Saturday, August 10, 2013

Mg Soleil Project-11

V.  Magnesium Fuel Cell Technology
5.1 Self-Discharging
5.2 Kohama MgFC technology

5.3 Present Status of MgFC
5.4 Resistive to Disaster
5.5 Major Advantages of MgFC
       H2FC major Advantages

5.3 Present Status of MgFC
The description to be given is based on the information gathered at the end of May 2012.  When gaining new information, I will add them to the description soon.

Major specs of Kohama MgFC at the end of May 2012:
Rated capacity: 60Ah
Rated voltage: 1.5V/cell
Cell size: 42 x 225x 15 mm
Mass: 470 g/cell
Mass energy density: 200Wh/kg
For details, reference is made to pdf file, 7 to14 pages.

In the pdf file, description is made about the construction of the MgFC, home-use permanent power source example, performance test examples, applications of MgFC, and others. The MgFC could continuously power a small motor for 3 weeks or longer. The basic performances of the MgFC have already been secured (Prof. Kohama said). The MgFC successfully charged 120 mobile phones at 360 W as its output. In use, the salt water (electrolytic solution) was set to the FC body. The MgFC normally operates its rated output power even after it is left for several tens years in a state that the solution is not set to the FC body. The Mg FC was designed for emergency use at medical facilities, communication stations, homes, etc. Its application includes power sources for automobiles, as a matter of course. Commercialization of the Mg FC for automobiles is scheduled within one year. There will be somewhat less time lag from the targeted time.

An advanced MgFC (4 kWh) was tested in the early of December 2012. The MgFC, which was combined with an L-ion battery, was used for powering a trike. The trike succeeded in running a distance of 100 km on the public road. A schematic circuit for powering the trike will resemble the circuit diagram illustrated on page 11 of a pdf file.
It is recently revealed that the MgFC succeeds in continuously feeding current for 10 hours.
The price of the MgFC will be significantly low. The price of the MgFC will be almost half of that of the lead-acid battery currently and widely used by the automobile (Prof. Kohama said).

Prof. Kohama has long developed the next generation transportation system, called "AeroTrain". The AeroTrain will be described in detail later. For his academic specialities, please refer to a list of academic papers.
During the AeroTrain development, he accidentally found the fact that the flame-retardant magnesium alloy exhibits an excellent corrosion resistance against seawater. Upon the discovery, an MgFC was manufactured: negative electrode = flame-retardant magnesium alloy, positive electrode = air (oxygen), and electrolytic solution = 18 wt% salt water. Unexpected good results were produced: 1.5 V & 60 Ah/cell. The battery continuously and stably operated. This is a new finding. He also found another fact that the magnesium can store electric energy. It is a common that it is impossible to store electricity. The fact completely denies the opinion commonly accepted.

5.4 MgFC is resistant to disasters
In the case of the hydrogen-based fuel cells currently used, for example, the residential CHP (ENEFARM) reforms city gas to produce hydrogen and uses the produced hydrogen for its fuel. In a disaster situation, if the city-gas pipeline is damaged, the H2FC-contained CHP will be inoperable even if the CHP itself is not damaged and is normally operable.
In this situation, however, the Mg FC is normally operable if the FC itself is not damaged and seawater (electrolytic solution) is available. The MgFC has a long life span (several tens years) as already described.

The MgFC may be used in the following way (see a photograph given below) in preparation for a disaster situation. A simple power supply system includes an MgFC, a controller, a switch and others. An output line of the power supply system is connected to a load, for example, TV in a state that a detecting line of the same for detecting an electric state of a power line in a house is coupled with the power line. When a grid power supply stops in an emergency, the controller detects the power supply stop, instructs a related portion of the system to inject the electrolyte into the MgFC body, while at the same time operate the switch to connect the output line to the TV. The MgFC in turn operates to start power supply to the TV. TV is ceaselessly operating and presenting a TV program, for example, news.
In the test conducted at the end of April 2012, the MgFC could continuously power a 9-inch TV and 96 LEDs for 25 hours for 25 hours. See [PDF. pages 9 & 10] [PDF. page 10]

See coresponding photo
Model of MgFC Emergency use

Prof. Kohama has experienced "Japan 2011 earthquake/tsunami disaster". He saw real disaster scenes with his own eyes. When power outage occurred, time is critical.  In the earthquake/tsunami disaster, victims could not know tsunami/earthquake information. This partly led to expansion of the damages. The following crossed his mind: If electric power supply could be continued for several days, the damage expansion would be minimized. Victims could get moment-to-moment changing disaster conditions from broadcasts. Air-conditioners, if operable, would help patients and sick persons keep their health conditions good. This would spur him on to accelerate his MgFC development having thus far been made, I suppose.

5.6 MgFC major advantages
MgFC has the following advantages. It seems to me that MgFC may relegate H2FC to a supporting role.
1) Energy density of the MgFC is high: 2 kWh/kg = about 5 times or higher than of the current L-ion battery and is comparable with that of the current H2FC. 1464mAh/g(MgFC)、150mA/g (L-ion battery) ←experimental values.
2) Non-toxic and clean, and safe.
Flame-retardant Mg alloy is used. It is significantly safe so as to allow its welding in air
3) MgFC is simple in structure, light in weight, and cheap in price.
The price is negligibly low compared to that of the hydrogen fuel cell (H2FC).
4) The lifespan of MgFC is significantly long, almost semi-permanent. It is 60 to 70 years if the salt water as the electrolyte is removed.
5) There is no need of using expensive infrastructure to supply fuel to the fuel cell. In the case of H2FC, 6 Oku Yen/one hydrogen station.
6) Mg as fuel can be transported in safe and simple way.
7) The Mg resource is almost limitless.
8) Used Mg is recyclable by its smelting.
9) Mg transportation is easy. The smelted Mg takes the form of grain.
10) Mg is also used as the light metal material. With its application development, Mg will supersede other metal materials currently used.

H2FC major advantages
In Japan, some types of the H2FC have entered the early market phase. At least 20,000 ENEFARM residential CHP) systems are now operating at ordinary homes. Fuel cell vehicles (FCVs) will be launched in around 2015 in the world.
Those types of the H2FC involve the following serious problems:
1) The price of H2FC CHP is still too high.
2) Large-scale infrastructure such as hydrogen stations, gas pipelines is essentially needed.
3) Hydrogen embrittlement problem is not yet solved.
4) H2FC still involves serious problems in generation, storage and transportation of hydrogen
>> To be continued to Mg Soleil Project-12

New technology on H2FC was developed. 
New technology: a catalyst to efficiently extract hydrogen from the MCH into hydrogen gas. The catalyst continues its function for about one year.
H2FC involves problems in 1) generation (of hydrogen), 2) storage and 3) transportation. 
The new technology substantially solved the problems 2) and 3) of those problems.  
Hydrogen is fixed to methylcyclohexane (MCH) through a chemical reaction of toluene and hydrogen (known technology).
The hydrogen is stored in the MCH and transported in this state. 
To use the hydrogen, it is extracted from the MCH (dehydrogenation). 
The hydrogen fixing and transportation are allowed to be performed at normal temperature and pressure. 
The volume is reduced to 1/500. 
Developer: Chiyoda-corp.

5.3 Kohama MgFCの現状
5.4 MgFCは災害に強い
5.5 マグネシウム燃料電池の主な利点

5.3 Kohama MgFCの現状
以下の記述はend of May 2012に収集した情報に基づいています。新しい情報が入り次第、追加、修正を行ないます。

Pdfでは、MgFCの構成について書かれている。家庭用永久電源の例、性能試験例、MgFCの適用例などについて書かれている。小型モーターを3週間以上駆動できた。MgFCの基本性能はすでに確保してある。このMgFCを用い360 W で120 mobile phonesを充電した。使用時に、食塩水(電解液)をMgFC本体にセットした。 数十年間放置しておいても、電解液を本体より外しておけば、このMgFCはそのセット後正常に作動する。このMgFCは医療、通信、家庭などでの緊急時の使用を想定して開発されている。自動車などへの利用も想定して開発が進められている。その完成を約1年後と想定しているようだ。
昨年12月の初旬、4kWhのMgFCをtrikeに積んで100 kmを走行し、成功している。公道での試験だ。L-ion batteryを駆動源とし、それにMgFCでchargeさせながらの走行にようである。駆動系の概略回路はpdf fileの11 pageに記したものに類似するものだろう。
最近、10 Aの電流を10時間流し続けたことを発表している。
価格は非常に低くなるようだ。現在使用されている自動車用の鉛電池(lead-acid battery)と比較するとその半値と言っている。

Prof. Kohamaは次世代高速輸送システム(AeroTrain)の開発に長い間携わっている。車体軽量化のため、最軽量金属材料である難燃性マグネシウム合金を車体に使用した。氏のご専門についてはa list of academic papers。この開発中に難燃性マグネシウムが海水に対する腐食性が非常に高いことを発見見した。 この発見を機に、金属―空気電池の負極に難燃性マグネシウムを使用することを試しみた。マグネシウム - 空気電池を作製した: 負極 = 難燃性マグネシウム合金、正極 = 空気(酸素)、電解液 = 18 wt% 食塩水。この電池は、1.5 V & 60 Ah/cellで連続して、安定的に動いた。予想外の結果である。新しい発見である。氏はもう一つの事実に気が付いた。マグネシウムは電気を貯蔵する、ということ。電気は貯蔵できない、これが一般的な意見である。これが見事に否定された。

5.4 MgFCは災害に強い
現在使用されている水素ベースの家庭用燃料電池 (ENEFARM) の場合、一般に都市ガスを改質し、水素を作り、それを燃料としている。災害が発生し、ガス供給用パイプラインが損傷を受けた場合、ENEFARMが正常でも使用できない。こういった場合、MgFCはそれ自身が損傷を受けない限り、海水など(電解液)があれば、そのまま動作する。 電解液(食塩水)をはずしておけば、数十年は持つ。

このMgFCを緊急用として使用する場合、次のような形で使用可能(下図)。MgFC、 コントローラ、切り替え器などを持つ簡単な電源システムを作る。電源システムの出力線をTVなどに、感知線を屋内の系統電力線に接続しておく。災害などで停電が発生した場合、コントローラが系統の断を感知線の状態から感知し、電解液のMgFC本体への注入の開始を関連箇所に指示し、同時に切り替え器を作動させ、電源システムの出力線をTVに電気的に接続する。MgFCが作動し、TVに電力の供給を開始する。TVは停止することなく、そのまま番組、例えば、ニュースを流し続ける。継続使用時間については、April 2012の下旬に行われた試験では、9-inch TVと96個のLEDを25時間駆動している。詳しくは、[PDF. page 10]

See coresponding photo
Model of MgFC Emergency use

Prof. Kohamaは"Japan 2011 earthquake/tsunami disaster"を経験し、その悲惨さを目の辺りにしている。停電が発生し、被災者が 出る地震/津波情報を知ることができず、これが被害拡大の一因となった。こういった場合、数日間はTVなどを、さらに冷暖房機器を稼動させ、病人などの体調維持を可能とする電源が必要であると考えた。これが氏のMgFCの開発意欲をさらに刺激したようである。

5.5 マグネシウム燃料電池の主な利点
1) MgFCのエネルギー密度が非常に高い。2kWh/kg ←現在のリチウム電池の5倍以上、水素燃料電池並み。1464mAh/g(MgFC)、150mA/g (Li電池) ←実験値。
2) 無害、クリーン、安全。
3) 構造が簡単、軽量、価格が安い (H2FCと比べると無視しうるほどに安い)。
4) 寿命が半永久である、実用レベルで見た場合。
現在開発中のもの:約60 to 70年、電解液(塩水)を外しておけば)。
5) 電池への燃料供給のために高額なインフラがいらない。6億円/水素ステーション。
6) 燃料であるMgの運搬が安全で、かつ容易である。
7) 燃料としてのMg資源はほぼ無限である。
8) その資源の再利用が可能→ Mg精錬
9) 燃料の輸送が容易→ 精錬したMgは粒状物。
10) Mgの軽量金属材料としても使用可能。その用途開発に伴い、他の金属材料を置きかえてゆくものと思われる。

H2FCの一部(例:エネファーム)は早期マーケットに入っている。FCV (燃料電池自動車) は2015ごろを目処に早期マーケットに入る。
1) 価格が高い。
2) 水素ステーション、ガス供給などの大規模なインフラが必要である。
3) 水素脆化の問題が完全に解決されたとの話は聞かない。
4) 水素の発生、貯蔵、運搬に問題を抱えている。

1) 水素の製造、2) 水素の貯蔵、3) 水素の輸送にH2FCの問題があるとされています。
この中の2) & 3)の問題が実質解決された。
Developer: 千代田化工建設


Tuesday, August 6, 2013

Mg Soleil Project-10

V.   Magnesium Fuel Cell Technology
5.1  Self-Discharging

5.2  Kohama MgFC technology
5.3  Present Status of MgFC
5.4  Resistive to Disaster
5.5  Major Advantages of MgFC

5.2 Kohama MgFC technology
Kohama MgFC technology may be defined as below.
1. In an MgFC, a negative electrode is made of a magnesium alloy containing aluminum and calcium, and an electrolytic solution into which magnesium ions emanating from the negative electrode elute. (← Claim 1)
2.In the MgFC (defined above), the aluminum contained in the magnesium alloy ranges from ≧3 wt% to ≦ 9 wt%, and the calcium contained therein ranges from ≧ 1 wt% to ≦ 3 wt%. (← Claim 2)
3. In the MgFC (defined above), the electrolytic solution is preferably one selected from among sodium chloride solution, sodium hydroxide solution, sodium bicarbonate solution, and sodium percarbonate solution. (← Claim 3)

The magnesium alloy thus composed has at least the following advantageous features.
Feature-1: Kohama MgFC, which uses the flame-retardant magnesium alloy for its negative electrode, successfully solved the self-discharge problem inherent to the conventional MgFC. Five samples having respectively different compositions were prepared. Those samples were immersed in a 18 (wt) % salt water. Weight decreases of those samples were measured. In the sample 1 (having the magnesium alloy containing 6 wt% of aluminum and 2 wt% of calcium), the magnesium alloy was little eluted into the salt water. The result shows that where the sample 1 is applied to the negative electrode of the MgFC, no self-discharge will occur in the battery.
Feature-2: 1) The magnesium alloy has a satisfactory reactivity. 2) It has an ability to control combustion (reaction). The characteristic 1) indicates that it is suitable for the battery material. The characteristic 2) indicates that it is suitable for the industrial material. Those contradictive characteristics of the magnetic alloy synergically operate to provide an excellent battery material.

The reason why the magnesium alloy has such characteristics:
"The alloy containing aluminum and magnesium has a bilateral structure consisting of two phases, i.e., a metal Mg phase (solid solution) and an Al2Ca compound phase.  "The compound phase is relatively inactive. The reactivity of the alloy is macroscopically low. The fact is empirically confirmed. Where the bilateral structure is sufficiently fine, the corrosion reaction (elution reaction) is uniform as a whole and gently progresses. The above fact will contribute to the reactivity and the reaction control. It appears that the parent phase of the magnesium alloy having high reactivity and the reaction control by the second phase being inactive cooperate to provide the good performance of the negative electrode."
Feature-3: The Kohama magnesium alloy is capable of producing electricity of about 80% of the theoretical electric capacity of the magnesium alloy. This is experimentally confirmed. The theoretical electric capacity of pure magnesium is 2.2Ah/g. The magnesium alloy contains 92 wt% of magnesium, for example. The electric capacity of the magnesium alloy is 1.63 AH/g.
An experiment was conducted under the following conditions.
Negative electrode: magnesium alloy containing 6 wt% of aluminum and 2 wt% of calcium
Positive electrode current collector: carbon felt
Electrolytic solution: 18 wt% salt water
The experiment results: decreased amount of the magnesium alloy = 0.601g, current amount per 1 g = 1630mAh/g, and electric power = 476mWh/g
Feature-4: The MgFC is capable of stably producing electricity for a long time. An experiment was conducted.  In the experiment, an MgFC was manufactured, and current was fed from the MgFC to a motor. The MgFC was roughly specified as follows:
Negative electrode: magnesium alloy containing 6 wt% of aluminum and 2 wt% of calcium
Positive electrode current collector: carbon felt
Electrolytic solution: 18 wt% salt water
A plate-like magnesium alloy was used. One side of the magnesium alloy plate is covered with a tape, while the other side is exposed to the electrolyte. The experiment result showed that the MgFC using the magnesium alloy continuously produces electricity more safely and longer than the MgFC not using the magnesium alloy. (Written based JPA No. 2012-234799)

As already described, the magnesium to be utilized is produced by the Kohama smelting process based on solar energy.  The smelted magnesium functions as a carrier carrying solar energy.  Electrically, a flow of the free electrons takes the flow of current in the MgFC. The phenomenon indicates that the smelted-magnesium stores electricity.  The fact disproved the popular opinion that it is impossible to store electricity. Thus, magnesium can safely store, transport, and utilize electricity. This is a revolutionary form of energy utilization.  The fact is significant. 

5.2 Kohama MgFC technology
Kohama MgFC technologyの大きな概念は次のようだ。
1.マグネシウム燃料電池において、負極材がアルミニウム及びカルシウムを含有するマグネシウム合金で構成される、そして電解液には負極材からマグネシウムイオンが溶出する。 (← Claim 1)
2.マグネシウム合金に含まれるアルミニウムは3重量%以上9重量%以下の範囲である。 カルシウムは1重量%以上3重量%以下の範囲である。 (← claim 2)
3.使用する電解液は、塩化ナトリウム水溶液、水酸化ナトリウム水溶液、炭酸水素ナトリウム水溶液、及び過炭酸ナトリウム水溶液からなる群から選ばれる少なくとも1つである。 (← Claim 3)

特徴―1: Kohama MgFCは自己放電の問題を解決した。
特徴―2:このマグネシウム合金は、1) 適当な反応性を有している、2) 燃焼(反応)を抑制する能力を有している。前者は電池材料に適していることを示している。後者は工業用材料に適していることを示している。このマグネシウム合金はこのように相反する特性を有している。が、これらが相乗的に働き、電池材料として優れた性能を発揮する。この特徴を何故持つかの推測:「アルミニウムとカルシウムを含むマグネシウム合金は、通常は金属Mg相(固溶体)と化合物相(Al2Ca)の2相からなる複層組織を持つ。化合物相が比較的不活性なので、この合金はマクロ的には反応性が低くなる。このことは、経験によって確かめられている。また、この複層組織が十分に微細な場合は、全体として腐蝕反応(溶解反応)は均一になり、穏やかに進行する。このことも、上記の反応性と反応抑制能力に一役買っているものと推測される。つまり、マグネシウム合金の反応性の高い母相と不活性な第2相による反応抑制が、電池の負極材としての優れた性能に大きく寄与していると考えられる。」
特徴―3: Kohama MgFC のマグネシウム合金からは、理論電気容量の約80%の電気を取り出すことが可能。このことは実験的に確認されている。純粋なマグネシウムの理論電気容量は、2.2Ah/gである。マグネシウム合金は、マグネシウムを例えば92重量%含んでいる。このマグネシウム合金の電気容量は1.63Ah/gである。
負極材 :Alを6重量%、Caを2重量%含むマグネシウム合金
電解液 :18重量%塩水
負極材 :Alを6重量%、Caを2重量%含むマグネシウム合金
電解液 :18重量%塩水
この実験結果より、マグネシウム合金を負極材として用いた場合には、従来のマグネシウム合金を用いた場合よりも、長期間に亘って安定的に電気を取り出すことができることが判明した。 少量が0.601gであり、マグネシウム合金1g当たりの電流量が1630mAh/gであり、電力量が476mWh/gであった。(Written based on JPA No. 2012-234799)
>> To be continued to Mg Soleil Project-11


Monday, August 5, 2013

Mg Soleil Project-9

V.   Magnesium Fuel Cell Technology
5.1  Self-Discharging
5.2  Kohama MgFC technology
5.3  Present Status of MgFC
5.4  Resistive to Disaster
5.5  Major Advantages of MgFC

V. Magnesium Fuel Cell Technology
The magnesium fuel cell (MgFC) has a mass energy density of 2.6 kWh/kg. The figure is 10 times larger than that of the lithium battery. MgFC is capable of powering the vehicle 500 km at 20 kg magnesium.  MgFC is now commercially available from MagPower Systems Inc. It is capable of driving the devices, for example, coffee maker. MagPower uses a "hydrogen inhibitor" as its properietry technology. Kohama Lab. et al.* are now actively developing the magnesium fuel cell (MgFC) functioning like a primary battery. The MgFC has been developed to such a level of an emergency-use battery. The MgFC uses a flame-retardant magnesium alloy for its anode (negative electrode).
* Co-developers = Tohoku university (Prof. Kohama), AIST, Furukawa battery, Nihon materials, and other companies

MgFC belongs to the "metal-air battery" category, and uses magnesium (special magnesium alloy to be described later) for its metal. "Magnesium, oxygen and water reactively cooperate to generate a magnesium hydride (Mg (OH)2), so that an electromotive force is generated between the positive and the negative electrodes. When a load, for example, a lamp, is connected between those electrodes, current flows through a circuitry including the load and the battery. The fact clearly shows that the MgFC is a chemical electric generator, which chemically generates electricity. Kohama MgFC operates like a primary battery that stops its electric generation when the magnesium at the negative electrode is used up.
The function of the MgFC may be roughly interpreted as follows.
The smelted magnesium has stored solar energy in the form of free electrons. When the magnesium is applied to the negative electrode of the metal-air battery, the above chemical reaction takes place in the battery.  Electrons flows from the negative electrode to the positive electrode.  The current is reverse to the electrons in flow.  The MgFC extracts the free electrons from the smelted magnesium, and feeds to the load them in the form of current. 

MgFC will continuously generate electricity if it has such a function as to continuous supply magnesium to the negative electrode. Such an improvement of the MgFC will be made in future. The hydrogen fuel cell (H2FC) is also a chemical electric generator, which generates electricity using hydrogen as its fuel. It continues its electricity generation so long as the fuel supply continues. As known, the ordinary battery is supplied with electricity from an external electric source, stores the electricity supplied, and feeds it to exterior. When the electricity stored in the battery is used up, it is necessary to charge the battery. If it is left for a long time, it naturally discharges and loses the electricity stored. Functionally, the ordinary battery is passive.  The MgFC generates electricity. It function is active.
5.1 Self-discharge phenomenon
The self- or natural discharge is known, which is inherent to this type of battery. When the magnesium (Mg) metal of the negative electrode dissolves, electrons are generated and those react with hydrogen ions to generate hydrogen. The hydrogen generation results in no or little flow of electrons to the positive electrode. No electrons-flow hinders increase of the battery capacity. Where the used electrolyte is acid, the self-discharge phenomenon is distinctive.
To avoid this, the alkaline electrolyte is used. In this case, another problem arises. When the alkaline electrolyte is used, a coating of insoluble magnesium hydroxide is formed on the surface of the magnesium of the negative electrode. The film allows neither electrons nor ions to pass through there. The battery reaction stops and the battery loses its function.  (Dr. Kurihara (SAITEC). 

Some solutions to self-discharge problem
1) Magpower systems successfully solved the self-discharge problem by using "hydrogen inhibitors" as its properietry technology. Reference is made to the company's website.
2) Susumu Suzuki succeeded in solving the self-discharge problem by using a polyvalent carboxylate aqueous solution. For details, reference is made to WO/2011/125150 MAGNESIUM BATTERY.
3) Prof. Kohama solved the same problem by using a special flame-retardant magnesium alloy for the negative electrode. The technology is detailed in JPA No. 2012-234799.

South-Korea's MgFC recently developed is newsed. The researchers succeeded in powering the car a distance of 200 km by the 40 kg MgFC set on the car. The positive and the negative electrodes of the MgFC are improved, and the battery structure is modified for improvement. The results are that the chemical reaction efficiency at the negative electrode and the chemical reaction rate are both increased, and that the energy efficiency and the energy density are doubled when compared with those of the conventional one. It is unknown how to overcome the self-discharge problem inherent to the MgFC.

V. マグネシウム燃料電池
マグネシウム燃料電池(MgFC) の理論エネルギー貯蔵量2.6Ah/g。 リチウムイオン電池の10倍以上。車に適用した場合、重量20kgで500kmの走行が可能。
現在、MgFCはMagPower Systems Inc. より入手可能である。コーヒーメーカーを駆動可能。MagPowerは"hydrogen inhibitor"(特許取得済み)を使用している。
Kohama Labo. et al.* もMgFCを開発している。緊急用電源程度までは実用化の域に達している。特殊な難燃性マグネシウム合金をアノード(負極)に使用している。
* Co-developers = Tohoku university (Prof. Kohama), AIST, Furukawa battery, Nihon materials, and other companies

MgFCは金属―空気電池であり、その金属がマグネシウム(特殊マグネシウム合金、後で詳しく述べる)である電池。この電池では、マグネシウム、酸素及び水から水酸化マグネシウム(Mg(OH)2)が生成され、その結果正負電極間に起電力が発生する。この両電極間に負荷を接続すれば、電気が流れる。 つまり、この電池は発電する。化学的に電気を発生する化学発電装置である。Kohama MgFCはマグネシウムを使い切れば発電機能が失われる一次電池のように働く。
一般の電池は電気の供給を受け、それを蓄電し、出力(放電)する。電池に蓄電した電気を使いきれば、再び充電する必要がある。放っておけば自然に放電する。機能的には 受動的だ。MgFCは発電する。機能的には能動的だ。

5.1 自己放電
MgFCの負極のマグネシウム金属が電解液に溶出し、電子が発生する。この電子が水素イオンと反応し水素を発生する。電子の正極への流れが阻害される。これが自己放電。これにより電池容量を大きくできなかった。これがMgFCの実用化を阻んできた。よく知られている。電解液が酸性(水素イオン濃度が高い)であると、この現象の発生の度合いが大きい。 これを避けるためアルカリ電解液を使用する。しかし、この場合、別の問題が発生する。アルカリ電解液の場合、負極のマグネシウムの表面に不溶性の水酸化マグネシウムの被膜が形成される。この皮膜は電気もイオンも通さない。熱も発生する。結果は電池反応が停止し、電池機能が停止する (栗原英紀博士(SAITEC) 。

1) Magpower systemsはhydrogen inhibitorsでこれを解決している。詳しくは同社のhomepageをご参照願いたい。
2) 鈴木進氏が、多価のカルボン酸塩の水溶液を用いることで自己放電の問題を解決している。詳しくは、特許公開2010-182435をご参照願いたい。
3) Prof. Kohama (Tohoku University) は特殊難燃性マグネシウム合金を負極に用いて自己放電問題を解決している。特開2012-234799に詳しく書いてある。

>> To be continued to Mg Soleil Project-10

Thursday, August 1, 2013

Mg Soleil Project-8

IV. Magnesium Smelting
4.1 Kohama Smelting Process
4.2 Solar Furnace Used by Experiment (Fig. 2)

4.1 Kohama Smelting Process
A Kohama smelting process uses a solar furnace to generate the smelting temperature of 1,200 degrees C.  It is essential to efficiently harvest solar energy.  Places suitable for the magnesium smelting are located in the sun-belt zone including the equator.  The best places are the deserts having seaside areas in the zone.  The solar energy density in the desert is significantly high. It is about 3kW/㎡, about 3 times higher than that in Japan. The quantity of solar energy is about 7.5 times or more than that in Japan. The area of about 70 km2 covers the total energy consumption of Japan.  It is clear that if we will have means to efficiently harvest solar energy, we will be free from restriction on the choosing of the sites at which the smelting plants are located.
Kohama smelting technology uses a solar furnace which reflects light energy on mirror surfaces and condenses the light energy at a target point to generate the smelting heat.  The light energy is directly converted into the smelting heat. There is no energy transformation from solar energy to another form of energy.

Little loss is generated during a process to generate heat by light energy.  The light to heat conversion efficiency is excellent, 70% or higher.  See “Quality of natural heats”. Page 4
The Kohama smelting process employs the well-known Pidgeon process for the smelting process.  The magnesium smelting process comes in two varieties, reduction process (Pidgeon process) and electrolytic process. The Pidgeon process is mainly used at present.  The main reason for this is that the electrolytic process is expensive.  At present, China exclusively (about 90%) supplies smelted magnesium materials to countries in the world.  The Pidgeon process is carried at 1,200 degrees C and using a ferro-silicon (reducing agent). The smelting temperature is produced by burning Koks, resulting in emission of a large amount of carbon dioxide gas.

There is no problem in securing the smelting temperature of 1,200 degrees C.  The University of Prof. Kohama has long utilized the solar furnace for material research. The solar furnace produced high temperature near to 4,000 degrees C. Use of the plane mirror, not the parabolic mirror, suffices for the reflecting mirror, to produce 1,200 degrees C. It was experimentally confirmed that the Kohama smelting process operated as intended. This will be described in detail in “4.2 Solar Furnace Used by Experiment (Fig. 2)” to be given later.   In the current Pidgeon process, a ferro silicon is used for the reducing agent.  The ferro silicon is produced by using electric energy.   This is not economical.  Solar energy may be used in place of expensive electric energy.  Another catalyst of a high quality may be developed, if necessary.  This is not a difficult work. 

Yabe smelting process:
There is another professor who is developing another new magnesium smelting process.  He is Prof. Yabe (Tokyo Institute of Technology).  The Yabe smelting process uses a proprietary solar pumped laser for generating a temperature required for smelting magnesium.  The solar pumped laser generates a temperature of 20,000 degrees C, which is high enough to smelt magnesium.  The solar pumped laser is under demonstration test.  For details, please ask PEGASOS ELECTRA Co. Ltd. Prof. Yabe describes the basic concept of the "Mg soleil project" for realizing the “sustainable society” in "Magnesium Civilization", written by Prof. Yabe and Yamaji, published from PHP Shinsho. The Kohama project is somewhat different from the Yabe project. The difference resides in the smelting process. The Yabe smelting process uses the solar pumped laser, while the Kohama smelting process uses the solar furnace. 

4.2 Solar Furnace Used by Experiment (Fig. 2)
1.5m parabola mirror (search light used by Battleship YAMATO),
* Heliostat mirror
* Furnace core
* Smelted Mg
* Shell
Photograph-1 (Fig. 2)
Photograph-2 page 5 & 6

The heliostat tracking system using parabolic mirror elements was used in the experiment.
Magnesium-contained materials, reducing agents and heat sources, which were used in the experiment, are:
A. Magnesium-contained materials:
* Dolomite (from mine)
* Magnesium oxide (from final resultant material after use)
* magnesium hydroxide (from used generator)
* magnesium chloride
* magnesium chloride (seawater)
B Reducing agent:
* ferro-silicon (Pidgeon process)
* new carbon material
C. Heat source:
Heat source experiments were successfully conducted. Solar heat and electric furnace heat were used.
* Solar heat
* Biomass heat
* Waste heat from factory

A paper# describes the solar furnace that is currently used by Tohoku University. The solar furnace is of the heliostat type. The rotational parabolic mirror (diameter = 10 m, focal length = 3.2 m) is fixed. The heliostat is constructed such that seven mirror bands each consisting of plane mirrors are arranged one on another. The heliostat traces sunlight and applies solar energy concentrically to the target area. The computer controls the tracing operation of the heliostat. The temperature reached 3,727 degrees C at the target area. The solar furnace is installed at Research Institute for Scientific Measurements, Tohoku University.

# "Effects of the Miyagi-Earthquake on a Large Solar Furnace (Minor Special Issue on the Alternative Energy Technologies)"

DESERTEC project:
The project now progresses. Solar energy is condensed into thermal energy in the desert (Sahara Desert) being rich in solar energy.  The thermal energy generates steam, which in turn drives the steam turbine generator.  The generated electric energy is transmitted to the EU countries, through low loss HVDC transmission lines (submarine cables laid in the Mediterranean Sea). The average distance is 1,500 km between the desert and the EC countries. 6,000 km is the distance from the desert to Japan. It is clear that application of the DDESERTEC method to Japan is impossible.  Long transmission lines construction, high cost, and large power loss are inevitable.

IV. マグネシウム精錬
4.1 Kohama精錬

4.2 実験に使用したマグネシウム精錬用太陽炉設備(Fig. 2)
Kohama精錬法は太陽炉を用い1,200℃の精錬温度を得る。太陽光エネルギーの効率的な収集が必要である。精練所に適する場所は赤道付近のサンベルト地帯にある。この地帯の臨海地を持つ砂漠が最適だ。砂漠での太陽光のエネルギー密度は非常に高い。日本の3倍(約3kW/㎡)。日射量は約7.5倍。 日本の全消費エネルギーを約70㎞2の面積で賄える。太陽光の集光効率の高い手段ができれば、精錬所設置場所の選択の制約が緩和される。明らかである。
Prof. Kohamaの精錬では太陽炉を用い、光を鏡面で反射し集光し、それを熱源に直接利用している。太陽炉を用いた場合、太陽光を直接熱源に使用する。他のエネルギー形態への変換がない。光で熱を発生させる過程でのロスがほとんどない。その変換効率は70% 以上で圧倒的だ。See 「自然界で得られ熱の質」、page 4。
精錬には旧来のピジョンprocessを用いている。マグネシウム精錬には還元法(ピジョン法)と電解法がある。現在、ピジョン法が主流となっている。電解法は電気のコストが高いがその主な理由である。中国がピジョン法を採用しマグネシウムを世界にほぼ独占的に (90%前後) 供給している。ピジョン法では、1,200 ℃の温度とフェロシリコン(還元剤)を用いて還元が行われる。現在使用されているピジョン法ではコークスを燃やし、この高温を得ている。大量の炭酸ガスの発生は避けられない。
このprocessで必要とされる1,200 ℃の精錬温度の確保は全く問題がない。太陽炉については、Prof. Kohamaの大学は金属物性研究で古い実績を持っている。4,000 ℃近い温度を出している。1,200 ℃の温度を得るには反射鏡は平面鏡構成で十分であるとしている。
Kohama 精錬法はlabでその成功を確認してある。この実験で用いた設備を「実験に使用したマグネシウム精錬用太陽炉設備(Fig. 2)」に後述してある。

Yabe 精錬法:
今、別の角度から新しいマグネシウム精錬法を開発している学者がいる。Prof. Yabe (Tokyo Institute of Technology) だ。Yabe精錬法は独自の太陽光励起レーザー(solar pumped laser)を用いている。20,000℃の高温を得ている。これを用いて精錬に必要な温度を得ている。この太陽光励起レーザーは現在実証試験中。詳しくは、 (株)ペガソス・エレクトラ (PEGASOS ELECTRA Co. Ltd. ) にお問い合わせ願いたい。Prof. Yabeは「マグネシウム文明論」 (東工大の矢部孝・山路達也著, PHP新書)でマグネシウム循環社会の考え方を示している。Prof. Yabeのマグネシウム循環社会はPro. Kohamaのそれとはその実行の手法で少し違う。主な違いの一つがMgの精錬法である。

4.2 実験に使用したマグネシウム精錬用太陽炉設備(Fig. 2)
パラボラ鏡: 1.5m parabola mirror (戦艦大和の探照灯)
ヘリオスタッド: heliostat mirror
炉心: furnace core
精錬Mg: smelted Mg
Photograph-1 (Fig. 2)
Photograph-2 page 5 & 6
* ドロマイト(鉱山から)
* 酸化 Mg(使用済み最終酸化物から)
* 水酸化 Mg(使用済み発電器から)
* 塩化 Mg(海水から)
B. 還元剤:
* フェロシリコン(ピジョン法)
* 新炭素材料
C. 熱源:
* 太陽熱
* バイオマス熱
* 工場排熱

# "Effects of the Miyagi-Earthquake on a Large Solar Furnace  (Minor Special Issue on the Alternative Energy Technologies)"

DESERTEC project:
太陽光エネルギーの密度の高い砂漠で行われる。発電した電力を送電線(地中海に海底ケーブルを敷設)介してEU 諸国に送電する。平均距離 1,500kmである。DDESERTEC手法の日本へ適用は不可能。ここから日本への距離は6, 000kmである。


Wednesday, July 31, 2013

Mg Soleil Project-7

III. Magnesium
3.1 Excellent Properties of Magnesium
3.2 Magnesium Market and its Trends
3.2.1 World Market

3.2.2 Japanese Market
3.3    Something to be solved

3.2.2 Japanese Market
2013magnesium demand in Japan (predicted) (JMA)
1) Structural material section – 7,845 tons (decreased 4.5% on the previous year)
2) Additive agent section – 28,250 tons (decreased 1.1% on the previous year)
3) Overall – 37,395 tons  (decreased 1.6% on the previous year)

The above predicted figures are affected by overseas transfer of production bases and weak Yen.  The current magnesium demand keeps at around 40,000 tons.  70% or higher of the total magnesium demand is the additive agent to the aluminum alloy.  The die casting magnesium alloy is only about 10%. 
Also in Japan, application of magnesium die casting to automobiles parts will enter a full-fledge stage at high possibility. This is based on the facts that at least environment issue guides the automobile to their weight reduction and the automobile market is giant.  Note that magnesium (specific gravity = 1.8) is the lightest of the metals. 
Examples of magnesium die casting products:
1) steering, engine blocks, oil pan, etc. (automobiles), and 2) housings of single-lens reflex cameras, laptop PCs, mobile phones, etc. (electronics devices). 
Reference-1: (from 1960)
* Domestic Chronology (application to cars); -
  Toyota, Honda, Nissan, Mitsubishi
* Foreign Chronology (application to cars); -
  a) Northern America - GM、Ford、Chrysier
  b) European - VW、BMW、Daimier、Benz、Porsche、Fiat、Cromodla、 Audi


3.3 Something to be solved
It is predicted that the magnesium products for automobiles will increase in amount and expand in
the range of their applications.  At present, China exclusively (around 90%) supplies the smelted magnesium to the most of the countries in the world.  The fact shows that the magnesium used in Japan largely and inevitably depends on the import of the magnesium from China.  World economic affairs and the will of the manufacturing country greatly affect the magnesium supply and price in Japan.  The magnesium supply and price in Japan are not stable. 
It is said that manufacturing costs, including labor costs, caused the handling of the magnesium smelting business by China.  The smelting process used is the Pidgeon process.  The magnesium smelting based on the Pidgeon process was industrially carried out around 20 years ago also in Japan. It is said that the smelting technology in China has advanced to such a level that the CO2
emission/ton is comparable with that of the aluminum smelting process.
Japan is in a serious state of magnesium import dependency.  Use of the magnesium die casting products for automobiles will be in a full-fledge state, as referred to above.  The domestic magnesium market will increase in amount and expand in its application range from now on.  With the trend, the used magnesium will increase.  It is clear that problem how to make a disposal of the increase amount of the used magnesium will arise.  In this situation, a revolutionary magnesium smelting process has been proposed in Japan.  The new smelting process can effectively cope with the problem cleanly and inexpensively.  The smelting process has a potential to supersede the current smelting process.  The component technologies thereof have already been developed.  It is in an experimental stage.

Kohama Smelting Process:
Prof. Kohama proposes an innovative magnesium smelting process.  The most important feature of the
smelting process is to use solar energy for generating the smelting temperature.  The smelting process is a modification of the Pigeon process currently used. The conventional smelting process smelts magnesium by burning cokes and at 1,200 degrees C.  A large amount of CO2 emission is
inevitable in executing the smelting process. The Kohama smelting process uses a solar furnace for generating the smelting temperature of 1,200 degrees C.  Note that light is reflected on a mirror surface and the reflected light is directly used to generate the smelting temperature.  Little loss is generated during the light to heat conversion process.  The light to heat conversion efficiency is 70% or higher.  The heating process is clean as a matter of course.

3.2.2 日本の市場
日本の2013 年の需要予測 (JMA)
1) 構造部門: 7,845 トン (前年比 4.5%減)
2) 添加材部門:28,250 トン(前年比 1.1%減)
3) 全体:37,395トン (前年比 1.6%減)


自動車向けダイカスト製品の例: 1) ステアリング、エンジンブロック、オイルパン等 (自動車用)、2) ノート

ご参考-1: (1960年代からの)
* 車への適応年表(国内):
* 車への適応年表(国外):
    欧州:VW、BMW、Daimier、Benz、Porsche、Fiat、Cromodla、 Audi

3.3 課題など
現在、中国がマグネシウムを世界にほぼ独占的に (90%前後) 供給している。



Pro. Kohamaは新しいマグネシウム精錬法を提案している。特徴は精錬温度の確保に太陽光を利用している。現在主流となっているピジョン法の変形である。従来の方法では1,200℃の温度と触媒を使用してマグネシウム

Mg Soleil Project-6A (Table of Contents)

Mg Soleil Project
Table of Contents

I. Introduction
1.1 Solar energy and Magnesium
1.2 Magnesium smelting
1.3 Magnesium
1.4 Magnesium Fuel Cell (MgFC)

II. Mg Soleil Project
2.1 Magnesium Recycling Society
2.2 Economic Effects

III. Magnesium
3.1 Excellent Properties of Magnesium
3.2 Magnesium Market and its Trends
  3.2.1 World Market
  3.2.2 Japanese Market
3.3  Something to be solved

         -  Kohama Smelting Process
IV. Magnesium Smelting
4.1 Kohama Smelting
4.2 Solar Furnace for Magnesium Smelting Used in Experiment (Fig. 2)

V. Magnesium Fuel Cell Technology
5.1 Self-Discharging
5.2 Kohama MgFC technology
5.3 Present Status of MgFC
5.4 Resistive to Disaster
5.5 Major Advantages of MgFC

VI. AeroTrain

I. Introduction
1.1. 太陽光エネルギーとマグネシウム
1.2. マグネシウム精錬と太陽光エネルギー
1.3 マグネシウム
1.4 マグネシウム燃料電池

II. Mg Soleil Project
2.1 マグネシウム循環社会
2.2 Mg 循環社会の効果

III. マグネシウム
  3.2.1 世界の市場
  3.2.2 日本の市場
3.3 課題など

      -  Kohama Smelting Process
IV マグネシウム精錬
4.1 Kohama精錬
4.2 実験に使用したマグネシウム精錬用太陽炉設備(Fig. 2)

V. マグネシウム燃料電池 (MgFC)
5.1 自己放電
5.3 小濱MgFC technology
5.4小濱MgFC technologyの現状
5.5 MgFCは災害に強い
5.6 MgFC の主な利点

VI. AeroTrain

Tuesday, July 30, 2013

Mg Soleil Project-6

III.    Magnesium
3.1      Excellent Properties of Magnesium
3.2      Magnesium Market and its Trends
3.2.1 World Market
3.2.2 Japanese Market
3.3  Issues and Problems

III. Magnesium
3.1 Excellent Properties
Magnesium is available anywhere in the world. There is no fear that the magnesium resources are consumed up to exhaustion.  Magnesium never solely exists in a natural state.  Magnesium may be utilized anywhere if it may be smelted.
Magnesium has many excellent properties as the light metal.  Specific gravity: Mg = 1.8、and Al = 2.7、Fe = 7.9. Of those metals, magnesium is the lightest metal.  The strength of magnesium when used as a structural material is significantly high.  Magnesium has a good heat radiation property.  It also has a good shielding property against the electromagnetic waves. It has many excellent properties of, for example, specific strength, specific rigidity, shock absorption, machinability, depression resistance.  Its dimension little varies with respect to temperature and time.  Its recyclability is good. 

3.2      Magnesium Market and its Trends
3.2.1   World Market
882 x 1000 tons in 2015, and 1279 x 1000 tons in 2020 = a prediction of the world demand of magnesium.  A predicted value of the world magnesium demand in 2012 749 x 1000 tons (C & M company, material disclosed by 2010 IMA international meeting, and JMA). 

The world magnesium demand over a range from 2012 to 2020 sharply increases as clearly shown through comparison of those figures of the magnesium demand.  Note that the die casting magnesium alloy (automobile parts) occupies the most of the magnesium demand increase. 

Magnesium demands: (JMA)
1) Additive agent for aluminum-based alloy (40% of total demand)
2)Die casting for automobile parts
3) Die casting for other fields
4) Desulfurization for steel production
5) Others

Note that of those demand items the die casting for automobile parts sharply increases: 191 (in 2011)、216 (2012)、308 (2015)、521 (2020) (unit: x 1000 tons).  Automobile manufacturers in Europe actively use magnesium parts for automobiles, for example, instrument panels, engine cradles, and roof rails.  To cope with environment and resource issues, automobile emission regulations become stricter.  The tendency of the emission regulations forces the manufacturers to reduce weight of automobiles.  The tendency is worldwide and will be intensified more and more. 
Prediction is made such that the magnesium demand will sharply increase in the world.  It is said that China has a plan to make large scale production of magnesium. Posco (Korean) proceeds with a project to construct an integrated production system ranging from the magnesium smelting to plateworking.

III. マグネシウム

マグネシウムの比重:Mg = 1.8。アルミニウムと鉄の比重:Al = 2.7、Fe = 7.9。
リサイクル性がよい。Japan Magnesium Association (JMA)

3.2       マグネシウム市場とその動向
3.2.1          世界の市場
マグネシウムの世界の需要推移は全体として882 (2015)、1279 (2020) (単位:千トン)と予測されている。2012が749 (予測値) である(C&M社 2010年IMA国際会議発表資料、日本マグネシウム協会)。これらの値を比較するとかなりの増大である。その増加のほとんどが鋳造用マグネシウム合金 (自動車部品用)。

1) アルミニウムをベースとした合金種への添加材(全体の約40%)
2) ダイカスト向け(自動車)
3) ダイカスト向け(その他) 
4) 鉄鋼脱硫向け
5) その他

注目すべきは、これら項目の中で、自動車用ダイカストの伸びが著しい:191 (2011)、216 (2012)、308 (2015)、521 (2020)。