Airtight butyl rubber under high pressures in the storage tank of CAES‐G/T system power plant

Abstract The compressed air up to the maximum pressure of 8 MPa is stored in the storage facility of the Compressed Air Energy Storage Gas Turbine (CAES‐G/T). The interior of the storage facility is covered by air‐tight sheets to prevent a leak of this compressed air. Electricity by a power‐generating system using such a facility is the first of its kind in the world. So, we have examined the materials of the airtight sheet and found that polymeric materials were suitable. Then, a normal pressure gas permeation test was done on several synthetic resins and rubbers. Butyl rubber (IIR) was found to show the smallest gas permeability. Moreover, a high‐pressure gas permeation test was done on IIR and natural rubber (NR). The permeability of IIR at 10 MPa was estimated, and it was clear that IIR was a suitable air‐tight material for CAES‐G/T. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 95: 173–177, 2005