Microfluidic Alkaline eleCtrolysis for Green HYdrogen Via Electrochemical Reactions

Project Information

MacGhyver

Grant agreement ID: 101069981

DOI

10.3030/101069981

EC signature date 24 June 2022

Start date 1 September 2022

End date 31 December 2026

Funded under

• The European Innovation Council (EIC)

Total cost

€ 3 644 380,00

EU contribution

€ 3 644 380,00

Coordinated by

EDEN TECH
France

Periodic Reporting for period 2 - MacGhyver (Microfluidic wAstewater treatment and Creation of Green HYdrogen Via Electrochemical Reactions)

Reporting period: 2023-09-01 to 2025-02-28

Summary of the context and overall objectives of the project

MacGhyver is set to achieve several groundbreaking advancements, each of which contributes to a more efficient and sustainable approach to hydrogen production. At the core of MacGhyver is a compact, energy efficient system that serves a dual purpose by also acting as a wastewater treatment device. The core of this innovation is the microfluidic electrolyzer design, characterized by its highly parallelized interconnection of microchannels. This design facilitates the processing of large volumes of water with minimal pumping losses. Notably, the microscale design minimizes turbulence, enabling a flow-through configuration that eliminates the need for a membrane separator. Furthermore, the closely spaced electrodes, less than 1 mm apart, result in negligible ohmic losses. This design also enables the use of sustainable electrolytes like wastewater. MacGhyver also uses non-critical raw material electrodes, balancing cost-effectiveness with high efficiency. MacGhyver has structured WPs aimed at innovation in compression and separation systems to enhance compactness and efficiency. To ensure widespread market acceptance, MacGhyver actively engages with key stakeholders in both regulatory and market domains. The present cost of green hydrogen production ranges from $3/kg - $6.55/kg while fossil-based hydrogen costs ~$1.80/kg. To attain market acceptance, it is imperative to reduce electrolysis plant costs by 40% in the short term and 80% in the long term. The system sets an impressive target of achieving 45 kWh/kg H2, leading to a production cost of just $1/kg H2. The microfluidic stack, in particular, stands out for its superior performance compared to traditional electrolyzers in terms of design, energy efficiency, and compactness. The use of non-CRM electrodes is not only cost-effective but also reduces the environmental impact by diminishing the dependence on rare and expensive materials. The electrochemical hydrogen compressor is a novel addition that enhances the system's efficiency by compressing hydrogen gas at lower energy costs. Furthermore, MacGhyver introduces a comprehensive LCA and LCC study into the project. These systematic methods provide a holistic view of the environmental and economic impact of the product, accounting for every facet of the product's life cycle, from raw material extraction to disposal.

Work performed from the beginning of the project to the end of the period covered by the report and main results achieved so far

In WP2, MacGhyver has made substantial progress in the exploration of non-precious metal electrode materials for the microfluidic electrolyzer as documented in D2.1 where an evaluation of key parameters and physical properties of Ni- and Fe-based materials, along with their electrochemical performance in aqueous alkaline electrolytes, has been conducted. The project has made informed choices in selecting steel felt and mesh for OER and nickel mesh for HER. Furthermore, the project has actively developed non-CRM catalysts for hydrogen evolution, with preliminary findings favoring MoO3. Plans are in place to integrate these materials into doped carbons and explore higher temperature conditions to enhance performance. The project is also in the process of upscaling experiments using a flow cell electrolyzer setup, adopting a unique approach to evaluate process efficiency, particularly in the context of hydrogen peroxide production.
In WP3, MacGhyver has achieved significant developments with the creation of a membrane-less microfluidic electrolyzer. The design features a compact, optimized stack of microchannels and innovative electrode integration. Currently, the project is actively engaged in the fabrication and testing phases, with the ultimate goal of enhancing efficiency through iterative design adjustments based on experimental findings.
WP4 focuses on in-depth exploration of limitations and potentials in the domain of electrochemical compression and storage solutions. MacGhyver has identified certain limitations, particularly those related to water transport at high current density and is actively working on solutions to address these challenges. The project has made substantial progress in developing a technical model for electrochemical hydrogen compression.
In WP5, MacGhyver has outlined objectives centered on assembling components and optimization. However, as of now, the planned activities within this work package have not yet commenced as originally scheduled. The consortium partners are currently directing their efforts toward the development of individual device models in alignment with the project's goals.
WP6 is actively engaged in assessing the environmental and life cost impacts attributed to the project. This comprehensive assessment includes evaluations of cost-effectiveness, risk mitigation strategies for the microfluidic electrolyzer, and an exploration of socio-economic impacts.

Progress beyond the state of the art and expected potential impact (including the socio-economic impact and the wider societal implications of the project so far)

As a result of the WP2, the priority list of the most promising non-CRM electrodes for OER (steel felt and mesh) and HER (nickel mesh) have been selected for integration into a lab-scale experimental setup. The results obtained during the WP2 will be exploited during implementation of T3.3. The investigation of non-CRM indicated that the most active material for hydrogen evolution reaction can be pure metal particles, not necessarily its oxide as the literature shows. This brings about a need for further experiments considering oxidation state of transition metal and eventually surrounding non-metal type (oxygen, sulphur, etc.). Type and the crystal structure of material influence must be thoroughly examined and described to understand the mechanism. Such operations may lead to the rational selection of best performing catalysts. In the case of H2O2 production, it was noted that electrolyte flow rate has a significant impact on the key process efficiency. In fact, water oxidation is strongly dominated by oxygen production. The manipulation of the residence time of the electrolyte in the electrolyser can increase the two-electron oxidation mechanism towards production of H2O2 and what seems more important, help to prevent its simultaneous decomposition to the product of higher oxidation state (oxygen).
As a result of WP3, the microfluidic design for the electrolyzer has been finalized. We defined our Minimum Viable Product, which is envisaged as a 150W stack comprising 15 cells arranged in series within a bipolar configuration. This assembly will draw its power from a power supply with specifications of 30V and 5A. The projected flow rate for a single-cell device is around 1m3/day (12cm3/s), with a total pressure drop of less than 0.2bar. We have successfully realized our initial microfluidic membraneless electrolyzer design, demonstrated in CAD and validated through analytical and numerical methodologies.
Within WP4, the electrochemical domain and the CFD coupling are working and able to produce results. The Simulation results already showed the need to improve on membrane material choice to ensure high water retention and conductivity. The acquisition of alternative membrane materials to compare with Nafion has already begun.
As a result of WP5, we are currently able to calculate LCoH for the MacGhyver system and other hydrogen production systems.

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