A New Numerical Approach for a Detailed Multicomponent Gas Separation Membrane Model and AspenPlus Simulation

Abstract

A new numerical solution approach for a widely accepted model developed earlier by Pan [1] for multicomponent gas separation by high-flux asymmetric membranes is presented. The advantage of the new technique is that it can easily be incorporated into commercial process simulators such as AspenPlus TM [2] as a user-model for an overall membrane process study and for the design and simulation of hybrid processes (i.e., membrane plus chemical absorption or membrane plus physical absorption). The proposed technique does not require initial estimates of the pressure, flow and concentration profiles inside the fiber as does in Pan's original approach, thus allowing faster execution of the model equations. The numerical solution was formulated as an initial value problem (IVP). Either Adams-Moulton's or Gear's backward differentiation formulas (BDF) method was used for solving the non-linear differential equations, and a modified Powell hybrid algorithm with a finite-difference approximation of the Jacobian was used to solve the non-linear algebraic equations. The model predictions were validated with experimental data reported in the literature for different types of membrane gas separation systems with or without purge streams. The robustness of the new numerical technique was also tested by simulating the stiff type of problems such as air dehydration. This demonstrates the potential of the new solution technique to handle different membrane systems conveniently. As an illustration, a multi-stage membrane plant with recycle and purge streams has been designed and simulated for CO 2 capture from a 500 MW power plant flue gas as a first step to build hybrid processes and also to make an economic comparison among different existing separation technologies available for CO 2 separation from flue gas.

Transport Properties of Asymmetric Hollow Fiber Membrane Permeators for Practical Applications: Mathematical Modelling for Binary Gas Mixtures

“…Equations (24)(25) were obtained with the help of Equation (12) and an equation derived from the sum of Equations (12)(13). Equations (26) and (27) were derived from Equations (21) and (16) using dimensionless parameters, respectively.…”

Simulation of binary gas separation through multi-tube molecular sieving membranes at high temperatures

“…(2) contains both the advection term @ðJx H2 Þ @l and the diffusion term @ @l D @ðcx H2 Þ @l . In liquid or low temperature gas separation in small scale modules, advection is far more intense than diffusion, so diffusion is always omitted in the component mass balance equation [15][16][17][18][19][20]. As a result, Eq.…”

Membrane Separation Processes for Post-Combustion Carbon Dioxide Capture: State of the Art and Critical Overview

“…The simulation of membrane based gas separations has been investigated for decades and the possibility to correctly predict the separation performances of a unit through a series of key equations and associated assumptions is abundantly documented (Bounaceur et al, 2006;Kaldis et al, 2000;Chowdhury et al, 2005;Coker et al, 1999;Matson, 1983;Zanderighi, 1996). Similarly to numerous studies in this field, a cross-plug flow model has been used for the simulations shown in this section.…”