Ашық рұқсат
Рұқсат берілді
Тек жазылушылар үшін
Том 15, № 4 (2025)
Membrane Gas Separation of CO-containing Mixtures: Current State and Prospects
Аннотация
The review presents the current state of research in the field of membrane separation of gas mixtures containing carbon monoxide (CO). The main advantages of the membrane method in comparison with traditional approaches such as cryogenic distillation and adsorption are considered, as well as its key limitations. The literature data on the transport properties and selectivity of various classes of membrane materials for the separation of practically important mixtures of CO/H₂, CO/CH₄, CO/CO₂, CO/N₂ and CO/O₂ are summarized. The main research directions, including the use of polymer, carbon, inorganic membranes, as well as membranes based on ionic liquids, are considered. The main difficulties limiting the industrial application of membrane technologies have also been identified, and promising directions for their development have been outlined in order to increase the efficiency of CO-containing mixtures separation processes.
Membranes and Membrane Technologies. 2025;15(4):223-245
223-245
The Impact of Alkyl Substituents in the Polycation Structure: Physicochemical and Gas Separation Properties of Poly(Ionic Liquids) Based on Butylimidazolium and Triethylammonium
Аннотация
The influence of the polycation structure on the physicochemical and gas separation properties of poly(ionic liquids) was investigated while maintaining the same set of counter anions (BF 4 – , PF 6 – , Tf 2 N – ). It was found that increasing the alkyl chain length and replacing the imidazolium cation with a triethylammonium one lead to changes in interionic interactions, a decrease in density and surface polarity, and an increase in the free volume of the polymer matrix. These structural modifications affect the gas transport properties of the membranes: samples containing the Tf 2 N – anion exhibit the highest CO 2 permeability values while maintaining high selectivity for CO 2 /CH 4 and CO 2 /N 2 gas pairs. The results demonstrate that a combined variation of the alkyl substituent in the polycation and the weakly coordinating anion allows for targeted tuning of the structure and gas separation performance of poly(ionic liquid)-based membranes, making them promising materials for CO 2 capture and separation applications.
Membranes and Membrane Technologies. 2025;15(4):246-256
246-256
Transfer Features of Succinic Acid through Heterogeneous and Homogeneous Anion Exchange Membranes
Аннотация
In this work , the transfer of succinic acid through anion -exchange membranes of various types was studied at different pH values in a wide range of current densities. The results of the study showed that at pH = 8.0, when all succinic acid is in solution in a double- charged form, the mechanism of its transfer does not differ from the transfer of ions of strong electrolytes. At pH = 4.8, when all three forms of succinic acid (C 4 H 6 O 4 , C 4 H 5 O 4 - and C 4 H 4 O 4 2- ) are present in the solution , its transfer significantly depends on the type of membranes. The voltage characteristics of the membranes differ from the “classical” type of VAC measured in solutions of stro ng electrolytes. It has been found that at pH = 2.0 , succinic acid transfer increases with increasing electric current density, despite the fact that it is in molecular form.
Membranes and Membrane Technologies. 2025;15(4):257-268
257-268
Possibility of Using the Both-Sided Irradiated Track-Etched Membrane with 0.2 Micron Pores for High-Color Natural Water Treating
Аннотация
The possibility of using a both-sided irradiated track-etched membrane of increased strength (20 µm thick) with pores of 0.2 µm in an individual water treatment module for purifying natural high-color water containing dissolved and highly dispersed humic impurities is substantiated. The methods of dynamic light scattering, spectrophotometry and spectroturbidimetry were used to analyze the dispersed state of humic compounds in the original natural water of high color, and also when introducing different doses of coagulant into it. The results of filtration of these waters in a module with a both-sided irradiated track-etched membrane (with pores of 0.2 µm) a nd a drainage of three-dimensional weave nylon were experimentally obtained and explained. Filtration of the original water resulted in rapid pore clogging (pore adsorption). When introducing a minimum dose of coagulant, effective water purification occurred due to the interaction of micellar and highly dispersed humic compounds with colloids of aluminum aquahydroxocomplex and the formation of aggregates on the fibers of the drainage and partially on the surface of the track-etched membrane, which was confirmed by microscopic analysis. A filtration regime for high-color natural water with backwash has been worked out. It has been shown that the track-etched membrane of increased strength can withstand at least seven process cycles with constant productivity and a high degree of water purification.
Membranes and Membrane Technologies. 2025;15(4):269-282
269-282