Preparation And Performance Analysis Of Composite Desiccant Material

Indoor humidity control plays an important role in many aspects of the daily life. It is also an essential factor for storage and manufacture processes. In this study, the technology of membrane dehumidification and solid desiccant are adopted and a novel desiccant material is proposed for air dehumidification. The base material of fiber glass paper or silica gel is modified by adding PAAS(sodium polyacrylate) or PVA(polyvinyl alcohol) to prepare the composite desiccant. Moisture adsorption tests are carried out and the effect of content ratio of PAAS, PVA or other additives on moisture adsorption is studied. Results show that it is good to modify the base material by PAAS / PVA. The silica gel modified by PVA and lithium chloride demonstrates optimum performance. Moreover, the composite desiccant is assembled to a honeycomb type desiccant rotor and tested. The moisture adsorption capacity of this desiccant rotor is 0.495 g/g at the air relative humidity of 90%, which is much higher than 0.187 g/g of the commercial rotor product. Further, a test rig is set up and the performance of the desiccant rotor on various processed humidity and regeneration temperature is tested. Results show that desiccant rotor performs better as the air humidity and regeneration temperature are increased. DCOP is a performance index to the balance between dehumidification process and regeneration process. As regeneration temperature is 60°C and air humidity is higher than 80%, DCOP is in the range of 0.8 ~ 1, which indicated that the rotor performs well.