Safety of using ammonia in for the hydrogen economy

人们越来越关注氢技术及其在未来低碳经济发展中可能发挥的作用。与压缩的气态或液态形式相比，在工业中使用氨及其在全球范围内的运输方面积累的经验为储存和运输大量氢气提供了实用的、具有成本效益的手段。氨的特点是其在环境条件下的液态，高体积和重量能量密度。在工业环境中，由于氨被广泛应用于化学加工、食品生产、作为农业肥料等，因此氨的使用本身就更安全，这方面有大量的记录和经验。氨以不同的能力出现，即作为氢载体，要求重新评估其对生命、财产和环境带来的危害和相关风险。该博士项目旨在制定科学支持的安全策略和工程解决方案，以处理在运输和船上储存过程中作为氢载体的大量氨以及使用相关基础设施。该项目将审查安全处理氨时的危害，包括毒性影响、现有的预防和缓解安全战略。将调查与扩大使用氨以实现氢经济相关的新做法，将确定并优先考虑在围场和开放大气中计划外氨释放的情况。预计研究结果将以更安全的氨用于氢应用的建议形式出现，可能包括，例如，处理氨的外壳通风要求，氨管道和泵送压力的选择策略，确定开放大气中不同释放情景的危险距离的方法，等等。预计该研究将依靠计算流体动力学（CFD）来研究氨云在意外排放和蒸发后的传播、氨浓度的积累及其对接触者的影响。成功的候选人需要在以下学科中有很强的背景，数学，物理，化学，流体动力学，传热传质，燃烧。有理论分析或数值研究经验者优先考虑。这项研究将在hsafeer中心进行。

There is a growing focus on hydrogen technologies and the role they likely to have in the development of the future low-carbon economy. The experience accumulated with use of ammonia in industries and its transportation around the globe offers practical, cost-effective means for storage and transport of large quantities of hydrogen compared to compressed gaseous or liquid forms. Ammonia is characterised by its liquid state at ambient conditions, high volumetric and gravimetric energy density. There is a substantial track record and experience on the inherently safer use of ammonia in the industrial environment as it is widely utilised in chemical processing, food production, as an agricultural fertiliser, etc. Emerging of ammonia in a different capacity, i.e. as hydrogen carrier, calls for a reassessment of hazards and associated risks it presents to life, property and environment. This PhD project aims to develop scientifically underpinned safety strategies and engineering solutions for handling large quantities of ammonia used as hydrogen carrier during transport and storage onboard and using relevant infrastructure. The project will review hazards, including toxicity effects, existing prevention and mitigation safety strategies when dealing safely with ammonia. New practices associated with extended use of ammonia for hydrogen economy will be investigated, scenarios of unscheduled ammonia release in enclosures and the open atmosphere will be identified and prioritised. The research outcomes are expected in the form of recommendations for inherently safer use of ammonia for hydrogen applications and may include, e.g. requirements to ventilation in enclosures where ammonia is handled, strategy for the choice of ammonia piping and pumping pressures, a methodology to define hazard distances for different release scenarios in the open atmosphere, others. It is envisaged that the research will rely on the use of Computational Fluid Dynamics (CFD) to study the propagation of ammonia cloud following its accidental discharge and evaporation, the build-up of ammonia concentration and its effect on exposed people. The successful candidate is expected to have a strong background in one of the following disciplines, mathematics, physics, chemistry, fluid dynamics, heat and mass transfer, combustion. Any previous experience of theoretical analysis and or numerical studies is welcome. The research will be conducted at the HySAFER Centre.