The operating costs heavily depend also on the required performance
of acid gas removal. The results discussed above all refer to
a HCl outlet concentration of 2 mg/N m3. However, depending on
local regulations and requirements, systems might be operated on the basis of other emission limit values (ELVs). Thus, an
assessment was carried out considering different ELVs for hydrogen
chloride beside the base-case (2 mg/N m3) considered above:
1, 5 and 10 mg/N m3. The latter value, being the ELV prescribed
by Directive 2010/75/EU, identifies the minimum performance
currently allowed in the European framework.