N. I. Fedorova

Processing low-grade oxidized coal to produce effective carbon sorbents

High-porosity sorbents may be produced by carbonization of low-grade oxidized coal in the presence of alkali.

Porous structure of adsorbents based on naturally oxidized Kuznets Basin coal

The specific surface, total pore volume, and volume of micropores and mesopores are determined for carbon sorbents obtained by the thermolysis of naturally oxidized Kuznets Basin coal, in the presence of potassium hydroxide (mass ratio of KOH and coal RKOH = 1.0 g/g). The porous characteristics of the adsorbents are calculated on the basis of the isotherms of low-temperature (77 K) nitrogen adsorption and desorption.

Thermal Dissolution of Oil Shale in Benzene with an Ethanol Additive under Supercritical Conditions

The results of the thermal dissolution of oil shale from some deposits in Russia in a benzene solvent under supercritical conditions in a semiflow system are reported. It was found that the addition of ethanol significantly increased the yield of liquid products due to the hydrogenating and alkylating properties of the alcohol.

Effect of the mechanoactivation treatment of coals mixed with an alkali on the properties of adsorbents obtained on their basis

The effect of the preliminary mechanoactivation crushing of raw coal in the presence of potassium hydroxide (alkali/coal ratio, 1.0 g/g) on the porous structure parameters of carbon sorbents synthesized on their basis. It was established that the carbon materials obtained based on the coal-alkali mixtures mechanically activated in an AGO-2 apparatus possessed a more developed porous structure and high adsorption activity.

Modification of Mongolian coals using a low-temperature oxygen plasma

The results of a study of the effect of the treatment of coals from the Khar Tarvagatai, Nuurst Khotgor, and Khushuut deposits of Mongolia in a low-temperature oxygen plasma are presented in this article.

Influence of alkali treatment on the properties of adsorbents based on naturally oxidized Kuznets Basin coal

The influence of alkali treatment on the properties of adsorbents derived from naturally oxidized Kuznets Basin coal is considered. The alkali used in the research is potassium hydroxide, when the mass ratio of KOH and coal is RKOH = 1.0 g/g. The pore structure is compared for two series of samples obtained by different methods: steeping of the coal with aqueous alkali solution and subsequent drying; and mechanical mixing with solid KOH.

Modification of coal tar in low-temperature oxygen plasma

Oxidative modification of coal tar by activated components of low-temperature plasma is considered. Such modification of tar is accompanied by polarization and polycondensation processes, with consequent increase in thermostability of the product.

Thermal dissolution of mechanically activated Barzas sapromyxite coal with benzene under supercritical conditions

The results of the thermal dissolution of Barzas sapromyxite coal in benzene under supercritical conditions in a flow system are reported. It was found that the mechanical pretreatment of coal under intense impact bending conditions resulted in an increase in the yield and a change in the group composition of the liquid products: in the high-temperature region of the process, the concentration of high-molecular-weight components (preasphaltenes, asphaltenes, and resins) increased.

Composition of the Products of the Supercritical Benzene Extraction of Combustible Shale from the Kashpirskoe Deposit

A change in the group composition of the liquid products of the supercritical fluid extraction of combustible shale under nonisothermal conditions at various solvent pressures was found. As the solvent pressure was increased, the yield of liquid products was found to increase mainly at the expense of high-molecular-weight substances (preasphaltenes and asphaltenes).

A Thermogravimetric Analysis Study of the Kuzbass Coals of Different Ranks

The coals of different ranks from the Kuznetsk Coal Basin were studied by thermogravimetric analysis in inert and oxidizing atmospheres. Correlations between thermal decomposition characteristics [maximum decomposition temperatures (Tmax, °C), maximum rates of decomposition (Vmax, %/min), and sample weight losses in different temperature ranges (Δm, %)] and proximate analysis [yields of volatile substances (Vdaf, %)] and petrographic analysis [vitrinite reflectance (Ro)] data and NMR-spectroscopic data [aromaticity factor ( fa)] as the characteristics of the degree of maturity of the test coals were established.