scholarly journals Chemical Plant Utility – Nitrogen System Design

2021 ◽  
Vol 9 (11) ◽  
pp. 1560-1567
Author(s):  
Prasad J. Parulekar
Keyword(s):  
High Purity ◽  
Pressure Swing Adsorption ◽  
Membrane Separation ◽  
Hollow Fibre ◽  
Air Separation ◽  
Separation Technique ◽  
Flow Diagram ◽  
Efficient Technology ◽  
Atmospheric Air ◽  
Pressure Swing

Abstract: The study is been conducted to understand the different techniques to separate nitrogen from atmospheric air. Separation of nitrogen takes place by following techniques: Cryogenic air separation, Pressure swing adsorption and Membrane separation technique. Cryogenic air separation operates at a very low temperature, which uses the principle of rectification to separate nitrogen at a very high purity (99.999%). Pressure swing adsorption rely on the fact that higher the pressure, more the gas is adsorbed which results in high purity (95-99.99%) of nitrogen. Membrane separation technology is the process that uses hollow fibre membranes to separate the constituent gases in air, which gives the purity in the range of 93%-99.5%. After the comparative study, it is understood that membrane separation technique is the most efficient technology based on the cost, purity, flexibility in terms of adjusting the purity, maintenance, availability; it operates without heating and therefore uses less energy than conventional thermal separation processes. Different step designs of membrane separation techniques are discussed. A Process Flow Diagram and Piping Instrumentation Diagram is been added for single step membrane separation technique. Keywords: Atmospheric air, nitrogen, Cryogenic air separation, Pressure swing adsorption, Membrane separation technique.

scholarly journals Advances in Pressure Swing Adsorption for Gas Separation

2012 ◽  
Vol 2012 ◽  
pp. 1-13 ◽  
Author(s):  
Carlos A. Grande
Keyword(s):  
Gas Separation ◽  
Continuous Improvement ◽  
Pressure Swing Adsorption ◽  
Process Engineering ◽  
Air Separation ◽  
Separation Technique ◽  
Hydrogen Purification ◽  
Pressure Swing

Pressure swing adsorption (PSA) is a well-established gas separation technique in air separation, gas drying, and hydrogen purification separation. Recently, PSA technology has been applied in other areas like methane purification from natural and biogas and has a tremendous potential to expand its utilization. It is known that the adsorbent material employed in a PSA process is extremely important in defining its properties, but it has also been demonstrated that process engineering can improve the performance of PSA units significantly. This paper aims to provide an overview of the fundamentals of PSA process while focusing specifically on different innovative engineering approaches that contributed to continuous improvement of PSA performance.

scholarly journals Optimization and analysis of pressure swing adsorption process for oxygen production from air under uncertainty

2020 ◽  
Vol 26 (1) ◽  
pp. 89-104 ◽  
Author(s):  
Evgeny Akulinin ◽  
Oleg Golubyatnikov ◽  
Dmitry Dvoretsky ◽  
Stanislav Dvoretsky
Keyword(s):  
Pressure Swing Adsorption ◽  
Gas Flow ◽  
Optimization Problem ◽  
Air Separation ◽  
Interval Uncertainty ◽  
Problem Solution ◽  
Resource Saving ◽  
Heat And Mass Exchange ◽  
Atmospheric Air ◽  
Pressure Swing

Pressure swing adsorption (PSA) units are widely used for atmospheric air separation and oxygen concentration. However, the efficiency of such installations is reduced due to accidental changes in the characteristics of the atmospheric air to be separated. The article formulates and solves the problem of optimizing the regimes of operation of PSA units with zeolite adsorbent 13X, according to the criterion of oxygen recovery rate in the conditions of interval uncertainty of composition, temperature and pressure of atmospheric air. The optimization problem also takes into account the fulfillment of the requirements on purity of oxygen, productivity of the unit and resource saving of granulated adsorbent from granule abrasion. It is proposed to provide adsorbent saving by limiting the speed of incoming flow in the frontal layer of the adsorbent by means of "soft" stepwise change of the degree of opening of control inlet and outlet valves of the unit. The problem (including the search for time change programs for the degree of opening of control valves) was solved with the use of the developed mathematical model of cyclic heat- and mass exchange processes of adsorption-desorption in a PSA unit and a heuristic iterative algorithm. The comparative analysis of the results of the optimization problem solution, with and without taking into account the constraint on the gas flow velocity in the frontal layer of the adsorbent, is carried out. The influence of the specified requirements for the performance of the PSA unit and the purity of oxygen on the degree of its recovery has been studied.

scholarly journals Single-Stage Vacuum Pressure Swing Adsorption for Producing High-Purity Oxygen from Air

2015 ◽  
Vol 54 (39) ◽  
pp. 9591-9604 ◽  
Author(s):  
Daniel Ferreira ◽  
Patrick Bárcia ◽  
Roger D. Whitley ◽  
Adélio Mendes
Keyword(s):  
High Purity ◽  
Pressure Swing Adsorption ◽  
Single Stage ◽  
Vacuum Pressure ◽  
Vacuum Pressure Swing Adsorption ◽  
Pressure Swing

High-purity Nitrogen by pressure-swing adsorption

AIChE Journal ◽  
1997 ◽  
Vol 43 (2) ◽  
pp. 419-424 ◽  
Author(s):  
Arthur I. Shirley ◽  
Norberto O. Lemcoff
Keyword(s):  
High Purity ◽  
Pressure Swing Adsorption ◽  
Pressure Swing

Numerical Analysis and Optimization of Oxygen Separation from Air via Pressure Swing Adsorption

2011 ◽  
Vol 6 (1) ◽  
Author(s):  
Seyyed M. Ghoreishi ◽  
Z. Hoseini Dastgerdi ◽  
Ali A Dadkhah
Keyword(s):  
Time Constant ◽  
Pressure Swing Adsorption ◽  
Separation Efficiency ◽  
Optimization Procedure ◽  
Air Separation ◽  
Oxygen Separation ◽  
13X Zeolite ◽  
Oxygen Generation ◽  
Pressure Swing ◽  
Energy And Momentum

A pressure swing adsorption air separation process in a commercial aircraft using 13X zeolite with a more complex cycle than the classic Skarstrom was simulated via a predictive dynamic model to evaluate and optimize oxygen generation system. The coupled mass, energy, and momentum differential equations were discretized using the implicit central finite-difference technique and the obtained equations were solved by Newton-Raphson method. The validated model in conjunction with an optimization procedure (Successive Quadratic Programming) was utilized to investigate the oxygen separation efficiency as a function of β (ratio between the bed time constant and the particle diffusion time constant), Cfp (purge orifice coefficient), θcycle (cycle time), Cff (feed valve), Cfe (exhaust valve) and pH* (high pressure operation). A set of optimum values (β=150, Cfp=0.7, θcycle=1.5, Cff=31, Cfe=52 and pH*=3.8) was obtained and recommended to achieve maximum recovery (0.26) at 98% purity.

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