الملخص الإنجليزي
One of the main concerns in the oil and gas industries is to reduce CO2 emission. Most of these industries try to reduce the CO2 emission into the atmosphere by separating it from other gas mixture using conventional techniques. However, these techniques require high capital and operational costs. In addition, polymeric and inorganic membranes are used as alternatives of the conventional methods. In fact, these membranes have low permeability as well as selectivity. Therefore, the aim of this research is to design and fabricate new membrane designs that have high permeability and high selectivity using cost-effective local materials. The preparation and characterization of new inorganic composite membranes and their supports were studied. The membrane support tubes of 23 mm in diameter and 365 mm in length were fabricated using the conventional slip casting method using inexpensive Omani ceramic natural materials like Hamra, White, Muscat, and mudar. X-Ray Diffraction (XRD) analysis technique was used in the selection of the proper material for this application. The results showed that Hamra and White clays have prominent characteristics such as high silica, high alumina, quartz and feldspars, which are suitable for the fabrication of ceramic supports with a high mechanical strength. The fabricated membrane supports tubes were further characterized using various analysis techniques such as XRD, Scanning Electron Microscopy (SEM), Thermal Gravimetric Analysis (TGA), Three Point Test and Surface Area; and Porosity Analyzer (ASAP) to find the phase identification, defects, percentage weight loss, mechanical strength and pore size distribution, respectively. From the obtained results, it was found that the Hamra support tubes were highly homogeneous and had a smooth inside surface. Wherein, these results proved that the Hamra Omani clay can successfully be used to manufacture durable membrane support tubes that can withstand high temperatures. The fau (Y-type) zeolite membrane was fabricated on the highly positively-charged (using Redifloc polymer) prioritized Hamra support surface from a prepared gel containing sodium hydroxide, sodium aluminate, water glass and deionized water, which was further subjected to microwave hydrothermal treatment (replicated). The presence of zeolite layer was investigated using XRD, SEM, and Energy Dispersive X-ray Spectroscopy (EDX) analyzing technique. From morphological and crystalline viewpoint, the NaY zeolite membrane was successfully fabricated with a thickness ranging from 6-10 um. The CO2 separation properties of the fabricated ceramic support and fau-zeolite membrane were studied by single and binary gas permeation of six different inlet CO2/N2 gas mixture ratios. The separation results showed that the membrane exhibits a high separation of N2 compared to CO2 and their permeances increase with pressure drop. At a permeation temperature of 18°C and a pressure drop ranging from 20 to 35 kPa, an average calculated permeability for the Hamra support tube was 3.48x10 mol/m' sec Pa for CO2 and 3.73x102 mol/m2 sec Pa for N2 and a preferred permeance for membrane for CO2 and N2 are 2.24x102 mol/m2 sec Pa and 2.49x102 mol/m- sec Pa, respectively. The high permeance results from low-cost inorganic composite membranes are promising and require further investigation.
