell and over the electrodes; a dish-shaped air deflector supported on said post below said air outlet; and a source of air under pressure connected to the said air inlet for forcing a flow of air through the aqueous liquid contained in the cell in operation thereof; the cell having in. its upper region a common outlet for exhausting the combustible mixture comprising air forced through the cell and hydrogen and oxygen produced by electrolysis of said liquid in said cell.

12. The apparatus claimed in claim 10 or 11 comprising electrodes in the form of perforated horizontal plates, and having,an air inlet below said plates whereby the air will rise through the said plates.

13. The apparatus claimed in claim 10, 11 or 12 further including means for heating the electrolyte in the cell.

14. The apparatus claimed in any of claims 10 to 13 further including a pump connected to the cell for supplying air thereto.

15. The apparatus claimed in any of claims 10 to 14 in a vehicle having an internal combustion engine with a carburettor, the cell being connected to supply the produced mixture of air, oxygen and hydrogen to the carburettor.

16. The apparatus claimed in claim 15 further including a pump connected between the cell and the carburettor for supplying the said mixture to the latter.

17. Apparatus for producing a combustible mixture containing hydrogen, oxygen and air, substantially as herein described with reference to the accompanying drawings.

18. A method of producing a combustible mixture containing hydrogen, oxygen and air, as claimed in any of claims 1 to 6 and substantially as herein described.