A flue gas treatment process and system is presented. The system includes a fan capable of moving a flue gas through a flue gas desulfurizer, direct contact cooler, and CO2 absorber, without the need for a booster fan. The system also includes a direct contact cooler and CO2 absorber that are configured to withstand gas conditions present at the flue gas desulfurizer exit. When the direct contact cooler and CO2 absorber are shutdown, the speed of the fan is lowered and the flue gas continues to flow through the cooler and CO2 absorber and out a chimney. The overall cost of installing, operating, and maintaining the system is lower than that of conventional processes and systems.