Site items in: Energy Efficiency

Presentation

Electrochemical Nitrogen Reduction Reaction on Transition Metal Nitride Nanoparticles in Proton Exchange Membrane Electrolyzers

Xuan Yang Jared Nash Jacob Anibal Marco Dunwell Yushan Yan Bingjun Xu

Transition metal nitride nanoparticles are synthesized and utilized as catalysts for electrochemical nitrogen reduction reaction (ENRR) to produce ammonia in a proton exchange membrane electrolyzer (PEMEL). The catalysts show an average ENRR rate and Faradaic efficiency (FE) of 3.3 × 10−10 mol s−1 cm−2 (6.6 × 10−10 mol s−1 mg−1) and 5.95% at −0.1 V within 1 h, respectively. Both the ENRR rate and FE are approximately two orders of magnitude higher than those of noble metal catalysts. Time-dependent results suggest that the catalytic activity of transition metal nitride nanoparticles is stable at −0.1 V, with the catalytic activity decreasing…

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…

Article

Ammonia technology portfolio: optimize for energy efficiency and carbon efficiency

Trevor Brown March 23, 2018

Earlier this month, I had the pleasure of speaking at the International Fertilizer Association's (IFA) conference on the subject of Innovations in Ammonia. A key point was the benefit of technology diversification: as with any portfolio, whether an investment account or a global industry's range of available technologies, concentration in any area represents risk, and diversification represents resiliency. Unfortunately, the ammonia industry has grown highly concentrated, and its dependency upon one technology and one feedstock represents significant risk in tomorrow's markets. This article features five charts that aim to demonstrate why energy efficiency is insufficient as the only measure of technology improvement, why it is better to optimize instead of maximize, and why market evolution is necessary to support investment decisions in sustainable ammonia synthesis technologies.

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…

Presentation

Design Optimization of a Distributed Ammonia Generation System

Matthew Palys Alon McCormick Prodromos Daoutidis

Distributed ammonia generation located near farms is a promising alternative to the current practice of large-scale, centralized production. This production mode would reduce the need for transportation of ammonia over long distances currently caused by the mismatch between production and consumption locations. In addition, a small-scale ammonia synthesis process could more easily take advantage of distributed power generation based on wind or sunlight to reduce energy costs and lessen the dependence on fossil fuels. Distributed, renewables-based fertilizer production would largely insulate farmers against market uncertainty while also increasing the sustainability of the agricultural supply chain. However, a technically proven, economically…

Presentation

Load Range Enhancement of Haber-Bosch Process Designs for NH3 Sustainable Energy Storage By Multi-Parametric Optimization

Izzat Cheema Florian Baakes Ulrike Krewer

With the world’s major shift towards renewable energy, the need of chemicals-based energy storage has drastically increased, as renewable energy is intermittent and energy storage medium is required. Among several chemical energy storage options, ammonia is promising for renewable energy on utility-scale. The Haber-Bosch ammonia synthesis was the first heterogeneous catalytic system employed in the chemical industry and developed over a period of century. However, the conventional ammonia process has been designed and optimized for steady state operation and high capacity. Power-to-ammonia requires a more flexible operation, small size reactors and decentralized production. The impact of adjustable parameters, such as,…

Presentation

LiH Mediated Ammonia Synthesis Under Mild Condition

Jianping Guo Ping Chen

Having a hydrogen content of 17.6 wt% NH3 is an attractive hydrogen carrier. The key issue for NH3 synthesis and decomposition is the development of non-noble metal based, highly active and stable catalysts that can be operated under mild condition. With the understanding on the interaction of LiH and Li2NH with 3d metals or their nitrides, novel catalyst systems, i. e., LiH-3d transition metals for NH3 synthesis and Li2NH-3d transition metal for NH3 decomposition, that have activities surpassing the highly active Ru-based catalysts were developed. The unique chemistry among TM, Li, N and H creates a two-reactive center mediated pathway…

Presentation

Influence of H2 / N2 Ratio on Dynamic Behavior of Ammonia Production on Ru Catalyst Under Low Pressure Condition

Hideyuki Matsumoto Javaid Rahat Tetsuya Nanba

Recently deployment of renewable energy such as sunlight and wind power or deployment of process technologies for carbon dioxide capture and storage (CCS) is indispensable to reduce the CO2-emission. However, there are some issues to be solved in order to accelerate the mass deployment of renewable energy. Since amount of renewable energy quite changes unstably with time, which depends on weather and place, development of process systems technology is an issue for stable and effective utilization of electric power that is generated by fluctuating renewable energy. Those in national institute of National Institute of Advanced Industrial Science and Technology (AIST)…

Presentation

Early Transition Metal Carbide and Nitride Supported Catalysts for Ammonia Synthesis

Zixuan Wang Levi T. Thompson

More than 180 million tons of NH3 are produced annual via the Haber-Bosch process which converts N2 and H2 at high temperatures (400 – 500°C) and pressures (150 – 300 bars). Ammonia synthesis also accounts for 1-2% of global energy consumption.1 The development of higher activity catalysts that can operate under less severe conditions would enhance the economics associated with and sustainability of NH3 synthesis. Research described in this paper investigates the performance of transition metal carbide and nitride supported metals for NH3 synthesis. Previously, Mo2C and Mo2N have been reported to be more active than Ru-based catalysts, but slightly…

Presentation

Design of Iron-Nickel Nanocatalysts for Low-Temperature Electrochemical Ammonia Generation

Lauren F. Greenlee Shelby Foster Prashant Acharya David Suttmiller Charles Loney Julie Renner Wayne Gellett Katherine Ayers

The Haber-Bosch industrial process for ammonia production is the cornerstone of modern commercial-fertilizer-based agriculture. Haber-Bosch ammonia fueled the global population growth of the 20th century, and approximately half of the nitrogen in human bodies today originates from ammonia-based fertilizer produced by the Haber-Bosch process. However, the Haber-Bosch process operates at high temperature and high pressure to achieve high conversion efficiencies, and the hydrogen input comes from steam reforming of coal or natural gas. In addition to the energy costs, the large production of carbon dioxide as a greenhouse gas and the large required economies of scale motivate research efforts to…