Production of non-delignified IONCELL® fibres via steam explosion
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Journal Title
Journal ISSN
Volume Title
Kemian tekniikan korkeakoulu |
Master's thesis
Authors
Date
2022-08-23
Department
Major/Subject
Materials and Biopolymers
Mcode
CHEM3057
Degree programme
Master's Programme in Biological and Chemical Engineering for a Sustainable Bioeconomy
Language
en
Pages
47+8
Series
Abstract
Steam explosion is a simple, fast and sustainable single step defibration process to robustly remove hemicellulose from birch chips. The result is defibrated wood with a high internal surface area with improved chemical accessibility while maintaining high cellulose and lignin content using only water and steam energy with a low liquid-to-wood ratio. Oxalic acid was added to increase the severity of the steam explosion and thus directly adjust the desired degree of polymerisation of the cellulose and obtain a spinnable cellulose-lignin solution. As a side effect, almost all the hemicellulose was removed from birch wood. Exploded wood has been directly dissolved in an efficient ionic liquid (IL), 1,5-diazabicyclo[4.3.0]non-5-ene acetate ([DBNH][OAc]), at elevated temperature and subsequently extruded through an airgap and spun into lignin-rich cellulose fibres using the IONCELL-F process. The resulting lignin-rich fibres have comparable mechanical strength to that of viscose fibres and previously reported high strength lignin-cellulose hybrid fibres with a similar share of lignin. Moreover, the liquid fraction containing dissolved sugars, furanic compounds, organic acids, and lignin could be further valorized. Thus, steam explosion of birch chips has opened a new avenue of biorefinery.Description
Supervisor
Sixta, HerbertThesis advisor
Le, HuyquangKrumme, Andres
Keywords
steam explosion, hemicellulose removal, lignin-rich cellulose fibres, IONCELL-F process, biorefinery