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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…

Presentation

Material Discovery and High Throughput Exploration of Ru Based Catalysts for Low Temperature Ammonia Decomposition

Katie McCullough Travis Williams Benjamin Ruiz Jochen Lauterbach

High throughput experimentation gives us the unique ability to generate massive, multidimensional datasets that are not typical for heterogeneous catalysis studies. Here, we show the synthesis and catalytic screening of over 100 different Ru based bimetallic catalyst combinations using 33 different metals that were synthesized via incipient wetness impregnation. The catalysts were analyzed using Wide Angle X-ray Scattering (WAXS) for phase identification. Catalysts were screened for ammonia decomposition activity using a 16-channel parallel plug flow reactor. Fourier transform infrared (FT-IR) imaging was used to analyze all 16 effluent streams in parallel in under one minute. All results obtained from WAXS…

Presentation

Development of a Highly Efficient COx-Free Ammonia Dehydrogenation System for Fuel Cell Applications

Young Suk Jo Junyoung Cha Hyuntae Sohn Suk Woo Nam Chang Won Yoon

The shortage of fossil fuels and emission of carbon dioxide to the environment have attracted an interest in discovering renewable energy as the next generation energy source. Owing to its intermittent and unpredictable nature, however, excess renewable energy needs to be stored and reused on demand. In the regard, hydrogen, which possesses a high gravimetric energy density and carbon free combustion process, has been extensively researched as a promising renewable energy carrier. However, the distribution and storage of hydrogen still raise important challenges due to the low volumetric energy density of hydrogen for its wide utilization. Currently, gaseous hydrogen transportation…

Article

Future Ammonia Technologies: Electrochemical (part 3)

Trevor Brown December 28, 2017

This series of articles on the future of ammonia synthesis began with a report on the NH3 Energy+ conference presentation by Grigorii Soloveichik, Program Director at the US Department of Energy's ARPA-E, who categorized the technologies as being either improvements on Haber-Bosch or electrochemical (with exceptions). ARPA-E invests in "transformational, high-risk, early-stage research," and recently began funding ammonia synthesis technologies, not to make renewable fertilizer but to produce "energy-dense zero-carbon liquid fuel." This article will introduce the six electrochemical technologies currently in development with funding from ARPA-E.

Presentation

Dense Metallic Membrane Reactor Synthesis of Ammonia at Moderate Conditions and Low Cost

Thomas F. Fuerst Sean Lundin Zhenyu Zhang Simona Liguori J. Douglas Way Colin A. Wolden

Commercial ammonia synthesis relies on the Haber–Bosch process that has remained largely unchanged for a hundred years. The equilibrium constant of this exothermic reaction quickly becomes unfavorable above 200 °C, but the catalyst requires temperatures above 400 °C to have sufficient activity. To overcome these conflicting requirements the process is conducted at extremely high pressure (100 – 200 atm) using multiple passes with inter-stage cooling to achieve sufficient conversion. A cost analysis reveals the compressors needed to reach the required pressures consist of 50% the capital cost for Haber-Bosch. Therefore, a longstanding scientific challenge has been to achieve NH3 synthesis…