Abstract:
A device for converting solid waste to gaseous form. The device includes a chamber for holding waste material and molten eutectics. The chamber has at least one opening for receiving the waste material into the molten eutectics. An oxygen supply and an ozone supply bring oxygen and ozone into the molten eutectics. The waste is heated by the molten eutectics and combines with the oxygen and ozone to form at least carbon dioxide, which can be removed for use, disposal, or storage. In one embodiment, a grate contains the solid material and prevents it from reaching a top surface of the molten eutectics and a blade mixes the eutectics, waste material, oxygen and ozone. Also provided is a method for converting solid waste to gaseous form.

Description:
FIELD OF THE INVENTION  
       [0001]      1  The present invention relates generally to waste, and more particularly relates to the conversion of solid wastes to the gaseous form.  
       BACKGROUND OF THE INVENTION  
       [0002]     Waste products can be divided into three main categories: municipal wastes; garden and farm wastes; and sewage.  
         [0003]     Municipal wastes include typical household solid wastes, such as paper, plastic, food, and the like. Until the 1980&#39;s, most municipal wastes were disposed of by incineration. Tall chimneys emitted smoke from the burned waste into the atmosphere. The smoke contained some solids and a mixture of gases. The particles gradually fell to earth up to 25 miles away from the chimney. The gaseous product, primarily CO 2  and NO 2 , added to environmental pollution.  
         [0004]     Laws and regulations were ultimately created to prevent the spread of a community&#39;s pollution on itself and the surrounding areas. The alternative has been to create “landfills,” in which waste is compressed and piled on top of other waste and then filled over with dirt.  
         [0005]     Landfills suffer from the disadvantages of needing large amounts of valuable land, having a maximum storage limit on each particular piece of land, emitting foul smells into the surrounding areas, allowing dangerous chemical seepage to enter water aquifers below or in the proximity of the landfill, and other similar problems.  
         [0006]     Garden and farm wastes include waste from vegetation. Two remedies for disposing of garden and farm wastes are incineration and landfills, which suffer from the disadvantages discussed above.  
         [0007]     The final type of waste is sewage, which includes human waste. Sewage is very hazardous to humans and animals. Disposal and handling of sewage are important problems that have led to several solutions. However, all current solutions lead to undigestable solids that are distributed over land for disposal. Rain carries down toxic remains into aquifers and other water supplies and gradually decreases the purity of the water. All current sewage disposal solutions suffer from the disadvantage of ultimately placing dangerous substances back into contact with humans.  
         [0008]     Therefore a need exists to overcome the problems with the prior art as discussed above.  
       SUMMARY OF THE INVENTION  
       [0009]     Briefly, in accordance with one embodiment of the present invention, disclosed is a device for converting waste to safe gasses. The device includes a chamber for holding waste material and a molten substance, and an opening in the chamber for receiving the waste materials into the molten substance. An oxygen supply and an ozone supply supply oxygen and ozone into the molten substance. The waste is heated by the molten substance and combines with the oxygen and ozone to form primarily carbon dioxide.  
         [0010]     In one embodiment of the present invention, a grate is provided in the chamber for creating a barrier that prevents the waste materials from rising to an upper surface of the molten substance.  
         [0011]     Another embodiment of the present invention provides a method for disposing of waste. According to the method, a substance is heated beyond the melting points of the substance. Waste material is then received into the molten substance. Oxygen is then injected into the molten substance. Finally, ozone is injected into the molten substance. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0012]     The accompanying figures, where like reference numerals refer to identical or functionally similar elements throughout the separate views and which together with the detailed description below are incorporated in and form part of the specification, serve to further illustrate various embodiments and to explain various principles and advantages all in accordance with the present invention.  
         [0013]      FIG. 1  is block diagram illustrating one embodiment of a waste conversion device in accordance with the present invention.  
         [0014]      FIG. 2  is a block diagram illustrating one embodiment of a gas diffuser in accordance with the present invention.  
         [0015]      FIG. 3  is a block diagram illustrating one embodiment of a grate in accordance with the present invention.  
         [0016]      FIG. 4  is a flow diagram of the waste conversion process in accordance with a preferred embodiment of the present invention. 
     
    
     DETAILED DESCRIPTION  
       [0017]     While the specification concludes with claims defining the features of the invention that are regarded as novel, it is believed that the invention will be better understood from a consideration of the following description in conjunction with the drawing figures, in which like reference numerals are carried forward. It is to be understood that the disclosed embodiments are merely exemplary of the invention, which can be embodied in various forms. Therefore, specific structural and functional details disclosed herein are not to be interpreted as limiting, but merely as a basis for the claims and as a representative basis for teaching one skilled in the art to variously employ the present invention in virtually any appropriately detailed structure. Further, the terms and phrases used herein are not intended to be limiting; but rather, to provide an understandable description of the invention.  
         [0018]     The present invention, according to one embodiment, overcomes problems with the prior art by converting solid waste into gasses. The conversion reduces the amount of solid waste that must be placed in landfills and reduces the chemicals that are available to seep into the earth and aquifers.  
         [0019]     Described now is an exemplary physical structure according to an exemplary embodiment of the present invention. Referring to  FIG. 1 , a chamber  100 , according to an exemplary embodiment, is shown. The chamber  100  is an at least partially closed vessel for containing materials and can be any shape that will contain an amount of a molten substance  102 . In one embodiment, the molten substance  102  consists at least partially of salts and is referred to as “eutectics.” As will be explained later, in one embodiment of the present invention, the molten substance  102  is a mixture of molten silicates and borates for use at high temperatures. The molten substance  102  is continuously heated by an element  104 . In this exemplary embodiment, the chamber  100  is closed except for parts  106  and  120 .  
         [0020]     Material wastes  118  are placed down a chute  106  that delivers the wastes  118  into the molten substance  102 . A grate  108  is provided within the chamber  100  and below an upper surface  110  of the molten substance  102 . The grate  108  prevents the waste  118  from rising out of the hot molten substance  102 .  
         [0021]     Into the molten substance  102  is bubbled oxygen (O 2 )  112  and ozone (O 3 )  114  gasses through a gas diffuser  113 . To properly mix the waste  118  and gasses  112  and  114 , a spinning blade  116  is provided within the chamber  100 . As the blade  116  spins, the molten substance  102 , waste  118  and gasses  112  and  114  interact. As a result, the carbonaceous waste  118  and gasses  112  and  114  combine to form CO 2 , H 2 O, and in a much smaller fraction NO x . One or more ports  120  near the top of the chamber removes the CO 2  for sequestration. The NO x  can be removed for disposal, storage, or later use. The NO x  may also be usable in fuel cells.  
         [0022]     Describing now one embodiment of the present invention in more detail, the molten substances are eutectics, in this case, molten nitrates. Nitrates are compounds, typified by sodium nitrate and barium nitrate in a certain ratio, that result in a stable liquid of a specific melting point. Depending on the ratio of sodium nitrate and barium nitrate, which may involve metals of group IA and IIA of the Periodic Table, the melting point of the eutectics  102  can vary from approximately 400° C. to approximately 1000° C.  
         [0023]     The particular eutectic ratio is chosen so that the eutectics temperature is about 250° C. above a decomposition temperature of the waste material  118 . Typical decomposition temperatures of many organic substances are in the range of about 250-300° C. Therefore, eutectics  102  having a melting point of about 500-550° C. are particularly advantageous. However, a few organics do not decompose until 600-700° C., and hence the eutectic chosen in wastes known to contain high melting point compounds would need to have a melting point of about 850-950° C.  
         [0024]     As stated above, eutectics are a mixture of substances. The melting point of the mixture is lower than that of each substance alone. The advantage in mixing the substances is in the fact that there is a tendency for the molten mixture to change in composition, i.e., melting point, during prolonged use. This change is undesirable. By operating at as low a temperature as possible, a greater lifecycle can be realized for the mixture. Therefore, the particular eutectics ratio is preferably chosen to provide the minimum melting point, and thus, maximum stability to the mixture.  
         [0025]     In some rare cases, a particular material may not decompose until temperatures above those reachable with nitrate eutectics. To accommodate such high temperatures, mixtures of molten silicates and borates are used, e.g., CaO—SiO 2 . Examples of chamber materials for containing such high temperatures are molybdenum and tungsten.  
         [0026]     In one embodiment of the present invention, a heating element  104  is provided within the chamber  100  for heating the molten substance  102 , and ultimately the waste material  118 . The heating element is a resistive heat element or any other heating device capable of bringing the substance temperature within its desired range. In other embodiments, the heating element is outside the chamber  100  and heats the substance  102  by applying heat to a surface of the chamber  100 .  
         [0027]     The chamber material is chosen based on the desired temperature of the molten substance  102  to be contained within the chamber  100 . For example, glass can be used for temperatures less than 500° C., quartz for temperatures less than 1000° C., ceramic materials for temperatures above 1000° C., and molybdenum or tungsten for temperatures up to 1800° C. Many other materials or combinations of materials are readily available and can also be used.  
         [0028]     Into the molten substance  102  is bubbled a mixture of oxygen (O 2 )  112  and ozone (O 3 )  114  gas. In this embodiment, the oxygen  112  and ozone  114  come from pressurized containers  124  and  126 , respectively. In further embodiments, the gasses come from any known continuous oxygen and ozone producing processes.  
         [0029]     Referring now to  FIG. 2 , one embodiment of the gas diffuser  113  for introducing the gases  112  and  114  into the molten substance  102  is shown. It is advantageous that the bubbles be made relatively small. The diffuser  113  includes a number of inner channels  202  that are all connected by an outer channel  204 . The inner channels  202  and outer channel  204  are supplied with the gases  112  and  114  through inputs  206  and  208 . Each input  206  and  208  connects to a separate one of the two gas supplies.  
         [0030]     A plurality of holes  210  in the channels  202  and  204  allow the gasses  112  and  114  to exit the channels  202  and  204  and rise through the molten substance  102 . In a preferred embodiment, the bubbles are very small, which can be defined as being on the order of about 10μ (i.e. 10 −3  cm in diameter).  
         [0031]     In one embodiment, the rate of gas flow is at least enough for excess bubbles of oxygen to appear at the top of the molten substance  102 . Other methods and devices for supplying the gasses within the molten substance  102  can be used in further embodiments and are within the spirit and scope of the present invention.  
         [0032]     In addition, in some embodiments, the gasses  112  and  114  are mixed before entering the gas diffuser  113  or are supplied in two separate gas diffusers  113 , where the two gasses  112  and  114  mix in the molten substance  102  once released from the diffuser  113 . Additionally, in some embodiments, chlorine (CL 2 ) or hydrogen (H 2 ). Oxygen (O)  112  and ozone (O 3 )  114 , may be introduced into the molten substance  102  along with CL 2 .  
         [0033]     Additionally, in some less used embodiments, chlorine, or, separately, hydrogen, may be introduced into the molten materials containing the waste instead of oxygen and ozone. In yet another embodiment, chlorine is the substance introduced, although in this case, care is taken so that the chlorine entry is sufficiently small so that all is consumed by the waste and none escapes into the atmosphere.  
         [0034]     In these alternative embodiments, the products for sequestration would change. With hydrogen, the primary product is methane. The chlorine would produce CCl 4  and would be used only in a preliminary treatment to break up high resistant matter. Chlorine treatment would be followed by a burst of oxygen and ozone.  
         [0035]     The waste material  118 , when exposed to the temperatures of the molten substance  102  in the presence of oxygen becomes converted, the greatest part being CO 2 . When the ozone (O 3 )  114  reaches the temperature of the molten substance  102 , it decomposes to yield atomic oxygen (O), a powerful oxidizing agent. The O atoms and O 2  molecules are bubbled with the waste material  118  and combine with the carbon atoms produced by the decomposition of the waste material  118  in the molten substance  102 . The result is CO 2 , H 2 O, and in a much smaller fraction NO x , where x represents the number of oxygen atoms. There will also be traces of other materials, according the nature of the wastes and the temperature of the molten substance. However, there are a very few organic materials that could withstand 500° C.-plus temperatures in the presence of O 2 +O 3 .  
         [0036]     An exemplary chemical formula for the conversion of paper to CO 2  may be written 
 
C n H m +3/2 nO 2 →nCO 2 +m/2H 2 O 
 
         [0037]     where n and m are integers and m/2=n. The melt may also contain other elements, depending on the type and quality of the wastes.  
         [0038]     To ensure that the molten substance  102 , waste  118 , and gasses  112  and  114  are properly mixed, a blade  116 , or other moving object is provided within the chamber  100 . As the blade  116  spins, the molten substance  102  are moved within the chamber  100 , along with the waste material  118  and gasses  112  and  114 . In one embodiment of the present invention, the chamber  100  is made of glass or quartz and the blade  116  is driven by magnetic induction from a motor located on the outside of the chamber  100 . In another embodiment, the blade  116  is driven by a shaft attached to a motor located outside the chamber. The blade  116  can be replaced with one or more blades that move in the same direction or in different directions. Other devices or methods for stirring or mixing the solution, such as a low-frequency sonic wave generator, can be used in further embodiments without departing from the spirit and scope of the present invention.  
         [0039]     A grate  108 , or screen-type structure, prevents the solid waste material  118  from rising to the surface of the molten substance. One embodiment of the grate  108  is shown in  FIG. 3 . As shown, the grate  108  is a circular disk with a plurality of small openings  302 . The openings  302  are constructed so as to be smaller than the smallest expected piece of waste material  118 . For example, in one embodiment, the openings  302  are 0.75 μm. In one embodiment, the grate  108  is removable for cleaning. In another embodiment, a scraper is provided within the chamber for clearing the grate  108  openings  302 . Other embodiments of the grate  108  that prevent or inhibit solid waste material particles  118  from rising to the surface can be used in further embodiments, without departing from the spirit and scope of the present invention.  
         [0040]     In some other embodiments of the present invention, the grate  108  is heated to a temperature greater than the average temperature of the molten substance  102  which fill the chamber  100 . For instance, the grate  108  can be heated to approximately 50° C. less than the boiling point of the molten substance  102 . The higher temperature of the grate  108  works to further advance the conversion of the material  118 .  
         [0041]     In one preferred embodiment of the present invention, the waste material is subjected to one or more processes aimed at reducing the particle sizes. Methods of reducing particle size are known. For instance, the wastes  118  can be subjected to chopping in a guillotine-type device. The wastes  118  can further be treated in a homogenizer. In still further embodiments, the material  118  can be placed in a mill and ground down further. Once the particles are down to about 0.1 mm or less, the material can be exposed to ultrasound, whereby the material is subject to intense vibrations, which break apart, or separate the material, and produce smaller particle sizes on the order of about 1 μm or less. Other processes, such as crushing, tearing, bending, grinding, compressing, and the like, can be used as well.  
         [0042]     The chopped-up, powder-like material  118  is then injected into the chamber  100  near the bottom of the chamber  100 . In the embodiment of  FIG. 1 , the waste material  118  is forced down the port  106  and into the molten substance  102  by applying O 2  under pressure. The O 2  has the added benefit of further facilitating the waste conversion process. The pressure from the O 2  also prevents the molten substance  102  from rising into the material port  106 . In further embodiments, other techniques and methods that introduce the waste material  118  into the chamber  100  can be used without departing from the spirit and scope of the present invention.  
         [0043]     The rate of material injection is dependent upon the consumption rate within the chamber  100 . After the process is underway, the inflow of waste should not exceed the consumption rate. For this reason, the rate of material introduction within the chamber may be material dependent and dynamically vary as the process takes place. In one embodiment, waste does not exceed 5% of the total volume within the chamber.  
         [0044]     Metallic materials will not combine with O 2  and O 3  to form gasses and are, therefore, not suitable for the conversion process. If the metallics are not removed, the chamber  100  may eventually become filled, thus diminishing the effectiveness of the device  100 . Even light aluminum is heavier per unit volume than carbonaceous wastes. Therefore, metallic substances, in particular, aluminum, will be shaken free of the waste materials before they are introduced into the melt.  
         [0045]     In one embodiment of the present invention, at temperatures below the Curie temperature of iron (about 800° C.), the grate  108  is magnetized so as to attract any iron-like particles within the chamber  100 . The grate  108  can then be scraped or removed for cleaning and removal of the particles.  
         [0046]     A port  120  in the chamber  100  receives the gaseous output  128  of the process described above. The output  128  is either CO 2 , NO x , or a combination thereof. The output  128  is captured and utilized for other purposes, stored, or disposed of safely.  
         [0047]     Although a one atmosphere environment is likely to be sufficient for the above-described waste conversion process, some waste materials may decompose more rapidly when placed under pressure. In one embodiment of the present invention, the chamber  100  is sealed and maintains a pressure of up to 10 atmospheres. Exemplary chamber materials in such embodiments are nickel and stainless steel, although for the rare cases in which temperatures are above 1250° C., other ceramic materials and atmospheres may have to be used.  
         [0048]     Referring now to  FIG. 4 , a flow chart of the process for converting waste materials according to a preferred embodiment of the present invention is shown. The process begins at step  400  and moves directly to step  402 , where the substance  102  is heated sufficiently to melt the substance  102 . The waste material  118  is made into small pieces in step  404 . Next, in step  406 , the waste material  118  is placed into the molten substance  102 . Oxygen  112  and ozone  114  are injected into the molten substance  118  within the chamber  100  in step  408 . The molten substance is then stirred, in step  410 , to evenly distribute the waste materials  118 , oxygen  112 , and ozone  114 . The result of the process  128  is a byproduct including CO 2 , which is collected at the top of the chamber  100 , in step  412 . The process then returns to step  406  where more material is added to the chamber  100 . While this process is shown as a series of discrete steps, in further embodiments, the steps can happen simultaneously, such as steps  408 ,  410 , and  412 .  
         [0049]     As described above, embodiments of the present invention allow waste, whether municipal wastes, garden and farm wastes, or sewage, to be disposed of safely and efficiently by converting the waste to gaseous byproducts. The process relieves current concerns with solid waste storage. Additionally, large areas of land dedicated to the storage of solid waste can be freed for more useful purposes. Furthermore, the present invention reduces concerns regarding ground pollution and water contamination.  
         [0050]     Although specific embodiments of the invention have been disclosed, those having ordinary skill in the art will understand that changes can be made to the specific embodiments without departing from the spirit and scope of the invention. The scope of the invention is not to be restricted, therefore, to the specific embodiments, and it is intended that the appended claims cover any and all such applications, modifications, and embodiments within the scope of the present invention.  
         [0051]     The terms “a” or “an”, as used herein, are defined as one or more than one. The term plurality, as used herein, is defined as two or more than two. The term another, as used herein, is defined as at least a second or more. The terms including and/or having, as used herein, are defined as comprising (i.e., open language). The term coupled, as used herein, is defined as connected, although not necessarily directly, and not necessarily mechanically.