A1 Journal article (refereed), original research

Purification process for recovering hydroxy acids from soda black liquor


Publication Details
Authors: Hellstén Sanna, Lahti Jussi, Heinonen Jari, Kallioinen Mari, Mänttäri Mika, Sainio Tuomo
Publication year: 2013
Language: English
Related Journal or Series Information: Chemical Engineering Research and Design
Volume number: 91
Issue number: 12
ISSN: 0263-8762
JUFO-Level of this publication: 1
Open Access: Not an Open Access publication

Abstract
Black liquor, a side product of chemical pulping, contains hydroxy acids that have many potential applications, e.g., as polymer precursors. Currently there are no feasible separation processes available for recovery of hydroxy acids from such solutions. Neutralization is usually though to be a necessary pre-treatment, but it adds into chemical consumption and may impede the integration of the recovery process to a pulp mill. In this work, an experimental investigation of a new process concept for the recovery and purification of hydroxy acids from soda black liquor without neutralization is presented. The process consists of ultrafiltration, size-exclusion chromatography, ion-exchange, adsorption, and evaporation. Mixtures of hydroxy acids in high purity were produced from black liquor of soda pulping using the process. A reduction of 99% in lignin content of the organic acid fraction was achieved. In the chromatographic separation step, the recovery of sodium hydroxide was almost 100%. The average purities of hydroxy acids isolated from softwood and hardwood black liquors were 81% and 63% on mass basis, respectively.

Research Areas

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