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 shives, 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 °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.