Cold hydrogen delivery in glass fiber composite pressure vessels: Analysis, manufacture and testing

This paper describes Lawrence Livermore National Laboratory (LLNL) and Spencer Composites Corporation (SCC) efforts in demonstrating an innovative approach to hydrogen delivery. This approach minimizes hydrogen delivery cost through utilization of glass fiber pressure vessels at 200 K and 70 MPa to produce a synergistic combination of container characteristics and properties of hydrogen gas: (1) hydrogen cooled to 200 K is similar to 35% more compact for a small increase in theoretical storage energy (exergy); and (2) these cold temperatures (200 K) strengthen glass fibers by as much as 50%, expanding trailer capacity without the use of much more costly carbon fiber composite vessels. Analyses based on US Department of Energy H2A cost and efficiency parameters and economic methodology indicate the potential for hydrogen delivery costs below $1/kg H-2 (not including storage at the terminal, and cascade, compression, and chilling at the forecourt, but including compression and refrigeration at the terminal). Further savings are possible by integrating the delivery trailer into the station cascade to avoid chilling typically required for 700 bar hydrogen dispensing. The report also describes experimental work leading to demonstration of the potential for low cost delivery, starting with measurement of cold glass fiber strengthening, and continuing with subscale and full-scale pressure vessel development and testing, and concluding with successful development of an ASME X certifiable full-scale (60 cm diameter) glass fiber pressure vessel made of innovative materials with potential to meet the cost targets when integrated into an insulated tube trailer. Copyright (C) 2013, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved.