Chemically Treated Rice Husk Blends as Green Desiccant Materials for Industrial Application

The use of rice husks (RHs), treated RHs, and blends thereof as desiccants was studied. Bare RHs, treated RHs, and blends were characterized, and their water absorbances compared. Acid-treated RHs showed better moisture absorbance than alkali-treated RHs and hence were used to prepare blends. Moisture absorption of RH materials and silica gel were compared. Blends with a higher content of acid-treated RHs showed higher water and moisture absorbency. The moisture absorbency of the blends was enhanced, and they exceeded the silica-gel limit at 48 h of exposure time. The higher absorbency in blends with higher contents of acid-treated RHs is likely due to higher porosity and improved adhesion properties owing to surface OH groups. Moreover, RH blends require shorter regeneration times than silica gel.