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Ammonia is the world’s most common and widely used nitrogen-based fertilizer in the agricultural sector. Due to the exponential growth in world population over the last 140 years, the demand for ammonia continues to rise. Besides its value in agriculture, ammonia has also received significant consideration within the hydrogen economy for its potential as a viable hydrogen carrier to enable safe transportation over long distances and periods in large quantities. However, traditional ammonia manufacturing uses fossil fuel, such as methane, as the source of the hydrogen needed for the reaction. Utilization of this hydrogen source makes it responsible for 1.5–2% of global CO2 emissions, a technology colloquially defined as «grey». Commonly termed «green ammonia», electrochemically synthesized ammonia with the use of electricity from renewable sources is an interesting zero-carbon emission alternative.
Swan-H, a start-up company founded in late 2021, contributes to the decarbonization of ammonia production by fixing freely available nitrogen from the atmosphere. They are actively working on a unique nitrogen activation process patented together with the University of Toulouse and the French Research Council (CNRS). To learn more about green ammonia production and the process that the Swan-H team is developing, we interviewed Dr. Augustin De Bettignies (external communicator, CCO – Chief Commercial Officer), Dancheng Legrand (laboratory manager), and Nicolas Mézailles (research director, CSO – Chief Science Officer).
Augustin, Swan-H is a company dedicated to the novel production of ammonia. Can you introduce your team and their roles?
The Swan-H team is an international group of eight, composed of four founders and four researchers. This collection of experts includes Dr. Nicolas Mézailles – the founder of the company and head of research, the entrepreneurial chemist Dr. Steve van Zutphen as the CEO, Dr. Willem Schipper acting as CTO in charge of industrialization, and I (Dr. Augustin De Bettignies) am the business party.
The synthetic pathway invented by Swan-H is said to be more sustainable, but how exactly does it differ from other types of ammonia production?
The reaction between N2 and H2 to produce NH3 is a particularly difficult one. The well-known Haber-Bosch process was widely adopted as the standard industrial procedure for ammonia production since the beginning of the 20th century. This industrialized process facilitates ammonia production only under very demanding conditions of elevated temperatures (400 °C) and pressures (>100 bar), and also requires the use of a heterogeneous catalyst [1]. Moreover, hydrogen molecules used in the process are generated from methane steam reforming (MSR) [2].
Learn more about the development of the Haber-Bosch process in our blog post.
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To reduce the carbon footprint of this reaction, some ammonia manufacturers now utilize H2 produced from a water splitting reaction in an electrolyzer. The result of this modernized Haber-Bosch process is known as «green ammonia». However, this process still requires high temperatures and pressures and a catalyst to synthesize NH3. It is also clearly less compatible with the intermittent energy output of wind and solar power farms because the high temperature and pressure must be sustained to run the process at all times.
Philosophically, Swan-H has a different mindset compared to the Haber-Bosch industry. Our process is performed at room temperature and atmospheric pressure, significantly reducing the required energy input for ammonia production which currently accounts for 1.5–2% of global energy consumption. Our strategy relies on the generation of carefully designed radicals which react in a stepwise mechanism with the nitrogen molecule rather than using «brute force» (high temperature and pressure) to split it using the catalyst.
The Swan-H method also employs water as a source of hydrogen instead of carbon-based materials. This results in a process that is less energy-demanding, electrode surface-independent, and has a minimal carbon footprint. «Electrode surface-independent» refers to the fact that nitrogen activation occurs in solution and, in addition to the aforementioned benefits, it has advantages for the subsequent scale-up. This sets the Swan-H process apart from others which combine N2 activation and reduction on the same surface.
Learn more about the production of clean («green») hydrogen from water via electrolysis in our blog posts.
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The technology your research team is developing takes place in an electrolyzer powered by a constant potential/current. Can you describe the electrochemical step occurring at the negative terminal or cathodic compartment in a bit more detail?
The uniqueness of the Swan-H technology is to be able not to activate nitrogen at the electrode surface, but rather to activate a mediator which then reacts with nitrogen. This allows the nitrogen activation process to occur in the entire volume of solution and not be limited by the surface area of the electrode. Thus, we electrochemically activate a chemical mediator which becomes a high energy radical species. This radical species manages to react chemically with N2 molecules dissolved in the electrolyte. In the successive step, the amine (nitrogen-containing derivative) product reacts with a hydrogen source (e.g., water) turning the overall process into a hybrid-type of reaction (electrochemical-chemical). It is the combination of both steps that leverages the main properties of the individual events, maximizing the overall potential of ammonia production.
A reactor prototype based on the hybrid reaction process has been designed and tested. What is its current state?
Our first version prototype is currently functioning in batches with a production of milligrams at TRL 4 (Technology Readiness Level 4). It enables normalized discussions across different fields and technological sectors in a safe manner.
We are gathering data to quantify the amount of energy needed per unit of ammonia generated by using VIONIC powered by INTELLO. By the end of the year, this prototype should evolve into more autonomous and continuous manufacturing with higher productivity reaching TRL 5.
You have mentioned two main application sectors for ammonia: fertilizers and hydrogen technology. Which particular organizations and institutions will benefit from the Swan-H process?
There are only about 100–120 ammonia production plants across the globe, meaning that it is a very centralized production for approximately 200 million tons/year overall. This creates strong reliance on these production facilities. Ammonia producers are looking for ways to make the production cycle greener by working with a hydrogen source produced with locally available renewable power, preferably with processes that do not require huge plants.
We envisaged the production of units of different sizes based on Swan-H technology at regional levels decentralizing ammonia production and strengthening local economies. This includes companies—and even countries—aiming to be independent of foreign natural gas sources. Furthermore, our vision is to be able to provide equipment that can be turned on, produce NH3 when excess energy is available, and then be turned off again. Used in such a way, ammonia will serve as an energy storage chemical with elevated hydrogen content.
As a user of VIONIC powered by INTELLO, what is your experience with Metrohm Autolab in general and what are the features of VIONIC that advance your research?
The Swan-H team has had the most pleasant interaction with Metrohm Autolab’s local support in France, and we have enjoyed working together on the software. The INTELLO interface is very handy to use and is a pretty powerful software regarding the number of analyses on the same screen. They highlighted its accessibility of plotting and visibility of real-time acquisition to us.
Considering the capabilities of VIONIC – we anticipate a high solution resistance in the research conditions, and this instrument can handle high voltages and compliance needs, making us decide on Metrohm Autolab and VIONIC. The team also valued the untethering feature of INTELLO because they can release their computers from VIONIC during several hours of measurements and reconnect them for data recovery instead of dedicating full resources to the experiment.
Summary
The transition to a more sustainable ammonia production process is within reach, utilizing nitrogen activation via coupled electrochemical-chemical reactions. The production method in development by Swan-H is a cheaper, safer, and more environmentally friendly option compared to the traditional Haber-Bosch procedure.
Furthermore, the hybrid process invented by the Swan-H group uses radical mediators to activate N2 and liberate it as NH3 after H2 uptake. Electrochemical instrumentation with specifications and features which fit the needs of the application, such as VIONIC powered by INTELLO, plays an important role in the discovery and optimization of the revolutionary «greener» ammonia process.
Contact your local Metrohm distributor for a free demonstration of VIONIC powered by INTELLO.
References
[1] Haber-Bosch process. Britannica. https://www.britannica.com/technology/Haber-Bosch-process (accessed 2023-05-11).
[2] Methane Steam Reforming - an overview. ScienceDirect Topics. https://www.sciencedirect.com/topics/engineering/methane-steam-reforming (accessed 2023-05-11).
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