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Cracking Ammonia: panel wrap-up from the Ammonia Energy Conference

When should we be cracking ammonia? How much should we be cracking? How could better cracking technologies open up new end uses? What are the critical challenges still to be overcome for cracking ammonia? On November 17, 2020, the Ammonia Energy Association (AEA) hosted a panel discussion moderated by Bill David from Science and Technology Facilities Council (STFC), as well as panel members Josh Makepeace from the University of Birmingham, Joe Beach from Starfire Energy, Gennadi Finkelshtain from GenCell Energy, Camel Makhloufi from ENGIE, and Michael Dolan from Fortescue as part of the recent Ammonia Energy Conference. All panelists agreed that cracking technology as it stands has a number of key areas to be optimised, particularly catalyst improvements and energy efficiency. But, successful demonstrations of modular, targeted cracking solutions are accelerating the conversation forward.

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Ammonia cracking: when, how, and how much?

Cracking ammonia to produce hydrogen underpins many of the fuel-based uses of ammonia, and as such is a lynchpin technology in the case for ammonia energy. While in many ways ammonia cracking is a mature technology, systems which are designed specifically for these applications are less common. In this presentation, a general overview of the potential roles of ammonia cracking in facilitating the use of ammonia for energy applications will be outlined, including a survey of established and emerging cracking and purification technologies. A forthcoming project to produce an AEA Ammonia Cracking Technical Paper will be introduced.

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Starfire Energy’s ammonia cracking and cracked gas purification technology

Ammonia cracking is important for both combustion and fuel cell applications. Starfire Energy has verified that a blend of 70% ammonia + 30% cracked ammonia can burn well in a conventional natural gas burner with very low ammonia slip and acceptable NOx using a stoichiometric fuel-air mixture. A 10 MW turbine or internal combustion engine using such a blend will need about 1.44 tonnes of cracked ammonia per hour. Starfire Energy’s monolith-supported cracking catalyst may be ideally suited for this application. Fully cracked ammonia retains several thousand parts per million of ammonia due to thermodynamic limitations. Residual ammonia can damage…

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Ammonia Synthesis from Water and Nitrogen Under Ambient Condition Using Single Atom Nickel

Our dependence on ammonia is not limited to development of fertilizers and other chemicals. Ammonia is being considered an energy vector, capable of being used for energy storage as well as fuel, due to its high energy density, ease of storage and transportation. Growing need for ammonia has forced development of alternate strategies for synthesis worldwide to serve as back up of Haber Bosch. Electrochemical ammonia synthesis is one such alternative. Earlier, we found that, nitrogen vacancy in metal-organic framework-derived disordered carbon is active for nitrogen reduction in alkaline electrolytes. We tried to investigate Fe-N4 sites for nitrogen reduction. It…

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Mechanistic Insights into Electrochemical Nitrogen Reduction Reaction on Vanadium Nitride Nanoparticles

Renewable production of ammonia, a building block for most fertilizers, via the electrochemical nitrogen reduction reaction (ENRR) is desirable; however, a selective electrocatalyst is lacking. Here we show that vanadium nitride (VN) nanoparticles are active, selective, and stable ENRR catalysts. ENRR with 15N2 as the feed produces both 14NH3 and 15NH3, which indicates that the reaction follows a Mars–van Krevelen mechanism. Ex situ and operando characterizations indicate that VN0.7O0.45 is the active phase for ENRR and the conversion of VN0.7O0.45 to the VN phase leads to catalyst deactivation. Quantitative isotopic labeling results identify the amounts of two different types of…

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Ammonia Yields during Plasma-Assisted Catalysis Boosted By Hydrogen Sink Effect

Plasma-catalytic ammonia synthesis is known since early 1900s but the possible reaction pathways are currently under investigation. In this article, we present the use of various transition metals and gallium-rich alloys for plasma-catalytic ammonia synthesis. The best three metallic catalysts were identified to be Ni, Sn and Au with the highest ammonia yield of 34%. Furthermore, as compared to its constituent metals some alloys presented about 25-50% better yields. The metals employed were classified in two different categories according to their behavior during ammonia plasma-catalysis. Category I metals are nitrophobic and the measured concentration of Hα in the gas phase…

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Effect of Preparation Condition on Ammonia Synthesis over Ru/CeO

Development of the hydrogen carrier system is of great interest to utilization of renewable energy. To store renewable energy, especially for the electricity from photovoltaic and wind turbine, fluctuation of the generated electricity is not appropriate for the stable supply of the electric power. Also, the hydrogen production by the water electrolysis with the fluctuating electricity results in the fluctuation of hydrogen production. When we store the hydrogen derived from renewable energy in the carrier compounds, it is necessary to consider the reduction or smoothing of fluctuation in the hydrogen flow rate as a feed of chemical process. Although the…

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Yittria-Stabilized Zirconia (YSZ) Supports for Low Temperature Ammonia Synthesis

NH3 is important as the raw material for fertilizer production and high hydrogen density (17.7 wt. %) energy carrier. Conventionally, NH3 is synthesized through the well-known Haber-Bosch process at 400-500°C and P~150 bar. Both critical reaction conditions and massive production (145 mt NH3 in 2014 globally) make it one of the most energy extensive process, consuming 1-2% of the world’s total energy expense. Here we introduce YSZ as a more active Ru catalyst support than traditionally used supports such as Al2O3. The addition of Cs promoter increased rates an order of magnitude higher by reducing the apparent activation energy from…

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Electrochemical Reduction of Dinitrogen to Ammonia Using Different Morphologies of Copper As Electro Catalysts

Ammonia is an effective hydrogen storage medium due to ease of transport as liquid, high storage capacity (17.65%) and it can easily be converted to hydrogen by electro-chemical oxidation. Haber-Bosch process is used for the synthesis of ammonia which is energy intensive as it requires high temperature and pressure. It also causes intense carbon emissions as the hydrogen is produced by steam reforming. Alternatively, ammonia can be synthesized electrochemically at ambient conditions from nitrogen and water by employing renewable energy in the presence of an electro catalyst. The major challenge in electrochemical synthesis of ammonia is low Faradaic efficiency. This…