October saw a seismic shift, with the global 海运 和 航空 两个行业都承诺到 2050 年实现净零排放。对于航运业而言，这是里程碑式的进一步进展 波塞冬原理. 对于航空而言，这显示了一个新的雄心。
但是这两个行业都很难脱碳，一个核心问题仍然存在：他们将如何实现？
我们还没有将使用的技术的所有细节——但这些行业也没有。 国际航运商会 (ICS) 表示，为了实现净零排放，到 5 年，全球航运船队的 2030% 将需要实现零排放。这意味着建造和部署基于尚未实现的新技术的数千艘船舶。尚未大规模部署，并建立燃料供应链来支持它们。
航空业提出了对行业运营模式影响较小的解决方案——尽管在这里，新技术和新型飞机也可能发挥越来越大的作用。 在这两种情况下，为研究和扩展解决方案提供更多资金至关重要。
In this blog, we will look at some of the more likely potential technologies that both maritime shipping and aviation could deploy to decarbonize their fleets and operations.
Electrification for short-haul
For both ships and planes, there is a solution for short-distance trips that is already familiar from ground transportation: electrification. Since December 2019, North America’s largest seaplane airline has been taking test flights of battery-powered electric aircraft. Harbour Air, which operates in the Vancouver, B.C., region, is pursuing regulatory approval to 到 2023 年让乘客乘坐电动飞机 并计划将其 42 架飞机的整个机队转换为电池供电。
Norwegian company Yara International announced that it will transport cargo for the first time in its new, autonomous battery-powered container ship.
今年夏天，挪威公司 Yara International 宣布将首次使用其新的、 自主电池供电的集装箱船. Both developments show the promise of electrification for short-distance trips, including the airplane trips that serve as lifelines for remote communities in places such as the Australian Outback, parts of Canada and other areas not easily accessible by road.
“Short-haul for both shipping and aviation can likely be electrified,” notes Thomas Koch Blank, a senior principal in RMI’s Climate-Aligned Industries program. However, he understatedly describes the electrification of longer international and intercontinental routes for both industries as “challenging.”
For aviation, the challenge is the weight of batteries. For shipping, it is their bulk. “The volume of batteries needed is crazy,” notes Koch Blank. In both cases, the battery solutions that are revolutionizing ground transport simply don’t have the energy density to take on mid-or long-distance routes. And these longer routes are where most fuel is consumed.
可持续航空燃料
For aviation, the only low-carbon solution being deployed commercially is sustainable aviation fuel (SAF). While SAF can be made from a variety of sources including crop residues, waste vegetable oils and CO2 本身，全球市场领导者 SkyNRG 目前分销由废油制成的生物燃料.
任务可能的伙伴关系 — 一个包括 RMI 在内的致力于重工业脱碳的组织联盟 — 将 SAF 描述为减少航空碳排放的唯一可行的短期选择。 这是因为它可以作为商用飞机中使用的喷气燃料的直接替代品，并且还与机场加油基础设施兼容。 此外，SAF 没有范围限制。
但为了让 SAF 发挥重要作用，它需要大幅扩展，这将需要大量投资。 目前，SAF 的全球供应来自 Global Energy 在南加州运营的一家工厂，该工厂可以生产不到该行业年燃料需求的 0.01%。
But while SAF may play a major near-term role, there are limitations on the potential supply of waste oil and other biological sources of SAF for the aviation industry. A next-generation approach known as power-to-liquids (PtL) is less mature but carries even greater carbon-reducing potential. PtL uses electricity and CO2 合成液态烃燃料，如果电力由可再生能源提供，则可以真正实现零碳。
Hydrogen-powered skies
从长远来看，MPP 正在探索一系列航空选择。 该组织表示，氢动力飞机对于减少中长期飞行的排放至关重要。 这些飞机包括燃料电池飞机和氢燃烧飞机。
几家有前途的初创公司已经在该领域开展业务，其中包括 ZeroAvia，该公司于 2020 年夏季进行了客机试飞。此外，欧洲飞机制造商空中客车公司还公布了 一系列氢动力概念飞机.
European plane maker Airbus has unveiled a series of hydrogen-powered concept planes.
虽然只排放水的飞机似乎仍然遥不可及，但 MPP 表示，到 2030 年，燃料电池客机可能会占据中程航班的一部分，到 2035 年，氢燃烧甚至可以为长途飞行提供动力。
Hydrogen on the open sea
For shipping, hydrogen may play an even larger role. RMI’s Koch Blank notes that much of the available biofuel resources will need to be directed to airlines. “If you aren’t doing biofuels, your zero-carbon options are hydrogen, ammonia or e-methanol,” explains Koch Blank. But ultimately, these other sources may also require hydrogen. A main method for producing ammonia requires hydrogen as a feedstock and e-methanol is derived from hydrogen and CO2.
氢气和氨气都已经作为燃料进行了测试，法国航运公司 CFT 正计划提供一个 氢动力集装箱船试运行 今年晚些时候在塞纳河上。 此外，航运巨头马士基已下订单 八艘可以靠甲醇行驶的船，第一个计划于 2024 年部署。
But for hydrogen-powered shipping to be emissions-free, the fuel needs to be produced in a way that does not emit greenhouse gases — namely, electrolysis using renewable energy to produce “green” hydrogen. In order for green hydrogen to power global shipping, we’re going to need a lot more electrolyzers than we have — and fast.
RMI 气候相关产业计划的助理 Tessa Weiss 估计，从 3.6 年开始，每年将需要 5.2 万至 2030 万公吨的氢气，具体取决于所使用的燃料组合，以实现 ICS 将 5% 的氢气脱碳的目标。海上贸易。 制造这么多绿色氢气需要 41-60 吉瓦的电解槽，容量系数为 50%。
That’s around 14 to 20 times the 0.3 gigawatts of electrolyzers that are currently operational, and more than the 40 GW of electrolyzer projects that BloombergNEF is tracking. However, it is only a small portion of the 850 GW that will be needed by 2030 for green hydrogen to play its role in a net-zero world. Beyond aviation and shipping, large volumes of hydrogen will also be needed for a number of applications, including steel production.
One bright spot for shipping is that as the world decarbonizes, one of the main cargoes of long-haul routes will disappear: petroleum and other fossil fuels. Koch Blank estimates that fossil fuels constitute 40 percent of what is transported over the ocean, and so decarbonization could cut back on the demand for energy carriers, as well as the energy requirements of those ships.
Vision and will
There are multiple potential pathways to decarbonize both aviation and shipping, but it is not necessary or even possible to know all the details of how this will play out. What is important is the will to carry out the vision that the aviation and maritime shipping industries are showing.
In both cases, this transformation will need investment in research, development and early-stage deployment of zero-carbon solutions. This includes not only building zero-carbon vessels, but also the fuel production and supply chains that will feed them.
We have the vision to bring aviation, shipping and other heavy industries to a sustainable pathway. Now comes the hard work of doing it.
Source: https://www.greenbiz.com/article/shipping-and-aviation-plan-go-net-zero-how
