TY - JOUR
T1 - Mathematical model of a parallel plate ammonia electrolyzer for combined wastewater remediation and hydrogen production
AU - Estejab, Ali
AU - Daramola, Damilola A.
AU - Botte, Gerardine G.
N1 - Funding Information:
The authors would like to thank the financial support of the Center for Electrochemical Engineering Research (CEER) at Ohio University and the Department of Defense through the U.S. Army Construction Engineering Research Laboratory ( W9132T-12-2-0006 ). The content of the information does not reflect the position or the policy of the U. S. government.
Publisher Copyright:
© 2015 Elsevier Ltd.
PY - 2015/6/5
Y1 - 2015/6/5
N2 - A mathematical model was developed for the simulation of a parallel plate ammonia electrolyzer to convert ammonia in wastewater to nitrogen and hydrogen under basic conditions. The model consists of fundamental transport equations, the ammonia oxidation kinetics at the anode, and the hydrogen evolution kinetics at the cathode of the electrochemical reactor. The model shows both qualitative and quantitative agreement with experimental measurements at ammonia concentrations found within wastewater (200-1200mgL-1). The optimum electrolyzer performance is dependent on both the applied voltage and the inlet concentrations. Maximum conversion of ammonia to nitrogen at the rates of 0.569 and 0.766mgL-1min-1 are achieved at low (0.01MNH4Cl and 0.1M KOH) and high (0.07M NH4Cl and 0.15M KOH) inlet concentrations, respectively. At high and low concentrations, an initial increase in the cell voltage will cause an increase in the system response - current density generated and ammonia converted. These system responses will approach a peak value before they start to decrease due to surface blockage and/or depletion of solvated species at the electrode surface. Furthermore, the model predicts that by increasing the reactant and electrolyte concentrations at a certain voltage, the peak current density will plateau, showing an asymptotic response.
AB - A mathematical model was developed for the simulation of a parallel plate ammonia electrolyzer to convert ammonia in wastewater to nitrogen and hydrogen under basic conditions. The model consists of fundamental transport equations, the ammonia oxidation kinetics at the anode, and the hydrogen evolution kinetics at the cathode of the electrochemical reactor. The model shows both qualitative and quantitative agreement with experimental measurements at ammonia concentrations found within wastewater (200-1200mgL-1). The optimum electrolyzer performance is dependent on both the applied voltage and the inlet concentrations. Maximum conversion of ammonia to nitrogen at the rates of 0.569 and 0.766mgL-1min-1 are achieved at low (0.01MNH4Cl and 0.1M KOH) and high (0.07M NH4Cl and 0.15M KOH) inlet concentrations, respectively. At high and low concentrations, an initial increase in the cell voltage will cause an increase in the system response - current density generated and ammonia converted. These system responses will approach a peak value before they start to decrease due to surface blockage and/or depletion of solvated species at the electrode surface. Furthermore, the model predicts that by increasing the reactant and electrolyte concentrations at a certain voltage, the peak current density will plateau, showing an asymptotic response.
KW - Ammonia electrolysis
KW - Hydrogen production
KW - Waste-energy recovery
KW - Wastewater remediation
KW - Water deammonification
KW - Water-energy nexus
UR - http://www.scopus.com/inward/record.url?scp=84926480519&partnerID=8YFLogxK
U2 - 10.1016/j.watres.2015.03.013
DO - 10.1016/j.watres.2015.03.013
M3 - Article
C2 - 25864004
AN - SCOPUS:84926480519
SN - 0043-1354
VL - 77
SP - 133
EP - 145
JO - Water Research
JF - Water Research
ER -