A. N. Ryzhov

Modeling of heats of combustion and shale oil yields in oil shale semicoking

15 Oil shale is a promising source for power generation and chemical production. Information on the proper ties and chemical composition of oil shale mined from various deposits has been summarized in [1]. Among the oil shale properties, heats of combustion and shale oil yields in oil shale semicoking as a function of com position, different in different deposits, are of great practical interest. In this work, we made an attempt to model these properties as a function of chemical com position of oil shale. In searching for quantitative structure–property relationships (QSPR [2–4]) for organic compounds, topological indices are commonly used [5, 6]. How ever, in our case, the structures of all compounds con stituting oil shale are unknown; therefore, only the elemental composition of oil shale was used as descriptors. Only the contents of C, H, N, S, and organic substances reported in [1] were taken into account. Table 1 presents the characteristics of oil shale samples from different deposits, and Table 2 summa rizes information on their chemical composition [1, pp. 140–143]. It is worth noting that data in [1] are expressed in different units: for S, in percentage of the CHEMISTRY

The necessary and sufficient conditions for chemical equilibrium

The article concerns a widely accepted but incorrect concept of conditions for chemical equilibrium. The authors present a mathematically rigorous derivation of the necessary and sufficient conditions for chemical equilibrium of systems of arbitrary complexity.

Time dependence of the yields of hydrocarbon fractions in visbreaking of heavy oil residues at various temperatures and chemical compositions of feedstock

The yields of gasoline, light and vacuum gas oils, and gas fraction in thermal cracking of heavy oil residues (visbreaking) were mathematically modeled. Calculation formulas with high statistical characteristics were obtained.

Mathematical simulation of the kinetics of visbreaking of tars

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.

Computer-aided modeling of physicochemical characteristics of various energy sources

The authors’ review presents original methodical development works and integrates the research on the modeling of processes and estimation of physicochemical characteristics of natural (hydrocarbons) and chemical (energetic materials) energy sources. A fundamentally new method of energy generation based on transition of excited helium atoms to the superstable state in superstrong magnetic fields is described. A hypothetical possibility for these states to exist was predicted by one of the authors and confirmed by calculations.

Dependence of the yields of hydrocarbons on the conditions of oil shale thermal treatment

Models of the low-molecular-weight hydrocarbon contents of the gas obtained as a result of the steam treatment of oil shale were obtained in this study. Formulas for their prediction are proposed.

Simulation of the dependence of gas composition on the conditions of the thermal treatment of oil shale

Empirical formulas for calculating the concentrations of substances such as hydrogen and carbon(II) oxide and also the smallest possible concentration of carbon(IV) oxide in gas prepared by the steam treatment of oil shale were obtained. It was found that, as the temperature was increased above 600°C, the gasification of shale occurred under thermodynamic equilibrium conditions, and catalysts based on NiO made it possible to reach maximum yields of hydrogen at lower temperatures.

Dependence of the hydrogen content of oil-shale gas on the oil-shale gasification conditions

An important challenge of solid fuel chemistry is to theoretically predict the chemical composition of the gas produced by oil shale gasification, or oil shale gas. In this work, we studied the dependence of the hydro gen content Y of oil shale gas on temperature t and steam mass flow rate w in the gasification of the oil shale mined at the Kashpirskoe and Leningradskoe deposits (Table 1). In all the cases, 10 g oil shale sam ples were tested. The experimental procedure was described previously [7].