MHI's Simple Zero Liquid Discharge System for Wet FGD

摘要

MHI has developed low capital technologies for truly achieving zero liquid discharge (ZLD) from wet FGD. Two technologies are being offered commercially through Advatech: the Wastewater Evaporation System (WES) and the Wastewater Spray Dryer (WSD). Both eliminate a purge stream from the wet FGD process, even of treated water. When employed in combination with MHI's Oxidation-Reduction Potential (ORP) Control System, both the dissolved and suspended solids present in the required wet FGD purge stream are collected with the fly ash in the existing particulate control device and the heavy metals are effectively stabilized in the collected ash, minimizing the potential for leaching. The WES and WSD are easy to retrofit and required significantly less power than the conventional brine evaporator. Several plants have already implemented the WES process over the past 10 years. This paper presents the updated laboratory & pilot-scale test results for the WSD.