Modelling study of membrane cell performance during chlor alkaliprocess using CFD method

The main aim of this study is the investigation of various operating parameters effects on the cell voltage and current efficiency of a laboratory-scale chloralkali (CA) membrane cell were studied at low caustic concentrations (5–22 g/L) by using computational fluid dynamic (CFD) method. To this purpose, a twodimensional isothermal CFD model was developed and its validation was realized by comparing thetheoretical results with experimental data achieved with A.A Jalili et al[1]. In this work, the CFD model was presented by COMSOL- Multiphysics software version 5.2.1. According to validation results, a good agreement between modeling results and experimental data was found. Two process parameters studied include brine concentration (200–300 g/L) and current density (1–4 kA/m2). Taguchi and ANOVAtechniques were employed for experimental design and data analysis, respectively. Current density was found to be the most striking parameter on the cell voltage with contribution percentage (P value) of 60%. However, in case of current efficiency, the highest P value is due to brine concentration (25%). The caustic current efficiency was between 80%–85%. The results from voltage balance analysis revealedthat the main contributors to the CA cell voltage at low caustic concentration are voltage drop due to the membrane, nickel cathode and the catholyte. The impact of other cell resistance components is minor. The measured and estimated cell voltages were found to come close at higher current densities.

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Department of Chemical Process Engineering , College of Chemical Engineering , Ahar Branch , IslamicAzad University , Ahar , Iran