Measuring the Dehumidification Efficiency of Zeolite Nanostructured Membrane with TiO۲ Layer under Different Operating Conditions in Dehumidification of Light Gas Mixture

In this research, TiO۲ zeolite nanocomposite membranes were first synthesized in order to remove moisture from the gas. Then, field tests were performed on the characteristics of the membrane, by performing several tests of gas selectivity and permeability in measuring different parameters and comparing the relevant graphs of membrane performance, it was obtained that it showed the separation of water from gas. A route for crystal transformation to prepare TiO۲ at ۷۰-۱۱۰ °C under laboratory reflux conditions has been followed. The prepared titanium hydroxide gel crystallizes for ۵ to ۱۰ hours under reflux and stirring conditions. The formation of TiO۲ Nano crystallites is confirmed by X-ray diffraction (XRD) study. The anatase phase transforms into TiO۲ composite zeolite when crystallized at ۷۰۰°C for ۱۳ hours. Several experiments were also performed to verify both TiZ-V and NaA zeolites. Transmission Electron Microscopy (TEM) investigations showed that the average particle size for the TiZ-V phase was ۱۰ nm, while for NaA it was ۳۵ nm. In order to further investigate the performance of the membrane under different operating conditions, the efficiency was measured. The tests of changing the relative humidity of the feed have shown better performance of the membrane at relative humidity lower than ۸۰%, so that the selectivity of the membrane has increased under the condition of lower relative humidity of the feed. Next, the membrane was measured under different gas flow rates, which shows the stability of Esha under the tested high flows and the absence of a large drop in its selectivity. Also, in all these experiments, despite the increase in gas flow rate, the degree of superiority of the water component over the gas component in the percolation was evident to a high extent, which shows the high separation of water from gas even in the condition of high gas flow. Next, the membrane was measured under different flow rates of the gas flow, which shows the stability of the membrane under the tested high flows and the absence of a large drop in its selectivity. Also, in all these experiments, despite the increase in gas flow rate, the degree of superiority of the water component over the gas component in the percolation was evident to a high extent, which shows the high separation of water from gas even in the condition  of high gas flow. At the end, in order to further increase the efficiency of the membrane, The sweeper gas was added from inside the membrane. which increased the water concentration gradient and decreased the gas concentration gradient on the sides of the membrane wall and as a result increased the selectivity of the membrane to the best level of ۵۴۳.and also to check the stability of the membrane during operation, the test of increasing the operation time was performed. In the results, there was no decrease in relative humidity, and its selectivity had little change, which shows the stability of the membrane performance increasing dehumidification operation time.

کلیدواژه ها:

Dehumidification ، Natural gas ، Nano composite membrane ، TiO۲ zeolite