1. Field of the Invention
The present invention relates to a method for producing hydrogen, and particularly to a method for producing hydrogen through a chemical reaction or simultaneously through an electrochemical reaction to improve hydrogen production rate and thereby generate an electrolyte solution of metal ions after producing hydrogen, the electrolyte solution of metal ions able to be reduced and recycled as electrode material of rechargeable batteries, or as a metal by electrolysis method for producing hydrogen, so as to completely achieve economical and practical purposes of carrying out oxidation-reduction and prevent the second environmental pollution.
2. Related Art
Hydrogen is a clean energy resource, which can be adopted as fuel and energy for industrial applications, such as desulfurization materials for oil working, chemical industrial, metallurgy industrial, and semi-conductor industry. Besides, hydrogen reacted in fuel cells do not produce carbon dioxide, therefore, hydrogen is expected to be an alternative resource of energy in the proceeding development. It is no doubt that research and needs of hydrogen are inevitable to be risen in the near future. Thus the study of application of hydrogen production is very important.
As is well known, elemental hydrogen is relatively rare on earth, so people try many ways to produce hydrogen. Main conventional techniques of producing hydrogen are as follows: steam reforming technique, partial oxidation technique, gasification technique, or use an electrolyte solution to produce hydrogen; however, processes of producing hydrogen with the first three techniques mentioned above generate lots of carbon dioxide as well, which seriously causes bad effect on global warming. Unfortunately, the fourth technique mentioned above requires large electricity consumption during processes of producing hydrogen and therefore its cost is relatively high.
Another way to produce hydrogen is to take Sodium borohydride (NaBH4) in an alkaline solution and react with a catalyst to produce hydrogen, by which way hydrogen can be produced quickly and simply. However, NaBH4 must be refined from borates, which costs highly about USD 80 to refine one kilogram NaBH4; besides, worldwide borates are merely separated in a few countries (for example, America and Turkey) and therefore are not easy to be obtained.
Still, another way to produce hydrogen is to use metal scrap; for example, recycle wasted aluminum cans as reaction object for producing hydrogen. However, coatings of the recycled aluminum cans have to be eluted by sulfuric acid, which arises the problem of treating industrial wastewater and leads to a second environmental pollution.
Accordingly, an object of the present invention is to provide an innovative method for producing hydrogen which takes metal, metallic alloys, or metal scrap as reaction object to react with an electrolyte solution through a chemical reaction or simultaneously through an electrochemical reaction to produce hydrogen, which can be utilized in industrial plants (such as a steel-making plant or incinerating plant), large hydrogen devices (stationary fuel cells) or portable hydrogen devices. In addition, an electrolyte solution of metal ions generated after hydrogen production reaction is able to be recycled as electrolyte and electrode material of rechargeable batteries or regenerated to a metal by electrolysis method as material for producing hydrogen, which completely achieves economic and practical purposes of carrying out oxidation reduction and prevents the second environmental pollution.
Another object of the present invention is to provide a method for producing hydrogen much more effective by accelerating hydrogen production rate, in which method organic acid or non-organic acid is added during a process of a chemical reaction or during processes of the chemical reaction and an electrochemical reaction at the same time.
To achieve the above-mentioned objects, the method for producing hydrogen of the present invention includes a reaction and formation step, which is able to be performed in several ways, wherein one of the ways to perform the reaction and formation step is defined by taking metal, metallic alloys, or metal scrap as reaction object, the reaction object after being cleaned and contacted with an electrolyte solution resulting in chemical reaction thereby to produce hydrogen and by-products thereof.
According to the above-mentioned reaction and formation step, the electrolyte solution is of electrical conductivity or is acidic aqueous solution.
Still further, another way to perform the reaction and formation step is defined by cleaning dissimilar metals and then combining the dissimilar metals to be used as reaction object for producing hydrogen, the combined dissimilar metals being immersed in an electrolyte solution or water to result in electrochemical reaction due to reduction potential difference between the dissimilar metals thereby to produce hydrogen and by-products thereof.
According to the above-mentioned reaction and formation step, one of the dissimilar metals of lower reduction potential is defined as a positive electrode as an anode metal selected from metal scrap material such as magnesium alloy, aluminum alloy and so on, while the other one of the dissimilar metals of higher reduction potential is defined as a negative electrode as a cathode metal being stainless steel or platinum; moreover, the electrolyte solution causing the electrochemical reaction is sodium chloride, physiological saline, KCl or solutions of electrical conductivity.
The method for producing hydrogen further includes a reaction and acceleration step, which is able to be performed in several ways, wherein one of the ways is to add organic acid or non-organic acid to the reaction and formation step to accelerate hydrogen production over the chemical reaction.
According to the above-mentioned reaction and acceleration step, the organic acid is acetic acid, formic acid or citric acid, and the non-organic acid is hydrochloric acid, sulfuric acid or nitric acid.
Still further, another way to perform the reaction and acceleration step is to combine the metal, metallic alloys, or metal scrap with a catalyst, and then immersed in an acidic electrolyte solution to result in chemical and electrochemical reactions thereby to accelerate hydrogen production rate.
Still further, the method for producing hydrogen further includes an extended treatment step, in which an electrolyte solution of metal ions generated after hydrogen production reaction is able to be reapplied to rechargeable batteries by being dried and treated with appropriate solutions or the electrolyte of metal ions can be reduced by way of electrolysis to be recycled for hydrogen production.
Referring to
The reaction and acceleration step 3 is performed by adding organic acid (such as acetic acid, formic acid or citric acid and so on) or non-organic acid (hydrochloric acid, sulfuric acid or nitric acid and so on) 30 to the electrolyte solution 22 of the reaction and formation step 2 in order to accelerate hydrogen production rate through the chemical reaction, a reaction formulation for the acceleration being as follows:
Mt+RCOOH→RCOOMt+½H2
Mt+HCl→MtCl+½H2
In addition, the reaction and acceleration step 3 can be performed by binding the reaction object 20 of either metal, metallic alloys, or metal scrap with a catalyst in an acidic electrolyte solution to result in a chemical or electrochemical reaction to accelerate hydrogen production rate.
The extended treatment step 4 is performed by utilizing electrolyte solution of metal ions 52 produced after hydrogen production reaction for extended applications, wherein the electrolyte solution of metal ions 52 is being dried 40 and treated with an appropriate solution, such as absolute alcohol or tetrahydrofuran (THF) 41, for being applied to rechargeable batteries 61; alternatively, the electrolyte solution of metal ions 52 can be separated by way of electrolysis 42 to be recycled as material for producing hydrogen with the method 1 or reapplied as an electrode material 62 of the rechargeable batteries 61.
Referring to
Particularly mention that an optimal value of a mutual potential difference between the anode and the cathode metals 201′, 202′ is within 0.71V to 3.49V, the electrolyte solution 25′ is sodium chloride or KCl solution, and when the anode metal 201′ is magnesium alloy and the cathode metal 202′ is stainless steel mesh of model AISI 304, a formulation for the electrochemical reaction is as follows:
Mg+2H2O→Mg(OH)2+H2.
The reaction and acceleration step 3′ is performed by adding organic acid or non-organic acid 30′ to the reaction and formation step 2′ to accelerate hydrogen production rate over the chemical reaction, wherein the organic acid is acetic acid, formic acid or citric acid, and the non-organic acid is hydrochloric acid, sulfuric acid or nitric acid, a reaction formulation for the acceleration being as follows:
Mt+RCOOH→RCOOMt+½H2
Mt+HCl→MtCl+½H2
The extended treatment step 4′ is performed by drying 40′ an electrolyte solution of metal ions 52′ and further treating it with appropriate solutions 41′ (such as absolute alcohol or tetrahydrofuran, THF) so that it can be reapplied to rechargeable batteries; alternatively, the electrolyte solution of metal ions 52′ can be separated by way of electrolysis 42′ to be recycled for producing hydrogen with the method 1′ or reapplied as an electrode material 62′ of the rechargeable batteries 61′.
According to the above-mentioned first and second embodiments, the method 1, 1′ can produce not only hydrogen but also by-products of magnesium hydroxide, which can be used as fire retardant materials of heat-resistant products. Further referring to
Referring to
Accordingly, the reaction object of the method of the present invention is metal, metallic alloys, or metal scrap, and such materials are harmless to our environment and prevent second pollution; moreover, by-products—hydroxide, organic or non-organic metallic compound, generated from the method are useful raw materials for other products, the by-products increase added value of the present invention and provide the present invention with wide industrial applications; furthermore, the electrolyte solution of metal ions generated after hydrogen production reaction is able to be recycled as electrolyte and electrode material of rechargeable batteries, which completely achieves economical and practical purposes of carrying out oxidation and reduction.
It is understood that the present invention may be embodied in other forms without departing from the spirit thereof. Thus, the present examples and embodiments are to be considered in all respects as illustrative and not restrictive, and the invention is not to be limited to the details given herein.
Number | Date | Country | Kind |
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097146845 | Dec 2008 | TW | national |