Techno-economic system analysis of membrane distillation process for treatment of chemical mechanical planarization wastewater in nano-electronics industries

Membrane distillation (MD) is a promising separation technology for the treatment of chemical mechanical planarization (CMP) wastewater releasing from nano-electronics industries. In order to determine the feasibility of the process at industrial scale, the most important factors are large-scale system evaluation and related economics. Since membrane distillation is a thermally driven process, therefore, different integration possibilities between an air gap membrane distillation (AGMD) system and low-grade heat sources are identified and analyzed in this work. Global mass and energy balances are conducted around AGMD system for CMP wastewater treatment in a typical nano-electronics manufacturing facility. It is determined that around 100 GWh of thermal energy can be readily recovered via internal sources and reused to treat 120,000 m(3) CMP wastewater/ year with MD feed temperature of 80 degrees C. Along with the technical feasibility of the system, the detailed economic evaluation has also been performed. Annual capital investment and operating cost showed that the expected CMP wastewater treatment cost can be as low as 3 $/m(3), which is estimated to be nearly 95% lower than the wastewater treatment cost using electro-chemical systems.