Ultra-Lightweight Hydrogen Gas Storage Tanks

Future generations of high altitude airships (HAA) will require power systems with increased specific energy production and storage capability in order to enhance operational capability or reduce overall system weight. Regenerative fuel cell solutions hold much promise toward providing this capability. A key systemic obstacle for implementing this solution is the lack of ultra-lightweight hydrogen gas storage tanks of sufficient size and storage capability that can be operated in the HAA environment between 60,000 and 70,000 feet. New and innovative materials and design approaches are required to produce ultra-lightweight hydrogen gas storage tanks. This project proposes to develop a cost effective, ultra-lightweight composite hydrogen gas storage tank that will meet all HAA design requirements. The hydrogen gas storage tank will be based on a pressure vessel design that uses a dicyclopentadiene (DCPD) polymer as the tank liner material, and carbon fiber composite for the tank structural shell. The DCPD polymer has optimal properties for use as a lightweight liner material, with excellent mechanical properties and extremely low permeation and absorption characteristics. DCPD will also be evaluated for use as the filament winding resin for the tank shell since it allows a very high fiber volume laminate to be produced.