Method and a system for producing hydrochloric acid from flue gases

A system (100, 300, 500, 600) arranged to produce aqueous hydrochloric acid from flue gases, the system comprising:

• a first conduit (101, 201, 301, 401, 501, 601, 701) configured to feed flue gas containing chlorides into a first scrubber (102, 202, 302, 402, 502, 602, 702),
• a second conduit (103, 203, 303, 403, 503, 703) configured to convey water to be used in a scrubbing liquid of the first scrubber (102, 202, 302, 402, 502, 602, 703),
• a line (112b, 212b, 312b, 412b, 512b, 712b) configured to convey scrubbing liquid comprising the water into the first scrubber (102, 202, 302, 402, 502, 602, 702) and
• a first line (105, 205, 305, 405, 505, 705) for expelling dilute hydrochloric acid as a scrubber bleed from the first scrubber (102, 202, 302, 402, 502, 602, 702), wherein:
• the first scrubber (102, 202, 302, 402, 502, 602, 702) is configured to scrub the flue gas containing chlorides with the scrubbing liquid, the first scrubber (102, 202, 302, 402, 502, 602, 702) thereby being configured to produce the scrubber bleed and a flue gas derivate (104, 204, 304, 404, 504, 704), and
• the system further comprises:
• a solids separator (192, 592, 692) for separating solids suspended by the scrubber bleed,
• an evaporation vessel (194, 594, 694) comprising a heater (197) for heating the scrubber bleed from which the solids have been separated, and
• a second line (193, 593) for conveying the scrubber bleed from the solids separator (192, 592, 692) into the evaporation vessel (194, 594, 694),
• the evaporation vessel (194, 594, 694) being configured to concentrate the scrubber bleed to produce hydrochloric acid vapor having a concentration of 5-22 wt-%.