Plasma activation on natural mordenite-clinoptilolite zeolite for water vapor adsorption enhancement

Water vapor is one of the crucial impurities in biogas which have to be removed for optimal performance. Utilization of natural zeolites as water vapor adsorbents is one of the proposed solutions. However, the small specific surface area of natural zeolite needs to be improved to increase the material adsorption capacity, one of the methods being physicochemical treatment. The consequences of the increased specific surface area by physicochemical treatment are the Si/Al ratio and hydrophobicity enhancement which counterbalance the benefits of the increased specific surface area. In this work, plasma activation treatment was applied successfully to increase the water adsorption capacity of natural zeolites after dealumination. The transformations of the chemical and physical properties of the material after plasma treatment are discussed. Our results point that the certain intrinsic properties on the zeolites in terms of Si/Al ratio and specific surface area are prerequisite to benefit from plasma activation. This work offers a new perspective on improving porous silica-based materials water adsorption characteristics which could lead to improved adsorbents in the future.