Green ammonia cracking for transport

能源生产和运输部门的脱碳对于帮助应对气候变化至关重要。一种方便的方法是使用不含碳的氢和/或氨。“绿色”氨是通过Haber-Bosch工艺以氢和氮作为输入原料生产的氨。氢是由水电解产生的，氮是由空气分离产生的，两者都是用可再生电力生产的。氨是可调度的，具有高能量密度和高氢重量含量，允许比氢更容易和更便宜的储存和运输。然后，氨可以被运输，并随后在需要它的地方和时间裂解成氢气。此外，氢也开始广泛应用于运输车辆的质子交换膜燃料电池或用于发电。因此，氨可以用作能量储存载体，允许按需调度可再生能源和运输。由于氨被广泛用于化肥，因此氨的储存和分销网络已经非常广泛，这对绿色运输燃料和可再生能源行业的影响是深远的。本项目旨在对运输用绿色氨裂解进行技术经济分析。调查的运输选择将是航空、船舶、重型货车、客运车辆、公共汽车和火车，这些都有可能使用氢作为燃料。其目的是确定最有效和最具成本效益的绿色氨裂解方案。氨输入的地理位置，从裂解装置到加油地点的距离，车辆（船，飞机，汽车等）必须行驶的距离，以及集中/分散系统将在经济和技术基础上进行调查，并进行优化。氨裂化需要能量输入，而且裂化反应转化不完全，在大规模上（100吨/天），尚未在商业或工业上得到证实。此外，氨裂解装置以前被建模为蒸汽甲烷重整器[4]，直到最近才在更有代表性的裂解条件下建模，因为氨裂解装置还不能在化学过程模拟器（如Aspen PlusTM）[2]中直接建模。因此，研究大规模运输应用的绿色氨裂解的技术和经济可行性将有助于为现有的研究空白提供答案。该项目属于EPSRC能源研究领域，特别是“氢和替代能源载体”和“能源存储”。[1]“氨：零碳肥料、燃料和能源储存。”英国皇家学会，伦敦，英国，pp. 1-40, 2020C. Makhloufi和N. Kezibri，“用于纯氢生产的绿色氨的大规模分解”，英。《氢能源》第46卷第1期。70, pp. 34777-34787, 2021。[3]“氢运输——为未来加油”。ARUP，伦敦，英国，第1-12页，2021Z. Cesaro， M. Ives， R. Nayak-Luke， M. Mason和R. Bañares-Alcántara，“氨发电：预测大型发电厂绿色氨发电的平均成本”，《应用》杂志。能源，vol. 282, p. 116009, 2021。

Decarbonization of energy generation and the transportation sector is crucial to help combat climate change. A convenient way to do this is using hydrogen and/or ammonia, which do not contain carbon. 'Green' ammonia is ammonia produced via the Haber-Bosch process with hydrogen and nitrogen as input feed reactants. Hydrogen is produced from water electrolysis and nitrogen from air separation, both with renewable electricity [1].Ammonia is dispatchable and has a high energy density and high hydrogen gravimetric content, allowing for easier and cheaper storage and transportation than hydrogen. Ammonia can then be transported and subsequently cracked back to hydrogen where and when it is needed [2]. Moreover, hydrogen is beginning to be widely used in proton exchange membrane fuel cells in transport vehicles or for electricity generation [1].Thus, ammonia can be used an energy storage vector, allowing for on-demand dispatchable renewable energy and for transport. The impact of which is far reaching in green transport fuels and renewable energy industries, given ammonia's already extensive storage and distribution networks [2] since ammonia is widely used in fertilisers [1].The aim of the project is to provide a techno-economic analysis of green ammonia cracking for transport. The transport options investigated will be aviation, ships, heavy goods vehicles, passenger vehicles, buses and trains, which all have potential for using hydrogen as a fuel [3].It is aimed to determine the most efficient and cost effective option from green ammonia cracking. The geographical location of the ammonia input, distance from the cracker to the location of fuelling, distance the vehicle (ship, plane, car etc.) must travel, and centralised/decentralised systems will be investigated on an economic and technical basis, and optimised. Ammonia cracking requires energy inputs and the conversion of the cracking reaction is not complete, on a large scale (>100 tons per day), it has not been proven commercially or industrially yet [2]. Moreover, ammonia crackers have previously been modelled as steam methane reformers [4] and only very recently in more representative cracking conditions, since ammonia crackers can't yet be straightforwardly modelled in chemical process simulators (such as Aspen PlusTM) [2]. Thus, investigating the technical and economic viability of green ammonia cracking for large scale transport applications will help provide answers to existing research gaps.This project falls within the EPSRC energy research area, specifically in 'Hydrogen and alternative energy vectors' and 'Energy Storage'. [1] "Ammonia: zero-carbon fertiliser, fuel and energy store." The Royal Society, London, UK, pp. 1-40, 2020.[2] C. Makhloufi and N. Kezibri, "Large-scale decomposition of green ammonia for pure hydrogen production," Int. J. Hydrogen Energy, vol. 46, no. 70, pp. 34777-34787, 2021.[3] "Hydrogen Transport - Fuelling The Future." ARUP, London, UK, pp. 1-12, 2021.[4] Z. Cesaro, M. Ives, R. Nayak-Luke, M. Mason, and R. Bañares-Alcántara, "Ammonia to power: Forecasting the levelized cost of electricity from green ammonia in large-scale power plants," Appl. Energy, vol. 282, p. 116009, 2021.