Seawater flue gas desulfurization: Its technical implications and performance results

Abstract

Abstract Increasingly, flue gas desulfurization (FGD) systems are being installed to control sulfur dioxide emissions in power plants utilizing coal or oil. For power plants located on an ocean coast, utilization of seawater from the cooling system of the plant to scrub sulfur dioxide has become a promising and attractive alternative to using other alkaline chemicals, such as limestone and magnesium hydroxide. Sulfur dioxide is absorbed and subsequently oxidized to sulfate, which is a native constituent of seawater. Prior to discharge, the acidified seawater effluent undergoes neutralization using the natural alkalinity present in seawater (the carbonate‐related system). Compared to the conventional wet limestone system, the seawater FGD system offers many advantages in terms of process, design, operation and cost effectiveness. This paper describes the technical and environmental aspects of a seawater FGD system. The performance test results of an existing seawater FGD system employed at a 600‐MW e power plant in China are also presented, focusing on the desulfurization efficiency and the seawater effluent quality. Different design configurations for a seawater FGD absorption system are compared.