Method and apparatus for producing synthetic gas using aluminum dross and a thermoplastic

"METHOD AND APPARATUS FOR PRODUCING SYSTHETIC GAS USING ALUMINUM DROSS AND A THERMOPLASTIC" The following statement is a full description of this invention, including the best method performing it known to me/us: METHOD AND APPARATUS FOR PRODUCING SYNTHETIC GAS USING ALUMINUM DROSS AND A THERMOPLASTIC TECHNICAL FIELD The present invention relates to a method and an apparatus for producing synthetic gas using aluminum dross and a thermoplastic which makes it possible to produce a synthetic gas using a recyclable resource which used to be incinerated as a waste and to be buried in a burial place. BACKGROUND ART A conventional method for producing a synthetic gas is generally implanted by using a vapor (H 2 0) and fuel, with a natural gas, coal, naphtha, etc. being added as a material. Since aluminum is a positive metal which can easily oxidize, aluminum dross is generally produced when aluminum is melt. The aluminum dross is produced together with a metallic aluminum when the substances oxidized on a molten surface of a melting furnace are removed during a casting procedure following melting aluminum ingot. Part of the same generally remains in a melting furnace or a crucible when a molten aluminum is poured into a mold or is produced as a metallic aluminum is oxidized in a molten runner while a molten metal is being cast. The component of aluminum dross consists of above 70% of oxidized aluminum, above 10% of metallic aluminum, above 5% of nitride aluminum, above 5% of carbon and below 10% of other impurities. As a conventional method for treating aluminum dross, there is a common treatment method which is characterized in that wastes (aluminum dross) used to be buried in a waste burial place, the wastes being produced during an aluminum ingot production procedure in which wastes (aluminum dross) or aluminum scraps, which are generally produced when melting aluminum ingots at a company manufacturing vehicle parts or various home appliances by melting aluminum, are collected, and during an aluminum casting procedure of melting the aluminum ingot. When the aluminum dross is buried in a waste burial place, ammonia gas is naturally generated due to underground water or rain, thus spreading bad smell, and hydrogen gas is produced, which could make a fire. As mentioned above, a conventional aluminum dross treatment method is directed to burying in a waste burial place, so a severe environment problem might occur or resource consumption might increase, which results in no more use of the materials. So, a more directive and efficient treatment method is urgently needed. All of the waste plastics such as waste tires or something are buried or incinerated except for a recyclable product such as PE, PP, PET, PVC, etc., so it is known that the waste plastics are one of the most contamination causing materials following vehicles and thermal power plant in sequence. So, it is possible to prevent an environment contamination while achieving a low carbon emission effect in such a way that aluminum dross and waste plastics are used to produce a synthetic gas which is a clean energy. DISCLOSURE OF THE INVENTION Accordingly, it is an object of the present invention to provide a method for producing a synthetic gas using aluminum dross and waste plastics, thus preventing an environment contamination due to burial and resource consumption by recycling aluminum dross and waste plastics which are industrial wastes. It is another object of the present invention to provide a method for producing a synthetic gas using aluminum dross ad waste plastics which make it possible to save a lot a manufacture cost of a melting furnace in a steel mill since a synthetic gas can be produced with a lower cost. To achieve the above objects, there is provided a method for producing a synthetic gas using aluminum dross and thermoplastics which comprises a process for first generating hydrogen gas using a caustic soda aqueous solution in a reactor 10 of a sealed mixing container with aluminum dross which is an industrial waste; a process for melting and thermally decomposing the waste plastic with the aid of a high temperature vapor generating when the hydrogen gas is reacted with the oxygen in the drier 20 which is a first thermal decomposer, and a process for producing a synthetic gas (Syngas) by cool-reacting the hydrogen gas in the high temperature thermal decomposition reactor 30 which is a second thermal decomposer. ADVANTAGEOUS EFFECTS The present invention is basically directed to obtaining a cost saving effect and preventing an environment contamination which used to occur due to a conventional burial method since aluminum dross and waste plastics, which are industrial wastes, are not buried in the present invention, and an import substitution effect can be obtained in the present invention since natural gas, alumina cements, etc., which used to be mainly imported from other countries, are produced from wastes in the form of raw materials. Besides, an advanced manufacture technology and a design technology of a synthetic gas according to the present invention are dominated, which largely contributes to a plant export and a technology export, thus obtaining a large export effect along with an import substitution effect. BRIEF DESCRIPTION OF THE DRAWINGS The present invention will become better understood with reference to the accompanying drawings which are given only by way of illustration and thus are not limitative of the present invention, wherein; Figure 1 is a view illustrating a construction of an apparatus for manufacturing a synthetic gas using aluminum dross and thermoplastic according to the resent invention. MODES FOR CARRYING OUT THE INVENTION The preferred embodiments of the present invention will be described in details. In the following detailed descriptions, a representative embodiment of the present invention will be described to help overcome the technical problems of the conventional art. Other embodiments which might be suggested in the present invention will be substituted with the descriptions in terms of the construction of the present invention. Figure 1 is a view illustrating a construction of an apparatus for manufacturing a synthetic gas using aluminum dross and thermoplastic according to the resent invention. First, there is provided a reactor 10 - a sealed containerin which a caustic soda aqueous solution (sodium hydroxide) is reacted with metallic aluminum contained in aluminum dross, thus generating hydrogen gas. There is provided a drier 20 for thermally melting and decomposing thermoplastics such as waste plastics using a high temperature vapor by oxidizing the hydrogen gas with oxygen, the drier 20 being connected with the reactor 10 by way of a tubular part 11 transferring the hydrogen gas and oxygen from the reactor. The drier 20 comprises a waste input device 22 for inputting thermoplastics such as waste plastics or something, and a discharge device 24 for discharging ashes. The thermal decomposition reactor 30 for thermally decomposing the dry gas, namely, CnH 2 n÷ 2 , coming from the drier is connected with the discharge device 24 which discharges ashes. A high temperature vapor can be transported by way of a tubular part 11 connected between the reactor 10 and the drier for transporting hydrogen gas, and burners 12 and 14 connected between the tubular part 21 connected with the thermal decomposition reactor 30 and the reactor. There is provided a cooling reactor 40 which cools a high temperature synthetic gas (CO + H 2 ) coming from the high temperature thermal decomposition reactor 30 and eliminates hydrogen chloride which is a harmful gas, the cooling reactor 40 being connected to the thermal decomposition reactor 30 by way of the tubular part 31 The synthetic gas generated from the cooling reactor 40 is stored in a storing tank 50 or is moved to a certain space for the use. Hydrogen chloride coming from the cooling reactor is inputted into the cooling reactor 40 by way of a cooling tower 44 and a precision filter 42 with the aid of a circulation pump There is provided a neutralization agent supplier 32 for neutralizing sulfite gas and hydrogen chloride coming from the high temperature decomposition reactor 30 and the cooing reactor 40, and the neutralization agent is inputted into the thermal decomposition reactor and the cooling reactor 40 by way of a certain tubular part. There is provided a boiler 60 which supplies vapor to the drier and the high temperature thermal reactor by using part of the synthetic gas coming from the cooling reactor The method for producing synthetic gas using a synthetic gas producing apparatus according to the present invention will be described. First of all, as shown in Figure 1, powder aluminum contained in aluminum dross, which is an industrial waste, is collected, and hydrogen gas is first generated using caustic soda aqueous solution in the reactor of the sealed mixing container (hydrolysis). When caustic soda aqueous solution is mixed with aluminum dross and is reacted with the same, heat is generated and metallic aluminum (AL) is reacted with sodium hydroxide (NaOH) contained in caustic soda aqueous solution and is converted into sodium aluminate (NaAIO 2 ), thus generating hydrogen gas. The reaction formula is as follows. Reaction of hydration 60°C - 80°C - H 2 0 + NaOH + AI > NaAIO 2 + 1 1/2 H 2 The hydrogen gas is oxidized as it is reacted with oxygen in the drier 20 which is a first thermal eco position unit, thus generating a high temperature vapor. At this time, the reaction formula for oxidation of hydrogen and oxygen is as follows. Oxidation reaction - H 2 + 1/2 0 2• > H 2 0 (2,500°C) 28,300kcal/kg In addition, the high temperature vapor melts and thermally decomposes at 400-500°C the waste plastics inputted together. When the ,sodium aluminate is treated in hydrolysis (130"135°C) with heat, it is converted into sodium hydroxide (NaOH) and aluminum hydroxide (AI(OH) 3 ), and the sodium hydroxide has a high solubility, so it is water-soluble. So, the sodium hydroxide is filtered with a precision filter and is reused for the purpose of aluminum dross (AD) reaction, and the aluminum hydroxide is treated through an oxidation firing, and alumina is reused. The reaction formula is as follows. hydrolysis - NaAIO 2 + 2 H 2 0 ........................................... > AI (OH) 3 + NaOH 120-130°C Thereafter, the saturated hydrocarbon which is dry gas coming from the drier is reacted with vapor at 1,200-1,500°C of the high temperature thermal decomposition reactor 30, thus generating a synthetic gas (Syngas) based on the following reaction formula. High temperature thermal decomposition - CnH 2 n, 2 + nH 2 0> riCo + (n+2)H 2 1200-1500°C As described above, the substance produced by means of the chemical reactions is synthetic gas (CO + H 2 ). The produced synthetic gas is used for oxidation aluminum firing, and the fired oxidation aluminum is used for the purpose of production of unshaped refractory (ball caster), accelerating agent, and corrosion resistance alumina cement. DESCRIPTIONS OF REFERENCE NUMERALS 10: reactor 20: drier 30: high temperature thermal decomposition reactor 40: cooling reactor 50: storing tank 60: boiler