2.1. Methodology adopted in the comparison of alternative
technologies
A methodology was developed to allow the comparison of the
total cost of operation of alternative dry technologies for acid gas
removal from flue gas, given as input data the elemental composition
of the waste feed and the required emission limits for HCl and
SO2. The methodology is summarised in Fig. 1. The composition of
the flue gas leaving the combustion system, if not available from
operational data, is calculated from the waste composition through
a simplified mass balance approach. Given the concentration of the
acid components in the flue gas and the required removal performance,
the conversion model of Antonioni et al. (2014) allows
quantifying the associated consumption of solid reactants and
the generation of solid residues that need to be disposed. Eventually,
the costs related to reactant purchase and solid residue disposal
are summed to the annualised cost of equipment and to
other ancillary costs (utilities, replacement parts, maintenance)
to determine the total operating cost per annum of the treatment
system.
The key