Dehydration of gases is crucial in industry. Current dehydration methods have concerns about high energy consumption and environmental pollution. In this work, natural gas, an important energy source, was selected as a model gas to investigate dehydration using a cost-effective biosorbent in a pressure swing adsorption process. The biosorbent was developed from flax chives, a byproduct of the flax industry, and are representative of renewable cellulose materials. The morphology, surface functional groups, and thermal stability of the biosorbent were investigated by FE-SEM, XPS, and TGA. The biosorbent has higher water adsorption capacity (up to 0.9 g/g) and higher water selectivity compared to those of conventional adsorbents. Adsorption of the main component of natural gas, i.e., nonpolar methane, was negligible. In addition, the most significant operation factors and interaction among them were determined with regards to their effects on water adsorption capacity. The water adsorption equilibrium data was simulated well by the Redhead and Fowler-Guggenhein (F-G) models. On the basis of the Redhead modeling results, the surface area was determined for water adsorption. The F-G modeling results indicated the adsorbed water molecules on the surface of the biosorbent were attracted to one another; however, the interaction was weak. The length of mass transfer zone under various operating conditions was also calculated. Furthermore, the water-saturated biosorbent was regenerated at room temperature at a fast rate. The biosorbent was used for 70 adsorption-desorption cycles without deterioration. The TGA results showed that the biosorbent was stable at temperatures up to 200 degrees C even though the dehydration process effectively operated at room temperature in this work. The results indicate that the biosorbent or similar can be used in a pressure swing adsorption process for dehydration of natural gas and other nonpolar gases in industry.