(333a) Adsorptive Storage of Mechanical Energy (Work) for Transportation Applications

Adsorptive storage of gases has been extensively studied over the past few decades. In general, overall gas density in a vessel packed with an adsorbent is higher than compressed gas up to about 35-50 bar beyond which the volume lost to the solid matrix overwhelms the advantage of liquid like densities in the pores. Hydraulic accumulators are commonly used in industry to store mechanical energy (work) to prevent intermittent operation of hydraulic pump; a gas contained in a vessel is compressed to very high pressures (200-300 bar) when there is no demand for power as the pump is ?idling.? Inclusion of a solid adsorbent in a hydraulic accumulator operating at such high pressures may first seem counter intuitive based on adsorptive gas storage studies mostly operating close to isothermal conditions. In contrast hydraulic accumulators, particularly for transportation applications, operate under adiabatic conditions making it possible to exploit adsorption phenomena in a different mode. In this presentation, we will explain the application and provide experimental data for several solid-gas pairs under realistic conditions up to 330 bar pressure.