TWI644858B - Device and method of high temperature steam vaporization of hydrogen storage particles with generated hydrogen - Google Patents
Device and method of high temperature steam vaporization of hydrogen storage particles with generated hydrogen Download PDFInfo
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- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
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Abstract
一種高溫水蒸氣催化氫化鎂微粒應需即生氫氣方法與裝置，該方法包括：通入一高溫蒸氣與一儲氫微粒進入一反應器中；該高溫蒸氣之分子接觸一儲氫載體表面反應產生氫氣和表面氧化，該反應器溫度上升直到可以直接裂解該儲氫微粒產生一氫氣並分解為一金屬微粒。 A high-temperature steam-catalyzed magnesium hydride microparticles should be a hydrogen-generating method and apparatus, which comprises: introducing a high-temperature vapor and a hydrogen storage microparticle into a reactor; the high-temperature vapor molecules are contacted with a hydrogen storage carrier surface to generate a reaction Hydrogen and surface oxidation, the reactor temperature rises until the hydrogen storage microparticles can be directly cracked to produce a hydrogen gas and decompose into a metal particle.
Description
本發明係有關一種氫氣產生方法與裝置，特別是有關一種高溫水蒸氣催化應需即生氫氣方法與裝置。 The invention relates to a method and a device for generating hydrogen, in particular to a method and a device for catalyzing the demand for hydrogen at a high temperature steam.
水是自然界中最豐富之元素，性質穩定且安全，其組成成分中之氫原子，更可形成氫氣做為一乾淨之能源供人類使用。數十年來，業界均在努力尋找一經濟安全有效之方法，來製造出廉價而方便使用之氫氣做為能源。 Water is the most abundant element in nature. It is stable and safe in nature. The hydrogen atoms in its composition can form hydrogen as a clean energy source for human use. For decades, the industry has struggled to find an economically safe and effective way to make cheap and easy-to-use hydrogen as an energy source.
習知藉由有機酸製造氫氣反應實驗圖(美國專利US7,704,484B2)。藉由加伐尼腐蝕反應所製造之氫氣反應一開始非常迅速，然而，伴隨著放熱反應溫度上昇，待金屬鎂分解水產生之氫氧根離子的濃度(也就是pH值)高於11.5後，隨即因有機酸陽極金屬鎂(Mg)氧化為鎂離子(Mg+2)與電子(2e-)，此時如果電解質水溶液含有足夠濃度的氫離子(H+)，則氫離子(2H+)與電子(2e-)反應生成氫氣(H2)，水(H2O)則因此分解成氫離子(2H+)與氫氧根(2OH-)，氫氧根(2OH-)則與陽極鎂離子(Mg+2)反應成氫氧化鎂(Mg(OH)2)。氫氧化鎂(Mg(OH)2)形成於金屬鎂表面形成所謂阻隔層，然後電解質水溶液中的氯離子(Cl-)會攻擊氫氧化鎂(Mg(OH)2)表面，致使後續的加伐尼腐蝕反應以一相當低的速率進行。 A hydrogen reaction experimental diagram for the production of hydrogen by an organic acid is known (U.S. Patent No. 7,704,484 B2). The hydrogen reaction produced by the Galvanic corrosion reaction starts very quickly, however, as the temperature of the exothermic reaction rises, the concentration of hydroxide ions (ie, pH) produced by the magnesium metal decomposition water is higher than 11.5. Immediately, the organic acid anode magnesium metal (Mg) is oxidized to magnesium ion (Mg +2 ) and electron (2e - ). At this time, if the electrolyte aqueous solution contains a sufficient concentration of hydrogen ions (H + ), the hydrogen ion (2H + ) and The electron (2e - ) reaction generates hydrogen (H 2 ), and the water (H 2 O) is thus decomposed into hydrogen ions (2H + ) and hydroxide (2OH - ), and hydroxide (2OH - ) and anode magnesium ions (Mg +2 ) is reacted to magnesium hydroxide (Mg(OH) 2 ). Magnesium hydroxide (Mg(OH) 2 ) is formed on the surface of the magnesium metal to form a so-called barrier layer, and then the chloride ion (Cl - ) in the aqueous electrolyte solution attacks the surface of the magnesium hydroxide (Mg(OH) 2 ), causing subsequent calcination. The Ni corrosion reaction proceeds at a relatively low rate.
另外，美國專利US3,256,504揭露一種使用不同金屬如金屬鈦網表面鍍鉑(Pt)再沾粘金屬鎂(Mg)，冷卻收縮後固定於鉑表面形成雙金屬，再浸泡至含有鹽水之電解液形成加伐尼電池電動勢(Galvanic Potential)，可以得到為金屬鎂(Mg)(-1.67V) 與鉑(+0.88V)鈦網耦合之加伐尼腐蝕電位差(VSCE)為2.55V並可反應產氫。美國專利US3,256,504亦同時揭露利用金屬鎂(Mg)(-1.67V)與不鏽鋼304(-0.38V)鈦網耦合之加伐尼腐蝕電位差(VSCE)為1.29V並可反應產氫。然而，無論是金屬鎂(Mg)與鉑或金屬鎂(Mg)與不鏽鋼在加伐尼腐蝕作用下於含鹽水之電解液反應產氫氣，其共同特徵是金屬鎂表面形成一層固相氫氧化鎂，而嚴重影響後續腐蝕反應之進行。表1所示為金屬鎂(Mg)或鎂合金(Mg alloy)與一般金屬於重量百分比3%~6%氯化鈉水溶液中之平均腐蝕電位值。 In addition, U.S. Patent No. 3,256,504 discloses the use of different metals such as titanium metal mesh surface platinized platinum (Pt) and then adhered to metallic magnesium (Mg), which is cooled and contracted and fixed on the surface of platinum to form a bimetal, and then immersed in an electrolyte containing brine. The Galvanic Potential is formed, and the Galvanic corrosion potential difference (V SCE ) coupled to the magnesium (Mg) (-1.67V) and platinum (+0.88V) titanium mesh is 2.55V and can be reacted. Hydrogen production. U.S. Patent No. US3,256,504 also discloses the use of metallic magnesium simultaneously (Mg) - plus galvanic corrosion potential difference (1.67V) and the stainless steel 304 (-0.38V) titanium mesh coupling of (V SCE) is 1.29V and the hydrogen production reaction. However, whether metal magnesium (Mg) and platinum or magnesium metal (Mg) react with stainless steel under the action of galvanic corrosion to produce hydrogen in the brine containing electrolyte, the common feature is that a solid phase magnesium hydroxide is formed on the surface of the magnesium metal. , and seriously affect the progress of the subsequent corrosion reaction. Table 1 shows the average corrosion potential values of metallic magnesium (Mg) or magnesium alloy (Mg alloy) and general metals in 3% to 6% by weight aqueous sodium chloride solution.
雖然，使用旋轉研磨除去金屬鎂(Mg)表面之氫氧化鎂(Mg(OH)2)，並且同時監測控制電解質水溶液之溫度與pH值分別保持在50℃與7.3，可使加伐尼腐蝕反應產生之氫氣反應得以快速進行。然而，無論是金屬鎂(Mg)與鉑或金屬鎂(Mg)與不鏽鋼在加伐尼腐蝕作用下於含鹽水溶液反應產氫氣之方法，因其陽極為金屬鎂(Mg)，陰極為金屬觸媒(如鉑或不繡鋼)，吾人可得知其電化學反應式如下：陽極：Mg→Mg+2+2e- (1) Although the use of rotary grinding to remove magnesium hydroxide (Mg(OH) 2 ) from the surface of magnesium metal (Mg), and simultaneously monitoring the temperature and pH of the controlled aqueous electrolyte solution at 50 ° C and 7.3, respectively, can cause the Galvanic corrosion reaction The hydrogen reaction produced is fast. However, whether it is metal magnesium (Mg) and platinum or magnesium metal (Mg) and stainless steel in the treatment of hydrogenation in the aqueous solution of salt under the action of galvanic corrosion, because the anode is metal magnesium (Mg), the cathode is metal touch The medium (such as platinum or stainless steel), we can know that its electrochemical reaction formula is as follows: anode: Mg → Mg + 2 + 2e - (1)
陰極：2H2O+2e-→H2+2OH- (2) Cathode: 2H 2 O+2e - → H 2 + 2OH - (2)
(Mg)容易失去電子而加速腐蝕反應而產生氫氣，其電化學反應式如下：Mg+2H2O(aqueous)→H2+Mg(OH)2 (3) (Mg) readily lose electrons to accelerate the corrosion reaction to generate hydrogen gas, the electrochemical reaction is as follows: Mg + 2H 2 O (aqueous ) → H 2 + Mg (OH) 2 (3)
需注意的是，(1)式中之氫氧化鎂(Mg(OH)2)為「固相」且不溶於水，會影響後續有機酸進行。換言之，使用旋轉研磨除去金屬鎂(Mg)表面之氫氧化鎂(Mg(OH)2)，並且監測控制 電解質水溶液之溫度與pH值產氫方法之瞬間產氫速率亦是非常不穩定。 It should be noted that the magnesium hydroxide (Mg(OH) 2 ) in the formula (1) is "solid phase" and insoluble in water, which may affect the subsequent organic acid. In other words, the magnesium hydroxide (Mg(OH) 2 ) on the surface of the magnesium metal (Mg) is removed by spin grinding, and the instantaneous hydrogen production rate of the method of controlling the temperature of the aqueous electrolyte and the pH of the hydrogen production is also very unstable.
另一方面美國專利US7,704,484B2，添加檸檬酸(citric acid)確實可以改善反應速率，然而反應之副產物為甲醛(formaldehyde)，其化學分子式為CH2O。然而，甲醛CH2O，除了本身為一易燃、毒性之腐蝕性氣體外，且反應水溶液之pH值等會影響後續有機酸進行，因此必須額外監測反應水溶液之pH值，並即時更新電解質水溶液，雖然可以解決加伐尼腐蝕反應速率不足現象，但是使用酸當作催化劑還是容易造成元件管路的腐蝕，在連結至燃料電池前需要增加去除酸處理。 On the other hand, U.S. Patent No. 7,704,484 B2, the addition of citric acid can indeed improve the reaction rate, however, the by-product of the reaction is formaldehyde, and its chemical formula is CH 2 O. However, formaldehyde CH 2 O, in addition to itself being a flammable, toxic corrosive gas, and the pH of the reaction aqueous solution may affect the subsequent organic acid, so the pH of the aqueous solution must be additionally monitored, and the aqueous electrolyte solution should be updated immediately. Although it can solve the problem of insufficient rate of Galvanic corrosion reaction, the use of acid as a catalyst is still likely to cause corrosion of the component piping, and it is necessary to increase the acid removal treatment before being connected to the fuel cell.
另，水蒸氣催化低熔點無機氫化金屬亦可產生氫氣。為說明起見，以下以氫化鎂微粒為例說明。然其非限制本發明之實施例。低熔點無機氫化鎂在一實施例中，低溫下氫化鎂微粒幾乎不與水的反應，如果提高溫度其化學反應如下：2H2O+MgH2→Mg(OH)2+2H2 (4) In addition, water vapor catalyzed low melting inorganic hydrogenation metal can also produce hydrogen. For the sake of explanation, the following description is made by taking magnesium hydride fine particles as an example. It is not intended to limit the embodiments of the invention. Low-melting inorganic magnesium hydride In one embodiment, the magnesium hydride fine particles hardly react with water at a low temperature, and if the temperature is raised, the chemical reaction is as follows: 2H 2 O+MgH 2 →Mg(OH) 2 +2H 2 (4)
如(4)式所示，在氫化鎂表面會形成一氫氧化鎂薄膜並產生氫氣，氫氣氣泡(bubble)帶出表面，薄膜不溶於水分子，很快地阻擋水分子擴散進入與未反應的氫化鎂繼續反應生成氫氣，反應速率很快的就會停止在一開始水接觸氫化鎂表面所形成氫氧化鎂(Mg(OH)2)薄層，產生的氫氣氣泡(bubble)則被帶出水表面。 As shown in the formula (4), a magnesium hydroxide film is formed on the surface of the magnesium hydride and hydrogen gas is generated. The hydrogen bubbles are carried out of the surface, and the film is insoluble in water molecules, which quickly blocks the diffusion of water molecules into and unreacted. magnesium hydride hydrogen reaction continued, the reaction rate will stop soon magnesium hydroxide (Mg (OH) 2) formed by a thin layer of magnesium hydride water contact surface of a start, the generated hydrogen bubbles (bubble) with water were surface.
另，當反應溫度從室溫提高到水的沸點100℃和一大氣壓力下，水蒸氣(steam)和氫化鎂的化學反應如下： H2O(steam)+MgH2→MgO+2H2 (5)該反應為放熱反應，反應熱為每一莫耳240千焦耳。圖1所示為水蒸氣催化氫化鎂微粒反應速率的實驗圖。如圖1所示的STEP 1，反應在表面生成氧化鎂薄層，放熱反應產生的高熱量，水蒸氣分子45~60瓦/公尺．度(W/mK)的熱傳導(conduction)通過氧化鎂(MgO)薄層，進入未反應的核心氫化鎂(MgH2)繼續反應產生氧化鎂(MgO)與氫氣(H2)，氫氣以2000~3000瓦/平方公尺．度(W/m2K)對流(convection)帶出表面，如圖二所示反應消耗了大部分新鮮氫化鎂轉化為氫氣，反應一開始在很短時間內(~0.01秒)反應速率達到最大值。 In addition, when the reaction temperature is raised from room temperature to the boiling point of water of 100 ° C and an atmospheric pressure, the chemical reaction of steam and magnesium hydride is as follows: H 2 O (steam) + MgH 2 → MgO + 2H 2 (5 The reaction is an exothermic reaction with a heat of 240 kJ per mole. Figure 1 is an experimental diagram showing the reaction rate of steam-catalyzed magnesium hydride microparticles. As shown in Figure 1, STEP 1, the reaction produces a thin layer of magnesium oxide on the surface, the high heat generated by the exothermic reaction, water vapor molecules 45 ~ 60 W / m. The degree of heat transfer (W/mK) passes through a thin layer of magnesium oxide (MgO) and enters the unreacted core magnesium hydride (MgH 2 ) to continue the reaction to produce magnesium oxide (MgO) and hydrogen (H 2 ). Hydrogen is 2000~ 3000 watts / square meter. Degree (W/m 2 K) convection brings out the surface, as shown in Figure 2, the reaction consumes most of the fresh magnesium hydride and converts it to hydrogen. The reaction starts to reach the maximum rate in a short time (~0.01 seconds). value.
非室溫下的高溫水蒸氣分子水解和一般水解是不同的，主要是化學反應轉化大部分新鮮氫化鎂為氫氣。一開始很短時間內(開始~0.01秒)反應速率達到最大值，薄層的厚度增加到一極限值tc，水蒸氣分子只能透過表面擴散通過薄層與核心未反應的氫化鎂繼續產生氫氣，但是此時反應速率從STEP 1對流轉變為擴散(diffusion)的機制，擴散反應成為反應的限制，反應時間從0.1秒開始，反應速率逐漸減少，如圖1所示的STEP 2。這是因為氫氧化鎂(Mg(OH)2)層的厚度持續增加，造成水分子通過氫氧化鎂進入未反應的氫化鎂核心的時間延遲。 High temperature water vapor molecular hydrolysis and general hydrolysis at room temperature are different, mainly chemical reaction to convert most of the fresh magnesium hydride to hydrogen. At a very short time (starting ~0.01 seconds), the reaction rate reaches a maximum, and the thickness of the thin layer is increased to a limit value t c . The water vapor molecules can only be diffused through the surface through the thin layer and the core unreacted magnesium hydride. Hydrogen, but at this time the reaction rate changes from STEP 1 convection to diffusion mechanism, the diffusion reaction becomes the reaction limit, the reaction time starts from 0.1 second, and the reaction rate gradually decreases, as shown in Figure 2 of STEP 2. This is because magnesium hydroxide (Mg (OH) 2) thickness of the layer continues to increase, causing water molecules into the core of magnesium hydride by reaction of magnesium hydroxide is not a time delay.
為解決上述技術問題，本發明公開了一種高溫水蒸氣催化氫化鎂微粒應需即生氫氣方法，包括：通入一高溫水蒸氣與一氫化鎂微粒進入一反應器中；該高溫水蒸氣之分子接觸一氫華鎂微粒表面反應產生氫氣和表面氧化，一反應器溫度上升直到可以直 接裂解該氫化鎂微粒產生一氫氣與分解為一更細的金屬鎂奈米微粒。 In order to solve the above technical problems, the present invention discloses a high-temperature steam-catalyzed magnesium hydride microparticles, which is a method for producing hydrogen gas, comprising: introducing a high-temperature steam and a magnesium hydride fine particle into a reactor; the high-temperature water vapor molecule Contact with the surface of hydrogen hydride particles to produce hydrogen and surface oxidation, a reactor temperature rises until it can be straight The magnesium hydride fine particles are lysed to generate a hydrogen gas and decompose into a finer metal magnesium nanoparticle.
本發明還公開了一種高溫水蒸氣催化氫化鎂微粒應需即生氫氣裝置，一種高溫水蒸氣催化氫化鎂微粒應需即生氫氣裝置，包括：一高壓氫氣鋼瓶，反覆通入一氫氣經一高壓氫氣通入口以將一反應器內空氣排出乾淨；一高溫水蒸氣通入口，通入一定量的高溫水蒸氣與一氫化鎂微粒進入該反應器；一壓力計，顯示反應壓力，並藉以調整該高溫水蒸氣的溫度與壓力；一攪拌器，用以攪拌一氫化鎂微粒、該高溫水蒸氣與該氫化鎂微粒，使得高溫水蒸氣之分子接觸該反應器內之該氫化鎂微粒，其中，該氫化鎂微粒放置於該反應器內；一燒結多孔過濾器和氫氣排出口，用以過濾並排出該反應器反應所產生之一氫氣；一熱交換器，當該反應器之溫度過高，減緩或停止供應該高溫蒸氣和/或回收熱能以降低該反應器之溫度；一溫度監控器，當該反應器之溫度若開始下降，再通入一定比率之該高溫水蒸氣和該氫化鎂微粒一直到該反應器之溫度不再增加，且當通入一定比率之該高溫水蒸氣和該氫化鎂微粒但該反應器不再反應時，結束反應並釋出該氫氣。 The invention also discloses a high-temperature steam-catalyzed magnesium hydride microparticles, which should be a hydrogen generator, and a high-temperature steam-catalyzed magnesium hydride microparticles should be a hydrogen generating device, comprising: a high-pressure hydrogen cylinder, which repeatedly passes a hydrogen gas through a high pressure. a hydrogen inlet to discharge the air in a reactor; a high-temperature steam inlet, a certain amount of high-temperature steam and a magnesium hydride particle are introduced into the reactor; a pressure gauge, showing the reaction pressure, and thereby adjusting the a temperature and a pressure of the high-temperature steam; a stirrer for stirring a magnesium hydride fine particle, the high-temperature steam and the magnesium hydride fine particles, so that the molecules of the high-temperature steam contact the magnesium hydride fine particles in the reactor, wherein The magnesium hydride fine particles are placed in the reactor; a sintered porous filter and a hydrogen discharge port for filtering and discharging one hydrogen generated by the reactor reaction; and a heat exchanger, when the temperature of the reactor is too high, slowing down Or stop supplying the high temperature vapor and/or recovering heat energy to lower the temperature of the reactor; a temperature monitor, when the temperature of the reactor starts Lowering, then introducing a certain ratio of the high temperature steam and the magnesium hydride particles until the temperature of the reactor no longer increases, and when a certain ratio of the high temperature steam and the magnesium hydride fine particles are introduced, the reactor is no longer Upon reaction, the reaction is terminated and the hydrogen is released.
1‧‧‧高壓氫氣鋼瓶 1‧‧‧High pressure hydrogen cylinder
2‧‧‧高溫水蒸氣通入口 2‧‧‧High temperature steam inlet
2-1‧‧‧高溫水蒸氣 2-1‧‧‧High temperature steam
2-2‧‧‧氫化鎂微粒 2-2‧‧‧Hydrogen hydride particles
3‧‧‧壓力計 3‧‧‧ pressure gauge
4‧‧‧高壓氫氣通入口 4‧‧‧High pressure hydrogen inlet
5‧‧‧撹拌器和氫化鎂微粒 5‧‧‧ stirrer and magnesium hydride particles
6‧‧‧燒結多孔過濾器和氫氣排出口 6‧‧‧Sintered porous filter and hydrogen discharge
7‧‧‧熱交換器或熱電裝置 7‧‧‧Heat exchangers or thermoelectric devices
8‧‧‧溫度監控器 8‧‧‧ Temperature monitor
9‧‧‧反應器 9‧‧‧Reactor
11‧‧‧氫化鎂微粒 11‧‧‧Magnesium hydride particles
300‧‧‧本發明一實施例高溫水蒸氣催化氫化鎂微粒應需即生氫氣裝置 300‧‧‧ An embodiment of the present invention for high-temperature steam-catalyzed magnesium hydride microparticles requires a hydrogen generating device
圖1係習知之水蒸氣催化氫化鎂微粒的反應速率圖。 Figure 1 is a graph showing the reaction rate of conventional steam-catalyzed magnesium hydride microparticles.
圖2係本發明之高溫水蒸氣催化氫化鎂微粒的反應速率圖。 Figure 2 is a graph showing the reaction rate of the high temperature steam catalyzed magnesium hydride microparticles of the present invention.
圖3係本發明一實施例高溫水蒸氣催化氫化鎂微粒應需即生氫氣裝置。 Fig. 3 shows a hydrogen generating device for high-temperature steam-catalyzed magnesium hydride fine particles according to an embodiment of the present invention.
以下將對本發明的實施例給出詳細的說明。雖然本發明將結合實施例進行闡述，但應理解這並非意指將本發明限定於這些實施例。相反地，本發明意在涵蓋由後附申請專利範圍所界定的本發明精神和範圍內所定義的各種變化、修改和均等物。應理解圖示並未按照比例繪製，且僅描述其中部分結構，以及顯示行程這些結構之各層。 A detailed description of the embodiments of the present invention will be given below. While the invention will be described in conjunction with the embodiments, it is understood that the invention is not limited to the embodiments. Rather, the invention is to cover various modifications, equivalents, and equivalents of the invention as defined by the scope of the appended claims. It should be understood that the illustrations are not drawn to scale, and only a
由於非室溫下的高溫水蒸氣和一般水解是不同的化學反應，一開始反應消耗了大部分新鮮氫化鎂轉化為氫氣。很短時間內(開始~0.01秒)反應速率達到最大值，薄層的厚度增加到一極限值tc，水蒸氣分子透過表面擴散通過薄層與核心未反應的氫化鎂繼續產生氫氣，但是此時反應速率從STEP 1對流轉變為擴散(diffusion)的機制，擴散反應成為反應的限制，反應時間從0.1秒開始，反應速率逐漸減少，如圖1所示的STEP 2。這是因為氧化層的厚度持續真增加，造成水分子通過氧化層進入未反應的氫化鎂核心的時間延遲。 Since high temperature water vapor at room temperature and general hydrolysis are different chemical reactions, the initial reaction consumes most of the fresh magnesium hydride converted to hydrogen. A very short time (start ~ 0.01 seconds) the reaction rate reaches a maximum, the thickness of the thin layer is increased to a threshold value t c, the molecular diffusion of water vapor through a thin layer of magnesium hydride with a core of unreacted hydrogen through the surface continues to produce, but this The reaction rate changes from STEP 1 convection to diffusion mechanism. The diffusion reaction becomes the reaction limit. The reaction time starts from 0.1 second and the reaction rate gradually decreases, as shown in Figure 1 of STEP 2. This is because the thickness of the oxide layer continues to increase, causing a delay in the passage of water molecules through the oxide layer into the unreacted magnesium hydride core.
此時，如果通過一開始的加熱氫化鎂微粒和超過沸點溫度(100℃)汽化轉為水蒸氣，高溫水蒸氣和氫化鎂反應產生大量放熱，產生的熱量視氫化鎂莫耳數量和反應熱的乘積。當氫化鎂核心溫度超過287℃時開始發生熱分解(decomposition)，產生為更細的奈米鎂金屬粉末(Mg)和氫氣(H2)，高溫(>287℃)的氫氣讓壓力超過一大氣壓力，發生膨脹(inflated)和***(explosion)，如圖2所示的STEP 2部分，其化學反應如下：MgH2→Mg+H2 (6) At this time, if the magnesium hydride fine particles are heated and vaporized to a water vapor at a boiling temperature (100 ° C), the high-temperature steam and the magnesium hydride react to generate a large amount of heat, and the heat generated depends on the amount of the magnesium hydride and the heat of reaction. product. When the magnesium hydride core temperature exceeds 287 ℃ starts thermal decomposition (decomposition), generated as a finer powder of metal nano magnesium (Mg) and hydrogen (H 2), high temperature (> 287 ℃) so that the pressure exceeds one atmosphere of hydrogen Force, inflated and explosion, as shown in the STEP 2 part of Figure 2, the chemical reaction is as follows: MgH 2 →Mg+H 2 (6)
(6)式為吸熱反應，反應吸收熱量為每一莫耳75 千焦耳，此外，如圖2所示的STEP 2，占絕大部份的核心部分熱分解氫氣增加反應速率，讓反應速率達到最大值。接下來，更細的奈米鎂金屬粉末接觸高溫水蒸氣發生以下反應：H2O(steam)+Mg→MgO+H2 (7) (6) is an endothermic reaction, the heat absorbed by the reaction is 75 kJ per mole. In addition, STEP 2, as shown in Figure 2, accounts for the majority of the core portion to thermally decompose hydrogen to increase the reaction rate, allowing the reaction rate to reach Maximum value. Next, the finer nano magnesium metal powder is exposed to high temperature water vapor and the following reaction occurs: H 2 O (steam) + Mg → MgO + H 2 (7)
更微細的奈米鎂金屬粉末接觸高溫水蒸氣反應完全氧化為氧化鎂和氫氣，讓反應達到100%的產率(yield)如圖2所示的STEP 3。 The finer nano-magnesium metal powder is completely oxidized to magnesium oxide and hydrogen in contact with a high-temperature steam reaction, and the reaction is brought to a yield of 100% as shown in Fig. 2 of STEP 3.
一般水解反應氫氣的產率取決於粒度和反應溫度，但是奈米粉末在空氣中和潮濕環境下有保存不易和成本太高的問題難以接受。通過使用高溫水蒸氣的溫度和氣體形態的水解反應可以獲得氫化鎂微粒接近100%的產率。更高的反應溫度可以減少對反應速率增強劑的需要，例如昂貴的合金添加劑或腐蝕性酸性溶液。 The yield of hydrogen in the general hydrolysis reaction depends on the particle size and the reaction temperature, but the problem that the nanopowder is difficult to store and the cost is too high in air and in a humid environment is unacceptable. A yield of nearly 100% of the magnesium hydride microparticles can be obtained by a hydrolysis reaction using a temperature of a high-temperature steam and a gas form. Higher reaction temperatures can reduce the need for reaction rate enhancers, such as expensive alloying additives or corrosive acidic solutions.
此外，在高溫下工作的水蒸氣取代水另一個明顯的優點是更有效地利用熱電發電機或熱機中放熱反應產生的熱量的能力。 In addition, another significant advantage of replacing water with water at high temperatures is the ability to more efficiently utilize the heat generated by the exothermic reaction in thermoelectric generators or heat engines.
氫化鎂(MgH2)為一種為低熔點無機氫化鎂，它含有7.66重量%的氫氣，水解反應含有6.42重量%的氫氣，水蒸氣水解反應含有9.03重量%的氫氣，並已被研究為潛在的儲存氫氣的介質，於一大氣壓下當溫度高於287℃亦會開始吸熱分解為金屬鎂和氫氣。在一實施例中，無機氫化金屬亦可以為氫化鋁鋰(LiAlH4)，氫化鈉鋁(NaAlH4)，氫化鎂鋁Mg(AlH4)，氫化鋰硼(LiBH4)，氫化鈉硼(NaBH4)，氫化鎂硼(Mg(BH4)2)。表2所示為低熔點氫化金屬的分解溫度和氫百分比。 Magnesium hydride (MgH2) is a low-melting inorganic magnesium hydride containing 7.66% by weight of hydrogen, a hydrolysis reaction containing 6.42% by weight of hydrogen, and a steam hydrolysis reaction containing 9.03% by weight of hydrogen, which has been studied as a potential storage. The medium of hydrogen, when the temperature is higher than 287 ° C under atmospheric pressure, will also start to absorb heat into metal magnesium and hydrogen. In one embodiment, the inorganic hydrogenation metal may also be lithium aluminum hydride (LiAlH 4 ), sodium aluminum hydride (NaAlH 4 ), magnesium aluminum hydride (AlH 4 ), lithium hydride (LiBH 4 ), sodium hydride (NaBH). 4 ), magnesium hydride boron (Mg(BH 4 ) 2 ). Table 2 shows the decomposition temperature and hydrogen percentage of the low melting point hydrogenation metal.
由於(6)式反應的放熱足夠啟動(7)式反應所需要的吸收熱能，如果只有反應(6)式的放熱，很快的反應器內的溫度將增加到攝氏一千度，超過大部分材料可以忍受的溫度。除此以外，加入反應(7)式可以平衡反應(6)式的放熱，避免過量氧化物覆蓋在微粒表面阻礙反應持續進行。 Since the exothermic reaction of the (6) reaction is sufficient to initiate the absorption of heat energy required for the (7) type reaction, if only the exothermic reaction of the reaction (6) is obtained, the temperature in the reactor will soon increase to a thousand degrees Celsius, exceeding most of the temperature. The temperature the material can tolerate. In addition to this, the addition of the reaction (7) formula can balance the exotherm of the reaction of the formula (6), and avoid excessive oxide coverage on the surface of the microparticles to prevent the reaction from continuing.
從以上分析可以瞭解高溫水蒸氣(>287℃)與氫化鎂(MgH2)可以進行氫化鎂的分解化學反應，進而直接釋放氫氣和金屬鎂。由於表層氧化鎂的密度(3.58g/cm3)與內部氫氣分解後金屬鎂的密度(1.738g/cm3)的兩倍差異改變，造成崩解和內部高壓氫氣的釋出，破壞表面氧化層使得反應得以持續進行，不會因為持續反應(1)的過量氧化物覆蓋在微粒表面阻礙反應持續進行。 From the above analysis, it can be understood that high temperature steam (> 287 ° C) and magnesium hydride (MgH 2 ) can carry out the decomposition chemical reaction of magnesium hydride, thereby directly releasing hydrogen and magnesium metal. Since the difference in the density of the surface magnesium oxide (3.58 g/cm 3 ) and the density of the metallic magnesium after the internal hydrogen decomposition (1.738 g/cm 3 ) is changed, the disintegration and the release of the internal high-pressure hydrogen are caused, and the surface oxide layer is destroyed. The reaction is allowed to continue without impeding the reaction on the surface of the microparticles by the excessive oxide covering the continuous reaction (1).
綜上，本發明一實施例之高溫水蒸氣催化氫化鎂微粒應需即生氫氣步驟如下：(a)反覆通入氫氣將一反應器內空氣排出乾淨；(b)放入低熔點之氫化鎂微粒進入反應器中，通入一定量的高溫水蒸氣與氫化鎂微粒，水蒸氣分子接觸氫化鎂微粒，表面反應產生氫氣和金屬鎂表面氧化；在一實施例中，氫化鎂微粒平均粒徑為5微米~15微米； (c)反應器之溫度開始上升，一直到可以直接裂解氫化鎂微粒產生氫氣，並且分解氫化鎂微粒為更細的金屬鎂奈米微粒；在一實施例中，第一來源為氫化鎂分解高溫水蒸氣為氫氣和氧化的放熱反應；另一來源則是因放熱反應產生的高溫直接裂解氫化鎂粉粒的吸熱反應；第三來源為鎂奈米金屬微粒分解水蒸氣反應生成氫氣和形成氧化鎂，該反應為的放熱反應。在另一實施例中，氫氣來自兩個不同的放熱和一個吸熱反應，高溫放熱反應產生的熱量必須要使得反應溫度超過吸熱反應達到核心未反應部分的最低熱裂解溫度(>287℃)；(d)金屬鎂奈米微粒與水蒸氣反應繼續產生氫氣和形成氧化鎂；(e)當反應器之溫度過高，此時減緩或停止供應高溫水蒸氣或使用熱交換器或熱電裝置回收熱能發電以降低反應器溫度；(f)當反應器溫度若開始下降，一直到反應溫度不再增加即當不再通入水蒸氣；(g)反應結束並釋出氫氣。 In summary, the high-temperature steam-catalyzed magnesium hydride fine particles according to an embodiment of the present invention should be hydrogen-producing as follows: (a) repeatedly introducing hydrogen into a reactor to discharge air; (b) placing a low-melting magnesium hydride The particles enter the reactor, pass a certain amount of high-temperature steam and magnesium hydride particles, the water vapor molecules contact the magnesium hydride particles, and the surface reacts to generate hydrogen and metal magnesium surface oxidation; in one embodiment, the average particle size of the magnesium hydride particles is 5 microns to 15 microns; (c) the temperature of the reactor begins to rise until it is possible to directly cleave the magnesium hydride microparticles to produce hydrogen, and to decompose the magnesium hydride microparticles into finer metal magnesium nanoparticles; in one embodiment, the first source is pyrite decomposition high temperature The water vapor is an exothermic reaction of hydrogen and oxidation; the other source is the endothermic reaction of directly cleavage of the magnesium hydride powder by the high temperature generated by the exothermic reaction; the third source is the decomposition of water vapor by the magnesium nanoparticle to form hydrogen and form magnesium oxide. The reaction is an exothermic reaction. In another embodiment, the hydrogen is derived from two different exotherms and one endothermic reaction, and the heat generated by the high temperature exothermic reaction must be such that the reaction temperature exceeds the lowest thermal cracking temperature (>287 ° C) of the endothermic portion of the core; d) the metal magnesium nanoparticle reacts with water vapor to continue to generate hydrogen and form magnesium oxide; (e) when the temperature of the reactor is too high, at this time slowing or stopping the supply of high temperature steam or using heat exchangers or thermoelectric devices to recover heat energy To reduce the reactor temperature; (f) when the reactor temperature begins to decrease until the reaction temperature no longer increases, that is, when water vapor is no longer introduced; (g) the reaction is completed and hydrogen is released.
此外，亦可結合其他的製程及步驟與此處所討論之製程與步驟，亦即，此處所顯示及描述之步驟之前、中間、及/或之後可有多種製程及步驟。重要的是，本發明之實施例可結合其他製程及步驟而實施之，並不會對其造成重大影響。一般而言，本發明之各種實施例可取代習知製程的某些部分，而不會對其週邊製程及步驟造成重大影響。 In addition, other processes and steps may be combined with the processes and steps discussed herein, that is, there may be multiple processes and steps before, during, and/or after the steps shown and described herein. Importantly, embodiments of the present invention can be implemented in conjunction with other processes and steps without significant impact. In general, the various embodiments of the present invention may replace portions of the conventional process without significantly affecting its peripheral processes and steps.
圖3所示為根據本發明一實施例高溫水蒸氣催化儲氫微粒應需即生氫氣裝置300，包括：高壓氫氣鋼瓶1，反覆通入氫氣經一高壓氫氣通入口2以將一反應器9內空氣排出乾淨；一高 溫水蒸氣通入口4，用以通入一定量的高溫水蒸氣2-1與氫化鎂微粒2-2進入反應器9；一壓力計3，顯示反應壓力，並藉以調整高溫水蒸氣的溫度與壓力；一攪拌器5，一燒結多孔過濾器和氫氣排出口6，與一溫度監控器8。 3 is a diagram showing a hydrogen storage device 300 for high-temperature steam catalyzed hydrogen storage microparticles according to an embodiment of the present invention, comprising: a high-pressure hydrogen cylinder 1, which is repeatedly introduced with hydrogen through a high-pressure hydrogen gas inlet 2 to bring a reactor 9 The air inside is discharged clean; a high The warm water vapor inlet 4 is used to pass a certain amount of high-temperature steam 2-1 and the magnesium hydride fine particles 2-2 into the reactor 9; a pressure gauge 3, which shows the reaction pressure, and thereby adjusts the temperature of the high-temperature steam and Pressure; a stirrer 5, a sintered porous filter and a hydrogen discharge port 6, and a temperature monitor 8.
在一實施例中，通入高溫蒸氣2-1與氫化鎂微粒2-2經由高溫水蒸氣通入口2進入一反應器9中。攪拌器5，用以攪拌氫化鎂微粒11、高溫水蒸氣2-1與氫微粒2-2，使得高溫水蒸氣分子接觸反應器9內之氫化鎂微粒11表面，其反應為產生氫氣和表面氧化。反應器9之溫度開始上升一直到可以直接裂解儲氫微粒產生並分解為金屬微粒。其中，所加入高溫水蒸氣反應溫度高於>287℃。在一實施例中，反應所生成之氫氣由燒結多孔過濾器和氫氣排出口6排出。在另一實施例中，氫氣的輸出包括經過熱交換器7進行氫氣冷卻或一壓縮機(未示出)進行加壓。 In one embodiment, the high temperature vapor 2-1 and the magnesium hydride fine particles 2-2 are passed through a high temperature water vapor inlet 2 into a reactor 9. a stirrer 5 for stirring the magnesium hydride fine particles 11, the high temperature water vapor 2-1 and the hydrogen fine particles 2-2 such that the high temperature water vapor molecules contact the surface of the magnesium hydride fine particles 11 in the reactor 9, and the reaction is to generate hydrogen gas and surface oxidation. . The temperature of the reactor 9 begins to rise until it is possible to directly cleave the hydrogen storage particles to be generated and decomposed into metal particles. Among them, the high temperature steam reaction temperature is higher than >287 °C. In one embodiment, the hydrogen generated by the reaction is discharged from the sintered porous filter and the hydrogen discharge port 6. In another embodiment, the output of hydrogen includes hydrogen cooling via heat exchanger 7 or pressurization by a compressor (not shown).
在一實施例中，通入之高溫水蒸氣2-1和氫化鎂微粒2-2的質量比為1：5~1：20。 In one embodiment, the mass ratio of the high temperature water vapor 2-1 and the magnesium hydride fine particles 2-2 that are introduced is 1:5 to 1:20.
當反應器溫度過高，此時可利用減緩或停止供應高溫水蒸氣和/或於反應器9之外部使用熱交換器7或熱電裝置以回收熱能發電以降低反應器溫度。 When the reactor temperature is too high, it is possible to reduce or stop the supply of high-temperature steam and/or use the heat exchanger 7 or the thermoelectric device outside the reactor 9 to recover thermal energy to reduce the reactor temperature.
壓力計3，用以監測反應器之內部壓力。溫度監控器8，用以當反應器溫度若開始下降，再通入一定比率的高溫水蒸氣一直到反應溫度不再增加；當通入高溫水蒸氣不再反應時，反應結束，氫氣完全釋出。 A pressure gauge 3 is used to monitor the internal pressure of the reactor. The temperature monitor 8 is configured to pass a certain ratio of high-temperature steam until the temperature of the reactor begins to decrease until the reaction temperature is no longer increased; when the high-temperature steam is no longer reacted, the reaction ends and the hydrogen is completely released. .
上文具體實施方式和附圖僅為本發明之常用實施例。顯然，在不脫離申請專利範圍所界定的本發明精神和發明範圍的前提下可以有各種增補、修改和替換。本領域技術人員應該理解，本發明在實際應用中可根據具體的環境和工作要求在不背離發明準則的前 提下在形式、結構、佈局、比例、材料、元素、元件及其它方面有所變化。因此，在此披露之實施例僅用於說明而非限制，本發明之範圍由後附請求項及其合法等同物界定，而不限於此前之描述。 The above detailed description and the accompanying drawings are only typical embodiments of the invention. It is apparent that various additions, modifications and substitutions are possible without departing from the spirit and scope of the invention as defined by the appended claims. Those skilled in the art should understand that the present invention can be used in practical applications according to specific environmental and working requirements without departing from the invention guidelines. Changes in form, structure, layout, proportions, materials, elements, components, and other aspects. The presently disclosed embodiments are, however, to be construed as limited in
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| CN205773309U (en) * | 2016-05-17 | 2016-12-07 | 武汉凯迪工程技术研究总院有限公司 | Magnesium hydride generating hydrogen-storing integrated device |
| CN106684406A (en) * | 2017-02-14 | 2017-05-17 | 武汉市能智达科技有限公司 | MgH2 hydrogen-storage material reaction cavity and fuel cell generation device thereof |
| CN106865497A (en) * | 2017-03-17 | 2017-06-20 | 南开大学 | A kind of preparation method of the growth in situ nanometer magnesium-supported high-ratio surface material of hydrogenation |
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