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1. (WO2018046791) A SYSTEM AND A METHOD FOR PRODUCING AQUEOUS SULPHURIC ACID

Pub. No.:    WO/2018/046791    International Application No.:    PCT/FI2017/050579
Publication Date: Fri Mar 16 00:59:59 CET 2018 International Filing Date: Fri Aug 18 01:59:59 CEST 2017
IPC: D21C 11/00
D21C 11/04
D21C 11/06
Applicants: VALMET TECHNOLOGIES OY
Inventors: HUMALAJOKI, Asta
VÄLJÄ, Antti
AIRIKKALA, Heikki
TUOMINIEMI, Seppo
BJÖRKLUND, Peter
Title: A SYSTEM AND A METHOD FOR PRODUCING AQUEOUS SULPHURIC ACID
Abstract:
A system (100) for producing aqueous sulphuric acid. The system (100) comprises a first heat exchanger (410) configured to cool water and/or aqueous sulphuric for producing cooled water and/or cooled aqueous sulphuric acid; a pre-cooling unit (200) configured to pre-cool some gas containing sulphur trioxide, the pre-cooling unit (200) comprising an inlet or inlets (212, 214) for receiving [i] the gas containing sulphur trioxide and [ii] the cooled water and/or the cooled aqueous sulphuric acid, an outlet (216) for letting out aqueous sulphuric acid and the gas containing sulphur trioxide, and a first nozzle (220) for spraying the cooled water and/or the cooled aqueous sulphuric acid onto the gas containing sulphur trioxide to cool the gas containing sulphur trioxide. The system further comprises a condensation tower (300) comprising a first inlet (302) for receiving the cooled gas containing sulphur trioxide and aqueous sulphuric acid from the pre-cooling unit (200) and means (320) for circulating the aqueous sulphuric acid within the condensation tower (300) by spraying in order to strengthen the aqueous sulphuric acid. In addition, a method for producing aqueous sulphuric acid. Furthermore, a pre-cooling unit (200) suitable for cooling gas comprising sulphur trioxide from a temperature of at least 400 °C to a temperature of at most 150 °C.