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Modification of coals prepared from wood wastes

“…Because pH of the aqueous extract of coal prepared from TL was about 2.5 [2,3,5], fur further tests the initial sample was washed with hot distilled water to рН ~7 of the aqueous extract, which was followed by special liquid-phase oxidation with 25% nitric acid on a boiling water bath, aimed to impart to the coal the properties of effective cation exchangers [10], and by modifi cation of the carbon surface with alkali metal ions of various sizes.…”

“…Sorption of alkali metal ions on the carbon material was performed at рН 10-10.5 [5,6] attained in 4 h. Thermal analysis was performed with a Q-l500 derivatograph (MOM, Hungary). The samples were heated in air at a rate of 5 deg min -1 .…”

“…Previously [5,6], using modern analytical methods, we determined the main structural parameters of carbon sorbents based on TL, found their specifi c surface area (S sp ~2000 m 2 g -1 ) and total volume of sorption pores (W s ~1.4 cm 3 g -1 ), revealed the prevalence of micropores, and calculated their radii (r ~20 Å). We examined the ability of the microporous sorbents based on TL to sorb certain toxic metal ions (Pb 2+ , Cd 2+ , Сu 2+ ) and NH 4 + ions.…”

“…For example, technical lignin (TL), which is a large-tonnage waste from chemical processing of wood, is a valuable raw material for the synthesis of carbon adsorbents, which are prepared by steam-and-gas activation after preliminary carbonization of the raw material [1][2][3][4][5][6]. The adsorbents thus prepared have a mixed pore structure with the prevalence of micropores and exhibit high sorption properties, making them promising in installations for methane accumulation [7][8][9].…”

“…Among alternative kinds of fuel, particular place is occupied by methane as the most readily available, the cheapest, and environmentally relatively clean fuel. Adsorption systems for methane storage [3][4][5]8] are characterized by lower fi lling and storage pressure and higher level of fi re and explosion safety, because the major fraction of fuel is stored in the adsorbed state.…”