Process for treating lignin

This invention provides improvements to processes for making granular lignin from black liquor. One of the improvements is that the use of a pre-carbonation column reduces the CO2 flow into the sparger of a carbonation column. The pre-carbonation column is used to reduce the pH of the black liquor t...

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Bibliographic Details
Main Authors Lake, Michael A, Blackburn, John C, Hayden, J. George
Format Patent
LanguageEnglish
Published 09.01.2024
Subjects
APPARATUS THEREFOR
CHEMISTRY
COMPOUNDS OF UNKNOWN CONSTITUTION
METALLURGY
ORGANIC CHEMISTRY
PAPER-MAKING
PRODUCTION OF CELLULOSE
PRODUCTION OF CELLULOSE BY REMOVING NON-CELLULOSE SUBSTANCESFROM CELLULOSE-CONTAINING MATERIALS
REGENERATION OF PULPING LIQUORS
TEXTILES
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Summary:This invention provides improvements to processes for making granular lignin from black liquor. One of the improvements is that the use of a pre-carbonation column reduces the CO2 flow into the sparger of a carbonation column. The pre-carbonation column is used to reduce the pH of the black liquor to about 12. Another improvement is that it has been found that coalescing droplets into a bulk liquid-lignin phase can be enhanced by placing the exit of the carbonation column at or slightly beneath carbonated black liquor/liquid-lignin interface. It has also been found that operating the carbonation settler at a low pressure and pumping the liquid-lignin from the carbonation settler to the acidification reactor operating at a higher pressure allows recycling the vent gas from the acidification reactor to the pre-carbonation column. The invention also provides for a vent gas absorber.
Bibliography:Application Number: US202117372872