Open-source Project Feasibility Tools for Supporting Development of the Green Ammonia Value Chain

Ammonia plays a vital role in feeding the world through fertilizer production, as well as having other industrial uses. However, current ammonia production processes rely heavily on fossil fuels, mostly natural gas, to generate hydrogen as a feedstock. There is an urgent need to re-design and decarbonise the production process to reduce greenhouse emissions and avoid dependence on volatile gas markets and a depleting resource base. Renewable energy driven electrolysis to generate hydrogen provides a viable pathway for producing carbon-free or green ammonia. However, a key challenge associated with producing green ammonia is managing low cost but highly variable wind and solar renewable energy generation for hydrogen electrolysis while maintaining reliable operation of the less flexible ammonia synthesis unit. To date, green ammonia production has only been demonstrated at pilot scale, and optimising plant configurations and scaling up production facilities is an urgent task. Existing feasibility studies have demonstrated the ability to model and cost green ammonia production pathways that can overcome the technical and economic challenges. However, these existing approaches are context specific, demonstrating the ability to model and cost green ammonia production for defined locations, with set configurations. In this paper we present a modelling framework that consolidates the array of configurations previously studied into a single framework that can be tailored to the location of interest. Our open-source green ammonia modelling and costing tool dynamically simulates the integration of renewable energy with a wide range of balancing power and storage options to meet the flexible demands of the green ammonia production process at hourly time resolution over a year or more. Unlike existing models, the open-source implementation of our tool allows it to be used by a potentially wide range of stakeholders to explore their own projects and help guide the upscaling of green ammonia as a pathway for decarbonisation. Using Gladstone in Australia as a case study, a 1 million tonne per annum (MMTPA) green ammonia plant is modelled and costed using price assumptions for major equipment in 2030 provided by the Australian Energy Market Operator (AEMO). Using a hybrid (solar PV and wind) renewable energy source and Battery Energy Storage System as balancing technology, we estimate a levelized cost of ammonia (LCOA) between 0.69 and 0.92 USD kgNH3 -1 . While greater than historical ammonia production costs from natural gas, falling renewables costs and emission reduction imperatives suggest a major future role for green ammonia.