公开(公告)号：US20190177914A1

公开(公告)日：2019-06-13

申请号：US16323758

申请日：2017-08-17

Applicant: Valmet Technologies Oy

Inventor： Asta HUMALAJOKI ,  Antti VAELJAE ,  Heikki AIRIKKALA ,  Seppo TUOMINIEMI ,  Peter BJOERKLUND

IPC: D21C11/06 ,  D21C11/00 ,  C01B17/80

CPC classification number: D21C11/06 ,  B01D5/003 ,  B01D5/0054 ,  B01D5/0075 ,  C01B17/60 ,  C01B17/803 ,  C01B17/806 ,  D21C11/0064 ,  D21C11/04

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

公开(公告)号：US20200291574A1

公开(公告)日：2020-09-17

申请号：US16768189

申请日：2018-12-20

Applicant: Valmet Technologies Oy

Inventor： Risto HÄMÄLÄINEN ,  Seppo TUOMINIEMI

IPC: D21C11/08 ,  D21C11/00

Abstract: The invention relates to a method and a system for adjusting S/Na-balance of a sulphate pulp mill, wherein a pulp mill CNCG stream containing sulphur compounds is first scrubbed with an aqueous scrubbing solution containing an alkaline agent, thereby producing an aqueous spent scrubbing solution containing sulphides, which is then oxidized in a bioreactor by means of sulphur-oxidizing microbes, thereby obtaining an aqueous suspension containing elemental sulphur from which the elemental sulphur can be separated as a precipitate and the residual solution may be used for replenishing the aqueous scrubbing solution.