Microcrack-Resistant Resin Systems for Cryo-Compressed Hydrogen Storage

The U.S. National Clean Hydrogen Strategy and Roadmap outlines pathways to reducing carbon emissions through expanded use of hydrogen in place of fossil fuels. Development of hydrogen fuel systems for transportation such as medium to heavy duty trucking, agriculture, mining and construction equipment is of particular interest as these economic sectors account for over 30 % of current greenhouse gas emissions. Cryo-compressed hydrogen storage (CcH2) is widely regarded as a high-potential storage option, providing the maximum storage density while avoiding vent losses in nearly all scenarios. There are, however, some challenges to be addressed before full implementation of CcH2 storage. Specifically, fatigue performance resulting from combined pressure and thermal loads must be proven for both the Type III metal liner and the composite overwrap. This Phase I program focuses on ensuring the performance of the composite overwrap during the expected cycle life of the unit through the use of novel microcrack-resistant resin systems for the composite construction. .In this program, Composite Technology Development, Inc. (CTD), in partnership with Verne Inc., will develop microcrack resistant resin systems that will demonstrate high performance during thermal and pressure cycling associated with cryo-compressed fill and drain cycles. The material design will target a composite overwrap that shows minimal degradation from damage propagation after 11,000 ľ 15,000 cycles. In Phase I CTD will formulate and evaluate toughened resin systems suitable for filament winding while providing minimal outgassing after cure. Mechanical properties of composites based on these resin systems will be evaluated at both ambient and cryogenic temperatures using flat laminates produced at CTD. Two subscale Type III composite vessels will be fabricated, one with a traditional epoxy resin and one with the down-selected toughened resin developed by CTD. The vessels will be pre-conditioned by thermally dipping them in liquid N2. Subsequently hydrostatic cycle tests will be conducted under ambient conditions to show improved fatigue life of the vessel fabricated with the toughened resin. Both laminate and pressure vessel test data will then be used by Verne to develop full size COPVs, which will be fabricated and tested during Phase II. Conversion of trucking, mining and heavy industry to hydrogen-based power is a key part of the United States strategy to reach net-zero greenhouse gas emissions by 2050. The technology developed in this program will reduce risk for cryo-compressed hydrogen storage that is a key enabler for conversion of medium and heavy-duty trucking to hydrogen fuels, thereby offering the potential for accelerating decarbonization of one industrial sector. The technology may also find additional applications in liquid hydrogen storage moving forward.