Site items in: Electrochemical Ammonia

Presentation

Ammonia has a potential as a carbon-free energy carrier since it contains 17.6wt% of hydrogen and can be easily stored and transported safely and efficiently. The state-of-the-art industrial process for ammonia production is the Haber-Bosch process. Although high temperature (450–500 °C) and pressure (150–300 bar) are used to dissociate triple-bonded nitrogen and to maximize the ammonia formation, the efficiency of the Haber–Bosch process is limited to 10–15%. Moreover, the process accompanies high greenhouse gases emission since hydrogen is produced from natural gas. In order to overcome the drawbacks of the Haber-Bosch process, the electrochemical ammonia synthesis has been developed as…

Applications of hydrogen permeable membranes in ammonia synthesis and decomposition
Presentation

It is well known that ammonia is being considered as a method of storing hydrogen. Although some fuel cells are being developed that can use ammonia directly as a fuel source, many fuel cell technologies still require an outside cracker to revert ammonia back into hydrogen for efficient use. In this regard, hydrogen permeable membranes, such as Pd and its alloys, have been targeted as potential membrane reactors in which the ammonia is cracked while the hydrogen is simultaneously separated. Pd and its alloys are expensive, but offer potentially perfect hydrogen purity that is highly preferable for certain fuel cells…

Progress in the Electrochemical Synthesis of Ammonia
Presentation

Ammonia is one of the most important and widely produced chemicals worldwide with a key role in the growth of human population. Nowadays, the main route for ammonia synthesis is the Haber-Bosch process, developed one century ago. In this process, Fe-based catalysts are usually employed at temperatures between 400 and 500°C and pressures between 130 and 170 bar. As opposed to the industrial process, in nature, plants and bacteria have been producing ammonia for millions of years at mild conditions. Atmospheric nitrogen is reduced by solvated protons on the FeMo cofactor of the metalloenzyme nitrogenase. The natural method of nitrogen…

Presentation

Electrochemical synthesis of ammonia from water and nitrogen at atmospheric pressure could be an alternative to the current ammonia synthesis process (i.e. Harbor-Bosch) and solve the inherent problems of the process including its high energy consumption and greenhouse gas emission. This study reports electrochemical ammonia synthesis from water and nitrogen in molten salts at atmospheric pressure and temperatures exceeding 623K. Modifications on surface materials of the nitrogen activation electrode were made, tested, and their ammonia synthesis rates were compared.

Presentation

Besides its current applications, ammonia (i.e. carbon-free fuel) could play important roles in preparing for oil depletion and coping with climate change since it releases only nitrogen and water when burned. Ammonia contains 17.6wt% of hydrogen and has significant advantages over hydrogen in storing and transporting energy. The current industrial ammonia production is based on the Haber-Bosch process, which has the drawbacks of high greenhouse gas emission, reaching up to 2.16 kg CO2/kg NH3 and large energy consumption over 30 GJ/ton NH3 resulting from the production of the reactants and the high pressure-high temperature synthesis of ammonia. In order to…