Carbon Mass

Field of the Invention This invention relates generally to electrolytic process for producing combustible gases, and more particularly, to an apparatus and method for electrolytically producing combustible gas from carbon mass at generally room temperature and pressure.

Background of the Invention

In conventional processes of coal gasification, coal is wet -milled to size of about 100 microns before being combined with water to form coal -water slurry. The slurry is fed to the gasifier with oxygen or air. Gasification takes place at slagging temperature, typically at about 1400 ⁰ C and 30 atm where there is insufficient oxygen for the combustion of the coal. This leads to the production of hydrogen and carbon monoxide as the principal products. The synthetic gas, also called "water gas", can be used in a large variety of applications ranging from home heating and powering of automobiles and other vehicles to a wide range of industrial applications, for example, for the production of Synthetic Natural Gas or Fischer-Tropsch coal -derived liquid fuels. There were quite a number of problems involved with this process. The container, called a stove or generator, was very costly because of the lining materials which have to withstand the high temperatures and pressures involved in the process. However, most importantly, the water gas so produced contains a number of impurities including CO ₂ , N ₂ and O ₂ which are undesirable from the standpoint of safe and efficient combustion. O ₂ is a particularly undesirable as it rendered the gas to be combustible without the introduction of O ₂ from the atmosphere or an external source, thereby making the gas dangerous to handle and store. Moreover, the process is generally inefficient as the large amount of heat energy generated by the coal or coke is wasted.

In consideration of these problems, there came up with the methods in recent decades. US Patent No. 4226683 discloses for the first time operating an electrolysis cell containing coal or carbon dust and water at ambient temperature and atmospheric pressure to produce hydrogen. However, carbon dioxide, as one of main impurity, is also generated from the process and involvement of an inert dielectric liquid makes the following gas separation process more complicated.

US Patent No. 4302320 discloses several apparatuses for producing water gas by electrolysis from carbon and water, wherein the electrochemical reaction of carbon and water with a solute such as sulphuric acid is carried out to produce clean water gas, but impurities still exist in the product though it is in small amount. In another US Patent No. 4670113 relating to a process for the gasification of combined gasification and liquefaction of carbonaceous materials in a electrolytic cell, it was mentioned that by utilizing generated atomic hydrogen to activate the chemical reaction between the ions of dissociated water and the carbon in an electrolysis cell, the gasification happens without high energy input. Generally, in all the prior arts the method of electrolysis makes a key role in solving the high energy input problem, but impurity problem have not been settled down. These apparatuses and methods fulfill their respective, particular objectives and requirements, but these apparatuses and methods have various drawbacks and shortcomings as mentioned above. Therefore, there exists a need for a new apparatus for producing combustible gases substantially free of impurities at ambient temperature and atmospheric pressure.

Summary of the Invention

The present invention has been developed to fulfill the needs noted above and therefore has a principle object of the provision of an apparatus for producing combustible gases that are substantially free from impurities from carbon mass and water at ambient temperature and atmospheric pressure.

Another object of the invention is to provide an apparatus for producing combustible gases from carbon mass and water which is significantly more economical and convenient to operate than the apparatuses in the prior art. A yet further object of the invention is to provide a method for producing combustible gases that are substantially free from impurities from carbon mass and water at ambient temperature and atmospheric pressure.

These and other objects and advantages of the invention are satisfied by providing an apparatus for producing combustible gases, comprising an electrolyzing vessel including at least one electrolytic cell, said electrolytic cell having: at least one cathode chamber for housing electrically conductive carbon mass, said cathode comprising at least one cathode and a first vent for collecting and removing combustible gases; at least one anode chamber for housing water, said anode comprising at least one anode and a second vent for collecting and removing gaseous by-product; at least one separator for segregating said cathode chamber and said anode chamber and allowing passage of ionic substances and water molecules; and means for applying a direct current between said cathode chamber and said anode chamber for causing electrolysis.

According to the invention, the combustible gases include a mixture of CO, H ₂ and C _x H _y O _z wherein x is an integer from 0 to 9, y is an integer from 0 to 20, and z is an integer from 0 to 3.

In one embodiment of the invention, the electrolyzing vessel includes one electrolyzing cell having one cathode chamber and one anode chamber, said cathode chamber and said anode chamber are disposed vertically or horizontally.

In another embodiment of the invention, the electrolyzing vessel includes one electrolyzing cell having one cathode chamber and one anode chamber, said cathode chamber and said anode chamber are segregated by two spaced apart separators . In a further embodiment of the invention, the electrolyzing vessel includes two electrolyzing cells standing side by side with the cathode chambers and the anode chambers being disposed alternately.

In a preferred embodiment of the invention, the anode chamber further houses conductive porous elements to enhance conductivity of this chamber. According to the invention, the conductive porous elements are selected from a group consisting of carbon mass, perforated metal, expanded metal and metallic foam. The conductive porous elements may be arranged as electrode stacks and positioned adjacent to and in electrical contact with one another.

Preferably, the cathode camber has a first outlet for introducing liquid products out, and the anode chamber has a second outlet for introducing liquid by-products out. According to the invention, the carbon mass is a carbon containing substance selected from the group consisting of carbon, coal, coke breeze, active carbon, activated carbon, charcoal and graphite. Preferably, the carbon mass is moist or wet .

The carbon mass may be in the form of powders, porous granules or reticulation, and arranged as electrode stacks. The invention also relates to a method for producing combustible gases from carbon mass and water, comprising the steps of : providing an electrolyzing vessel including at least one electrolytic cell, said electrolytic cell having: at least one cathode chamber for housing electrically conductive carbon mass, said cathode chamber comprising at least one cathode, and a first vent for collecting and removing combustible gases; at least one anode chamber for housing water, said anode chamber comprising at least one anode, and a second vent for collecting and removing gaseous by-product; and at least one separator for segregating said cathode chamber and said anode chamber and allowing passage of ionic substances and water molecules; feeding water into said anode chamber, and feeding electrically conductive carbon mass into said cathode chamber; and applying a direct current between said cathode chamber and said anode chamber for causing electrolysis. Preferably, the carbon mass to the water is fed at a ratio ranging from 10: 1 to 1:1.

In contrast to the apparatuses and methods available in the prior art, the apparatus and method of the invention utilizes direct electrolysis on carbon mass, and one or more separators between the cathode chamber and the anode chamber, and therefore can be carried out at ambient temperature and pressure. The direct electrolysis on the carbon mass allows the anode chamber becomes acidic while the cathode chamber becomes alkaline, which is much favorable for the composition of the combustible gases. Meanwhile, the use of the separator allows to obtain the pure combustible gases from the cathode chamber. Therefore, the apparatus and the method according to the invention are relatively simple in configuration, low in cost to produce pure combustible gases.

To have a better understanding of the invention reference is made to the following detailed description of the invention and embodiments thereof in conjunction with the accompanying drawings .

Brief Description of the Drawings

Figure 1 is a schematic view of an apparatus for producing combustible gases constructed in accordance with an embodiment of the invention.

Figures 2A to 2C are schematic views of some examples of the electrolytic vessels utilized in the invention.

In the various figures of the drawings, like reference numbers are used to designate like parts.

Detailed Description of the Preferred Embodiments

While this invention is illustrated and described in preferred embodiments, the apparatus may be produced in many different configurations, sizes, forms and materials.

Referring now to the drawings, Fig. 1 provides an apparatus constructed consistent with a preferred embodiment of the present invention. For the sake of clarity, the apparatus in this embodiment comprises an electrolytic vessel which consists of one electrolytic unit 100. This electrolytic unit 100 comprises a cathode chamber 10, an anode chamber 20, and a separator 30 which is disposed between the cathode chamber 10 and the anode chamber 20. The electrolytic unit 100 may be of any size, shape and configuration. In this embodiment, the electrolytic unit 100 is made of steel material and substantially rectangular. This electrolytic unit 100 is divided into two equal halves, the cathode chamber 10 and the anode chamber 20 segregated by the separator 30.

The cathode chamber 10 has a first vent 11 at its top and a first outlet 12 at its bottom. The first vent 11 is provided for collecting and removing the combustible gases to be produced, C _x H _y O _z where x is an integer from 0 to 9, y is an integer from 0 to 20, and z is an integer from 0 to 3. The first outlet 12 is provided for introducing out liquid byproducts that are organics such as methanol . A cathode 13 is housed vertically in the cathode chamber 10 which also contains carbon mass 14 that may be arranged as stacks, before the electrolysis take places. According to the invention, examples of the carbon mass are selected from the group consisting of carbon, coal, coke breeze, active carbon, activated carbon, charcoal, graphite and the like. The carbon mass can be in the form of powders, porous granules, reticulation or the like. Preferably, the carbon mass is moist or wet, and as an alternative, the carbon mass has its pores filled with water. This wetting is advantageous to the electrolytic process. In this embodiment, moist coke breeze is utilized.

The anode chamber 20 has a second vent 21 at its top and a second outlet 22 at its bottom. The second vent 21 is provided for collecting and removing the gaseous by-products to be produced, C _x H ₇ where x is an integer from 0 to 9, and y is an integer from 0 to 20. The second outlet 22 is provided for introducing out a liquid by-product which is a mixture of organic acids and water. An anode 23 is housed vertically in the anode chamber 20 which also contains water 25 and conductive porous elements 24 dispersed and immersed in the water. The porous elements may be arranged as stacks as the carbon mass, and preferably are positioned adjacent to and in electrical contact with one another. The conductive porous elements are used to enhance conductivity of the anode chamber. According to the invention, examples of the conductive porous elements are selected from a group consisting of carbon mass, perforated metal, expanded metal and metallic foam. In this embodiment, coke is used as the conductive porous element.

The cathode and the anode may be made from electrically conductive materials. Generally, the cathode and the anode are made from titanium, platinum, palladium, iron, nickel, copper, zinc and alloys thereof. The cathode and the anode may be made from non-metallic materials too, such as graphite. Moreover, these electrodes can be in various forms such as round or flat plate or mesh plate.

The separator 30 is made from a material which allows passage of ionic substances and/or water molecules. An example of the separator 30 is an ion exchange membrane. According to the invention, the separator can be made of single layer or multiple layers of membranes.

A direct current is applied between the cathode 13 and the anode 23 to enable the electrolytic process. The direct current may vary according to the different requirements in practice. For example, the direct current may range from 0 to 48 voltages. Because the moist coke breeze is housed in the cathode, the electrolytic process is directly on the moist coke breeze. In the presence of the separator 30 disposed between the cathode chamber 10 and the anode chamber 20, carbon atoms are activated and charged positively in the anode chamber 20 and charged negatively in the cathode chamber 10. These charged carbon atoms respectively migrate to the opposite chamber due to opposite charge attraction. In this case, the carbon atoms function as an electro-conductor and a carbon supplier to react with water. The separator 30 of the invention creates a certain electric potential difference, and therefore allows the reactions take place within the two chambers .

In the cathode chamber 10, main actions of C ⁺ and H ⁺ which migrate from the anode chamber are as follows: H ₂ O -» H* + OH ^"

H* + H* -> H ₂ C ^* + H ⁺ -> C _x H ₇ C ⁺ + H* -> C _x H ₇ C ^* + 0* ~> CO C ⁺ + H* + OH ^" -> C _x H ₇ O ₂ wherein x is an integer from 0 to 9, y is an integer from 0 to 20, and z is an integer from 0 to 3. H* and C ^* indicate the states of the atoms.

In the anode chamber 20, main actions are as follows: H ₂ O -> 2H ⁺ + 0*

C ⁺ + 0* -> CO CO + 0* -> CO ₂ C ^* + H ⁺ -> C _x H ₇ wherein x is an integer from 0 to 9, y is an integer from 0 to 20.

It would be understood that H* and 0* are intermediates, the activity of which is between their ion state and radical state .

The above reactions in the cathode chamber 10 allows for the production of pure combustible gases which is primarily comprised of hydrocarbon, carbon monoxide and hydrogen. These pure combustible gases can be used in a wide variety of applications without the need of further purification. The pure combustible gases escape from the vent 11 of the cathode chamber 10 and collected. At the same time, liquid organics such as methanol are obtained and collected through the outlet 12.

Likewise, the above reactions in the anode chamber 20 allows for the production of gaseous by-products such as carbon dioxide and hydrocarbon. The gaseous by-products escape from the vent 21 of the anode chamber 20 and collected. At the same time, liquid by-products, which are comprised of a mixture of organic acids and water, are obtained and collected through the outlet 22.

As alternatives of the electrolyzing vessel of this embodiment, Figs. 2A to 2C illustrate some examples of the electrolyzing vessels utilized in the current invention. In Fig. 2A, the electrolyzing vessel includes one electrolytic cell. The difference of this vessel from the one described hereinabove is that the cathode chamber and the anode chamber are segregated by two spaced apart separators . The electrolyzing vessel shown in Fig. 2B differs from the one descried hereinabove in the horizontal arrangement of the cathode and the anode. The vessel of Fig. 2B allows to produce the combustible gases at a higher rate, but the produced combustible gases contain carbon dioxide and therefore needs to be subject to a further purification step.

In Fig. 2C, the electrolyzing vessel includes two electrolytic cells which are arranged in a side-by-side manner. The cathode chambers and the anode chambers of these two electrolytic cells are disposed alternately. In this electrolyzing vessel, the ions in the adjacent anode and cathode chambers can migrate through the separator therebetween, and therefore main reactions take place in each of the cathode chambers and each of the anode chamber. It is obvious that this would be able to produce the combustible in a larger scale.

Example

The apparatus of Fig. 1 is used in this example. 25 Litre of water and 10kg of coke as conductive porous elements are housed in the anode chamber 20. In the cathode chamber 10, 30kg of coke is housed. A 30 volts of direct current at HA is applied between the cathode and the anode and hence between the coke within the cathode chamber 10 and the water within the anode chamber 20. As a result of the application of the direct current, electrolysis which is directly on the coke and the water takes place. The main reactions as mentioned above form in the cathode and the anode chambers to give combustible gases at a rate of 20L/hour.

According to this example, an advantage of the invention is that a very small amount of water and coke is consumed, and even cannot be measured out. This suggests that the energy consumption to produce the combustible gases is much smaller than the apparatuses and methods available in the prior art.

As described above, the apparatus of the invention is structurally simple and enables to produce the pure combustible gases at room temperature and pressure with a very low energy consumption. The combustible gases produced in this manner are pure sufficiently for use as fuel without the need of being subject to further purification.

While the embodiments described herein are intended as an exemplary apparatus, it will be appreciated by those skilled in the art that the present invention is not limited to the embodiments illustrated. Those skilled in the art will envision many other possible variations and modifications by means of the skilled person's common knowledge without departing from the scope of the invention, however, such variations and modifications should fall into the scope of this invention.