The effect of switchable ionic liquid (SIL) treatment on the composition and crystallinity of birch chips (Betula pendula) using a novel alkanol amine-organic superbase-derived SIL
2014 (English)In: Green Processing and Synthesis, ISSN 2191-9542, 2191-9550, Vol. 3, no 2, 147-154 p.Article in journal (Refereed) Published
Two-step treatment of birch chips (Betula pendula) was tested using diethanolamine (DEA)-1,8-diazabicyclo-[5.4.0]-undec-7-ene (DBU)-CO2-switchable ionic liquid (SIL), resulting in a 23% weight reduction in 24 h. The weight of the chips was reduced to 32% of their initial weight upon the second treatment with fresh SIL. SIL to wood ratio of 5:1, at 100°C for 24 h, without stirring, was applied in both steps. The relative amount of wood lignin reduced from 24% to 14% after two treatment cycles. The relative amount of cellulose of the undissolved fraction after SIL treatment increased from 43% (native birch wood) to 68% after the second cycle. Also, the undissolved material was efficiently fibrillated. The dissolved materials recovered from spent SIL, after treatment, contained high xylan content, about 90% of the total hemicelluloses, which was 85% of the recovered material. The powder X-ray diffraction (XRD) results revealed that the crystallinity of the undissolved material increased slightly, indicating dissolution of the amorphous material. Moreover, transformation of cellulose form I to form II in the remaining undissolved chips was not observed.
Place, publisher, year, edition, pages
2014. Vol. 3, no 2, 147-154 p.
birch chips, crystallinity, effective fibrillation, mild treatment, switchable ionic liquid (SIL)
IdentifiersURN: urn:nbn:se:umu:diva-91466DOI: 10.1515/gps-2013-0108OAI: oai:DiVA.org:umu-91466DiVA: diva2:736207