OXIDE FROM ALUMINUM

TECHNICAL FIELD

[0001] This application relates generally to aluminum recycling and hydrogen generation, and more specifically to a process and an apparatus for the generation of hydrogen and aluminum oxide from aluminum containing mixtures and acids while only requiring additional inputs of aluminum containing feedstock once the process is started.

BACKGROUND ART

[0002] Hydrogen can be generated by a variety of methods. However, generating hydrogen cheaply with little or no greenhouse gas (GHG) generation is the challenge facing today's hydrogen generation technology innovations. Hydrogen can be generated by natural gas reforming, coal gasification, electrolysis, thermal water splitting, biomass conversion and photo electrochemical methodologies. Natural gas reforming and coal gasification are mature technologies that are used by many industries, but these technologies generate greenhouse gases and in the future will require carbon sequestration. Electrolytic generation of hydrogen is also a mature technology, but it indirectly contributes to GHG generation unless renewable sources of energy such as wind and solar are utilized. Most of the other processes for hydrogen generation are not yet fully mature and require additional research and development to make them cost effective and/or technologically sound.

[0003] High purity alpha aluminum oxide is prized for its hardness, for its high melting temperature and especially for its use as the primary source in the production of aluminum. Bauxite is the main source of the feedstock material for the production of aluminum oxide by the Bayer process whereby hydrated aluminum oxide mixtures are converted to aluminum oxide. Corundum is produced by taking bauxite along with additional carbon and iron to above the melting point of the bauxite. The carbon and iron help remove impurities through chemical and separative processes and provide the hard alpha phase form of alumina, corundum. Both of these processes are quite mature having been used for many years. An alternative method to produce aluminum oxide is by reacting the bauxite ore with

hydrochloric acid to produce aluminum chloride hexahydrate followed by heating the aluminum chloride hexahydrate to temperatures as high as 1500 °C. [0004] Similarly, chlorinated and hydrated aluminum hydroxides of varying

concentrations (basic aluminum chlorides) can be generated by the reaction of aluminum with hydrochloric acid. These reactions are exothermic with the evolution of heat and hydrogen.

[0005] Scrap aluminum is recycled typically by filtering the aluminum chemically and mechanically from other metals and non-metallic components and heating the aluminum remaining to temperatures exceeding the melting point of aluminum. This secondary aluminum is much less expensive than the aluminum obtained from the production of aluminum by the Hall-Heroult process. However, scrap aluminum with high percentages of metallic impurities or high percentages of non-metallic materials are typically difficult to recycle economically. There therefore exists a need for a process to recycle such low value scrap aluminum that is relatively economical and environmentally friendly.

[0006] Thus there is a need in the art for a method and apparatus that permits for the recycling of scrap aluminum and the generation of hydrogen. Such a method and apparatus should be easy and robust to use, be flexible enough to produce a range of products, be cost effective, and be able to accept a range of contaminants in input scrap aluminum.

DISCLOSURE OF INVENTION

[0007] The present invention overcomes the disadvantages of the prior art by providing a reactive means to generate hydrogen, regenerate the reactants other than aluminum and produce a byproduct that has value - aluminum oxide. Furthermore, the processes and devices of the present invention can perform these functions without the need for external energy sources, with the generation of additional work from the steam produced and with only scrap aluminum as feedstock once the process has been initiated.

[0008] Certain embodiments described herein react contaminated scrap aluminum with acid to produce hydrogen and a solution that can be processed to provide aluminum oxide. One embodiment regenerates the acid from the chlorinated aluminum oxide solution through a drying and heating methodology and calcines the resulting solid mixture to sufficient temperature to produce a calcined aluminum oxide. Several purification steps may be performed to remove significant amounts of impurities from solutions, aluminum chloride hexahydrate and calcined aluminum oxide to give a significantly purified and calcined aluminum oxide. [0009] Various embodiments have certain advantages over the prior art. These include, but are not limited to:

• using aluminum containing mixtures as starting material - especially scrap aluminum - for the reaction with acid;

• regenerating acid by using internally generated heat due to the exothermic reaction and the burning of generated hydrogen; and

• generating a higher purity aluminum oxide such as corundum from the initial

contaminated scrap aluminum. This higher purity is achieved by both reactive and separation processes and is best affected by using the heat generated in the reaction and a portion of the hydrogen generated for heating.

[0010] This process and device can be cycled with only additions of contaminated scrap aluminum once the process is initiated.

[0011] One embodiment provides a method for producing hydrogen and aluminum oxides from aluminum and contaminants. The method includes accepting a feedstock including contaminants other than aluminum; reacting the accepted feedstock with an acid to produce hydrogen and other products of reaction; forming aluminum oxide from the other products of reaction; and collecting the aluminum oxide. The method also includes performing one or more of collecting the hydrogen, and generating heat from the chemical energy in the hydrogen. The generated heat is provided to assist in one or more of: the reacting the accepted feedstock with acid and the forming aluminum oxide.

[0012] Another embodiment provides a method for producing hydrogen and aluminum oxides from aluminum with a regenerated acid. The method includes: accepting a feedstock including aluminum and/or aluminum oxide; reacting the accepted feedstock with an acid to produce hydrogen and other products of reaction; forming aluminum oxide from the other products of reaction; and collecting the aluminum oxide. The method further includes performing one or more of collecting the hydrogen, and generating heat from the chemical energy in the hydrogen. The generated heat is provided to assist in one or more of: the reacting the accepted feedstock with acid and the forming of aluminum oxide. The method further includes recovering regenerated acid from one or more of the reacting of the accepted feedstock and the forming of aluminum; and providing the regenerated acid as the acid for the reacting of the feedstock and acid.

[0013] Yet another embodiment provides a device for producing hydrogen and aluminum oxides from a feedstock including aluminum and an acid. The device includes: a reaction vessel adapted to accept the feedstock and the acid and produce first gaseous products including hydrogen and non-gaseous products; a first heater for heating the reaction vessel; furnace collection vessel to accept the non-gaseous products and produce aluminum oxide and second gaseous products; a second heater for heating the furnace collection vessel; and a gas collection device to accept one or more of the first gaseous products and the second gaseous products; and an acid regeneration system to recover acid from the gas collection device and provide the regenerated acid to the reaction vessel. The device operates such that hydrogen and aluminum oxide may be produced using a regenerated acid.

[0014] These features together with the various ancillary provisions and features which will become apparent to those skilled in the art from the following detailed description, are attained by the system and method of the present apparatus and process, preferred embodiments thereof being shown with reference to the accompanying drawings, by way of example only, wherein:

BRIEF DESCRIPTION OF DRAWINGS

[0015] FIG. 1A is a schematic of an embodiment of a method for the generation of hydrogen and aluminum oxide from aluminum;

[0016] FIG. IB is a schematic diagram showing a first embodiment of an apparatus for the generation of hydrogen and aluminum oxide from aluminum;

[0017] FIG. 1C is a schematic diagram showing a second embodiment of an apparatus for the generation of hydrogen and aluminum oxide from aluminum that is optimized for the generation of primarily alpha phase aluminum oxide by using all or a portion of the hydrogen generated by the process for heating purposes;

[0018] FIG. ID is a schematic diagram showing a third embodiment of an apparatus for the generation of hydrogen and aluminum oxide from aluminum that is optimized for the generation of hydrogen and aluminum oxide with minimal external energy and power requirements; [0019] FIG. 2 is a more detailed schematic of one embodiment of an apparatus that is generally similar to the embodiment of FIG. 1C;

[0020] FIG. 3 shows the embodiment of FIG. 2 as used for the regeneration of acid as the purified solution is heated to dryness;

[0021] FIG. 4 shows the embodiment of FIG. 2 as used for heating aluminum oxide to produce alpha phase aluminum oxide;

[0022] FIG. 5 illustrates the purification of the aluminum oxide of any magnetic components;

[0023] FIGS. 6 and 7 are more detailed schematics of another embodiment of an apparatus that is generally similar to the embodiment of FIG. IB.

[0024] Reference symbols are used in the Figures to indicate certain components, aspects or features shown therein, with reference symbols common to more than one Figure indicating like components, aspects or features shown therein.

MODE(S) FOR CARRYING OUT THE INVENTION

[0025] Embodiments of the present invention are directed to the use of aluminum mixture, including scrap aluminum, to produce hydrogen and a final product such as aluminum oxide. Various embodiments described herein exemplify a range of embodiments ranging from a minimal process to extended processes that use more or less energy and/or produce other products.

[0026] Figure 1A is a schematic of an embodiment of a method 10 for the generation of hydrogen and aluminum oxide from aluminum. Method 10 is also referred to herein as the "MicroHyGen" or "MHG" process, for processing an aluminum-containing feedstock. The feedstock may, for example and without limitation, be aluminum and/or aluminum oxide, or may include a "scrap" aluminum that comprises contaminants other than aluminum.

Contaminants which may be processed by method 10 include, but are not limited to, other metals, compounds including other metals, paper, or organic compounds.

[0027] Method 10 includes the steps of adding a feedstock (Block 11), replenishing acid (Block 12), replenishing water (Block 14), and reacting the added or replenished feedstock and acid (Block 15). Method 10 may also, when necessary, include adding heat (Block 13), which is also used in Block 15. Method 10 also includes separating and collecting solid waste products (Block 16), separating and collecting aluminum products (Block 17), and separating and collecting hydrogen (Block 18). In general, the flow of material is one-way, as indicated by the arrows between blocks, with the exception of the two-way flow of acid between Blocks 12 and 15. In one alternative embodiment, hydrogen from Block 18 is provided to Block 13, where the hydrogen is reacted to release heat, as indicted by the dashed line between Blocks 13 and 18. In another alternative embodiment, steam that is generated in Block 15 and or Block 13 is provided to Block 19, where the steam is used to generate energy, such as electric power.

[0028] In a steady state operation, the feedstock and heat are provided for the reactions in Block 15 (Blocks 11 and 13, respectively) and valuable aluminum products and hydrogen are generated and collected (Blocks 17 and 18, respectively). Block 12 allows for control of the acid concentration or level in Block 15 by accepting or providing acid, as indicated by the arrows. Block 14 allows for replenishing water in Block 15.

[0029] In one embodiment, the feedstock in Block 11 contains contaminants, which are recovered as waste in Block 16, the acid replenished in Block 12 is hydrochloric acid, the aluminum separated and collected in Block 17 is aluminum oxide.

[0030] In certain embodiments, the reactions within Block 15 may include a first reaction, as in Block 15a, wherein the feedstock from Block 11 reacts with an aqueous hydrochloric acid solution from Block 12 and heat from Block 13 to generate hydrogen and a chlorinated aluminum oxide solution, and a second reaction, as in Block 15b, where the chlorinated aluminum oxide solution from Block 15a is heated with heat from Block 13 to create a mixture of waste and aluminum products, which are separated and collected in Blocks 16 and 17, respectively.

[0031] Apparatus for the generation of hydrogen and aluminum oxide from an aluminum- containing feedstock using method 10 are illustrated in the schematic diagrams of FIGS. IB, 1C, and ID, where FIG. IB shows a first embodiment as apparatus 100A, Fig. 1C shows a second embodiment as apparatus 100B optimized for the generation of primarily alpha phase aluminum oxide by using all or a portion of the hydrogen generated by the process for heating purposes, and FIG. ID shows a third embodiment as apparatus lOOC optimized for the generation of hydrogen and aluminum oxide with minimal external energy and power requirements.

[0032] Apparatus 100A, 100B, and lOOC each include a vessel 103 for storing an aluminum-containing feedstock, a vessel 105 for storing acid, a vessel 109 for storing water, a container 107 for collecting aluminum oxide, one or more heaters 111, and a vessel 212 for collecting hydrogen. Reactions take place in one or more vessels 150. As discussed subsequently, vessels 150 may be vessels in which the various reactants or byproducts of reaction are sequentially combined and reacted. FIGS. IB, 1C, and ID are labeled to show the relationship to method 10, as including arrows indicating Blocks 11, 12, 13, 14, 15, 16, 17 and 18.

[0033] Apparatus 100A is an embodiment of a general method 10. In one embodiment of apparatus 100A, an aluminum-containing feedstock that includes contaminants other than aluminum reacts with hydrochloric acid and water to generate hydrogen and a chlorinated aluminum oxide solution in a first reaction vessel. The chlorinated aluminum oxide solution is then heated causing the acid to be regenerated and the formation of aluminum oxide in a second reaction vessel.

[0034] Apparatus 100B is similar to apparatus 100A, and provides hydrogen from vessel 212 to heater 111. In certain embodiments, some or all of the generated hydrogen is used for heating to drive chemical reactions in vessels 150. Apparatus 100B is optimized for the generation of primarily alpha phase aluminum oxide because the hydrogen generated during reaction of the aluminum and acid is subsequently all or partially used for heating purposes.

[0035] Apparatus lOOC is similar to apparatus 100B, and provides steam from vessels 150 and heater 111 to generator 113 for producing electricity from the steam which may, in turn, be used to power one or more various devices, such as motors, valves, and the like, of apparatus lOOC.

[0036] More detailed schematics of apparatus for performing some or all of the processes of method 10 and/or apparatus 100A, 100B, and lOOC are illustrated in Figures 2, 3, 4, 5, 6, and 7.

[0037] Figure 2 is a more detailed schematic of one embodiment of an apparatus 200 that is generally similar to apparatus 100B, except as explicitly stated. [0038] Apparatus 200 includes vessel 103 for storing an aluminum-containing feedstock, vessel 105 for storing acid, vessel 109 for storing water, and a vessel 406 for collecting hydrogen. In apparatus 200: the vessels 150 of apparatus 100B include a reaction vessel 206 and a furnace collection vessel 405; heaters 111 of apparatus 100B include a reaction vessel burner 154 for heating a reaction vessel 206 and a furnace burner 156 for heating furnace collection vessel 405; and container 107 for collecting aluminum oxide from furnace collection vessel 405.

[0039] Apparatus 200 also includes: a condenser 210; a chiller 501; a hydrogen transfer device 211; an acid collection vessel 408; a furnace collection vessel valve 399; a separation device 401; a separation medium 402 such as a filter paper; a furnace 155 including burner 156 for heating furnace collection vessel 405; a first valve 213; and a second valve 214.

[0040] Apparatus 200 further includes pipes that connect the following components: vessel 103, vessel 105, and vessel 109 to reaction vessel 206; reaction vessel 206 to condenser 210, chiller 501, hydrogen transfer device 211, vessel 406, and acid collection vessel 408; and from reaction vessel 206 through furnace collection vessel valve 399 and separation device 401 to furnace collection vessel 405. The flow of hydrogen from vessel 406 is controlled to burner 154 by first valve 213 and from vessel 406 to burner 156 by valve 214.

[0041] FIG. 2 further shows, for illustrative purposes only, the flow of processed material as acid 104, acid vapors 108, steam 110, hydrogen 112, contaminants 116, and chlorinated aluminum oxide solution 322.

[0042] Apparatus 200 can be used for the reaction of a feedstock including aluminum that comprises contaminants other than aluminum or aluminum oxide, referred to herein and without limitation, as "scrap aluminum" 102 with acid 104; for the generation of hydrogen 112; for a purification of the chlorinated aluminum oxide solution 322; for the regeneration and collection of the acid 104 through condensation of the steam 110 and acid vapors 108; the collection and storage of the hydrogen using hydrogen collector 212 contained within vessel 406; the use of the hydrogen 112 for heating purposes using burner 154 and the drying and heating of aluminum oxides 514 using a burner 156 in furnace 155.

[0043] More specifically, in a first step in the operation of apparatus 200, contaminated scrap aluminum 102 and acid 104 are combined in reaction vessel 206 to generate a chlorinated aluminum oxide solution 322, hydrogen 112 and contaminants 116, as shown, for example in Block 15a of FIG. 1A. More specifically, the products of reaction vessel 206 may include gaseous products, including but not limited to hydrogen, steam, and acid vapors, and non-gaseous products, including but not limited to aluminum-containing compounds, contaminants, water, and acid.

[0044] The hydrogen 112 of the gaseous products is then passed through condenser 210 and hydrogen transfer device 211 to hydrogen collector 212 contained within vessel 406. Hydrogen 112 can be collected efficiently by compression with pressurized storage and by the absorption of the hydrogen by metal hydrides such as lanthanum nickel five (LaNis). This is a necessary step in this process if the hydrogen is to be used for other purposes or for heating within the process itself.

[0045] The heat of reaction of contaminated scrap aluminum 102 and acid 104 will cause the solution in reaction vessel 206 to increase in temperature and ultimately to reach a boiling point of about 120 °C. Steam and any acid vapors will flow through condenser 210 where they become liquids, and through hydrogen transfer device 211 for collection in acid collection vessel 408.

[0046] A second step in the operation of apparatus 200 occurs when the reaction of contaminated scrap aluminum 102 and acid 104 in vessel 206 has gone to completion, or is nearly complete, as shown, for example in Block 15b of FIG. 1A. At this point, the nongaseous products of vessel 206, which may include but are not limited to reacted aluminum, water, acid, and possibly some contaminants, are provided to furnace collection vessel 405. Thus, for example, at completion of the reaction of aluminum and acid, furnace collection vessel valve 399 may be opened, allowing chlorinated aluminum oxide solution 322 to pass through separation medium 402 within the separation device 401 and into furnace collection vessel 405.

[0047] The separation medium 402 removes contaminants 116 from the chlorinated aluminum oxide solution 322. The separation medium 402 would then be removed from the separation device 401 and the contaminants 116 discarded. The separation medium 402 would then be reinserted into separation device 401. This step may provide a more purified final aluminum oxide product, and assists in both the removal of certain metal oxides as well as for the removal of non-metallic constituents, such as paper. As an example of this next step in the operation of apparatus 200, Fig. 2 shows the purification of the chlorinated aluminum oxide solution 322 from contaminants 116 using separation device 401, separation medium 402 and furnace collection vessel 405. The resulting chlorinated aluminum oxide solution 322 collects in the furnace collection vessel 405 after separating the solid and liquid phases.

[0048] The furnace 155 is then operated to heat chlorinated aluminum oxide solution 322 to dryness at temperatures of the order of 120 °C. The steam so generated would pass back through separation medium 402, and reaction vessel 206, and is then condensed at the condenser 210. The water 120 so formed would then flow through the hydrogen transfer device 211 and into acid collection vessel 408.

[0049] Acid 104 collected in acid collection vessel 408 may be returned as regenerated acid into vessel 105.

[0050] As the chlorinated aluminum oxide solution 322 approaches a dry condition within furnace collection vessel 405 due to the heating by furnace 155, the temperature within the furnace collection vessel 405 increases to temperatures, for example, between 400 °C and 1500 °C, or between 1000 °C and 1500 °C, or may be for example and without limitation, approximately 1200 °C. During this heating process acid vapors 108 will be evolved and travel with the steam 110 and hydrogen 112 to condenser 210 where the acid vapors will condense with the steam and form acid 104. The acid 104 will flow through hydrogen transfer device 211 into the acid collection vessel 408, thereby providing regenerated acid for future use. Alpha phase aluminum oxide 614 is also obtained from this high temperature heating and is removed from the furnace collection vessel 405.

[0051] Figures 3 and 4 show the drying and heating process steps of apparatus 200, and is generally similar to apparatus 100B, except as explicitly stated.

[0052] FIG. 3 shows the steps for regeneration of acid as the purified solution is heated to dryness. Apparatus 200 may be operated similarly to collect chlorinated aluminum oxide solution 322 in furnace collection vessel 405 as described previously. As shown in FIG. 3, apparatus 200 provides hydrogen from hydrogen collection vessel 406 via furnace hydrogen valve 214 to a furnace burner 156. More specifically, furnace collection vessel 405, which contains chlorinated aluminum oxide solution 322, is heated by furnace 154 using previously generated hydrogen 112. The hydrogen is provided from hydrogen collector 212 contained within vessel 406 to fuel furnace burner 156 to generate steam 110 and acid vapors 108 that are thereafter condensed using chiller 501 and condenser 210 and collected in acid collection vessel 408. The heat is used to dry the chlorinated aluminum oxide solution 322, and then heat the resulting solids to sufficient temperature to drive out the steam 110 and acid vapors 108 that may still be contained within the solids. Temperatures from of order 100 °C to 400 °C are required for this step and are attained as furnace 155 is ramped to temperatures, for example, between 100 °C and 500 °C, or between 400 °C and 500 °C, or may be for example and without limitation, approximately 400 °C. This is advantageous because significant heat is required to boil off the water in the solution and the heat generated by the collection and burning of hydrogen reduces the need for external energy.

[0053] FIG. 4 highlights the use of apparatus 200 as used for heating dried aluminum oxide to produce alpha phase aluminum oxide 614. As shown in FIG. 4, apparatus 200 may also be used for the heating of dried aluminum oxide 514 in furnace collection vessel 405 to produce alpha phase aluminum oxide 614 by using furnace 155. This step is important to produce the phase transformation of the dried aluminum oxide 514 to alpha phase aluminum oxide 614 that has the purity, hardness or refractory characteristics desired from fused aluminum oxides. The temperature for this step may be, for example, between 400 °C and 1500 °C, or between 1000 °C and 1500 °C, or may be for example and without limitation, approximately 1200 °C.

[0054] A furnace 155 is one particular means to provide the heating required, but other heating methods are also applicable - especially those heating devices that can use the hydrogen being generated. A significant amount of hydrogen is generated by method 10, and this can provide most or all of the heat needed to reach the stated temperatures.

[0055] Figures 6 and 7 are more detailed schematics of another embodiment of an apparatus 600 that is generally similar to the embodiment of FIG. IB. As shown in FIG. 6, apparatus 600 includes an aluminum insertion device 802, a hydrogen output 812, a cooling coil 814 and a cooling water flow control subsystem 816. Apparatus 600 is similar to apparatus 100, except as discussed subsequently.

[0056] Apparatus 600 is configured to generate more hydrogen and a dried aluminum oxide, rather than the aluminum oxide product of apparatus 100A, so as to reduce the energy requirements of the process. In apparatus 600, the heating of the chlorinated aluminum oxide solution 322 may be performed using only internal heating and other energy sources so as to maximize hydrogen output 812. This process is simpler than some of the other apparatus embodiments discussed herein, but still provides a hydrogen output 812 from contaminated scrap aluminum 102 using a reaction with acid 104. Regeneration of acid is provided, so that the only feedstock required once this process is started are additional contaminated scrap aluminum 102.

[0057] Specifically, apparatus 600 may be used to react contaminated scrap aluminum 102 with acid 104 in reaction vessel 206 through the use of an aluminum insertion device 802 that provides a means to lower the contaminated scrap aluminum 102 into the solution. The reaction vessel 206 contains the acid 104 into which the contaminated scrap aluminum 102 is inserted. A cooling coil 814 is included in this embodiment to help control the temperature of the reacting solution so that it does not boil. Cooling water flow control subsystem 816 controls the flow rate of room temperature water through the cooling coil 814. Heating device 819 is connected to reaction vessel 206 to provide additional heating if necessary. Chiller 501 and condenser 210 are used to condense any significant water and acid vapors 108 and return them to the acid 104 and chlorinated aluminum oxide solution 322. Hydrogen 112 is generated and exits the system through hydrogen output 812.

[0058] The chlorinated aluminum oxide solution 322 generated by apparatus 600 may be removed via an exhaust valve (not shown) connected to the bottom of the reaction vessel 206 and then with the use of the portion of apparatus 600 shown in FIG. 7, acid 104 can be regenerated and the dried aluminum oxide 514 produced by drying the chlorinated aluminum oxide solution 322 by heating the solution to dryness within furnace collection vessel 405. Temperatures from of order 100 °C to 400 °C are required for this step and are attained as furnace 155 is ramped to temperatures, for example, between 100 °C and 500 °C, or between 400 °C and 500 °C, or may be for example and without limitation, approximately 400 °C. As described previously, the acid vapors 108 and steam 110 are condensed in condenser 210 and collected in acid collection vessel 408. Aluminum oxide 514 is obtained from furnace collection vessel 405.

[0059] Alternatively, the entire reaction vessel 206 of apparatus 200 can be placed in furnace 155 and the chlorinated aluminum oxide solution 322 heated to regenerate the acid 104 and obtain dried aluminum oxide 514.

[0060] Another alternative step of method 10 is the separation of aluminum oxide. Figure 5 illustrates the purification of the alpha phase aluminum oxide of any magnetic components that may be used in any one of apparatus 100A, 100B, lOOC, 200, or 600. Furnace collection vessel 405 is shown as including using a magnet 702. Contaminants 116 may include, for example, magnetic particles 701, such as some metal oxides. Aluminum oxide is not magnetic whereas other metal oxides such as iron oxide are magnetic. The use of magnet 702 provides additional purification via magnetic means. Thus, for example, magnet 702 may be inserted onto furnace collection vessel 405 to collect, and then remove such particles to produce a purified aluminum oxide 714.

ALTERNATIVE EMBODIMENTS

[0061] Several alternative embodiments are directly applicable to the embodiments presented above. While the above description has many specifics, it should be construed as one of several potential configurations and arrangements of components. Furthermore, several of the steps described so far can be removed from method 10 without dramatically affecting the results. For example, the filtering of the chlorinated aluminum oxide solution 322 to remove contaminants 116 may not be necessary dependent upon the requirements of the specific process and device. Similarly the final magnetic purification may not be needed. The minimum requirements of this process and device are that hydrogen 112 is generated through the reaction of at least aluminum and a byproduct from the reaction is processed to provide a material of greater purity than the starting contaminated scrap aluminum 102.

[0062] Other alternative embodiments should be recognized. The heating of solutions and solids does not necessarily need to use the burning of the hydrogen 112 generated by method 10. Any other standard heating methods can also be employed. Steam 110 could be used to generate useful forms of work, as in apparatus lOOC. Since no process is 100% cyclic without some input of minimally lost reactants, some additional hydrochloric acid 104 may need to be added occasionally to provide for small loses resulting during the hydrochloric acid regeneration process.

[0063] Furthermore, a number of alternative embodiments and the associated ramifications of these embodiments can be envisioned. For instance, the size of the apparatus to execute method 10 can be scaled all the way from the laboratory level to full scale plant operations. Furthermore, the form of the aluminum containing mixtures can range from powders to gross mixtures of varying metal components along with other non-metallic and organic components such as steel, paper and petroleum based organics. The aluminum mixtures can range all the way from pure aluminum to mixtures of aluminum, other metals, inorganics and organics. Aluminum can be mixed with other metals such as iron as in irony aluminum. Aluminum can be backed with paper to form paperbacked aluminum. Aluminum turnings can be mixed with water based and organic cutting solutions. These are just a few instances of mixtures that can be processed by the claimed processes and devices. Of particular note is the many forms of scrap aluminum: old mixed scrap aluminum, utensil aluminum scrap, aluminum turnings, scrap aluminum extrusions, scrap low copper aluminum, scrap litho sheets, scrap cast aluminum, scrap clean painted aluminum, painted aluminum insulated scrap, scrap coated aluminum, used beverage cans (loose), shredded used beverage cans, baled used beverage cans, briquetted used beverage cans, new beverage can stock scrap, remelt aluminum ingot, remelt aluminum sows, scrap mixed irony aluminum, scrap low grade irony aluminum, scrap auto transmissions, scrap aluminum auto rads, scrap insulated aluminum wire, scrap supported aluminum cable, scrap bare aluminum wire, scrap aluminum auto wheels, aluminum nodules, scrap aluminum foil, scrap paperbacked aluminum foil and aluminum auto fragments.

[0064] In addition, there are various means to purify solids, liquids and gases that can be included in apparatus for performing method 10. Adsorptive filtration as used in carbon traps, absorptive filtration as used in ion exchange filtration and metal hydride absorption and desorption should all be included as tools of the trade for separation and purification purposes. Mechanical separation techniques such as sorting, gravity based methods such as decanting, magnetic separation as well as other means to separate different phases from each other should be included as tools to achieve a particular process based upon this process. In particular, the magnetic separation of FIG. 5 could be performed at other points within the process such as after the dried aluminum oxide is prepared and before the dried aluminum oxide is heated or calcined. Filtration using both porous and filtering medium, centrifugal methods such as cyclone filtration, distillation methods such as condensation distillation, solubility differentiation methods such as precipitation filtration and electrochemical separation by reducing and oxidizing out of solution specific components such as in the plating of metals should be included as methods that are within the scope of method 10 as long as they contribute to the basic requirements of this process.

[0065] Acids which may be used may include hydrochloric acid, sulfuric acid, nitric acid and mixtures thereof. Other condensation methods such as cooling baths and the passing of heated vapors through water and mineral acid mixtures should be included as alternative methods to achieve the condensation of steam and acid vapors. In addition, low temperature gas and liquid phase cooling (such as liquid nitrogen and liquid nitrogen vapors) along with ice and other solid phase cooling (such as solid carbon dioxide) should be within the scope of method 10 as well as any standard methods known in the art that are used to cool heated vapors.

[0066] Different methods for the collection and storage of hydrogen may include the use of metal hydrides and the compression of hydrogen in pressurized storage tanks. These are the two main storage methods, but others exist that are applicable to performing the steps of method 10.

[0067] Other heat generating devices should be included such as using fuel combustion, hot plates, ovens, furnaces, microwave heating and microwave induction methods and any other means that impinges or causes heat to be generated within a process or device. In addition, other reactive regeneration methods such as gas phase product separation as is used in the high temperature heating of aluminum chloride hexahydrate should be within the scope of the present invention. Additionally, aluminum purification through aluminum production via electrolytic means is within the scope of the present invention, as long as one of the starting materials for aluminum production results from this process and device.

[0068] Accordingly, the scope of the present invention should not be determined by the embodiments illustrated, but by the breadth of the embodiments, the appended claims and their logical extensions.

EXAMPLES

[0069] The operation of method 10 will now be discussed, without limitation, with reference to the Figures. Apparatus 100A provides what is likely the most basic process for the several embodiments described. The primary minimal requirements of this process and device are that hydrogen 112 is generated through the reaction of contaminated scrap aluminum 102 with acid 104 and a byproduct containing aluminum from the reaction is processed to provide aluminum oxide 114. This process and device are especially suited to the use of contaminated scrap aluminum 102 with hydrochloric acid because of the reactions utilized, the ability to regenerate the hydrochloric acid and the purification methods utilized.

[0070] The following experiments and chemical analysis of products were obtained by a laboratory scale version of apparatus 100A. Type 4032 aluminum was used for these experiments with a composition as shown in Table 1 as determined by an external laboratory (West Penn Testing Group). A 12.05 gram sample of 4032 aluminum was reacted with 248 ml of 18.5 wt. % hydrochloric acid to completion. The resulting solution with both a solid phase of contaminants and a solution of chlorinated aluminum oxide was then decanted into two samples - one containing an excess of the solution with limited contaminants (the decanted solution) and one containing an excess of the solid residue (the residue solution). The residue solution was heated to dryness at temperatures up to 190 °C and then transferred to a furnace 155 and heated for four hours at temperatures up to 402 °C. Final weight of residue sample was 6.99 grams. The decanted solution was heated to dryness at temperatures up to 116 °C and then transferred to furnace 155 and heated for four hours at temperatures up to 391 °C. Final weight of decanted sample was 15.99 grams. The decanted 391 °C calcined sample was analyzed by West Penn Testing Group. Specifically, the sample was heated to a temperature of 950 °C over a period of four hours. The compositional analysis of this 950 °C calcined sample is shown both with respect to oxides and elements in Table 1. Of significance is the observation that appreciable S1O2 was removed by the decanting operation with a consequent improvement in the purity of the aluminum oxide 114 obtained.

Table 1. Aluminum and Aluminum Oxide Analyses

[0071] In another experiment 10.85 grams of 6063 type aluminum was reacted with 248 ml of 18.5 wt. % hydrochloric acid 104. The resulting solution with both a solid phase of contaminants and a solution of chlorinated aluminum oxide was decanted into two samples - one containing an excess of the solution with limited contaminants (the decanted solution) and one containing an excess of the solid residue (the residue solution). The residue solution was heated to dryness at temperatures up to 164 °C and then transferred to a furnace 155 and heated for four hours at temperatures of order 401 °C. Final weight of residue sample was 7.39 grams. The decanted solution was heated to dryness at temperatures up to 145 °C and then transferred to a furnace 155 and heated for four hours at temperatures of order 395 °C. Final weight of decanted sample was 15.14 grams. A portion of this powdered decanted sample was sent to Washington Mills for calcining at 1300 °C for one hour. X-ray diffraction was performed on this calcined aluminum oxide sample. The Washington Mills analysis of the x-ray diffraction pattern showed that the 1300 °C calcined sample was 95 to 97.7% alpha phase aluminum oxide (corundum). According to Washington Mills this was a very pure sample with only a small amount of secondary phases (2.3 to 5%) and no more than 1.75% amorphous phase.

[0072] The generation of hydrogen is best illustrated with the following experiment that used the apparatus described in Figs. 6 and 7. In one experiment, 1085 grams of 6063 type aluminum reacted with 22.7 liters of 18.5 wt. % hydrochloric acid. After reaction went to completion there was 396 grams of aluminum remaining and 892 liters of hydrogen collected. A 296 gram sample of the solution resulting from the reaction was heated to dryness at temperatures up to 136 °C and then 86% of the sample was transferred to a furnace and heated for four hours at temperatures of order 400 °C. Final weight of powder residue sample was 15.54 grams. By both gravimetric means and West Penn Testing Group analysis, samples calcined at temperatures of order 400 °C for four hours have a residual chlorine content of from 9 to 14 wt.%. Using these results it is found that the reaction process for this case generated approximately 96% of the maximum theoretical hydrogen and approximately 99% of the maximum theoretical dried aluminum oxide.

[0073] Reference throughout this specification to "one embodiment," "an embodiment," or "certain embodiments" means that a particular feature, structure or characteristic described in connection with the embodiment is included in at least one embodiment of the present invention. Thus, appearances of the phrases "in one embodiment," "in an embodiment," or "in certain embodiments" in various places throughout this specification are not necessarily all referring to the same embodiment. Furthermore, the particular features, structures or characteristics may be combined in any suitable manner, as would be apparent to one of ordinary skill in the art from this disclosure, in one or more embodiments.

[0074] It is thus to be understood that the invention includes all of the different combinations embodied herein. Throughout this specification, the term "comprising" shall be synonymous with "including," "containing," or "characterized by," is inclusive or open- ended and does not exclude additional, unrecited elements or method steps. "Comprising" is a term of art which means that the named elements are essential, but other elements may be added and still form a construct within the scope of the statement. "Comprising" leaves open for the inclusion of unspecified ingredients even in major amounts.

[0075] Similarly, it should be appreciated that in the above description of exemplary embodiments of the invention, various features of the invention are sometimes grouped together in a single embodiment, figure, or description thereof for the purpose of streamlining the disclosure and aiding in the understanding of one or more of the various inventive aspects. This method of disclosure, however, is not to be interpreted as reflecting an intention that the claimed invention requires more features than are expressly recited in each claim. Rather, as the following claims reflect, inventive aspects lie in less than all features of a single foregoing disclosed embodiment. Thus, the claims following the detailed description are hereby expressly incorporated into this detailed description, with each claim standing on its own as a separate embodiment of this invention.

[0076] Thus, while there has been described what is believed to be the preferred embodiments of the invention, those skilled in the art will recognize that other and further modifications may be made thereto without departing from the spirit of the invention, and it is intended to claim all such changes and modifications as fall within the scope of the invention. Steps may be added or deleted to methods described within the scope of the present invention.