| dc.description.abstract | Light hydrocarbon gases such as methane, ethane, propane, ethylene, and propene are commonly used in industrial manufacturing and are important for the chemical industry. For example, methane is the most common component of natural gas, and ethane and propane are very basic raw materials that can be used to produce acetic acid, rubber, and plastics. Ethylene and propylene can be synthesize into polymers. Traditionally, gas separation is mainly done by cryogenic distillation, which should be operated at high pressure and low temperature, and requires massive amounts of energy. Recently, many research studies found that metal–organic frameworks (MOFs) are potential gas storage and separation materials because of their high surface area, nontoxic properties, and large gas storage capacity. UiO-66, a relatively new type of MOF, and its modified materials have attracted increased attention, because they can be easily synthesized and are thermally and chemically stable. Therefore, UiO-66 and its modified materials are considered ideal candidates for gas storage and separation.
In this work, we studied UiO-66 and modified derivatives with functionalized organic linkers, such as –NO2, –NH2, –Br and –(CH3)2 to simulate mixed light hydrocarbons adsorption and separation, such as C2H6/CH4, C3H8/C2H6, C2H6/C2H4, and C3H8/C3H6 pairs and respective pure composition adsorption. Cambridge Crystallographic Data Centre (CCDC) database was used to find initial experimentally determined MOF structures, while grand canonical Monte Carlo (GCMC) calculations were performed to obtain adsorption isotherm and adsorption site energy distribution data. A major finding of this work, is the different behavior of the materials at low and high pressures. Modified UiO-66 exhibits higher selectivity than the unmodified structure at low pressure, and at high pressure UiO-66 has good selectivity and large gas storage. This research provides discussion aimed at improving our understanding of gas adsorption behavior in zirconium-based MOFs and related functionalized forms.
| en_US |