Том 50, № 1 (2016)

The composition, thermal characteristics, and reactivity of coal from the new Tsaydam Nuur deposit in Mongolia in the processes of pyrolysis, thermal dissolution, and the production of sorbents were determined. It was established that the coal is low-rank brown coal of the lignite type, which is characterized by high activity in degradation reactions. In the process of thermal dissolution in tetralin at 450°C without the use of hydrogen, the yield of products soluble in chloroform was as high as 80%. The yield of primary tar upon semicoking was 13%. Activated carbons with a sorption capacity of 510 mg/g for iodine were obtained by the steam activation of carbonization products.

The thermal degradation of polycarbonate in coal-tar pitch was studied. The composition of the liquid products of pyrolysis was determined with the use of gas chromatography–mass spectrometry; the modified coal-tar pitch and the pyrolysis residue were studied by Fourier transform IR spectroscopy, elemental analysis, and the determination of softening point, concentrations of substances insoluble in toluene and quinoline, and yields of volatile substances. Because of chemical interaction with coal-tar pitch, the thermal degradation of polycarbonate in coal-tar pitch occurs at considerably lower temperatures than destruction without a solvent with high selectivity for phenol and p-isopropylphenol. Hydrogen transfer from the coal-tar pitch to the polycarbonate degradation products initiates polycondensation reactions in the coal-tar pitch.

It was established that the main factors responsible for the yield and specific surface area of porous carbon materials obtained by the chemical activation of the wood of birch are the nature of a modifying agent and the temperature of pyrolysis. The additional opening of the porous structure of the product of the chemical activation of wood occurs at the stage of its water treatment as a result of the removal of water-soluble compounds. The conditions of the carbonization of birch wood modified with H₃PO₄, KOH, and ZnCl₂ were chosen in order to provide the significant development of the porous structure of carbon materials. The porous carbon material with the highest specific surface area (more than 2560 m²/g) was obtained by the water washing of the product of the carbonization of birch wood modified H₃PO₄ at 400°C.

Various versions of the activation of a small fraction of anthracite from the Gorlovo Basin (Novosibirsk oblast) were studied: treatment in atmospheres of air, air–steam mixture (100–400°C), and carbon dioxide (500–800°C). The adsorptive capacity of the activated samples for decane vapor was measured with the aid of a TEOM 1500 PMA gravimetric analyzer. The qualitative composition of functional groups on the surface of the processed samples and their influence on the static and dynamic adsorptive capacity characteristics were determined by temperature-programmed oxidation (TPO) combined with mass-spectrometric analysis.

The kinetics and thermodynamics of the adsorption of diclofenac sodium from aqueous solutions of different concentrations at different temperatures on activated carbon obtained from coconut shell were studied. It was found that the adsorption of diclofenac sodium is described by a pseudo-first-order equation and the adsorption isotherm at its concentration to 750 mg/L in the initial solution is adequately described by the Langmuir equation. It was found that the adsorption of diclofenac sodium is an endothermic process.

The synthesis of modified solid resorcinol–formaldehyde resins based on resorcinol and a fraction of water-soluble shale alkylresorcinols (T_b > 270°C) was studied. Styrene was used as a modifier. Data on the quality of the target products depending on a molar ratio between the initial components were acquired.