This paper is a theoretical comparison of the adsorptive natural gas dehydration in a single layer (3A Zeolite) bed with dehydration in a layered bed (silica-gel and 3A). The breakthrough time is the criterion chosen to carry out such a comparison. The results show as silica-gel length increases from 0 (5.5 m of 3A) to 3.7 m (1.8 m of 3A), the breakthrough time increases from 430 to 787 min; however, by adding more silica-gel to the bed, the bed would not be able to reach the standard output level of water concentration, and the breakthrough time drastically decreases.