FGD WASTEWATER DISPOSED OF VIA DEEP-WELL INJECTIONAT DUKE ENERGY’S GIBSON GENERATING STATION

摘要

Duke Energy’s Gibson Generating Station, one of the largest coal-firedpower plants in the U.S., is operated as a zero liquid discharge facility. With the decisionto install three new FGD scrubbers came the challenge of how to effectively treat anddispose of the final wastewater effluent. Duke Energy personnel determined that thebest alternative was to inject the wastewater effluent into two on-site deep wells. Thisfirst-of-its-kind method of FGD wastewater disposal requires that the wastewatertreatment process produce water that consistently meets strict water quality limits.Prior to FGD startup, laboratory testing and computer modeling was performed to predictwater quality conditions and chemical treatment requirements for solids/liquidseparation, dewatering and scale control throughout the wastewater treatment anddisposal process. Special laboratory simulations were done to identify the most effectivechemical treatment to prevent calcium-based scale formation under the anticipated downhole conditions of high temperature and pressure.