Factors Affecting Wood Dissolution and Regeneration of Ionic Liquids

Abstract

Three wood species, eucalyptus grandis (E. grandis), southern pine (S. pine), and Norway spruce thermomechanical pulp (N. spruce TMP) were pretreated by dissolution in the ionic liquid (IL) 1-allyl-3-methylimidazolium chloride ([AMIM]Cl). The wood was regenerated from the ionic liquid in high yield and the recycling of the ionic liquid was nearly quantitative. The lignin contents and the efficiencies of cellulase enzymatic hydrolyses of the regenerated wood were examined offering an understanding into the IL pretreatment efficiency. The components that remained within the recycled ILs were qualitatively characterized by 31 P NMR spectroscopy. Wood density, pulverization intensity, and the nature of the regeneration nonsolvents were investigated as factors affecting the overall process. An increase in the wood density decreased the efficiency of the pretreatment, whereas extended pulverization periods decreased the yield of the regenerated wood after the IL pretreatment,with more glucose being released during the enzymatic hydrolysis. The yield of wood after IL pretreatment using water as the regeneration nonsolvent was found to be much higher than that of using methanol. As the reuse cycles of IL increased the wood regeneration yield increased, while certain wood components enriched within the recycled IL. The efficiency of cellulase enzymatic hydrolysis on the regenerated wood decreased with increasing reuse cycles of the IL.

Integrating a Biorefinery into an Operating Kraft Mill

“…Ionic liquids can be tailored to dissolve the components of wood selectively (Xie et al 2009;Li et al 2010). Ionic liquids can be used to produce regenerated cellulose fiber at higher yield and better strength than conventional Lyocell fiber due to less polymer degradation (Sixta et al 2015).…”

Inovativna raba bukovine slabše kakovosti in ostankov

“…Z uporabo ionskih tekočin se odpira možnost za proizvodnjo celuloze pri nizkih temperaturah in atmosferskem tlaku. Visoka cena ionskih tekočin zaenkrat še onemogoča njihovo širšo uporabo v industriji (Kilpeläinen et al, 2007, Li et al, 2010.…”

The Utilization of Soybean Straw. II. Dissolution & Regeneration of Soybean Straw in LiCl/DMSO

“…R-4, which was regenerated from stems submitted to 4 h of ball-milling, could be dissolved completely in 8% LiCl/DMSO to form a homogeneous and clear solution. All losses of the regenerated fraction during the dissolution-regeneration procedure were caused by the ball-milling step, which could lead to the degradation of both cellulose and lignin and thus the formation of water-soluble products that cannot be precipitated readily with water (Guerra et al 2006;Li et al 2010). However, it could be concluded that although approximately 10.0% to 25.0% of the fractions were lost during the dissolutionregeneration procedure, most of the components could be regenerated from the suspensions or solutions, which could reflect nearly all of the same characteristics of the original stem cell wall components.…”