エネルギー
グリーンアンモニアによる世界的な航路の脱炭素化
航運排出削減のためのグリーンアンモニア
When we talk about carbon emissions, the first things that come to mind are cars & trucks, as well as coal and gas power plants. A lesser thought about major energy consumer and carbon emitter is the shipping industry.
世界の貿易の90％は船舶で輸送されており、しばしば大洋を横断します。これは世界の温室効果ガス排出量の36％に相当します。また、バッテリーはエネルギー密度が不足しているため、数千マイルの航海に必要なエネルギーを供給できず、現時点では実質的に電化が不可能なセクターでもあります。
炭素汚染だけが問題ではありません。航運業界は歴史的に最も低品質の石油、すなわちタール状の濃厚液体である「バンカーフューエル」または重油/残渣油に依存してきました。
出典: Wikipedia
さらに、ガザとイエメンでの紛争激化に伴い、紅海・スエズ運河の航路を回避しなければならなくなったため、航運業界は一時的にさらなる汚染を生む可能性があります。これにより、ヨーロッパとアジア間のすべての貿易で数千マイルの余分な航路が追加されます。
同時に、パナマ運河でのエルニーニョによる干ばつも、アジアと北米間の貿易を長距離ルートへ迂回させています。
この点は、2023年12月21日の記事「化石燃料供給の問題 – 川上の航運とエネルギー危機」で早くに警告していました。
出典: BBC
航運汚染の徐々なる改善
硫黄排出の削減
The use of bunker oil, the most polluting form of oil, has made the shipping industry responsible for the production of 18-30% of global nitrogen oxide and 9% of sulfur oxide. This problem can be even worse in localized areas, with, for example, only cruise ships producing 3x more sulfur pollution in Barcelona than all the cars in the city combined.
新しい規制がこの問題の解決を目指しています。2020年1月以降、国際海事機関（IMO）の新規則により大気中への硫黄排出が大幅に削減されました。
In response, the shipping industry had to adopt low-sulfur fuels or keep using heavy fuel oil with scrubbers. Still, these scrubbers often just remove the sulphur from the air emissions, only to put it in water and dump it into the ocean.
代替燃料
Another option is to switch to LNG (Liquid Natural Gas), as natural gas burns with much lower sulfur emissions and slightly lower carbon emissions than oil. The problem is one of infrastructure, as most ships are not equipped with engines able to burn LNG instead of low-sulfur oil or bunker oil.
いずれにせよ、低硫黄油やLNG用スクラバーは炭素排出を大幅に削減しているわけではありません。
This is why experts are now looking toward alternative fuels as a potential solution. A top candidate for such green fuel is green ammonia.
グリーンアンモニア入門
Ammonia, or NH3, is the second most highly produced chemical in the world. It is a fertilizer and can be burned or oxidized to produce nitrogen and water.
NH3 +O2 → N2 + H2O
したがって、理想的な条件下では有害でない副産物だけを生成する点で、水素燃焼にやや似ています。
水素との違いは、アンモニアはH2に比べてはるかに大きな分子であり、はるかに安定していることです。このため、輸送と貯蔵が格段に容易になります。また、アンモニアは液体水素の約50％以上のエネルギー密度を持ちます。
Ideally, an ammonia economy would rely on so-called green ammonia generated from renewable energy. This distinguishes it from other types of ammonia:
- Grey/brown ammonia: produced from fossil fuels.
- Blue ammonia: produced from fossil fuels but with carbon capture.
- Pink ammonia (sometimes also called yellow ammonia): produced from nuclear energy.
- Turquoise ammonia: produced from the pyrolysis of methane. This breaks down methane into hydrogen and solid carbon, with the hydrogen later converted to ammonia. The solid carbon can be stored or used for applications like carbon fibers.
航運に適したグリーン燃料
What makes ammonia a good candidate to replace bunker oil and other fossil fuels in shipping are its logistics qualities.
水素は揮発性が高く、エネルギー密度が不足しているため、遠洋航海には不向きです。バイオ燃料は炭素中立性が不十分であるか、航運業界の膨大なエネルギー需要を満たすだけの量が生産されていません。
対照的に、アンモニアは‑33°C（常圧）で液体として、または20°Cで7.5バール以上に加圧して保存できます。これによりエネルギーロスが大幅に抑えられ、貯蔵・輸送に必要な資本支出が実現可能になります。
さらに、貯蔵が容易であるため、太陽光や風力などの間欠的再生可能エネルギーで生産し、後で使用することが可能です。
Lastly, using liquid ammonia allows harbors to reuse existing infrastructure, such as storage tanks and piping, that is currently used for oil.
航運の集中構造を活用する
A new study has brought to light another fact that might help speed up the adoption of ammonia as a green shipping fuel. Researchers at Oxford, working at the Oxford Programme for Sustainable Infrastructure Systems (OPSIS) and the Oxford Green Ammonia Technology (OXGATE), have examined the infrastructure requirement for decarbonizing the shipping industry.
彼らは、燃料需要に基づく世界の上位10、50、100港を対象とすれば、累積グリーンアンモニア燃料需要の21.3％（21.8％）、45.7％（46.7％）および62.0％（62.6％）を満たすことができると算出しました。
This can be even more true in some regions, for example:
“in Oceania, North Africa, South Asia, and Southeast Asia, over 60% of fuel demand can be met by targeting the top 10 regional ports as measured by fuel demand”
“Optimal fuel supply of green ammonia to decarbonise global shipping”
Jasper Verschuur et al 2024 Environ. Res.: Infrastruct. Sustain. 4 015001
This is because while there are thousands of harbors in the world, the largest ones drive most of the traffic and service the largest (and most fuel-consuming) ships.
moderate ambitious (MOD-AMB) future scenario & highly ambitious (HIGH-AMB) – 出典: ERIS
研究者はまた、シナリオにおいてほとんどの生産が赤道付近や熱帯緯度に集中できると指摘しています。そこでは太陽エネルギーの効率が最も高く、「緯度30度（40度）以上で製造されるアンモニアは全体の10％未満」とのことです。
出典: IOP Science
必要な投資額
The Oxford researchers also tried to quantify the required investment to decarbonize shipping lanes with green ammonia. They found that most of the costs would come from the infrastructure to produce the ammonia, mostly solar farms in the tropics and deserts of Australia and the Middle East, replacing fossil fuel sources. The total estimated cost? ~ $2 trillion.
While this might seem like a lot, a not-dissimilar capex will be needed to find and refine the oil that the industry would consume in a business-as-usual scenario. So, this is more about changing the source of energy than increasing the costs of shipping.
航運の革命
Shipping has for a long time been an industry mostly reliant on manual labor and outdated technologies like bunker fuel-powered engines.
This is quickly changing, notably with the arrival of AI in the industry (something we covered in depth in our article “Securing Shipping Lanes Through the Use of Artificial Intelligence”), which will:
- Make sea travel safer.
- Allow for unmanned navigation.
- Optimize routes and fuel consumption.
The other revolution coming for the shipping industry is switching to renewables and non-polluting fuels. For now, the most likely candidate is green ammonia, as this is mostly a question of policy and investment, with all the key technologies (large-scale solar + ammonia production & storage) already mastered.
実際、唯一考えられる代替案はバイオ燃料生産の革命、特に藻類バイオ燃料です。このテーマは私たちの別記事「Algal Biofuel: The Next Energy Revolution?」で詳しく調査しています。
しかし、3rd 世代バイオ燃料（しばしば石油系燃料と化学的に同一）は航空業界が大規模に脱炭素化するために必要になる可能性が高く、結果としてアンモニアは航運、さらにはトラック輸送の脱炭素化の中心に留まると予想されます。
燃料株としてのアンモニア
This list looks to focus on green ammonia companies involved in deploying it in the shipping industry. Leaders in ammonia generation, like for example CF Industries Holdings, Inc. (CF) or Yara International ASA (YAR.OL) are mostly producing ammonia from natural gas currently. But they are likely to turn to green ammonia in due time and might be an option for investors as well.
1. Aker Horizons ASA
Aker Horizons is a subsidiary of the Aker group, which is centered around green energy. The Aker group is an important Norwegian conglomerate focusing on renewables and marine/offshore businesses. Aker Horizon is the holding company for several subsidiaries, including carbon capture, green hydrogen, and renewable energies.
出典: Aker
The company is notably very active in hydrogen and green ammonia generation, with a goal to decarbonize Arctic shipping.
So, Aker is not a purely green ammonia company but can handle the entire vertical integration of green ammonia, from offshore windmills to hydrogen generation to green ammonia production. It is also working on projects like waste-to-energy in France, a biomass plant in Germany, and carbon capture in the Middle East (Saudi Arabia and UAE).
This makes it a good stock for investors looking for exposure to the green energy sector at large, with a strong positioning on green ammonia & shipping, but also other green energies, and some geographical diversification.
2. AmmPower Corp.
AmmPower is similar to FuelPositive in that it provides modular ammonia generation systems, but at a larger scale, with its base module able to produce 4 tons/day. This puts the company’s clients more into the range of very large farms (10,000+ acres) or industrial operations like textiles, refrigeration, mining, pharmaceuticals, or semiconductors.
This modular system based on standard containers could also be right at home in harbors looking to progressively scale up their on-site ammonia production capacities.
出典: AmmPower
The company is in the process of building its order book, with the near-term booking potential estimated at $30M, and sale prospects for 690 units from 52 countries. The company estimates the electricity cost to be around $360/ton of ammonia.
The modularity of the system allows for a quick turnaround and deliveries, with less than a year compared to the 3-4 years of similar projects without the modular approach.
It is also working on technology to transform waste into ammonia, in a joint venture with CTEC Energy Sales USA.
To further the progress of ammonia into a hydrogen-ammonia economy, it is creating a dedicated subsidiary dedicated to cracking ammonia into hydrogen, which will look for additional funding separately.
By striking the scale that might fit most industrial usage, as well as shipping, AmmPower is aiming for clients and companies with deeper access to capital than most. Combined with ammonia cracking technology, this could allow it to scale up quickly following policies to push for the development of hydrogen & ammonia as an energy carrier.
Private Companies
First Ammonia is a developer of ammonia production for shipping, electricity, and other transportation.
Solydera is another fuel cell company with activity in green ammonia. Notably, it signed a Memorandum of Understanding (MoU) with KBR in 2023年10月.
You can also find other green hydrogen and green ammonia-related stocks, as well as an in-depth discussion of the technical advantages and limitations of ammonia, in our article “The Other Hydrogen Fuel – Top 5 Green Ammonia Stocks”。
