TY - JOUR
T1 - Dynamic behavior of high-temperature CO2/H2O co-electrolysis coupled with real fluctuating renewable power
AU - Sun, Yi
AU - Zheng, Wenjin
AU - Ji, Shiyu
AU - Sun, Anwei
AU - Shuai, Wei
AU - Zheng, Nan
AU - Han, Yu
AU - Xiao, Gang
AU - Ni, Meng
AU - Xu, Haoran
N1 - Funding Information:
The authors gratefully acknowledge the support from the Zhejiang Provincial Key R&D Program (NO.2022C01043), the Zhejiang Provincial Natural Science Foundation (NO. LR20E060001 ). M.NI also thanks the grants (Project Number: PolyU 152064/18E and N_PolyU552/20) from Research grant Council, University Grants Committee, Hong Kong SAR.
Publisher Copyright:
© 2022 Elsevier Ltd
PY - 2022/8
Y1 - 2022/8
N2 - Direct utilization of fluctuational renewable powers leads to rapid changes of working conditions and brings difficulties in the operation of solid oxide electrolysis cells (SOECs). Herein, a multi-physics SOEC model is established to investigate its dynamic characteristics using a real photovoltaic power supply for co-electrolysis of H2O and CO2. Dynamic responses of key performances including the current density, the average SOEC temperature, the H2O/CO2 conversion rate and the output H2/CO ratio are analyzed over a whole day. It is found that a high CO2 mole fraction can help inhibit average temperature fluctuation, where the maximum temperature difference decreases from 110 to 57 K with the inlet CO2 mole fraction increasing from 0.2 to 0.8. Besides, the largest temperature gradient occurs in the middle of the cell in the morning and gradually migrates to the inlet. Generally, a high inlet gas temperature can increase the outlet H2/CO ratio especially at low voltages. The outlet H2/CO ratio is also found to be closely related with the gas utilization rate, where a utilization rate of 0.6 shows 10% higher H2/CO ratio than that of 0.8. This study can provide a guideline for the performance optimization of SOECs with fluctuating power supply.
AB - Direct utilization of fluctuational renewable powers leads to rapid changes of working conditions and brings difficulties in the operation of solid oxide electrolysis cells (SOECs). Herein, a multi-physics SOEC model is established to investigate its dynamic characteristics using a real photovoltaic power supply for co-electrolysis of H2O and CO2. Dynamic responses of key performances including the current density, the average SOEC temperature, the H2O/CO2 conversion rate and the output H2/CO ratio are analyzed over a whole day. It is found that a high CO2 mole fraction can help inhibit average temperature fluctuation, where the maximum temperature difference decreases from 110 to 57 K with the inlet CO2 mole fraction increasing from 0.2 to 0.8. Besides, the largest temperature gradient occurs in the middle of the cell in the morning and gradually migrates to the inlet. Generally, a high inlet gas temperature can increase the outlet H2/CO ratio especially at low voltages. The outlet H2/CO ratio is also found to be closely related with the gas utilization rate, where a utilization rate of 0.6 shows 10% higher H2/CO ratio than that of 0.8. This study can provide a guideline for the performance optimization of SOECs with fluctuating power supply.
KW - Co-electrolysis
KW - Dynamic characteristic
KW - Numerical simulation
KW - Renewable energy storage
KW - Solid oxide electrolysis cell
UR - http://www.scopus.com/inward/record.url?scp=85131358780&partnerID=8YFLogxK
U2 - 10.1016/j.seta.2022.102344
DO - 10.1016/j.seta.2022.102344
M3 - Journal article
AN - SCOPUS:85131358780
SN - 2213-1388
VL - 52
JO - Sustainable Energy Technologies and Assessments
JF - Sustainable Energy Technologies and Assessments
M1 - 102344
ER -
