Experimental investigation on a combined system of vacuum membrane distillation and mechanical vapor recompression

Publication date: Available online 13 April 2019Source: Chemical Engineering and Processing - Process IntensificationAuthor(s): Zetian Si, Dong Han, Yan Song, Junjie Chen, Liantan Luo, Rongyi LiABSTRACTIn order to improve the product quality and reduce the energy consumption for the treatment of strongly corrosive solution, a new combined system of mechanical vapor recompression (MVR) and vacuum membrane distillation (VMD) was developed and constructed in this study, and performance tests were conducted utilizing polytetrafluoroethylene (PTFE) membranes with a pore size of 0.2 um. The effects of process operating parameters including feed temperature, feed flow rate, permeate-side absolute pressure and frequency of vacuumizing on water production were investigated and discussed. In addition, the energy consumption, economic and environmental benefits were performed through comparing with different VMD modes using electrical heater or heat pump as the heat source, it was found that the proposed system had the best energy saving effect, the specific thermal energy consumption (STEC) reached 145.4 kWh/t at the conditions of feed temperature of 83 ℃, feed flow rate of 26 m3/h and permeate-side absolute pressure in the range of 49-52 kPa. Therefore, careful integration of VMD in MVR process achieved great change in energy efficiency by recovering the latent heat of vaporization. Lastly, the proposed system showed excellent economic and environmental benefits and could be further...
Source: Chemical Engineering and Processing: Process Intensification - Category: Chemistry Source Type: research