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Presentation

Demonstration of CO2-Free Ammonia Synthesis Using Renewable Energy-Generated Hydrogen

Mototaka Kai Yasushi Fujimura Takayoshi Fujimoto Hideyuki Takagi Yuichi Manaka Tetsuya Nanba

In Japan, the government funding project SIP, Strategic Innovation Promotion Program, supports the research, development and demonstration of “Energy Carriers”. The concept of the “Energy Carriers” value chain is to produce hydrogen energy carriers overseas from fossil resources using CCS or renewable energy, and transport it to Japan for utilization as clean energy. The purpose of the program is to help realize a low-carbon society in Japan by using hydrogen. Among energy carriers, ammonia is the one of the most promising carriers, because of the ease of transportation as a liquid, higher hydrogen density, and proven technologies for commercial and…

Presentation

Analysis of influence of operating pressure on dynamic behavior of ammonia production over ruthenium catalyst under high pressure condition

Hideyuki Matsumoto Javaid Rahat Yuichi Manaka Mika Ishii Tetsuya Nanba

Process technologies on energy conversion of renewable electricity into hydrogen energy carrier are significant to deploy long-term storage and long-distance transport of much more renewable inside and outside Japan. Ammonia is a potential hydrogen carrier that contains 17.6 wt% of hydrogen. Moreover, as an energy carrier, ammonia is thought to be a clean fuel as only water and nitrogen are produced on direct combustion. Many researchers and engineers consider that ammonia plants using hydrogen produced by solar electricity or wind electricity will be much smaller than those currently used [1]. There is an issue of low pressure condition for feed…

Presentation

Highly-Selective Electrochemical Reduction of Dinitrogen to Ammonia at Ambient Temperature and Pressure

Qiang Zhang Xiaoyang Cui Cheng Tang

Catalytic conversion of dinitrogen (N2) into ammonia under ambient conditions represents one of the Holy Grails in catalysis and surface science. As a potential alternative to the Haber-Bosch process, electrochemical reduction of N2 to NH3 is attractive owing to its renewability and flexibility, as well as sustainability for producing and storing value-added chemicals from the abundant feedstock of water and nitrogen on earth. However, owing to the kinetically complex and energetically challenging N2 reduction reaction (NRR) process, NRR electrocatalysts with high catalytic activity and high selectivity are rare. In this contribution, as a proof-of-concept, we demonstrate that both the NH3…

Presentation

A Low Pressure Membrane Based Renewable Ammonia Synthesis

Sarbjit Giddey

Ammonia is currently mostly produced by the highly energy and carbon-intensive Haber–Bosch process, which requires temperatures of 450–500 °C and pressures of up to 200 bar. The feedstock for this process is hydrogen from natural gas (NG), coal or oil, and nitrogen produced from air by cryogenic route or pressure swing adsorption (PSA). The share of NG, coal and fuel oil feedstock for the global production of ammonia is 72%, 22% and 4% respectively, contributing to approximately 420 million tons of CO2 emissions per annum, representing over 1% of global energy related emissions. The energy consumed for ammonia synthesis by…

Presentation

Ammonia Synthesis Via Radiofrequency Plasma Catalysis

Javishk Shah Maria Carreon Weizong Wang Annemie Bogaerts

Introduction: In 1909, a compound named Ammonia was discovered. Through the 20th century, the immense potential of this chemical was exploited by using in almost every product, from process industry for fertilizer and chemical production to every use in cosmetics, household cleaners and medicines. Recently, fuel cells operating on liquid ammonia as working fluid have been developed on research scale. Despite of using 1-2% of total energy production for the synthesis of this compound, no significant changes have been made to the process since the first Haber-Bosch process plant has been setup. Plasma catalysis is the use of plasma and…

Presentation

Advanced Catalysts Development for Small, Distributed, Clean Haber-Bosch Reactors

Adam Welch Jonathan Kintner Joseph Beach Jason Ganley Christopher Cadigan Ryan O'Hayre

The traditional Haber-Bosch (HB) synthesis of anhydrous ammonia will adapt to clean power by sourcing the hydrogen from renewable electrolysis. However, the very large scale of current HB plant designs are not well-matched to smaller and more distributed clean power resources. Plant/reactor designs need to be made at a smaller scale in order to best utilize clean hydrogen. Small, megawatt scale HB reactors have an additional advantage of being better able ramp up and down with variable renewable power. This talk will detail ARPA-e funded work into the design and optimization of these smaller, clean NH3 reactors, which utilize much…

Presentation

Vanadium As a Potential Catalytic Membrane Reactor Material for NH3 Production

Simona Liguori Jennifer Wilcox

In solid or liquid states, ammonia salts and solutions are the active components of most synthetic fertilizers used in agriculture, which consume 83% of the world’s ammonia. Today, ammonia for fertilizers is industrially produced via the Haber-Bosch process at 400-500 °C and at pressures up to 30 MPa (300 bar). These harsh operating conditions are necessary due to the high affinity of dissociated nitrogen atoms towards the catalyst surface in addition to the high barrier associated with N2 dissociation. For these reasons, the need for advanced catalytic methods for the reduction of N2 to ammonia remains a requirement for sustainability…

Presentation

Ammonia Absorption and Desorption in Ammines

Collin Smith Mahdi Malmali Chen-Yu Liu Alon McCormick Edward Cussler

While adsorption onto solids is a common separation process, absorption into solids is much less often used. The reason is that absorption is usually assumed ineffective because it includes very slow solute diffusion into the solid. An exception may be the separation of ammonia from nitrogen and hydrogen using ammines, especially at temperatures close to those used in ammonia synthesis. There, ammonia can be selectively absorbed by calcium chloride; nitrogen and hydrogen are not absorbed. The kinetics of ammonia release seem to be diffusion controlled. The kinetics of absorption are consistent with a first order reaction and diffusion in series,…

Presentation

Importance of Reaction Mechanism Involved in Design of the Catalyst and the Reactor for Future Ammonia Synthesis

Ken-ichi Aika

The ammonia synthesis reaction is considered to involve several elementary steps [1]: N2 + 2＊ → 2N(a) (1) H2 + 2＊ → 2H(a) (2) N(a) + H(a) → NH(a) + ＊ (3) NH(a) + H(a) → NH2 (a) + ＊ (4) NH2 (a) + H(a) → NH3(a) + ＊ (5) NH3(a) → NH3 + ＊ (6) Here, the symbol ＊ indicates empty sites. For most metal catalysts, the dissociative adsorption of dinitrogen (step 1) is the rate-determining step, and all the other steps and its reverse step (from 2 to 6) are fast enough to be almost in equilibrium for…

Presentation

Development of Catalytic Reactors and Solid Oxide Fuel Cells Systems for Utilization of Ammonia

Koichi Eguchi Yosuke Takahashi Takahiro Matsuo Hayahide Yamasaki Hidehito Kubo Akihiro Okabe Takenori Isomura

Hydrogen is the primary fuel source for fuel cells. However, the low volume density and difficulty in storage and transportation are major obstacles for the practical utilization. Among various hydrogen carriers, ammonia is one of the promising candidates because of its high hydrogen density and boiling point and ease in liquefaction and transportation. The reaction temperature of ammonia cracking to nitrogen and hydrogen, being about 600°C or higher, is close to the operating temperature of solid oxide fuel cells (SOFCs). The integration of these two devices is beneficial in terms of heat and energy managements and will lead to the…