Silica gel polymer composite desiccants for air conditioning systems

In this study, we developed a composite material to be used in air conditioning systems by combining silica gel with both polyacrylic acid and sodium polyacrylate. A test was performed to determine the optimal mixing ratio. The results showed that the optimal composite material was produced at a mixing ratio of 10:1:1. Under a closed environment of 25 °C and a relative humidity of 70%, the material exhibited a sorption capacity 41% higher than silica gel on its own. Subsequently, tests were performed to assess the dehumidification performance of the material at varying air velocities, regeneration temperatures, and inlet temperatures and humidity. After 15 min of usage under conditions of an inlet air temperature of 30 °C, a relative humidity of 70%, and a regeneration temperature of 40 °C, the performance of the composite material maintained 80% of its highest dehumidification performance. In addition, the average dehumidification amount reached 2.73 g/min, which was higher than silica gel packed bed at 2.46 g/min. Moreover, the airflow design of the composite material facilitated a pressure drop of 149 mmAq/m, which was 0.69 times lower than the silica gel packed bed system. Given the above results, application of the silica gel/polymer composite desiccant to air conditioning systems has great energy-saving potential.