Tag Archives: Wind-to-Ammonia

Ammonia Absorption and Desorption in Ammines

Collin Smith, Mahdi Malmali, Chen-Yu Liu, Alon McCormick, E L Cussler*, University of Minnesota, USA

15th Annual NH3 Fuel Conference, Pittsburgh, PA, October 31, 2018
NH3 Energy+ Topical Conference at the AIChE Annual Meeting


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, so the rate controlling step changes with the amount of absorption. The potential of this separation in the distributed production of ammonia is discussed both as a source of fertilizer and as a means of wind energy storage.

Read the abstract at the AIChE website.


Download this presentation [PDF].


2018: Design Optimization of an Ammonia-Based Distributed Sustainable Agricultural Energy System
2017: Design Optimization of a Distributed Ammonia Generation System
2017: Lower Pressure Ammonia Synthesis
2016: Small Scale Low-Pressure Ammonia Synthesis
2015: Potential Strategies for Distributed, Small-Scale Sustainable Ammonia Production [PDF]
2014: Life-cycle greenhouse gas and energy balance of community-scale wind powered ammonia production
2013: Ammonia Production Using Wind Energy
2012: Lessons Learned in Developing a Wind-to-Ammonia Pilot Plant [PDF]
2011: Production of Anhydrous Ammonia from Wind Energy — Anatomy of a Pilot Plant, The Sequel [PDF]
2010: Production of Anhydrous Ammonia from Wind Energy — Anatomy of a Pilot Plant [PDF]
2009: Ammonia from Wind, Progress Update [PDF]
2008: Ammonia from Wind, an Update [PDF]
2007: Ammonia from Wind, an Update [PDF]
2006: Wind to Ammonia [PDF]


Department of Chemical Engineering and Materials Science, University of Minnesota
West Central Research & Outreach Center, University of Minnesota
Learn more about the 2018 NH3 Fuel Conference

Design Optimization of a Distributed Ammonia Generation System

Matthew Palys*, Alon McCormick, Prodromos Daoutidis
University of Minnesota, United States

NH3 Fuel Conference, Minneapolis, November 2, 2017
AIChE Annual Meeting, Topical Conference: NH3 Energy+


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 competitive small-scale ammonia synthesis process which would facilitate this distributed generation paradigm does not currently exist. A wind powered plant which uses a scaled-down Haber-Bosch process has been installed in Morris, Minnesota [1], but ultimately, this process is too complex to operate and too costly for deployment on the scale of a farm or small group of farms. Recently, a novel reactive-separation process for ammonia synthesis has been proposed and proven on a lab scale [2]. A conventional catalyst is used to carry out the synthesis reaction. Then, ammonia is removed via chemisorption while unreacted hydrogen and nitrogen are recycled. This allows equilibrium limitations to be overcome and can facilitate operation at lower pressure and without the large temperature change exhibited in the Haber-Bosch process. Continue reading

Lower Pressure Ammonia Synthesis

Mahdi Malmali1*, Alon McCormick1, Edward L. Cussler1, Joshua Prince1, Mike Reese2
[1] University of Minnesota; [2] University of Minnesota West Central Research and Outreach Center, United States

NH3 Fuel Conference, Minneapolis, November 1, 2017
AIChE Annual Meeting, Topical Conference: NH3 Energy+


Ammonia is a very important chemical, mainly produced through the Haber-Bosch process. This process requires high temperature (>400 °C) and pressure (>150 bar) in order to ensure fast kinetics and high conversions, respectively.1 As a result, ammonia synthesis is known to be very complex and energy-intensive.2 To alleviate the complexity and energy requirements of ammonia synthesis, and to reduce the CO2 emissions, we are proposing an innovative reaction-absorption process to synthesize carbon-free ammonia in small plants.3 This green ammonia can be synthesized in wind-powered plants, with hydrogen from electrolysis of water and nitrogen from pressure swing adsorption of air.4 Continue reading