Sustainable ammonia solutions by thyssenkrupp Uhde

Karan Bagga

Ammonia’s use as an energy and hydrogen vector is gaining more and more attention in addition to its traditional use as a precursor for nitrogenous fertilisers. This new use is prompting the development of new technology features and plant set-ups for harnessing low carbon or renewable energy as well as transporting it and using it at locations with energy intensive needs.

Hydrogen can be produced by using renewable energy via water electrolysis, completely free of carbon dioxide emissions, thus providing the means of storing and transporting renewable energy. Being a key precursor for many chemicals, green hydrogen also offers the potential to enable deep decarbonisation in industrial sectors in which it is difficult to abate with direct electrification, such as industrial chemicals, fertilisers and steel manufacturing.

However, the molecular and thermodynamic properties of hydrogen make it economically challenging to store and transport it globally. This is where ammonia offers a much more promising substitute. It can be produced from green hydrogen and nitrogen from air, without any CO2 emissions. Ammonia can also be produced from natural gas or other fossil resources with technology adjustment that can avoid or reduce the CO2 emissions. It has a higher volumetric energy density than hydrogen, which makes it an attractive medium for transporting renewable energy. At the destination, it can be used to recover hydrogen via cracking or used directly for a variety of important applications, such as low carbon fertiliser production

Additional uses are also emerging such as fuel for stationary power generation (co-firing with coal and gas), and bunker fuel for marine transport. Last, ammonia is already traded worldwide in large quantities (around 19 million t/year; therefore, safe handling is an established global standard, and the infrastructure is already in place.

Today, 80% of the annual global production of ammonia goes into fertiliser production, but it has been shown that potentially its use as a renewable energy vector will dwarf this figure in the conceivable low emission future. Therefore, it is important to focus on developing methods for safe and economical production of green ammonia on a large scale.

Green And Blue Ammonia Production

A green ammonia production facility produces hydrogen via the electrolysis of water using renewable energy. Green hydrogen then serves as a source for ammonia synthesis, together with nitrogen, which is cryogenically separated from the air in an Air Separation Unit (ASU). Ammonia synthesis as such is carried out according to the well-known HaberBosch-process. Further derivatives of ammonia, such as fertilisers, can be produced further downstream. Figure 2 compares a green ammonia production process with the conventional fossil fuel-based method.

The CO2 emission can be reduced by capturing the CO2 and sending it to a sink. If the CO2 emission is largely reduced, this is referred to as “blue ammonia”.

AMMONIA CRACKING

Ammonia cracking is a chemical process in which ammonia (NH3) is broken down into its constituent elements, nitrogen (N2) and hydrogen (H2), usually by heating the ammonia in the presence of a catalyst. An ammonia cracking unit enables production of carbon-neutral green hydrogen for applications ranging from green steel and green chemicals to power generation and fuel. The properties of ammonia make it much easier and economical to transport compared to hydrogen, both in gaseous and liquid form.

THYSSENKRUPP UHDE'S SOLUTIONS IN THE AMMONIA VALUE CHAIN

Today, thyssenkrupp Uhde offers an integrated solution covering the entire renewable ammonia value chain, from production, storage and transport to reconversion back to hydrogen.

Focusing more on green ammonia production, thyssenkrupp Uhde offers modularised, single train green ammonia plant solutions in the range of 50 to 5,000 metric tons per day (mtpd). These plants can be customized to meet the specific needs of each customer, including modular systems that can be easily scaled up or down, depending on demand. On the blue ammonia front, thyssenkrupp Uhde also offers large-scale Steam Methane Reforming (SMR) and Autothermal Reforming (ATR) based plants with carbon capture.

For ammonia cracking, thyssenkrupp technology uses a proprietary catalyst system that allows for high efficiency and a long catalyst life, which reduces operating costs. The system also includes a heat recovery system that captures and reuses the energy generated during the reaction, further improving efficiency. The company’s optimized, well-engineered heat integration technology provides the highest ammoniato-hydrogen ratio, in order to deliver the standard of purity required to fulfil the requirements of the specific end-application.

Ammonia is set to play an increasingly crucial role in the energy transition of the South- East Asian region, both as a low emissions feedstock for the fertiliser and chemicals industries as well as a renewable energy vector. Its properties are conducive to affordable transport of large-scale transport of renewable energy.

thyssenkrupp Uhde has developed proprietary solutions for flexible, safe and reliable production of green ammonia based on renewable energy sources as well as large-scale blue ammonia solutions based on SMR and ATR technology. Finally, thyssenkrupp is developing a large-scale ammonia cracking solution which will become increasingly important in the region for supporting energy transition.

Contact details:

Karan Bagga

Chief Technology Officer

thyssenkrupp Uhde Australia

info@thyssenkrupp.com

https://www.thyssenkruppindustrial-solutions.com