11/04/2024
By Danielle Fretwell

The Francis College of Engineering, Department of Energy Engineering - Renewable, invites you to attend a Doctoral Dissertation Proposal defense by Shabdiki Chaurasia on: "Flow Assisted Electrochemical Systems for Redox Mediated Water Electrolysis and Industrial Decarbonization."

Candidate Name: Shabdiki Chaurasia
Degree: Doctoral
Defense Date: Monday, Nov. 18, 2024
Time: 9:30 to 11:30 a.m.
Location: Perry 415

Committee:
Advisor: Ertan Agar, Associate Professor, Department of Mechanical Engineering, UMass Lowell

Committee Members*
1. Michael B. Ross, Assistant Professor, Department of Chemistry, UMass Lowell
2. Jianqiang Wei, Assistant Professor, Department of Civil and Environmental Engineering, UMass Lowell
3. Juan Pablo Trelles, Professor, Department of Mechanical Engineering, UMass Lowell
4. Fuqiang Liu, Associate Professor, Department of Mechanical Engineering, UMass Lowell

Brief Abstract:
The growing reliance on renewable energy highlights the urgent need for efficient energy storage systems to mitigate grid intermittency. While all-vanadium redox flow batteries (RFBs) offer promise, their low energy density and associated high costs call for alternative approaches. This thesis explores the potential of flow-assisted electrochemistry to enhance hydrogen production and contribute to industrial decarbonization, targeting net-zero carbon emissions by 2050. Dual-layer RFBs extend energy storage capabilities beyond traditional electrolytes by generating green hydrogen. By incorporating Mn³⁺/Mn²⁺ as a redox mediator in the catholyte and V³⁺/V²⁺ in the anolyte, the system enables redox-mediated water electrolysis in external catalytic reactors, maximizing hydrogen production during periods of surplus renewable electricity. The research tackles Mn³⁺ instability, which leads to MnO₂ formation and capacity fade, by employing advanced electrochemical stabilization strategies. The addition of V⁵⁺ to stabilize the Mn³⁺/Mn²⁺ redox couple is demonstrated, providing key insights into the enhancement of aqueous flow systems using manganese. Furthermore, the study addresses gas crossover challenges in large-scale electrolyzers by spatially separating the hydrogen evolution reaction (HER) from the oxygen evolution reaction (OER) in external reactors.

In parallel, the research promotes industrial decarbonization by applying flow-assisted electrolysis to cement manufacturing, a sector responsible for approximately 8% of global CO₂ emissions. A zero-gap, three-channel flow electrolyzer is developed to produce calcium hydroxide, a precursor to Portland clinker, overcoming major challenges such as membrane degradation. This work significantly advances the understanding of flow-assisted electrochemical systems, contributing to both sustainable hydrogen production and the reduction of emissions in cement manufacturing, and supports global decarbonization efforts.