The paper discusses the results of a numerical analysis of the properties and regimes of the adsorption air separation and oxygen concentration process with a purity of ∼ 40-60%, carried out in a ...2-adsorption vacuum-pressure plant with a granular zeolite adsorbent 13X with a productivity of 1.6 · 10-5 m3/s. Computational experiments were carried out using the developed mathematical model and the influence of temperature, pressure, reflux ratio, the duration of the adsorption and desorption stages, the harmonic fluctuations of the inlet pressure during the adsorption stage and the outlet pressure during the desorption stage on the kinetics, and the efficiency of the air separation process by the PSA method were investigated. It is established that the specially organized harmonic fluctuations of the inlet pressure at the stage of adsorption and outlet pressure during the desorption stage lead to an increase in the purity of product oxygen by 4% (vol.).
The paper discusses the numerical analysis results of the aerodynamic structure of a flow in the granular adsorbent layer in a pressure swing adsorption unit adsorber during atmospheric air ...separation and oxygen concentration. The computational experiments were carried out using one-dimensional and two-dimensional mathematical models to calculate the velocity field in the adsorbent bulk layer. While assessing the accuracy of calculating the aerodynamic structure of the gas flow in the adsorbent, it was found that the use of a two-dimensional mathematical model provides an increase in the accuracy of calculations by an average of ~1-2% compared with the one-dimensional model.
The paper discusses the results of numerical analysis of the properties and modes of the adsorption air separation process and oxygen concentration with purity of ∼90% carried out in a ...double-adsorber PSA unit with a 13X granular zeolite adsorbent with capacity of up to 2 l/min. Calculation experiments have been performed using the developed mathematical model and the influence of perturbations (temperature, composition and pressure of atmospheric air) on the dynamics of the process, the unit performance, the extraction degree and oxygen purity has been investigated. It has been established that the most effective control action is the pressure at the compressor outlet, the increase in which from 2 to 6×105 Pa leads to the increase in the extraction degree and oxygen concentration on average by ∼57% and ∼12 vol.% respectively.
—We fabricate and study experimentally a promising nanostructured composite adsorbent based on crystalline zeolite NaX. The adsorbent exhibits improved physical mechanical and adsorption properties ...and is intended for use in pressure swing adsorption systems. Fluoro derivatives of ethylene are found to be the most promising for creating the matrix of block-shaped composite adsorbent materials, since these ensure a mechanical strength and good adhesion between the matrix and incorporated adsorbent. We investigate the effects that the type, ratio of starting materials, and conditions of forming have on the adsorption and mechanical parameters of prepared composite adsorbents. The choice of materials for the adsorbent filler and polymer matrix used in synthesis of block-shaped sorption-active composite materials is substantiated. Studies of the adsorption parameters of prepared materials suggest that the film constituting the polymer (fluoroplastic) matrix, a base of our block-shaped adsorbents, is not continuous, which allows adsorbate molecules to penetrate the bulk of adsorbent. A comparative analysis establishes that the dynamic activity, as measured using water vapor, was 20 to 40% higher in our samples than in conventional commercial adsorbents of the NaX-V-1G type.
Physical experiments and mathematical modeling are used to study the kinetics of the reactions of carbon dioxide and water with potassium superoxide accompanied by oxygen release at various values of ...the temperature and humidity of the breathing gas mixture. The kinetics of the chemisorption is demonstrated to be limited by the rate of air regeneration in an airtight habitable facility. Experimental and analytical approaches are applied to determine the kinetic coefficients of the chemical reactions using the experimental data and a mathematical model of chemisorption kinetics. To perform the above chemical reactions, an original-design chemisorption reactor was developed, which contains plates with potassium superoxide nanocrystalline fixed on the fibers and pore surface of a fibrous polymer matrix. A mathematical model of chemical air regeneration is developed to calculate the guaranteed values of the parameters of the reactor and the protective effect time of the chemisorbent during which, at a given load, the reactor provides the appropriate concentrations of oxygen and carbon dioxide in the breathing gas mixture in an airtight habitable.
A task-oriented software and hardware system is designed for the operational selection of the instrumentation and process design options of pressure swing adsorption (PSA) processes. It will also ...control physical experiments to study the kinetics and dynamics of adsorption purification and separation of multicomponent gas mixtures and carry out mathematical modeling, optimization of operating cycles and optimal design of energyand resource-saving PSA units. The possibilities of a task-oriented system are demonstrated on the example of the adsorption separation of atmospheric air in order to obtain oxygen of high purity: 1) the time required to obtain, analyze and process experimental data (isotherms, kinetics and dynamics of adsorption, tuning the operating modes of PSA processes in the separation of gas mixtures, etc.), necessary for designing, identifying and analyzing the adequacy of mathematical models, were reduced by three times; 2) the time spent on mathematical modeling, the formulation and solution of the problems of optimization and optimal design of industrial PSA units in conditions of partial uncertainty of the initial data, as well as an experimental verification of the optimization results of these processes in a test unit , were reduced 8 times.
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