Novel method for the design and assessment of direct contact membrane distillation modules.pdfVIP

Journal of Membrane Science 513 (2016) 260–269 Contents lists available at ScienceDirect Journal of Membrane Science journal homepage: /locate/memsci Novel method for the design and assessment of direct contact membrane distillation modules Ho Yan Wu a, Mason Tay b, Robert W. Field a,n a Department of Chemical Engineering, University of Oxford, United Kingdom b Department of Chemical Engineering, National University of Singapore, Singapore article info Article history: Received 13 August 2015 Received in revised form 29 March 2016 Accepted 3 April 2016 Available online 5 April 2016 Keywords: Membrane distillation Direct contact Module performance Module sizing Process design abstract An equivalent effectiveness-number of transfer units (ε-NTUMD) method was developed for direct con- tact membrane distillation. Ef?cient performance rating and design sizing for individual DCMD modules can be rapidly made based upon limited experimental data. Using this method, the construction of a speci?c ?nite element model and their associated costs, involving both time and expenditure, are avoided. Instead the module performance or sizing requirements can be estimated ef?ciently using a set of expressions based on the conventional ε-NTU expressions used for the design of heat exchangers. The outlet temperatures are also predicted which is useful for the design of the overall DCMD process and module cascading networks. The ε-NTUMD method was validated against an experimentally validated discretized model of a ?at sheet DCMD module, built using MATLAB. A correction function is included in the ε-NTUMD method proposed which results in 100% of the derived data being accurate within 6% of model results. Method validation was done for both co- and countercurrent ?ow, with a range of module dimensions, ?owrates and membrane permeabilities. 2016 Elsevier B.V. All rights reserved. 1. Introduction Membrane distillation (MD) has become a popular research area in recent years, particularly for