METHOD AND APPARATUS FOR PRODUCING AND SEPARATING COMBUSTIBLE GASSES

Abstract

The electrolysing apparatus (10) produces and separates combustible fluid, particularly combustible fluid containing predominately oxygen and hydrogen, formed during the electrolysis of an electrolytic solution disposed in the apparatus (10). The apparatus (10) comprises a first outer electrode (12), being an anode, a second outer electrode (14), being a cathode and two spaced apart foraminous members, a first foraminous member (16) and a second foraminous member (18), arranged generally parallel to one another and located between the two end electrodes (12 and 14).

Description

FIELD OF THE INVENTION

This invention relates to a method and apparatus for producing and separating combustible gasses. More particularly, this invention relates to an electrolysis cell and method in which hydrogen gas and oxygen gas produced through the electrolysis of an aqueous electrolytic solution are separated upon production.

BACKGROUND TO THE INVENTION

An electrolysis cell uses electricity to convert water to hydrogen and oxygen in gas phase. A known electrolysis cell includes a proton exchange membrane in order to separate the hydrogen and oxygen gases produced through the electrolysis process. The electrolysis cell further includes an anode positioned along a first face of the proton exchange membrane and a cathode positioned along a second opposite face of the proton exchange membrane.

A known proton exchange membrane is a semi-permeable membrane generally made from ionomers and designed to conduct protons while being impermeable to gases, such as oxygen and hydrogen. The essential function of the proton exchange membrane, when incorporated into the electrolysis cell, is to separate reactants and to transport protons. Proton exchange membranes can be made from either pure polymer membranes or from composite membranes where other materials are embedded in a polymer matrix.

A first disadvantage of the known proton exchange membrane is the high cost of the membrane, since it requires that a noble-metal catalyst (typically platinum) be used to separate the hydrogen's electrons and protons. The platinum catalyst is also extremely sensitive to carbon monoxide poisoning, making it necessary to employ an additional reactor to reduce carbon monoxide in the fuel gas if the hydrogen is derived from an alcohol or hydrocarbon fuel. This again adds to the cost of using the known proton exchange membrane.

Further disadvantages of the know proton exchange membranes are their poor conductivity at lower relative humidity and their poor mechanical properties at temperatures above approximately 100° C. The operating temperature of these membranes is relatively low and temperatures near 100° C. are not high enough to perform useful cogeneration.

In this specification, the term “combustible fluid” includes within its scope combustible gas containing predominantly hydrogen and/or oxygen in gas phase.

OBJECT OF THE INVENTION

It is accordingly an object of the present invention to provide a method and apparatus for producing and separating combustible gasses, with which the above disadvantages may be overcome and which are useful alternatives to known electrolysis cells and methods for separating combustible gasses.

SUMMARY OF THE INVENTION

According to a first aspect of the invention there is provided a method for separating combustible fluid produced from an electrolytic solution during a process of electrolysis including the steps of:

• • providing an electrolytic solution;
  • providing an electrolysing apparatus having first and second spaced apart foraminous members, defining a first chamber between them, having at least one inlet, and both foraminous members being located between first and second electrodes so that a first combustible fluid collection chamber, having a first combustible fluid outlet, is defined between the first foraminous member and the first electrode and a second combustible fluid collection chamber, having a second combustible fluid outlet is defined between the second foraminous member and the second electrode;
  • passing the solution into the first chamber via an inlet, so that the solution passes simultaneously through both foraminous members into the first and second combustible fluid collection chambers; and
  • applying a voltage across the electrodes to electrolyse the solution in the first and second combustible fluid collection chambers, so that a first combustible fluid forms in the first combustible fluid collection chamber and a second combustible fluid forms in the second combustible fluid collection chamber, and the first combustible fluid passes out of the first combustible fluid collection chamber via the first combustible fluid outlet and the second combustible fluid passes out of the second combustible fluid collection chamber via the second combustible fluid outlet.

The first and second electrodes may be a first outer electrode and a second outer electrode and the method may include the step of providing a plurality of intermediate floating electrodes.

The first foraminous member and the second foraminous member defining the first chamber and having at least one inlet, may together be a set of foraminous members, and the method may include the step of providing a plurality of sets of foraminous members arranged in a back-to-back configuration with one intermediate floating electrode disposed between adjacent sets of foraminous members.

The electrolysing apparatus may define at least one inlet passage in fluid flow communication with all of the inlets and the method may include the step of passing the solution into the first chambers of all of the sets of foraminous members via the inlet passage.

The electrolysing apparatus may define at least one first combustible fluid outlet passage in fluid flow communication with all of the first combustible fluid outlets and a second combustible fluid outlet passage in fluid flow communication with all of the second combustible fluid outlets, the arrangement being such that the first combustible fluid formed in the first combustible fluid collection chamber passes out of the apparatus via the first combustible fluid outlet passage and the second combustible fluid formed in the second combustible fluid collection chamber passes out of the apparatus via the second combustible fluid outlet passage.

According to a second aspect of the invention there is provided an electrolysing apparatus in which combustible fluid produced from an electrolytic solution during a process of electrolysis is separated comprising:

• • first and second spaced apart electrodes;
  • first and second spaced apart foraminous members located between the first and second electrodes;
  • a first chamber defined between the first and second foraminous members;
  • a first combustible fluid collection chamber defined between the first foraminous member and the first electrode;
  • a second combustible fluid collection chamber defined between the second foraminous member and the second electrode;
  • at least one inlet into the first chamber for the electrolytic solution;
  • a first combustible fluid outlet from the first combustible fluid collection chamber; and
  • a second combustible fluid outlet from the second combustible fluid collection chamber,
    the arrangement being such that the electrolytic solution passes into the first chamber via the inlet and passes simultaneously through both foraminous members into the first and second combustible fluid collection chambers respectively where electrolysis takes place; and such that a first combustible fluid forms in the first combustible fluid collection chamber; and such that a second combustible fluid forms in the second combustible fluid collection chamber; and such that the first combustible fluid passes out of the first combustible fluid collection chamber via the first combustible fluid outlet; and such that the second combustible fluid passes out of the second combustible fluid collection chamber via the second combustible fluid outlet.

The first electrode may be a first outer electrode and the second electrode may be a second outer electrode, and the apparatus may include a plurality of intermediate floating electrodes.

The first foraminous member and the second foraminous member defining the first chamber and having the at least one inlet, may be a set of foraminous members and the apparatus may include a plurality of sets of foraminous members connected to one another in a back-to-back configuration with one intermediate floating electrode positioned between adjacent sets of foraminous members.

The electrolysing apparatus may include a gasket positioned in the peripheral region between the two foraminous members forming the set of foraminous members.

The gasket may be a first gasket and the electrolysing apparatus may include a plurality of second gaskets, each positioned in the peripheral region between adjacent sets of foraminous members, surrounding the outer periphery of the intermediate floating electrode.

Each foraminous member may be provided with spacing means projecting from both faces thereof to space the foraminous member from the adjacent foraminous member and electrode.

The first and second outer electrodes may each be provided with a connector for connecting to a power supply to supply a voltage over the electrolysing apparatus to electrolyse the electrolytic solution.

The electrodes and foraminous members may all be disc shaped, so that the apparatus is cylindrical in shape.

The apparatus may include circulating means, such as a pump, to circulate the solution through the apparatus and to force the solution into the first chamber.

The inlets of the foraminous members may be aligned to define an inlet passage, so that electrolytic solution is passed into all of the first chambers of the apparatus via the inlet passage.

The first combustible fluid outlets may be aligned to define a first combustible fluid outlet passage, so that first combustible fluid produced in all of the first combustible fluid collection chambers passes out of the apparatus via the first combustible fluid outlet passage.

The second combustible fluid outlets may be aligned to define a second combustible fluid outlet passage, so that second combustible fluid produced in all of the second combustible fluid collection chambers passes out of the apparatus via the second combustible fluid outlet passage.

The apparatus may include a first combustible fluid collection container connected to the first combustible fluid outlet passage and a second combustible fluid collection container connected to the second combustible fluid outlet passage.

The first and second combustible fluid collection containers may each have a second electrolytic solution outlet located towards the operatively bottom end of each container and a first combustible gas and second combustible gas outlet located towards the operatively top end of the first and second combustible fluid collection containers respectively, the arrangement being such that electrolytic solution may pass out of the first and second combustible fluid outlets from the first and second combustible fluid collection chambers, together with the respective gases, into the first and second combustible fluid collection containers respectively, whereafter first and second combustible gasses are passed out of the containers via the first and second combustible gas outlets and the electrolytic solution is passed out of the containers via the second electrolytic solution outlets and may be circulated back to the inlets via the circulating means.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will now be described further by way of a non-limiting example with reference to the accompanying drawings wherein:

FIG. 1 is an exploded perspective view of part of an electrolysis apparatus according to a preferred embodiment of the invention;

FIG. 2 is a perspective view of the electrolysis apparatus of FIG. 1; and

FIG. 3 is a cross-sectional side view of the apparatus of FIG. 2 along line III-III.

DESCRIPTION OF A PREFERRED EMBODIMENT OF THE INVENTION

Referring to the drawings, an electrolysing apparatus according to a preferred embodiment of the invention is generally designated by reference numeral 10.

The electrolysing apparatus 10 is adapted to produce and separate combustible fluid, particularly combustible fluid containing predominately oxygen and hydrogen, formed during the electrolysis of an electrolytic solution disposed in the apparatus 10. The apparatus 10 comprises a first outer electrode 12, being an anode, and a second outer electrode 14, being a cathode. The first and second outer electrodes 12 and 14 are arranged generally parallel to one another and are spaced from one another.

The apparatus 10 further includes two spaced apart foraminous members, a first foraminous member 16 and a second foraminous member 18. The two foraminous members 16 and 18 are also arranged generally parallel to one another, are spaced from one another, and are both located between the two end electrodes 12 and 14. A first chamber 20 is disposed between the first and second foraminous members 16 and 18. A first combustible fluid collection chamber, being an oxygen collection chamber 22 is disposed between the first foraminous member 16 and the first electrode 12 and a second combustible fluid collection chamber, being a hydrogen collection chamber 24 is disposed between the second foraminous member 18 and the second electrode 14.

The first chamber 20 has two inlets 26 for allowing electrolytic solution to pass into the first chamber 20. The oxygen and hydrogen collection chambers 22 and 24 are each provided with a combustible fluid outlet. The oxygen collection chamber 22 is provided with an oxygen outlet 28 and a hydrogen collection chamber 24 is provided with a hydrogen outlet 30.

The first and second foraminous members 16 and 18 defining the first chamber 20 forms a set of foraminous members. The apparatus 10 includes a plurality of sets of foraminous members arranged and connected to one another in a back-to-back arrangement. FIGS. 2 and 3 shows the apparatus 10 including 4 sets of foraminous members between the first and second outer electrodes 12 and 14.

The apparatus includes a plurality of intermediate floating electrodes 42, positioned between adjacent sets of foraminous members.

The electrolysing apparatus 10 further includes a plurality of first gaskets 32 and a plurality of second gaskets 34. The first gasket 32 is positioned in the peripheral region and between the first and second foraminous members 16 and 18 to seal the two members 16 and 18 to one another and the second gasket 34 is positioned in the peripheral region between adjacent sets of foraminous members, surrounding the intermediate electrode 42.

The foraminous members 16 and 18 are made of polypropylene so that they are inert, non-conductive and non-reactive. Each foraminous member 16 and 18 includes a centre portion 16.1 and 18.1 respectively, each defining approximately 200 holes therein and an outer boundary 16.2 and 18.2 respectively, each defining the inlets 26 and outlets 28 and 30. Each hole defined by the centre portion 16.1 and 18.1 of the foraminous members 16 and 18 has a diameter of approximately from 0.1 mm to 3 mm, particularly approximately 1 mm. Each foraminous member 16 and 18 is further provided with spacing means 36 on their faces to space the foraminous members 16 and 18 from each other and from the adjacent electrode 12, 14 or 42.

The first and second electrodes 12 and 14 are made of a conductive material, such as stainless steel, and both include a connector 38 on their respective outer faces, for connecting to a power supply (not shown). The powers supply thus supplies a voltage of between 1 V and 6 V, preferably 3 V over the electrolysing apparatus 10 to electrolyse the solution. The intermediate electrodes 42 are also made of a conductive material, such as stainless steel.

The first and second electrodes 12 and 14 and the first and second foraminous members 16 and 18 are all disc shaped, so that the apparatus 10 is cylindrical in shape. The apparatus 10 has a diameter of approximately 250 mm with the diameter of the first and second foraminous members 16 and 18 being approximately 250 mm. The first and second foraminous members 16 and 18 are located approximately 4 mm apart from one another, with the first electrode 12 located at a distance of approximately 2 mm from the first foraminous member 16. Similarly, the second electrode 14 is located approximately 2 mm from the second foraminous member 18.

Corresponding inlets 26 of the foraminous members of the apparatus 10 are aligned to define inlet passages 44, so that electrolytic solution is passed into all of the first chambers of the apparatus 10 via the inlet passages 44. The oxygen outlets 28 are also aligned to define an oxygen outlet passage 46, so that oxygen produced in all of the oxygen collection chambers 22 passes out via the oxygen outlet passage 46. Similarly, the hydrogen outlets 30 are also aligned to define a hydrogen outlet passage 48, so that hydrogen produced in all of the hydrogen collection chambers 24 passes out via the hydrogen outlet passage 48.

The apparatus 10 further includes a circulating means, such as a pump (not shown) to circulate the solution through the apparatus 10. The electrolytic solution flowing into the first chamber 20 via the inlets 26 is pressurised by being pumped into the apparatus 10 by the pump, so that the solution is forced through the holes in the foraminous members 16 and 18 into the hydrogen and oxygen collection chambers 22 and 24. The arrangement is such that electrolytic solution flows into the first chamber 20 via the inlets 26, through the holes of both foraminous members 16 and 18 into the oxygen and hydrogen collection chambers 22 and 24 respectively, where electrolytic separation takes place. The oxygen passes out of the oxygen collection chamber 22 via the oxygen outlet 28 and the hydrogen passes out of he hydrogen collection chamber 24 via the hydrogen outlet 30.

The apparatus 10 further includes a hydrogen collection container (not shown) connected to the hydrogen outlet passage 48 and an oxygen collection container (also not shown) connected to the oxygen outlet passage 46. The oxygen and hydrogen collection containers each have a second electrolytic solution outlet located towards the operatively bottom end of the containers and oxygen and hydrogen gas outlets located towards the operatively top end of each of the oxygen and hydrogen collection containers, respectively. Electrolytic solution passes out of the oxygen and hydrogen outlets 28 and 30 from the oxygen and hydrogen collection chambers 22 and 24, together with the respective gases, into the oxygen and hydrogen collection containers via the outlet passages 46 and 48. The arrangement is such that hydrogen and oxygen gasses passing into the respective containers are passed out of the containers via the oxygen and hydrogen gas outlets and the electrolytic solution passes out of the containers via the second electrolytic solution outlets. The second electrolytic solution outlets are connected to the inlet passages 44 and the solution is circulated back to the apparatus 10 by means of the pump.

It is foreseen that there is a positive flow from the first chamber 20 to the oxygen and hydrogen collection chambers 22 and 24 of the apparatus 10.

The pressurised flow of the electrolytic solution from the first chamber 20 to the oxygen and hydrogen collection chambers 22 and 24, through the holes, restricts oxygen gas, after formation on the first electrode (anode) 12, and hydrogen gas, after formation of the second electrode (cathode) 14, to enter the first chamber 20.

It is further foreseen that the hydrogen ions and electrons migrate back through the first and second foraminous members 16 and 18 to the second electrode (cathode) 14 where it recombines to form hydrogen.

It will be appreciated that variations in detail are possible with a method and apparatus for producing and separating combustible gasses according to the invention without departing from the scope of the appended claims. For example, the amount of holes in the foraminous member may vary and they could have different sizes. Furthermore, the size of the cell and the apparatus, as well as the spacing between the foraminous members and electrodes could also vary. The apparatus 10 could further include any number of sets of foraminous members and intermediate floating electrodes 42, depending on the voltage supplied over the apparatus 40.

Claims

1. A method for separating combustible fluid produced from an electrolytic solution during a process of electrolysis including the steps of:

providing an electrolytic solution;

providing an electrolysing apparatus having first and second spaced apart foraminous members, defining a first chamber between them, having at least one inlet, and both foraminous members being located between first and second electrodes so that a first combustible fluid collection chamber, having a first combustible fluid outlet, is defined between the first foraminous member and the first electrode and a second combustible fluid collection chamber, having a second combustible fluid outlet is defined between the second foraminous member and the second electrode;

passing the solution into the first chamber via an inlet, so that the solution passes simultaneously through both foraminous members into the first and second combustible fluid collection chambers; and applying a voltage across the electrodes to electrolyse the solution in the first and second combustible fluid collection chambers, so that a first combustible fluid forms in the first combustible fluid collection chamber and a second combustible fluid forms in the second combustible fluid collection chamber, and the first combustible fluid passes out of the first combustible fluid collection chamber via the first combustible fluid outlet and the second combustible fluid passes out of the second combustible fluid collection chamber via the second combustible fluid outlet.

2. The method according to claim 1, wherein the first and second electrodes are a first outer electrode and a second outer electrode and the method includes providing a plurality of intermediate floating electrodes.

3. The method according to claim 1, wherein the first foraminous member and the second foraminous member defining the first chamber and having at least one inlet, are together a set of foraminous members, and the method includes providing a plurality of sets of foraminous members arranged in a back-to-back configuration with one intermediate floating electrode disposed between adjacent sets of foraminous members.

4. The method according to claim 1, wherein the electrolysing apparatus defines at least one inlet passage in fluid flow communication with all of the inlets and the method includes passing the solution into the first chambers of all of the sets of foraminous members via the inlet passage.

5. The method according to claim 1, wherein the electrolysing apparatus defines at least one first combustible fluid outlet passage in fluid flow communication with all of the first combustible fluid outlets and a second combustible fluid outlet passage in fluid flow communication with all of the second combustible fluid outlets, the arrangement being such that the first combustible fluid formed in the first combustible fluid collection chamber passes out of the apparatus via the first combustible fluid outlet passage and the second combustible fluid formed in the second combustible fluid collection chamber passes out of the apparatus via the second combustible fluid outlet passage.

6. An electrolysing apparatus in which combustible fluid produced from an electrolytic solution during a process of electrolysis is separated comprising:

first and second spaced apart electrodes;

first and second spaced apart foraminous members located between the first and second electrodes;

a first chamber defined between the first and second foraminous members;

a first combustible fluid collection chamber defined between the first foraminous member and the first electrode;

a second combustible fluid collection chamber defined between the second foraminous member and the second electrode;

at least one inlet into the first chamber for the electrolytic solution;

a first combustible fluid outlet from the first combustible fluid collection chamber, and

a second combustible fluid outlet from the second combustible fluid collection chamber, the arrangement being such that the electrolytic solution passes into the first chamber via the inlet and passes simultaneously through both foraminous members into the first and second combustible fluid collection chambers respectively where electrolysis takes place; and such that a first combustible fluid forms in the first combustible fluid collection chamber; and such that a second combustible fluid forms in the second combustible fluid collection chamber; and such that the first combustible fluid passes out of the first combustible fluid collection chamber via the first combustible fluid outlet; and such that the second combustible fluid passes out of the second combustible fluid collection chamber via the second combustible fluid outlet.

7. The electrolysing apparatus according to claim 6, wherein the first electrode is a first outer electrode and the second electrode is a second outer electrode, and the apparatus includes a plurality of intermediate floating electrodes.

8. The electrolysing apparatus according to claim 6, wherein the first foraminous member and the second foraminous member defining the first chamber and having the at least one inlet, are a set of foraminous members and the apparatus includes a plurality of sets of foraminous members connected to one another in a back-to-back configuration with one intermediate floating electrode positioned between adjacent sets of foraminous members.

9. The electrolysing apparatus according to claim 6, wherein the apparatus includes a gasket positioned in the peripheral region between the two foraminous members forming the set of foraminous members.

10. The electrolysing apparatus according to claim 9, wherein the gasket is a first gasket and the electrolysing apparatus includes a plurality of second gaskets, each positioned in the peripheral region between adjacent sets of foraminous members, surrounding the outer periphery of the intermediate floating electrode.

11. The electrolysing apparatus according to claim 6, wherein each foraminous member is provided with a spacer projecting from both faces thereof to space the foraminous member from the adjacent foraminous member and electrode.

12. The electrolysing apparatus according to claim 6, wherein the first and second outer electrodes are each provided with a connector for connecting to a power supply to supply a voltage over the electrolysing apparatus to electrolyse the electrolytic solution.

13. The electrolysing apparatus according to claim 6, wherein the electrodes and foraminous members are all disc shaped, so that the apparatus is cylindrical in shape.

14. The electrolysing apparatus according to claim 6, wherein the apparatus includes a circulator to circulate the solution through the apparatus and to force the solution into the first chamber.

15. The electrolysing apparatus according to claim 6, wherein the inlets of the foraminous members are aligned to define an inlet passage, so that electrolytic solution is passed into all of the first chambers of the apparatus via the inlet passage.

16. The electrolysing apparatus according to claim 6, wherein the first combustible fluid outlets are aligned to define a first combustible fluid outlet passage, so that first combustible fluid produced in all of the first combustible fluid collection chambers passes out of the apparatus via the first combustible fluid outlet passage.

17. The electrolysing apparatus according to claim 6, wherein the second combustible fluid outlets are aligned to define a second combustible fluid outlet passage, so that second combustible fluid produced in all of the second combustible fluid collection chambers passes out of the apparatus via the second combustible fluid outlet passage.

18. The electrolysing apparatus according to claim 6, wherein the apparatus includes a first combustible fluid collection container connected to the first combustible fluid outlet passage and a second combustible fluid collection container connected to the second combustible fluid outlet passage.

19. The electrolysing apparatus according to claim 6, wherein the first and second combustible fluid collection containers each have a second electrolytic solution outlet located towards the operatively bottom end of each container and a first combustible gas and second combustible gas outlet located towards the operatively top end of the first and second combustible fluid collection containers respectively, the arrangement being such that electrolytic solution passes out of the first and second combustible fluid outlets from the first and second combustible fluid collection chambers, together with the respective gases, into the first and second combustible fluid collection containers respectively, where after first and second combustible gasses are passed out of the containers via the first and second combustible gas outlets and the electrolytic solution is passed out of the containers via the second electrolytic solution outlets and is circulated back to the inlets via the circulator.

20-21. (canceled)

22. The electrolysing apparatus according to claim 7, wherein

the first foraminous member and the second foraminous member defining the first chamber and having the at least one inlet, are a set of foraminous members and the apparatus includes a plurality of sets of foraminous members connected to one another in a back-to-back configuration with one intermediate floating electrode positioned between adjacent sets of foraminous members;

the apparatus includes a first gasket positioned in the peripheral region between the two foraminous members forming the set of foraminous members;

the apparatus includes a plurality of second gaskets, each positioned in the peripheral region between adjacent sets of foraminous members, surrounding the outer periphery of the intermediate floating electrode;

each foraminous member is provided with a spacer projecting from both faces thereof to space the foraminous member from the adjacent foraminous member and electrode;

the first and second outer electrodes are each provided with a connector for connecting to a power supply to supply a voltage over the electrolysing apparatus to electrolyse the electrolytic solution;

the electrodes and foraminous members are all disc shaped, so that the apparatus is cylindrical in shape;

the apparatus includes a circulator to circulate the solution through the apparatus and to force the solution into the first chamber;

the inlets of the foraminous members are aligned to define an inlet passage, so that electrolytic solution is passed into all of the first chambers of the apparatus via the inlet passage;

the first combustible fluid outlets are aligned to define a first combustible fluid outlet passage, so that first combustible fluid produced in all of the first combustible fluid collection chambers passes out of the apparatus via the first combustible fluid outlet passage;

the second combustible fluid outlets are aligned to define a second combustible fluid outlet passage, so that second combustible fluid produced in all of the second combustible fluid collection chambers passes out of the apparatus via the second combustible fluid outlet passage;

the apparatus includes a first combustible fluid collection container connected to the first combustible fluid outlet passage and a second combustible fluid collection container connected to the second combustible fluid outlet passage; and

the first and second combustible fluid collection containers each have a second electrolytic solution outlet located towards the operatively bottom end of each container and a first combustible gas and second combustible gas outlet located towards the operatively top end of the first and second combustible fluid collection containers respectively, the arrangement being such that electrolytic solution passes out of the first and second combustible fluid outlets from the first and second combustible fluid collection chambers, together with the respective gases, into the first and second combustible fluid collection containers respectively, where after first and second combustible gasses are passed out of the containers via the first and second combustible gas outlets and the electrolytic solution is passed out of the containers via the second electrolytic solution outlets and is circulated back to the inlets via the circulator.