Modeling and simulation of supersonic gas separations

Abstract Supersonic separation is an operation potentially applicable to gas processing in large scale chemical plants. Supersonic flows are achieved in properly sized converging–diverging nozzles, whose performance is simulated in this paper. The overall simulation procedure consists of different types of thermodynamic calculations, including the determination of phase equilibrium conditions and of thermodynamic sound speed in non-ideal single-phase and multiple-phase systems. The thermodynamic properties of the fluid are evaluated using the Peng–Robinson equation of state, but the procedure is general and compatible with other thermodynamic models. Despite being less detailed than computational fluid dynamics (CFD) simulations previously reported in the literature, the results are in very good agreement with CFD. The proposed procedure constitutes a tool for the preliminary design of supersonic separators that is conceptually simple and accurate, with rigorous evaluations of the thermodynamic properties.

[1]  Yuri S. Muzychka,et al.  Applications of CFD in Natural Gas Processing and Transportation , 2010 .

[2]  Vadim Alfyorov,et al.  Supersonic nozzle efficiently separates natural gas components , 2005 .

[3]  Chuang Wen,et al.  Numerical simulation of natural gas flows in diffusers for supersonic separators , 2012 .

[4]  Marcelo Castier,et al.  Thermodynamic speed of sound in multiphase systems , 2011 .

[5]  Michael L. Michelsen,et al.  Multiphase isenthalpic and isentropic flash algorithms , 1987 .

[6]  Feng Liu,et al.  A Design Method of Supersonic Separator Used in Natural Gas Liquefaction Process , 2012 .

[7]  R. Reid,et al.  The Properties of Gases and Liquids , 1977 .

[8]  M. M. Malyshkina.  The structure of gasdynamic flow in a supersonic separator of natural gas , 2008 .

[9]  Y. Çengel,et al.  Thermodynamics : An Engineering Approach , 1989 .

[10]  Jing Zhang,et al.  Evaluation of natural gas dehydration in supersonic swirling separators applying the Discrete Particle Method , 2012 .

[11]  José Luiz de Medeiros,et al.  Supersonic separation in onshore natural gas dew point plant , 2012 .

[12]  M. Michelsen.  The isothermal flash problem. Part II. Phase-split calculation , 1982 .

[13]  D. Peng,et al.  A New Two-Constant Equation of State , 1976 .

[14]  Majid Abedinzadegan Abdi,et al.  Selective dehydration of high pressure natural gas using supersonic nozzles , 2009 .

[15]  Esam Jassim,et al.  Computational Fluid Dynamics Study for Flow of Natural Gas through High-pressure Supersonic Nozzles: Part 1. Real Gas Effects and Shockwave , 2008 .

[16]  M. Michelsen.  The isothermal flash problem. Part I. Stability , 1982 .

[17]  Daniel Broseta,et al.  Calculation of isentropic compressibility and sound velocity in two-phase fluids , 2010 .

[18]  M. M. Malyshkina.  The procedure for investigation of the efficiency of purification of natural gases in a supersonic separator , 2010 .

[19]  A. Aguiar-Ricardo,et al.  Can the speed of sound be used for detecting critical states of fluid mixtures? , 2006, The journal of physical chemistry. B.

[20]  Jing Zhang,et al.  Optimization Design of Diffusers for Supersonic Separators , 2010 .

[21]  G. Soave.  Equilibrium constants from a modified Redlich-Kwong equation of state , 1972 .

[22]  Abbas Firoozabadi,et al.  Thermodynamics of Hydrocarbon Reservoirs , 1999 .

[23]  Renzo Arina,et al.  Numerical simulation of near-critical fluids , 2004 .

[24]  Esam Jassim,et al.  Computational Fluid Dynamics Study for Flow of Natural Gas through High-pressure Supersonic Nozzles: Part 2. Nozzle Geometry and Vorticity , 2008 .

[25]  Yan Yang,et al.  An unconventional supersonic liquefied technology for natural gas , 2012 .

[26]  A. B. Wood,et al.  A textbook of sound , 1930 .