skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: Solar-thermal Water Splitting Using the Sodium Manganese Oxide Process & Preliminary H2A Analysis

Abstract

There are three primary reactions in the sodium manganese oxide high temperature water splitting cycle. In the first reaction, Mn2O3 is decomposed to MnO at 1,500°C and 50 psig. This reaction occurs in a high temperature solar reactor and has a heat of reaction of 173,212 J/mol. Hydrogen is produced in the next step of this cycle. This step occurs at 700°C and 1 atm in the presence of sodium hydroxide. Finally, water is added in the hydrolysis step, which removes NaOH and regenerates the original reactant, Mn2O3. The high temperature solar-driven step for decomposing Mn2O3 to MnO can be carried out to high conversion without major complication in an inert environment. The second step to produce H2 in the presence of sodium hydroxide is also straightforward and can be completed. The third step, the low temperature step to recover the sodium hydroxide is the most difficult. The amount of energy required to essentially distill water to recover sodium hydroxide is prohibitive and too costly. Methods must be found for lower cost recovery. This report provides information on the use of ZnO as an additive to improve the recovery of sodium hydroxide.

Authors:
; ; ; ; ; ; ;
Publication Date:
Research Org.:
University of Colorado
Sponsoring Org.:
USDOE
OSTI Identifier:
1053709
Report Number(s):
DOE/05GO15044
DOE Contract Number:  
FG36-05GO15044
Resource Type:
Technical Report
Country of Publication:
United States
Language:
English
Subject:
14 SOLAR ENERGY; 08 HYDROGEN

Citation Formats

Francis, Todd M, Lichty, Paul R, Perkins, Christopher, Tucker, Melinda, Kreider, Peter B, Funke, Hans H, Lewandowski, A, and Weimer, Alan W. Solar-thermal Water Splitting Using the Sodium Manganese Oxide Process & Preliminary H2A Analysis. United States: N. p., 2012. Web. doi:10.2172/1053709.
Francis, Todd M, Lichty, Paul R, Perkins, Christopher, Tucker, Melinda, Kreider, Peter B, Funke, Hans H, Lewandowski, A, & Weimer, Alan W. Solar-thermal Water Splitting Using the Sodium Manganese Oxide Process & Preliminary H2A Analysis. United States. doi:10.2172/1053709.
Francis, Todd M, Lichty, Paul R, Perkins, Christopher, Tucker, Melinda, Kreider, Peter B, Funke, Hans H, Lewandowski, A, and Weimer, Alan W. Wed . "Solar-thermal Water Splitting Using the Sodium Manganese Oxide Process & Preliminary H2A Analysis". United States. doi:10.2172/1053709. https://www.osti.gov/servlets/purl/1053709.
@article{osti_1053709,
title = {Solar-thermal Water Splitting Using the Sodium Manganese Oxide Process & Preliminary H2A Analysis},
author = {Francis, Todd M and Lichty, Paul R and Perkins, Christopher and Tucker, Melinda and Kreider, Peter B and Funke, Hans H and Lewandowski, A and Weimer, Alan W},
abstractNote = {There are three primary reactions in the sodium manganese oxide high temperature water splitting cycle. In the first reaction, Mn2O3 is decomposed to MnO at 1,500°C and 50 psig. This reaction occurs in a high temperature solar reactor and has a heat of reaction of 173,212 J/mol. Hydrogen is produced in the next step of this cycle. This step occurs at 700°C and 1 atm in the presence of sodium hydroxide. Finally, water is added in the hydrolysis step, which removes NaOH and regenerates the original reactant, Mn2O3. The high temperature solar-driven step for decomposing Mn2O3 to MnO can be carried out to high conversion without major complication in an inert environment. The second step to produce H2 in the presence of sodium hydroxide is also straightforward and can be completed. The third step, the low temperature step to recover the sodium hydroxide is the most difficult. The amount of energy required to essentially distill water to recover sodium hydroxide is prohibitive and too costly. Methods must be found for lower cost recovery. This report provides information on the use of ZnO as an additive to improve the recovery of sodium hydroxide.},
doi = {10.2172/1053709},
journal = {},
number = ,
volume = ,
place = {United States},
year = {2012},
month = {10}
}