Vol 50, No 1 (2016)

A catalytic heater design was proposed for an external combustion engine. This design is based on the partial oxidation or autothermal conversion of hydrocarbon fuel to syngas and its further oxidation with heat generation in a radial catalytic reactor integrated with a tubular heat exchanger. The theoretical analysis of operational regimes for a catalytic heater with a thermal power of 25–50 kW was performed with regard to the distribution of gas and the mathematical modeling of processes in a catalyst bed integrated with a heat exchanger, and some estimates were given for the performance of an external combustion engine. The conditions providing a uniform distribution of gas along the length of a radial reactor with suction of a reaction mixture into the catalyst bed were determined. A design of catalytic heating system elements was developed, and some layout solutions that provide a rational mutual arrangement of system components were created.

In most multi-component systems, the predominant non-ideality occurs which lead to the occurrence of an azeotrope. The ternary systems classification and study are summarized in first part of this review. The next part covers thermodynamic knowledge of residue curve maps, univolatility and unidistribution curves. A feasibility criterion based on thermodynamic properties of ternary diagram is presented, they are considered as powerful tool for the flow-sheet development and conceptual design. Separation of azeotropic mixtures and close boiling mixtures require non-conventional distillation processes, among which the leading processes are pressure-swing distillation if the composition of the azeotrope changes significantly with pressure, azeotropic distillation, extractive distillation, reactive distillation, and salt-effect distillation. The final section provides an overview of concepts, history, and recent strategies in these non-conventional distillations.

An approach to modernizing aluminum production technology based on an intense beam of accelerated electrons representing a principally new energy carrier for this production branch is proposed. Physicochemical principles for creating a new technology and reasons based on interest in modernization are discussed. Some peculiarities of the effect of accelerated electrons on the initiation of chemical reactions in liquid and solid materials used in aluminum production industry are considered. The energy balance of the classic thermal aluminum production technology is analyzed, and conclusions about engineering, economics, and the environmental advisability of developing an approach to modernizing aluminum production technology with a new energy carrier, an accelerated electron beam, is formulated based on theoretical and experimental data. The parameters of some electron accelerators that satisfy the conditions needed to develop the proposed technology even now are given.

The goal of this work is to present a class of state observer in order to infer unavailable concentrations in a sulfate-reducing bioreactor containing an anoxic culture of Desulfovibrio alaskensis 6SR from the measurements of the sulfate concentration. The methodology is applied to the corresponding sulfate-reducing model considering modeling uncertainties. The proposed observer design presents a proportional term plus a sigmoid function structure. The model’s observability was locally analyzed by the observability matrix test, concluding that the sulfate-reducing bioreactor is detectable. A sketch of proof of the observer’s convergence is depicted in order to show the asymptotic convergence characteristics. Numerical experiments provide an overview about the superior performance of the proposed observer methodology compared to a sliding-mode and high order sliding mode observers.

The extraction of zinc(II) ions with DX-510A β-diketone from sulfate and ammonia–sulfate solutions is reported. The effects of the aqueous phase pH and extracting agent concentration on the process have been investigated. The highest zinc(II) ion recovery is observed at pH 8.5–9.0. The time to extraction equilibrium is no longer than 30 s; in back extraction, it does not exceed 70 s. The extraction of zinc(II) ions is accompanied by the formation of an ammonia-containing organic complex. A chemical formula is suggested for this compound.

A theoretical model of the industrial method of the compensation of thermal energy consumed on the endothermic dehydrogenation on a fixed catalyst layer has been described. The combination of endothermic dehydrogenation with interlayer (intermediate) oxidation of produced hydrogen has been considered based on the example of the dehydrogenation of isoamylenes to isoprene. The calculated results are compared with laboratory tests.

The piecewise linear character of the load–strain dependences of a granular medium consisting of fragile particles was experimentally established and theoretically substantiated. A model for grinding a granular medium in a conic or roller inertia mill was developed taking into consideration the features of its deformation behavior.

In this paper, synergistic principles and the mathematical apparatus of the catastrophe theory have been used to simulate the processes of the destruction of polymer materials. In polymer materials, the accumulation of damages at different scale levels is proposed to consider through a synergistic effect, which has been calculated here using the mathematical apparatus of the catastrophe theory. It has been shown that the transition of the system from one stable state to another occurs through the bifurcation point, the value of which is determined using a fold-type catastrophe.