Organic-inorganic green porous hybrid composite for gas separation

Abstract

The increasing of Earth’s average temperature is one of the major problems that are caused by the emission of greenhouse gases (CO2, CH4). CO2 is also considered as impurity gas in the natural gas, which mostly containing methane (CH4). In this work, green porous hybrid composites were investigated for membrane separation application. The composites were prepared from non-toxic materials— polyvinyl alcohols (PVA) as a matrix, calcium carbonate (CaCO3) was incorporated as a filler, and boric acid as a cross-linking agent—by using the freeze-drying method. The amounts of PVA and CaCO3 were varied in order to obtain synergistic properties. Moreover, the densities of the composites were characterized by helium pycnometer. In addition, the N2 adsorption/desorption isotherm (BET) and scanning electron microscopy (SEM) were used for the morphological study. The CO2 and CH4 permeability were determined by completing a single gas permeation experiment under room temperature and the pressure difference across samples of 10 psi. The composite showed better CH4 permeability than that of CO2 due to smaller molecular kinetic diameter travelling in the 3-D network pathways.