EP 3969645 A1 20220323 - RECOVERY OF CHEMICALS IN CELLULOSE SPINNING
Title (en)
RECOVERY OF CHEMICALS IN CELLULOSE SPINNING
Title (de)
RÜCKGEWINNUNG VON CHEMIKALIEN BEIM CELLULOSESPINNEN
Title (fr)
RÉCUPÉRATION DE PRODUITS CHIMIQUES DANS LE FILAGE DE CELLULOSE
Publication
Application
Priority
- SE 1950576 A 20190515
- SE 2020050475 W 20200508
Abstract (en)
[origin: WO2020231315A1] A process for separately recovering sodium hydroxide (NaOH) and a sodium coagulation salt, respectively, from an aqueous composition (10) comprising a dissolved sodium coagulation salt and dissolved sodium hydroxide (NaOH) and having a pH of more than 7. The process comprises the steps of: cooling the aqueous composition (10) to precipitate a first portion of the sodium coagulation salt (30), to provide a sodium coagulation salt reduced aqueous composition (11) comprising dissolved sodium hydroxide (NaOH); separating the precipitated, first portion of the sodium coagulation salt (30) from the sodium coagulation salt reduced aqueous composition (11) to provide recovered sodium coagulation salt; evaporating water from the sodium coagulation salt reduced aqueous composition (11), thereby increasing the concentration of sodium hydroxide (NaOH) and remaining sodium coagulation salt; and precipitating and separating a second portion of the sodium coagulation salt (12) from the concentrated aqueous composition (12), thereby providing a recovered aqueous sodium hydroxide solution (20).
IPC 8 full level
D01F 13/02 (2006.01); C08B 16/00 (2006.01); D01D 5/06 (2006.01); D01F 2/02 (2006.01)
CPC (source: EP)
C08B 1/003 (2013.01); C08B 16/00 (2013.01); D01F 2/02 (2013.01); D01F 13/02 (2013.01); Y02P 70/62 (2015.11)
Designated contracting state (EPC)
AL AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HR HU IE IS IT LI LT LU LV MC MK MT NL NO PL PT RO RS SE SI SK SM TR
Designated extension state (EPC)
BA ME
DOCDB simple family (publication)
WO 2020231315 A1 20201119; EP 3969645 A1 20220323; EP 3969645 A4 20230621
DOCDB simple family (application)
SE 2020050475 W 20200508; EP 20805931 A 20200508