New methods for determining the volumetric flow rate in the column and the retention time of the unretained substance in gas chromatography

New methods for calculating the mean volumetric flow rate of the carrier gas and the retention time of the unretained substance in the column under conditions of gas chromatography were proposed. The methods are based on preliminary isothermal calibrations of the flow rate and holdup time for a packed column. A theoretical substantiation of the methods was given. Procedures of plotting calibration dependences for determining the indicated quantities at a desired temperature were described. The calculation results were compared to experimental data obtained by traditional methods. It was demonstrated that the use of calculation methods substantially simplifies the determination of the specific retention volume over a wide temperature range.     

Kantorovich’s Fixed Point Theorem and Coincidence Point Theorems for Mappings in Vector Metric Spaces

Set-Valued and Variational Analysis - The fixed points and coincidence points of mappings of v-metric spaces, i.e., sets on which a vector metric is defined, are investigated. The values of such a...     

Analysis of Mixtures Containing Unknown Components by Gas Chromatography: Determination of Molecular Mass

New methods are proposed for the gas-chromatographic determination of the molecular masses of unknown components in complex mixtures within one cycle of analysis. The methods are based on the use of complex chromatographic data in the form of linear retention indices of compounds for a column with a nonpolar stationary phase and sensitivity indices of a thermal conductivity detector and a flame ionization detector.     

Comparison of Various Options for Designing the Direct Oxidation of Methane to Methanol

Russian Journal of Applied Chemistry - Various options for designing the direct oxidation of natural gas to methanol are considered: flow-through, with a distributed supply of the oxidizer along...     

Experimental study and macrokinetic simulation of the partial gas-phase oxidation of propane

The effect of process parameters on the propane conversion and the composition of oxidation products, particularly the methanol to carbon monoxide ratio, has been studied. A numerical study of the laws governing the partial oxidation of propane has been conducted in terms of a model that approximately describes the macrokinetics of the partial gas-phase oxidation of hydrocarbons in a flow tubular reactor.     

Activation of the radical-promoted conversion of light hydrocarbons by the products of a rich methane flame

The feasibility of the production of ethylene and heavier olefins by introducing methane into the products of a rich methane flame is experimentally demonstrated. Such a process is promising for the direct production of ethylene, propylene, and heavier olefins directly from methane, the main component of natural gas.     

Recent Results on Fast Flow Gas-Phase Partial Oxidation of Lower Alkanes

Recent experimental results and kinetic modeling of fast flow gas-phase oxidation of methane and other lower alkanes to methanol and other oxygenates are discussed,alongside with prospects and possible areas for applications of the processes.     

Effects of the gas medium and heterogeneous factors on the gas-phase oxidative cracking of ethane

The effects of the gas medium and heterogeneous factors on the gas-phase oxidative cracking of dilute ethane mixtures at atmospheric pressure, temperatures of up to 750°C, and an initial reactant ratio of [C₂H₆]₀/[O₂]₀ = 2 have been investigated.     

Kinetic features and technological perspectives of the partial oxidation of light alkanes

The characteristic features of the kinetics of the partial oxidation of light alkanes, the main component of natural gases, at moderate temperatures (300 < T < 1200°C) and the prospects for new technological processes on the basis of these reactions are discussed.