Abstract: At present, the sulfur content of coal in the actual operation of limestonegypsum wet desulphurization system is often far greater than the design value, which leads to the bypass opening operation because of the limitation of adaptive capacity for changes of sulfur content rate. In this paper, improving the design margin to suit the possible changes in sulfur content rate of coal was proposed for new projects. Searching for the optimal scheme by technoeconomic comparison based on local conditions was suggested for renovation projects explained by the real project.

Key words: flue gas desulphurization (FGD), change of sulfur content rate in coal, process design