Volume 50, Nº 5 (2016)

The hydrogenation of a light fraction of primary coal tar was carried out in the presence of ß-FeOOH, Fe₂O₃, and Fe₃O₄ nanocatalysts in a temperature range from 298 to 1000 K. Phenols were removed by extraction with an alcoholic solution. The thermodynamic functions, such as heat capacity, entropy, enthalpy, and Gibbs energy, of the fraction of primary coal tar and a dephenolized fraction of the primary coal tar were calculated.

The results of the mathematical simulation of the thermal cracking (visbreaking) of tars are reported. The methods of plotting kinetic curves were proposed for the determination of visbreaking product concentrations in a reaction mixture under given conditions. The effectiveness of the algorithms of plotting kinetic curves on a computer with specified computational resources was compared.

The kinetics of adsorption of benzoyl peroxide from solutions in ethanol and n-hexane on coconut shell activated carbon was studied. It was found that the kinetics of adsorption of benzoyl peroxide is described by a pseudo-first-order rate equation. The adsorption isotherm of benzoyl peroxide at its equilibrium concentrations from 0.07 to 1.25 g/L in solution is adequately described by the Langmuir equation. It was established that, in a solution in ethyl alcohol, the degradation of benzoyl peroxide with the formation of ethyl benzoate occurred along with adsorption.

The results of studying the Sr, Sc, Mn, B, and P contents of coals from Eastern Siberia are represented. Data on the distribution of these elements in the coal fractions of the most enriched samples are given. The concentrations of As, F, Hg, Be, Pb, and Cd in coals and their distribution in the coal matter are considered. The behavior of some toxic elements on the heat treatment of coals was studied.

By changing the drying temperature and residence time, a series of different degree dewatered lignite samples were prepared in the fixed-bed reactor under inert gas and their adsorbing moisture behaviors were investigated under certain re-adsorption conditions. Using SEM, nitrogen adsorption and in-situ FTIR analysis methods, the structure changes of dewatered lignite were measured and associated with the drying and re-adsorption behaviors. The results show that the higher the drying temperature, the higher the drying efficiency and the more obvious structure change of dewatered lignite. But the moisture re-adsorption amount of dewatered lignite showed different changing trends. Under the drying condition of 140°C and 50min, the total moisture content of coal after moisture re-adsorption was the lowest. Most pores are mesoporous in lignite and the macropore structure collapsed into mesopore during drying. When the drying temperature was higher than 120°C, oxygen-containing functional groups began to decompose; with the increase of drying temperature and time, decomposition rate increased. The hydrophilic strengths of -OH and COOH groups are stronger than that of others.