How the right chemistry in the FGD unit helps to improve the performance in the wastewater treatment plant

摘要

A number of trace elements can exist in several oxidation states in the process streams of a power plant. The most stable oxidation state will depend on the process conditions and the composition of the (co-fired) fuel and this will strongly influence the behaviour during flue gas cleanup. The wet flue gas desulphurisation (FGD) unit is of major importance for the effective removal of acid components such as SO_2 and HCl formed during combustion. However, the chemistry in FGD units is complex and far from constant, depending on fuel composition and flue gas conditions. Insight in how complex equilibria are influenced by specific process conditions will give a possibility to steer element removal and product quality of processes in and around the FGD unit.