Ali Khosravi
Water vapor is one of the most important impurities in gases, which leads to various problems. One of these problems is the condensation of water vapor and the formation of liquid hydrates, and it causes an increase in pressure drop, causes corrosion, total or partial blockage in transmission lines and equipment, decreases the heating value of gas, and occupies useful space in the system. In this research, in order to dehumidify the gas, the membrane contactor of polysulfone hollow fibers (PSF) modified by silicone coating (PDMS) and different percentages of hydrophobic silica nanoparticles (SiO2) Used. Diethylene glycol (DEG) absorbent liquid has also been used as a moisture absorbent. Parameters such as the effect of modifying the contact surface of the membrane on the surface properties, the effect of increasing the velocity of the gas and liquid phases on the water vapor absorption flux, and comparing the performance of the pure and modified membrane in the long term were studied. According to the obtained results, modification of the membrane surface improved the contact angle from 72̊ to 154˚. Also, the liquid inlet pressure was increased by 10 bar. By examining the effect of increasing the liquid speed on the water vapor absorption flux, it was observed that the liquid speed does not have much effect on the water vapor absorption flux. The obtained result shows that there is no mass transfer resistance in the liquid phase. On the other hand, increasing the velocity of the gas phase has shown a significant effect on the water vapor absorption flux and efficiency. In the long-term test, initially, the pure membrane reported a higher water vapor absorption flux due to the effective porosity of the higher surface. But with the passage of time, its efficiency decreased and on the 13th day, it was completely removed from the system. However, the membrane modified by silicone coating (PDMS) and hydrophobic silica nanoparticle have a lower effective poro