A3606LS – Improved-Lumped Formulations for Heat and Mass Transfer in Adsorbed Gas Storage

The purpose of this study is to provide an improved-lumped formulation for simulating adsorbed gas storage operations. The approach is shown to reduce the original spatial-dependent PDEs to two time-dependent ODEs, as similar to the ones obtained using classical lumped-system analyses (CLSA), the main differences being an additional equation that is required for calculating the reservoir wall temperature, and modified Biot numbers. The average reservoir temperature is then calculated with the improved lumped formulation, using two different approximation schemes, and compared with the results of the CLSA and the one-dimensional formulation that originated all approximate lumped models. A case of slow discharge with negligible wall heat capacity is analyzed, and the results show that, even for a large Biot number, one of the proposed approximation schemes can reproduce the 1D results with reasonable accuracy, while the CLSA yields very different results.