Site items in: Presentations

Future of Ammonia Production: Improvement of Haber-Bosch Process or Electrochemical Synthesis?
Presentation

Ammonia, the second most produced chemical in the world (176 million tons in 2014), is manufactured at large plants (1,000 – 1,500 t/day) using Haber-Bosch process developed more than hundred years ago. A simple reaction of nitrogen and hydrogen (produced by steam methane reforming or coal gasification) consumes about 2% of world energy, in part due to the use of high pressure and temperature. With the global transition from fossil fuels to intermittent renewable energy sources there is a need for long term storage and long range transmission of energy, for which ammonia is perfect fit. To make it practical,…

Novel Catalysts for Ammonia Cracking and Synthesis
Presentation

The most effective ammonia cracking catalysts are currently based on rare metals such as ruthenium and cobalt. While iron can efficiently crack ammonia at 600 °C, it is desirable to develop similarly inexpensive catalysts that are effective at lower temperatures between 350 °C and 500 °C. In this presentation, a new family of imide-based catalysts are described that crack ammonia around 400 °C to 550 °C. These materials do not behave as conventional surface-based catalysts and offer an affordable route for on-board cracking of ammonia for hydrogen fuel-cell cars. The operational parameters of a small 50W lab-based demonstrator will be…

Delivering Clean Hydrogen Fuel from Ammonia Using Metal Membranes
Presentation

The use of ammonia (NH3) as a hydrogen vector can potentially enable renewable energy export from Australia to markets in Asia and Europe. With a higher hydrogen density than liquid H2, plus existing production and transport infrastructure, and well-developed safety practices and standards, the financial and regulatory barriers to this industry are lower than for liquid H2 transport. The only significant technical barrier which remains, however, is the efficient utilisation of ammonia fuel at or near the point of use, either directly or through the production of H2. For H2 production from NH3, the purity of the product H2 is…

NH3 / N2 / O2 Non-Premixed Flame in a 10 kW Experimental Furnace – Characteristics of Radiative Heat Transfer
Presentation

There are severe issues on increasing amount of carbon dioxide (CO2) emission in the world. Many studies are devoted on alternative fuels. One of superior candidates is the utilization of hydrogen energy which can realize a low-carbon and hydrogen-based society. Ammonia might play an important role which is zero emission of CO2, and is useful for hydrogen energy carrier as a clean energy. Additionally, ammonia is an easily-liquefiable fuel with pressure of about 0.86 MPa and temperature of 293 K. Commercially, ammonia is produced in large quantity by the Haber–Bosch process. It is also to be produced by using catalyst…

Presentation

Ammonia is a carbon-free fuel, so it has potential to reduce carbon dioxide emission from power plants when used as a fuel. However, combustion characteristics of ammonia are notably different from hydrocarbon fuels, especially regarding NOx emission [1]. The nitrogen atom of the ammonia molecule may cause high NOx emission. Therefore, special techniques to reduce NOx emission are essential for gas turbine combustors which burn ammonia and natural gas. The results of our previous study [2] showed the characteristics of NOx emission in single-stage combustion. In this study, the concept for low-emission combustion in two-stage combustion has been examined numerically…

Presentation

Based on its well-known merits ammonia has been gaining special attention as a potential renewable energy carrier which can be replaced in power generation systems. Considering its low flame speed and its potential for producing fuel NOx as the main challenges of combusting ammonia, flame stability, combustion efficiency, and NOx formation are experimentally investigated. Focus is on premixed ammonia-hydrogen-air flames with high mixture fractions of ammonia (60-90% by volume) under standard temperature and pressure conditions. We introduce silicon-carbide (SiC) porous block as a practical and effective medium for ammonia-hydrogen-air flame stabilization which enables stable and efficient combustion of the mixtures…

Effects of the Thickness of the Burner Rim, the Velocities of Fuel and Air on Extinction Limit of Ammonia Coaxial Jet Diffusion Flame
Presentation

Ammonia is regarded as one of the alternative fuels because CO2 doesn’t emit during the combustion process of ammonia. Ammonia also has advantages in storage and transportation. In addition, ammonia has a potential to be a “hydrogen carrier” because of high amount of hydrogen content. However, there are several combustion related problems such as the low flammability, the low radiative power and the high NOx formation. To use ammonia as a fuel, therefore, it is necessary to understand the fundamental phenomena of the combustibility of the ammonia such as laminar burning velocity, strength of the radiation and extinction limit. Since…

Effect of Water on the Auto-Ignition of a Non-Carbon Nitrogen-Based Monofuel
Presentation

The fluctuating nature of renewable energy sources is becoming a limiting factor in their widespread utilization. Energy storage solutions must be developed to overcome this issue. Chemical fuels are considered to be a promising solution to this problem. We are studying the implementation of nitrogen-based fuels for this purpose. An aqueous solution of ammonium nitrate and ammonium hydroxide (AAN) is suggested as a carbon-free nitrogen-based synthetic monofuel. This solution may serve as a renewable nitrogen-based synthetic hydrogen carrier since it is safe to store, transport and utilize. Since ammonium hydroxide (AH) and ammonium nitrate (AN) act as reducer and net…

Direct Ammonia Fuel Cell Utilizing an OH- Ion Conducting Membrane Electrolyte
Presentation

We describe the techno-economic background and the R&D work scheduled for the ARPA-E project “Direct Ammonia Fuel Cells (DAFCs) for Transportation Applications,” which is about to start under the REFUEL program. The project is led by Shimshon Gottesfeld & Yushan Yan, University of Delaware, Jia Wang & Radoslav Adzic, Brookhaven National Laboratory, Chulsung Bae, Rensselaer Polytechnic Institute, and Bamdad Bahar, Xergy Inc. The multidisciplinary R&D work scheduled will cover the fields of advanced membrane and electrocatalyst development, MEA development and fabrication, and stack engineering. The latter two activities will be supported by work at POCellTech, with Miles Page as lead.…

Development of New Combustion Strategy for Internal Combustion Engine Fueled By Pure Ammonia
Presentation

Ammonia is considered as a promising hydrogen-carrier with good storability and transportability, which, then, can be used as a carbon-free fuel as needed. However, once the ammonia is produced from the regenerative sources, it is essential to develop the energy conversion device of the chemical energy stored in ammonia into some other useful forms, e.g. electricity. Among various candidates, we focus on an internal combustion engine as energy conversion device which can be applied on automobile, power plant and etc. and can use ammonia as fuel only by simple modification. There have been many studies on the use of ammonia…