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Article Citation - WoS: 9Citation - Scopus: 10Investigation of the Performance of High-Temperature Electrochemical Hydrogen Purification From Reformate Gases(Wiley, 2022) Durmus, Gizem Nur Bulanik; Durmuş, Gizem Nur Bulanık; Colpan, C. Ozgur; Devrim, Yilser; Devrim, Yılser; Durmuş, Gizem Nur Bulanık; Devrim, Yılser; Mechanical Engineering; Energy Systems Engineering; Mechanical Engineering; Energy Systems EngineeringIn the present work, the purification of hydrogen from a hydrogen/carbon dioxide/carbon monoxide (H-2:CO2:CO) mixture by a high-temperature electrochemical purification (HT-ECHP) system is examined. Electrochemical H-2 purification experiments were carried out in the temperature range of 140-180 degrees C. The effects of the molar ratio of the gases in the mixture (H-2:CO2:CO-75:25:0, H-2:CO2:CO-72:26:2,0 H-2:CO2:CO-75:22:3, H-2:CO2:CO-75:20:5, H-2:CO2:CO-97:0:3, H-2:CO2:CO-95:0:5) and the operating temperature on the electrochemical H-2 separation were investigated. As a result of the electrochemical H-2 purification experiments, it was determined that the operating temperature is the most important parameter affecting the performance. According to the results obtained, H-2 purity of 99.999% was achieved at 160 degrees C with the reformate gas mixture containing 72% H-2, 26% CO2, and 2% CO by volume. According to the polarization curves of the gas mixtures containing CO, high current densities at low voltage were reached at 180 degrees C, and it was observed that the performance increased as the temperature increased, whereas the gas mixture without CO gave the best performance at 160 degrees C.Article Mathematical Modeling of a Direct Dimethyl Ether Fuel Cell(Wiley-hindawi, 2022) Alpaydin, Guvenc Umur; Durmus, Gizem Nur Bulanik; Colpan, C. Ozgur; Devrim, YilserIn this study, a mathematical model of a direct dimethyl ether fuel cell (DDMEFC) is developed to examine the effect of operating conditions on voltage losses and cell performance. In modeling, the electrochemical relations and mass balances are used to find the cell voltage for the given conditions. The values of some modeling parameters are determined using experimental data through curve fitting. For validation purposes, in-house experimental studies are conducted. For this purpose, Pt50Ru25Pd25/C, Pt40Ru40Pd20/C, and Pt50Pd50/C anode catalysts are synthesized by the microwave method. The effects of these synthesized catalysts and the operating conditions (cell temperature, the molar ratio of dimethyl ether, and water) on the DDMEFC performance are discussed by comparing the activation and ohmic polarization as well as the polarization curves using the model developed. This cell-level modeling approach could be considered as a preliminary step in the design process of a DDMEFC stack.
