Flue gas desulfurization and humidification dehumidification in power plants

Abstract

A B S T R AC TPerformance evaluation is presented for fl ue gas desulfurization (FGD), humidifi cation and dehumidifi cation desalination (HDD) of fl ue gases emitted from power plants. The proposed system is based on use of seawater for SO 2 absorption and removal from the fl ue gases. The FGD and HDD processes are separated in order to achieve the highest possible effi ciency. This is because FGD requires low temperatures to achieve high rates of absorption and removal of SO 2 . On the other hand, HDD requires higher temperatures to provide suffi cient temperature difference and driving force for humidifi cation and dehumidifi cation. Analysis of both systems is applied to the emission rate data of power plants in Kuwait. The design results of the seawater SO 2 absorption column showed variations in the column height between 8.1-12.6 m as the power plant capacity was increased from 244-4173 MW. Analysis of the HDD system show that it might not be the optimum desalination alternative because of its limited production capacity. However, the process layout is simple and can be formed of two packed columns for humidifi cation and dehumidifi cation, which requires a small capital when compared to conventional thermal or membrane desalination.