SBIR-STTR Award

Off-shore wind is expected to grow rapidly over the next decade. However, if the HVDC lines and grid interconnection queues are not adequately accelerated it could lead to underutilized assets. By co-locating water electrolyzers off-shore, the wind developers can fully use capture an additional revenue stream of producing hydrogen for sale to the chemicals and/or fuel cell markets. Present designs use PEM electrolyzers for this purpose, but the PEM electrolyzers contain over $1,000,000 of precious metals, which makes them a theft target. Also, PEM electrolyzers need very pure water, which adds significant system complexity and cost to off-shore deployments. The objective here is to develop electrolyzers with no precious metals that can run directly on seawater and load-following to match the output of the wind turbine. If successful, this will lead to a system that is tailored for off-shore use. Alchemr already sells water electrolyzers based on anion exchange membranes. The cells have also undergone 12,000 hours of continuous testing and show VI characteristics similar to those of PEM electrolyzers, with no precious metals. The cells already contain many of the components of seawater, Na+ or K+, and Cl-. The high pH suppresses metal corrosion and scale formation. In Phase I, Alchemr’s scientists will test the operation of the systems running directly on seawater. We will do both steady-state and transient experiments to see how well the cells can follow duty cycles of off-shore wind farms. If this is successful, it will enable a Phase II effort where the cells are scaled up into stacks that can be offered for sale and tested at pilot- scale facilities with our potential customers. Upon success, Alchemr will be producing and electrolyzer designed for coupling with off-shore wind farms. Co-location with renewable resources will reduce the production and transportation cost to facilities like ports and chemical plants located near the shore. Manufacturing electrolyzers in the U.S. will create new jobs and revenues while boosting energy security for U.S. companies. It is also likely that we will be able to create and sell small AEM electrolyzer units to companies looking for low-cost alternatives to delivered hydrogen cylinders.

Hydrogen can decarbonize many carbonintensive sectors, increase national energy security, and provide flexibility to our power grid. Today, more than 95% of hydrogen is produced from cheap fossil fuels, contributing to more than 2% of global greenhouse gas emissions. Green hydrogen production by coupling water electrolyzers to offshore wind is the key for decarbonizing the economy. Directly coupling offshore wind with water electrolyzers for hydrogen production offers unique advantages, particularly related to reducing the cost of electric grid connections and reducing energy losses, by transporting hydrogen over long distances rather than transporting electricity. Although water electrolysis is a relatively well established technology in specialty applications, there are not currently any water electrolyzers deployed on offshore wind farms. One of the lessdiscussed requirements of lowtemperature water electrolyzer technologies is the availability of highly pure water feeds. The high capital cost and energy requirement of desalination systems, such as reverse osmosis, can become a bottleneck to realizing offshore wind coupled to water electrolysis. Instead, using seawater as the feedstock to water electrolysis can enable a lowcost, small footprint, and energy efficient green hydrogen production platform. In Phase I of this project, Alchemr demonstrated the robustness of its benchtop anion exchange membrane electrolyzer system under conditions that the system would be subject to when integrated with an offshore wind turbine. In addition, we experimentally evaluated various electrodes and catalyst materials in Phase I to feed our electrolyzer system with seawater. However, one of the key catalytic challenges which still should be addressed for seawater electrolysis is the competition between anodic chlorine evolution reaction and the oxygen evolution reaction on the anode electrode as well as reducing cell degradation in seawater corrosive environment. We successfully ran our 5 cm2 cell for more than 330 hours at <1.9 V. However, this was done at low current densities 30 mA cm2. In Phase II, we propose to evaluate more sophisticated catalyst materials and electrode preparation methods to improve cell performance. In collaboration with the University of Connecticut, Alchemr will develop a highperformance and durable anode electrode using the unique reactive spray deposition technology, based on the successful material identified in Phase I. We will also produce new oxygen evolution reaction selective catalysts e.g., MnMo oxides, MnMoW oxides, and NiFelayered double hydroxide. We will further develop a stable anode flowfield/current collector to enable increased current density and reduce cell degradation rates for seawater electrolysis. On the other hand, Phase I tests were performed on 5 cm2 and 25 cm2 cells. To increase hydrogen production, in Phase II, we propose investigating our electrolyzer's electrochemical behavior in a 3cell single stack with an active area of 750 cm2 250 cm2 per cell and seawater as the electrolyzer feedstock. Lastly, we propose to improve the technoeconomic model that we established in Phase I to include maintenance costs required due to running seawater through the system rather than purified water.