AMMONIA ELECTROLYSIS

Represents a solution to hydrogen storage, production and transportation. Provides alternatives/renewal sources of hydrogen and could be used as a remediation process to preserve the water and air environments. For more information contact Dr. Botte.

 

INTRODUCTION

Fuel cells are one of the most attractive distributed power generation technologies. They combine hydrogen and oxygen to produce electricity, with water and heat as the by-products. Since the conversion of the fuels to energy takes place directly without combustion, the process is highly efficient, clean, and quiet. However, problems associated with hydrogen sources and storage, and limitations in fuel flexibility are delaying the commercialization of fuel cells as a competitive technology for both transportation and stationary applications.
The Electrochemical Engineering Research Laboratory at Ohio University is working on the development of a new technology that can help confront all the issues mentioned above. The technology is called “Ammonia Electrolysis” and the electrochemical cell is called “Ammonia Electrolytic Cell (AEC).1,2,3
The AEC operates as follows: aqueous ammonia (NH3/H2O) in the presence of potassium hydroxide (KOH) is fed into the anode compartment of the AEC where NH3 is oxidized in the presence of OH- according to

2NH3 + 6OH- -------> N2 + 6H2O + 6e-

at the cathode a solution of KOH is supplied and water is reduced in alkaline medium according to

2H2O + 2e- -------> H2 + 6OH-

therefore the overall reaction is given by

2NH3 -------> N2 + 3H2

the theoretical voltage for the production of hydrogen at 25oC through electrolysis of ammonia in alkaline media is 0.058 V with an energy consumption of 1.55 W-h per gram of H2 produced. KOH is the electrolyte for the system and water acts as the solvent, that is, neither KOH nor water are consumables during the operation of the cell.

ADVANTAGES

  1. Low operating temperature. Maximum temperature about 60oC.
  2. Could operate with proton exchange membrane (PEM) fuel cells as a power source. Part of the energy of the PEM fuel cell can be used to power the AEC with still net energy left. See Ammonia Shoe-Sized Car as example.
  3. Potential use in residential houses due to low operating temperature. See Self-Sustainable-Ammonia-Power Houses project.
  4. Easy to operate with renewal energy sources (solar and wind energy)
  5. Could be extended to use ammonia from waste (e.g., farmers, waste water, etc). See Farm of the Future project.
  6. Hydrogen is produced on demand.
  7. The infrastructure for ammonia distribution and storage is already available.

PUBLICATIONS

  1. G. G. Botte, F. Vitse, and M. Cooper, "Electrocatalysts for the Oxidation of Ammonia and their Application to Hydrogen Production, Fuel Cells, Sensors, and Purification Processes", Pending Patent, US (2003).
  2. G. G. Botte, "Carbon fiber-electrocatalysts for the Oxidation of Ammonia, Ethanol, and Coal, and their Application to Hydrogen Production, Fuel Cells, and Purification Processes", Pending Patent, US (2004).
  3. F. Vitse, M. Cooper, and G. G. Botte, "On the Use of Ammonia Electrolysis for Hydrogen Production," J. Power Sources, 142, 18 (2005).
  4. M. Cooper and G. G. Botte, "Hydrogen Production from the Electro-oxidation of Ammonia Catalyzed by Platinum and Rhodium on Raney Nickel Substrate," J. Electrochem. Soc., 153, A1894 (2006).

SPONSORS

  1. Department of Defense. Army Research Office (DURIP award 2004).
  2. National Science Foundation. Path Award (2005).
  3. Ohio University Foundation (Early Stage Development Funds)
  4. Vice President for Research at Ohio University (1804 awards and Student Enhancement awards)
  5. Consortium for Economics Energy and the Environment
  6. Russ College of Engineering and Technology
  7. Hydra Fuel Cell Corporation

PROJECTS

VIDEOS

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Electrochemical Engineering Research Laboratory
183 Stocker Center
Athens, OH 45701
Phone: 740.593.9670
botte@ohio.edu