Patent ID: 10603624

Abstract:
Systems, apparatuses, and processes for controlling free ammonia in wet flue gas desulfurization processes in which an ammonia-containing scrubbing solution is used to produce ammonium sulfate. Such an apparatus includes an absorber having a contactor region through which a flue gas comprising sulfur dioxide is able to flow and a reaction tank containing a scrubbing solution containing ammonium sulfate. The tank has a sidewall and bottom wall that define the perimeter and bottom of the tank. Lance-agitator units are distributed around the perimeter of the tank, each having a lance that injects a mixture of oxygen and a dilute ammonia-containing fluid toward the bottom of the tank and an agitator that agitates the mixture and propels the mixture toward the bottom of the tank. The apparatus includes a source of the mixture of oxygen and dilute ammonia-containing fluid, and recirculates the scrubbing solution from the tank to the contactor region.