Desalination using membrane distillation: Experimental studies on full scale spiral wound modules

► Development of full-scale spiral wound membrane distillation modules with an effective membrane area of 5-14 m2. ► Development of pre-series production process and standardized characterisation procedure. ► This study shows the complex dependencies of the operation parameters with a focus on total output rate and specific thermal energy demand. ► Experiments with a feed water conductivity from 500 to 120 000 μS/cm have been performed. Throughout all experiments the product water conductivity is less than 3.5 μS/cm. The independence of the very high product water quality from feed water salinity is shown. ► High purity distillate with a electrical conductivity below 0.2 μS/cm was produced with a full scale module in an emulated double stage process.