Influence of Module Length on Water Desalination Using Air Gap Membrane Distillation Process: An Experimental Comparative Study

Abstract

The impact of the membrane module length on the air gap membrane distillation (AGMD) process performance was investigated experimentally under various operating parameters. In this work, two different lengths of the AGMD module (i.e., 0.59 m and 0.28 m) were tested separately to get the optimum in terms of lower energy consumption and higher water output. The mechanism of mass and heat transfer in the AGMD process is considered as well. The experimental results were subjected to the two-way analysis of variance (ANOVA) to examine the significant influence of operating parameters and modules at p 0.05) on the gained output ratio (GOR), energy consumption (STEC), and heat input (QH.I). Under optimal operating parameters of a flow rate of 18 L/h, feed temperature of 60 °C, coolant temperature of 20 °C, and feed salinity of 5000 mg/L, the Pw and GOR were increased by 64.50% and 50.00%; the STEC and QH.I were reduced by 57.78% and 34.09%, respectively, from the long module to the short one. Thence, changing the length of the membrane module from 0.59 to 0.28 m promoted remarkably the performance of the AGMD process.