Production and Application the Sorption Ability of Carbon Nanomaterials from Brown Coals for Hydrogen Storage
Kazankapova M.K. Yermagambet B.T. Kapsalyamov B.A. Dauletzhanova Z.T. Beldeubayev A. Radko T. Cygan A. Stelmach S. Malgazhdarova A.B. Kozhamuratova U.M. Mendaliyev G.K. Akshekina A.S.
September 2025Engineered Science Publisher
ES Energy and Environment
2025#29
Porous carbon-based sorbents were synthesized from lignite coals of the Maikuben basin, specifically the Shoptykol deposit. The physicochemical characteristics of the produced materials were systematically investigated. A detailed material balance was calculated for both the carbonization and activation processes. Scanning Electron Microscopy (SEM) analysis revealed the formation of numerous carbon nanotubes (CNTs) with diameters ranging from approximately 69.5 to 200.2 nm on the surface of the sample prepared with a carbon-to-KOH ratio of 1:1. These structures are likely generated through gas-phase deposition of carbon on metal-active sites (e.g., Ti or Fe), which serve as catalysts, thereby enhancing the specific surface area. The pore sizes ranged from approximately 44.5 to 451.0 nm. Following thermochemical activation, the Brunauer– Emmett–Teller (BET) specific surface area increased markedly from 3.222 m²/g in raw coal to 926.67 m²/g and 1145.08 m²/g for samples treated with KOH at ratios of 1:0.5 and 1:1, respectively—corresponding to increases of 287-and 355-fold. The coexistence of a type I isotherm and a type IV hysteresis loop in a single sample indicates a hybrid pore architecture composed of both micropores and mesopores. This structural feature enables effective adsorption of a wide range of gases, including hydrogen, across various pressure regimes, positioning the material as a promising candidate for hydrogen storage and transport applications. The hydrogen adsorption dynamics of the porous carbon sorbents were evaluated at 77, 273, and 298 K. Results demonstrate that KOH-impregnated samples with mass ratios of 1:0.5 and 1:1 achieved high hydrogen-accessible surface areas of 1165.97 m²/g and 1184.29 m²/g, respectively. However, the optimal impregnation ratio was found to be 1:0.5, as further increases in alkali content yielded only marginal improvements in hydrogen uptake—1.48% for 1:0.5 and 1.49% for 1:1. Temperature and surface-area-dependent adsorption behaviors were established, providing valuable insights into adsorption kinetics, capacity, and efficiency. These findings offer practical implications for the design and optimization of hydrogen storage systems in both industrial and research settings.
Activation , Adsorbent , Alkali , Brown coal , Carbonization , Hydrogen , Impergation , Porous carbon nanomaterials , Storage
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Institute of Coal Chemistry and Technology LLP, Astana, 010000, Kazakhstan
Kazakh University of Technology and Business named after K. Kulazhanov, Astana, 010000, Kazakhstan
L.N. Gumilyov Eurasian National University, Astana, 010000, Kazakhstan
ITPE – Institute Of Technology and Fuel Processing Technology, Zabrze, 41 803, Poland
Institute of Coal Chemistry and Technology LLP
Kazakh University of Technology and Business named after K. Kulazhanov
L.N. Gumilyov Eurasian National University
ITPE – Institute Of Technology and Fuel Processing Technology
10 лет помогаем публиковать статьи Международный издатель
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