Enabling green ammonia as future transport fuel

氨是一种高度氢化的分子，已被确定为支持向氢经济过渡的重要手段，因为由于已经存在用于运输和储存氨的基础设施，氨可以用于容易地储存和分配氢。如果要在使用点从氨中提取氢，则氨热催化回氢需要大量的能量。优选地，氨直接用作发电、船舶和长途车辆中的内燃机的无碳液体燃料，其中电池由于其低能量密度（因此体积和重量大）、高成本和长充电时间而不能使用。然而，氨的能量密度显著较低（以热值衡量），需要使用更大的燃料储存空间和重量。更重要的是，氨在内燃机中的直接应用由于氨的较高点火能量、较高自燃温度以及显著较低的火焰速度而遭受不完全燃烧和较差的发动机性能。为了解决氨和氢在运输应用中的上述挑战，本项目将采用先进的建模和实验技术研究和演示一种新型的液氨与氢的混合物。所提出的新型燃料具有氨和氢分子，并且将使得（1）在现有发动机中立即和更广泛地使用无碳氨和氢，特别是用于长途车辆、船舶和发电机，（2）通过增加能量密度、更快和完全燃烧显著改善发动机性能和降低排放。因此，开发的液氨与氢气混合将能够立即，具有成本效益和100%减少二氧化碳排放，到2050年及以后实现长途运输，航运和发电部门的净零目标，这将难以实现现有技术的使用或开发。

Ammonia, a highly hydrogenated molecule, has been identified as an important means to support a transition to hydrogen economy, as it can be used to store and distribute hydrogen easily because of the already existing infrastructure for transport and storage of ammonia. If hydrogen is to be extracted from ammonia at the point of use, the thermo-catalysis of ammonia back to hydrogen requires a high amount of energy. Preferably ammonia is used directly as a carbon-free liquid fuel for combustion engines in power generation, marine vessels and long-haul vehicles where batteries cannot be used due to their low energy density (hence large volume and weight), high cost and long charging times. However, the significantly lower energy density (as measured by calorific value) of ammonia requires much larger fuel storage space and weight to be used. More importantly, the direct application of ammonia in combustion engines suffers from incomplete combustion and poor engine performance due to ammonia's higher ignition energy, higher auto-ignition temperature as well as significantly lower flame speed. In order to address the aforementioned challenges of ammonia and hydrogen for their applications in transport, a new type of liquid ammonia blended with hydrogen will be researched and demonstrated in this project with advanced modelling and experimental techniques. The proposed novel fuel has both ammonia and hydrogen molecules, and will enable (1) immediate and wider use of carbon free ammonia and hydrogen in existing engines, particularly for long haul vehicles, marine vessels and power generators, (2) significantly improved engine performance and lower emissions through increased energy density, faster and complete combustion. Therefore, the developed liquid ammonia blended with hydrogen would enable an immediate, cost-effective and 100% reduction in CO2 emissions to achieve net zero target in long haul transport, shipping, and power generation sectors by and beyond 2050 that will be difficult to achieve with existing technologies in use or in development.