As shown in Fig. 5, calculated costs confirm the rankings of the
alternative technologies obtained for the base-case discussed in
Section 3.2. A single deviation appeared: the 1S technology results
more cost-effective than 2S system in scenario W_B when a HCl
outlet concentration of 10 mg/N m3 is considered.
As expected, the total costs of all technologies increase when
the ELV is decreased. In this framework, the 2S configuration
results more cost-effective when high performances are required.
In particular, when a HCl outlet concentration of 1 mg/N m3 is coupled
to an incoming waste rich in Cl and S (scenario W_C), the 2S
system provides savings as high as 1.11 M€ per annum compared
to the cheapest 1S alternative for the feed rate considered
(120,000 t/year waste).