Report: The Large Scale Green Ammonia Value Chain
Ammonia is a key vector in the energy transition. On the one hand, the existing ammonia market is causing significant greenhouse gas emissions and is only expected to grow, driven by increasing population and rising affluence worldwide. Thus, decarbonizing the existing ammonia market can substantially contribute to reducing carbon emissions. On the other hand, ammonia is expected to play a prominent role in the world’s push for decarbonization of other sectors, e.g. by using it as bunker fuel in shipping or as a transport medium for green hydrogen across the globe. Hence, pressure is mounting to find sustainable solutions that meet the growing ammonia demand, while minimizing environmental impact. In response to this challenge, Fichtner was contracted by the German Agency for International Cooperation (GIZ) to investigate the Large-Scale Green Ammonia Value Chain. The study addresses the entire green ammonia value chain of production, transport and storage with a particular focus on the safety aspects of each individual block.
The full report can be found here: The Large Scale Green Ammonia Value Chain
Focus on Production
The green NH3 value chain starts with decarbonized hydrogen (H2) obtained through electrolysis, using renewable energy sources. The second fundamental element is nitrogen, which is taken out of the air, as it makes up >75% of air by weight. The final step is the synthesis of ammonia through the reaction of nitrogen and hydrogen using an iron-based catalyst in a process called the Haber-Bosch process, which has remained fundamentally unchanged since the 1910s. This exothermic reaction naturally occurs at low temperatures. But in industrial settings, temperatures range from 350-550 °C and pressures range from
100-460 barg for ammonia synthesis.
Although the Haber-Bosch process is more than 100 years old, producing green ammonia comes with a new technical hurdle, namely designing a plant that uses renewable hydrogen sources instead of fossil fuels. Unlike consistent natural gas streams used for gray ammonia, renewable power generation is intermittent, leading to fluctuations in hydrogen supply to the ammonia synthesis loop. The report gives an overview of prominent ammonia licensors, who already hold a significant market share in the current ammonia industry. These players are now focusing on developing decarbonized solutions for ammonia synthesis. To address this, technology providers are working on enhancing process control technologies to achieve well-integrated operation of all the process blocks. For smaller to medium plant sizes of up to ≈ 600 Metric Tons per Day (MTPD), modularized (pre-fabricated) concepts are commonly offered by the licensors, allowing quick on-site installation and scalability. For larger plants, the solutions are tailor-made to the specific project needs to cut down on costs and are based on the “stick built” principle.
Focus on Transport
Regarding demand, approximately 85% of current ammonia production is dedicated to the manufacturing of synthetic nitrogen fertilizers. Nevertheless, under IRENA’s 1.5 °C scenario presented in the figure below, annual green ammonia production could reach 566 Mt by 2050, with 354 Mt being driven by the new emerging sectors of ammonia in power, shipping and as a hydrogen carrier. In order to accommodate this considerable expansion, transport will become a larger part of its value chain.
It is important to note that ammonia is already a globally traded commodity. It has been handled in large quantities for several decades, leading to a high maturity of infrastructure. Gaseous at ambient conditions, but relatively easy to liquefy, ammonia is always being handled as a liquid throughout the transport chain.
As an internationally traded chemical, ammonia offers various well-established transport options that cater to different distances, size scales and desired continuity of supply.
[1] Taking as a reference the Gulf Central Pipeline, the longest ammonia pipeline worldwide. [2] Maximum ammonia cargo per trip very much depends on the capacity of the RTC deployed as well as on the in-force regulations in each country, which vary considerably in terms of maximum length per train. |
Focus on Storage
To balance supply and demand in facilities operated with renewable energy, ammonia can be stored at the production site. To enable overseas transport, storage at the export or import terminals is necessary as evidenced by the various European ammonia port and tank storage developments. Applied ammonia storage technologies accompanied by their main technical characteristics are presented in the table below.
Method | Typical pressure (bar) | Design temp. (°C) | tNH3 / tsteel (-) | Storage capacity (ktNH3) | Refrigeration system |
Non-refrigerated (fully pressurized) | 16-25 | 20-25 | 2.8 | <1.5 | None |
Semi-refrigerated | 3-5 | 0 | 10 | 0.5-2.7 | Single stage |
Fully refrigerated | 1.2 | -33 | 41-45 | 5-45 | Two stages |
Focus on Safety
The responsibility for the health & safety of personnel and for the health & safety and protection of the environment and the public lies foremost with the facility owner/operator. Since ammonia production, transport and handling are well-established processes, a wealth of information for guidance in fulfilling these requirements is offered by (inter)national institutions, regulators and knowledge institutes as well as the respective industry itself. This is especially true for the design and construction phases of ammonia facilities, as well as the operation & maintenance of the plant. The report outlines relevant institutions and sources of know-how for Chile, USA, Germany, and Australia.
In summary, some challenges are to be expected in the green ammonia value chain. The main considerations include adapting the Haber-Bosch synthesis process for dynamic operations at scale and anticipating growth in transport and storage needs over the long term. Fortunately, this endeavor can be built upon the foundation of the existing gray ammonia value chain, leveraging the experience and good engineering practices developed over decades of application.
