A fixed-bed dehumidifying adsorption process with a phase-change material (PCM)-containing mesoporous silica SBA-15 was simulated, and various key parameters were varied to identify the optimal conditions for adsorption. The effectiveness of the PCM-containing SBA-15 adsorbent was evaluated based on the performance of the fixed-bed dehumidifying adsorption process, i.e. the amount of water adsorbed per unit time. To this end, the enthalpy of fusion and amount of the inserted PCM, along with the fluid temperature at the inlet of the adsorbent bed, were investigated as the key parameters governing the adsorption performance. Upon increasing both the enthalpy of fusion and the amount of the inserted PCM, the latent heat storage efficiency increased and the adsorption performance improved. Upon increasing the fluid temperature at the inlet, the adsorption performance increased drastically. On modeling the PCM-containing SBA-15 using the optimized conditions, the amount of adsorbed water was four times larger than that for the experimentally prepared PCM-containing SBA-15 in the initial stages of the process.