New Energies, new possibilities

パナソニックは燃料電池の製造に必要な電力を自家発電による再生可能エネルギーで100％賄う実証施設「H2　KIBOU　FIELD」（滋賀県草津市）で、純水素型燃料電池の発電時に発生する熱を吸収式冷凍機に活用する実証実験を始めた。吸収式冷凍機で冷やした水は、同施設内の業務用エアコンの冷媒冷却用に利用する。これにより、空調機全体で消費電力の50％削減を目指す。

今回、純水素型燃料電池の発電時に回収できる熱と吸収式冷凍機に必要な熱源の温度差をなくすため、双方を改良して連携を可能にした。 同電池の実証機10台は、回収できる温度を従来に比べ10度C引き上げて70度Cとした。高温化による触媒の劣化に対応するため、加湿性能を向上させるなどした。熱回収率を高めるため、内部には熱交換器を加えた。発電時の熱も活用し、同電池のエネルギー効率は95％を実現する。 吸収式冷凍機は生成した冷水を活用できるように、業務用エアコンの凝縮器を水冷式に変更し、冷媒の凝縮温度を大幅に低減。空調機全体の消費電力を削減する。

空調機の消費電力50％削減へ…パナソニック、燃料電池の排熱活用（ニュースイッチ） - Yahoo!ニュース

もはや“枯れた技術”で改善の余地が小さいと考えられてきたアルカリ水電解（AWE）技術でブレークスルーがあった。プロトン電解膜（PEM）形と呼ばれる方式を大きく超える水電解効率を実現する可能性がある。つまりは、安いグリーン水素の生産につながる。また、次世代水電解技術ともいわれるアニオン電解膜（AEM）形水電解にも応用できるという。

自動車会社の技術者も驚く

　この技術を開発したのは、同志社大学大学院理工学研究科教授である盛満正嗣氏の研究室。2024年7月にパシフィコ横浜で新エネルギー・産業技術総合開発機構（NEDO）が開催した「NEDO水素・燃料電池成果報告会2024」で初めて発表した。「日本の主要な自動車会社の人もこの成果に驚いていた」（盛満氏）

　開発した技術は、水電解の酸素発生（OER）極（アノード）に用いる触媒材料で、ビスマス（Bi）、ルテニウム（Ru）を主成分とする酸化物材料「BRO」だ。これまで、AWEではニッケル（Ni）もしくはNiと鉄（Fe）の化合物がアノードの触媒として主に使われていた。

　NiやFe系の触媒は、PEM形で用いる酸化イリジウム（IrO2）といったアノードの触媒に比べて安価である一方で、過電圧†が大きく、しかも電流密度を高めようとするとさらに過電圧が急激に上がってしまう課題があった。

　盛満氏の研究室は、2021年ごろからこのAWE向けアノードに用いる触媒の開発に取り組んでおり、これまでは、ナトリウム（Na）添加のBRO（NBRO）やマンガン（Mn）添加のBRO（MBRO）を開発してきた（図1）。いずれも、「パイロクロア構造」という、A2B2O7（AおよびBは金属元素）という結晶構造を基本とする酸化物材料に属する。

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図1　同志社大学が過去に開発したNBROの構造

黄色い球がNa、赤い球がO、青い球がRu、緑色の球がBi（出所：同志社大学／NEDO）

　今回の新触媒は「これまで空気電池向けに開発したものをAWEに転用してみた」（盛満氏）成果だという。これも、パイロクロア構造のBROの一種だが、添加材料は現時点では明らかにしていない。

同志社大がアルカリ水電解で技術革新、超低過電圧の触媒を開発 | 日経クロステック（xTECH） (nikkei.com)

OKUMA　DRONE（福島県大熊町、李顕一社長）は、飛行ロボット（ドローン）に搭載する新たな水素燃料電池（FC）の開発に着手した。現在活用しているFCを国産化し、大学・機関の技術を用いてセルの触媒層に貴金属を使わずに低コスト化する。まず1キロワット、3キロワット級のFCを開発し、定置型を非常用電源や基地局などとして使用。年内にドローンに搭載したプロトタイプ機の完成を目指す。 OKUMA　DRONEは水素FCを搭載したドローンを開発する。英インテリジェントエナジーが開発した水素FC4基と帝人製の水素高圧タンクを、6枚羽根のドローンに搭載。40キログラムのペイロードを積んで15分飛行する機体を開発、実証している。この水素FCを国産化してコストを大幅削減するため、福島県の補助も受けて開発する。 FCスタックのセルは、電解質膜と触媒層、ガス拡散層で構成する。触媒層は貴金属の白金をセラミック担体に担持しているが、均等な白金担持が難しいため歩留まりが悪く、コスト高要因になっている。この触媒層を国内調達可能な白金の代替材料を用い、従来とは異なる方法で製造する。ユアサ商事が製造・量産で協力する。 まず定置型FCを移動発電機として工事現場で、非常用電源として家庭や病院などで事業化する方針。同FCを搭載したドローンのペイロードは、実証中のドローンと同様の40キログラムを目指す。開発したFCスタックは2025年初から内外の展示会に出展する。 OKUMA　DRONEは水素ステーションでドローンへの燃料供給を実現するため、福島県水素ステーション連絡協議会（福島県浪江町）にも参加。日本自動車研究所（JARI）と共同で実用化開発に着手している。水素ステーションの充填ユニットに減圧装置を付けて高圧水素を減圧して活用する仕組みで、認証を取得して実用化を目指す。

低コスト水素燃料電池…OKUMA DRONE、ドローン搭載用開発（ニュースイッチ） - Yahoo!ニュース

Natural hydrogen: European interest heats up, France leading the way.

Potentially massive quantities of naturally produced hydrogen were discovered in France last year. Since then, prospectors across Europe have been on the lookout for more deposits and are calling for greater public support for their efforts.

Earlier this month, the European Court of Auditors heavily criticised the EU’s “unrealistic” targets for low-carbon hydrogen, which the Court considers to be “driven by political will”.

Irrespective of whether the targets were appropriate or not, the continent remains well short of hydrogen supplies which are supposed to store energy, produce alternative fuels or replace gas in industrial applications, as part of the EU’s journey to carbon neutrality.

In this context, there is growing interest in natural hydrogen, produced by underground chemical reactions. According to the latest studies, it is cheaper, less carbon-intensive than hydrogen produced from renewables or nuclear power, and potentially abundant.

For all these reasons, the so-called ‘natural’, ‘geological’, ‘native’ or ‘white’ hydrogen was the subject of a media boom in June 2023 when an estimated deposit of 45 million tonnes of hydrogen – more than twice the amount expected to be consumed annually in the EU by 2030 – was discovered in the north-east of France.

Since then, research and exploration permits have multiplied across Europe. In France, President Emmanuel Macron announced “massive investments” to explore the potential of this energy source.

A year of progress in France

The signs are promising. Five months after the discovery in the French northeast, the first exploration license was issued in November for a site in the south-west of the country, with drilling foreseen within two years.

Five other permits are currently being processed for sites across France. However, other projects are shielded by industrial confidentiality, Christophe Rigollet, a geologist at the CVA group consulting company, which is involved in several of these projects, told Euractiv.

He said the European authorities should ask oil and gas companies to make available their data on the state of the continent’s subsoil.

After the Nouvelle-Aquitaine (south-west) and Brittany (north-west), Bourgogne Franche-Comté (center-east) should soon be launching a review of its subsoil, Rigollet said.

The regional interest is spurring on national interest, as evidenced by Macron’s direct involvement and the funding in early July of a national project to improve methods of identifying the resource.

More broadly, the government launched a study last April to identify high-potential areas. The first results are expected in late 2024 – early 2025, according to Nicolas Gonthier, head of earth2, a cluster of European organisations focused on natural hydrogen.

European level

While France is the driving force, the rest of Europe is not far behind, with more than a dozen projects scattered across the continent.

In the east of Germany, a project is currently under appraisal by French company 45-8 Energy. In the north-east of Spain, drilling on the first site in the country to receive a permit should begin before the end of the year.

Last November, a British mining company announced an exploration contract in Eastern Europe without specifying the location. In Albania, French researchers discovered a potentially large deposit in February, while Finland’s authorities have published a map showing the concentrations of natural hydrogen in several gas wells.

In Poland, the authorities put in place the legal framework for natural hydrogen exploration last September, although no projects have yet been identified.

Other projects are also under development in Iceland, Serbia, Sweden, Norway, Ukraine, and Kosovo.

Mapping and support 

In its working programme for 2024, Clean Hydrogen, an EU-led public-private partnership supporting hydrogen activities, plans to fund a mapping study on the potential of natural hydrogen at the European level. Earth2’s Nicolas Gonthier, like other stakeholders, would like the project to be launched before the end of 2024.

Today, the scientific community does not yet have the fully appropriate methodology for assessing Europe’s hydrogen potential, acknowledges CVA’s Rigollet.

Moreover, this is a preliminary step before a ‘label’ for natural hydrogen in the EU’s green taxonomy rules, which determines which investments can be considered as ‘sustainable’ – something stakeholders are calling for and the Commission has hinted at.

“There is no credible data yet”, a European Commission representative said in response to a Euractiv request for comment.

However, in February, EU Energy Commissioner Kadri Simson acknowledged the possibility that the EU’s taxonomy definition of low-carbon hydrogen – less than 3.38 kilos of CO2-equivalent per kilo of hydrogen – “could include natural hydrogen”.

Streamlining administrative processes, such as permit issuing, and increasing public subsidies, could also contribute to the sector’s momentum, according to researchers and sectoral players.

While some policy measures can be taken now, it will be some time before natural hydrogen’s full potential is known. First European drillings, in France, are not expected before the end of 2028 at the earliest.

Source:Hydrogencentral

Researchers at the Fraunhofer Institute for Environmental, Safety, and Energy Technology UMSICHT and Ruhr University Bochum have discovered that carbon-based bipolar plates can be a more cost-efficient and scalable alternative to the titanium bipolar plates typically used in PEM electrolysis.

The focus of their investigation was a new carbon-based bipolar plate developed and patented by Fraunhofer UMSICHT. It consists of a thermoplastic polymer-bonded carbon matrix with conductive additives such as carbon black and is produced using a powder-to-roll process. This material and production method enable continuous manufacturing of an easily processed and welded bipolar plate, already commercially used in redox flow batteries.

The researchers subjected this carbon-based bipolar plate and a titanium bipolar plate to comprehensive ex-situ and in-situ tests. The ex-situ tests included electrochemical corrosion studies, scanning electron microscope analysis, and weight loss measurement to assess real-world suitability and parameter choices. During in-situ tests, the plates underwent accelerated aging tests with alternating current densities between 1 and 3 A cm⁻² for over 500 hours.

The scientists have published their results under the title ‘Bipolar Plates in PEM Water Electrolysis: Bust or Must?’ in the journal ‘Advanced Energy Materials’. In essence, they have discovered that the carbon-based bipolar plate has an ageing rate in the low µV h⁻¹ range and thus shows promising performance. This means that it can certainly compete with titanium bipolar plates and represents a much more cost-effective alternative. Another advantage: due to its material properties such as weldability, it enables completely new designs for PEM electrolysers. The potential to replace titanium bipolar plates in the PEM electrolysis stack and make electrolysis scalable at the same time is therefore definitely there. The task now is to further investigate and, if necessary, optimize the new material in order to further reduce the costs of electrolysis and thus make the production of green hydrogen more economical.

Source:Hydrogentechworld