Experimental investigation on adsorption and electro-osmosis regeneration of macroporous silica gel desiccant

In this paper, the possibility on electro-osmosis regeneration of macro-porous silica gel (MSG) desiccant has been investigated by testing the adsorption and electro-osmosis characteristic. The measured saturated moisture content of MSG is 113% in 300K temperature and 95% relative humidity. Its zeta potential is −10.92mV, which shows it has both good moisture absorption and electro-osmosis characteristic. The experiment bench is built to test the electro-osmosis regeneration performance on MSG by means of changing initial moisture content (105% and 110%) and applied voltage (40V, 50V and 60V) respectively. The D-value of moisture content between the bottom and upper half with voltage is much higher than that without voltage. For the 110% initial moisture content, there are many visible condensing water droplets on the inside surface of plastic film under the cathode. Based on experimental results, it can find electro-osmosis flow exists when the moisture content is lower than the saturated moisture content. Besides, the electro-osmosis regeneration is one potential method of MSG desiccant when it is applied in dehumidification.