"Aspetti chimico-ingegneristici dei principali processi di desolforazione ad umido dei fumi di combustione"

he need to control atmospheric pollution is making it necessary to reduce sulfur dioxide emissions, thus mandating the treatment of flue gases prior to discharge into the atmosphere. The more relevant desulfurization processes that have reached industrial scale are those effecting the sulfur removal by contacting the flue gases with an absorbing aqueous solution. These processes are generally referred to as 'wet flue gas desulfurization processes'. Differences between these processes can be found with regard to the fluid-dynamic conditions of the contact between the gas and the liquid phase, the nature of the absorbing compound, the possibility of reusing the sulfur, and the by-product characteristics. These characteristics determine the necessity of a more or less expensive disposal, or the possibility of selling the by-product in order to recover some of the costs of the process. In this paper the chemistry and engineering of the more diffused wet flue gas desulfurization processes are examined. The various processes are considered with regard to the sulfur dioxide removal efficiency, the operative conditions, the stage of process development, and the process reliability.