Influence of operation conditions on the performance of pilot-scale vacuum membrane distillation (VMD).

Although many studies have been done on membrane distillation (MD) for seawater desalination and wastewater treatment, relatively few works have been done in pilot- or full-scale plants. Accordingly, this study intended to investigate the performance of a vacuum MD system at pilot scale. Factors affecting MD flux were examined, including feed temperature, feed flow rate, and applied vacuum. Results showed that the MD flux was almost linearly proportional to feed temperature and flow rate. Moreover, the flux was also sensitive to the applied vacuum. Based on the analysis, the minimum feed temperature and vacuum to operate the MD pilot plant were determined to be 56°C and 0.28 bar, respectively. The flux and energy utilization ratio were analyzed as a function of feed temperature and flow rate, indicating that the feed temperature should be over 69°C to obtain flux over 4 kg/m² h and the feed flow rate should be over 5.6 m³ /h to achieve energy utilization ratio above 0.65. [ABSTRACT FROM AUTHOR]