However, in spite of
their growing industrial importance, the experience with twostage
technologies is mostly empirical (De Greef et al., 2013) and
scarce data are reported on the optimal performance of this process.
In particular, the optimal integration of first and second stage
to maximise efficiency and removal of acid gases still needs to be
explored (Acquistapace et al., 2014), since the operational optimum
depends on the concentration of acid pollutants in the flue
gas and ultimately on the waste composition. Only recently
Antonioni et al. (2014) developed an empirical model, which needs
to be calibrated on actual plant data, in order to describe the acid
gas removal efficiency of a two-stage (2S) system and to identify
the configuration operating at the optimal economic performance,
taking into account the costs for reactants and disposal of solid
residues.