03/12/2025
By Danielle Fretwell

The Francis College of Engineering, Department of Mechanical Engineering, invites you to attend a Doctoral Dissertation Proposal defense by Majid Ali on: "Feasibility Study and Demonstration of Renewable Energy/Regenerative Fuel Cell Hybrid Power System"

Candidate Name: Majid Ali
Degree: Doctoral
Defense Date: Tuesday, March 18th, 2025
Time: 11:30 a.m. - 1:30 p.m.
Location: Perry Hall, Room 215

Committee:
Advisor: Xinfang Jin, Ph.D., Associate Professor, Mechanical Engineering, University of Texas at Dallas
Co-Advisor: Fuqiang Liu, Ph.D., Associate Professor, Mechanical & Industrial Engineering, University of Massachusetts Lowell

Committee Members*
1. Ertan Agar, Ph.D., Associate Professor, Mechanical & Industrial Engineering, University of Massachusetts Lowell
2. David K. Ryan, Ph.D., Professor, Department of Chemistry, University of Massachusetts Lowell

Brief Abstract:
Hydrogen is increasingly recognized as a key enabler of clean energy transitions, with proton exchange membrane (PEM) technologies playing a crucial role in both hydrogen production and utilization. PEM electrolyzers offer an efficient means of generating hydrogen through water electrolysis, while PEM fuel cells enable the conversion of hydrogen into electricity with high efficiency and zero emissions. These technologies have gained significant attention for their potential to facilitate renewable energy integration, energy storage, and grid stability. However, real-world applications face critical challenges, particularly concerning the purity of produced hydrogen and the ability of PEM systems to operate efficiently under dynamic load conditions, as required in renewable energy-based power systems.
Despite advancements in PEM technology, several research gaps remain unaddressed. Existing studies primarily focus on steady-state operation, while the effects of transient and fluctuating loads, typically in renewable energy applications, are less explored. Additionally, limited experimental research has been conducted on the direct integration of PEM electrolyzers and fuel cells with renewable sources, particularly in terms of system degradation under real-world dynamic conditions. This research aims to bridge these gaps by developing an integrated experimental setup, conducting parametric analyses, and assessing system performance under both steady and transient conditions to optimize operation and improve long-term reliability.
Beginning with the PEM electrolyzer, the research explores the integration and optimization of a benchtop system for hydrogen production. Various moisture removal schemes were assessed, revealing that combining desiccant dryers with water filters effectively achieves hydrogen purity levels of 99.970%. To evaluate the impact of renewable power fluctuations on PEM electrolyzer performance, experiments were conducted focusing on the effects of current fluctuation frequency and standard deviation. The findings showed that rapid and significant current fluctuations increase power consumption, cause voltage instability, and reduce both voltage and stack efficiency compared to constant current operation.
The study then shifts focus to PEM fuel cells, examining key parameters that influence their efficiency, including fan-assisted airflow, stack temperature, and hydrogen supply pressure through extensive parametric analyses. Results indicated that fan-assisted airflow significantly enhances voltage output and overall efficiency, while increasing the stack temperature to 300 K improves reaction kinetics and reduces degradation. Higher hydrogen supply pressures also led to elevated performance metrics such as cell voltage and power density, demonstrating improved reaction transport.
Lastly, the research investigates the integration of PEM fuel cells with renewable energy sources, highlighting their ability to maintain energy stability during fluctuations in power production. This includes an analysis of the degradation mechanisms under varied load conditions. Findings revealed that lower fluctuations in power lead to better efficiency and stability, demonstrating a clear correlation between decreased hydrogen consumption and increased stack efficiency.
Overall, this work provides critical insights into the operational dynamics of PEM electrolyzers and fuel cells under various conditions, emphasizing their adaptability and performance within renewable energy systems. The research enhances understanding and promotes the practical application of PEM technology for clean and sustainable hydrogen production, thereby paving the way for broader adoption of these systems in an evolving energy landscape.