Aalto University, P.O. Box 11000, FI-00076 Aalto www.aalto.fi Author Mikhail Iakovlev Name of the doctoral dissertation SO2-ethanol-water (SEW) fractionation of lignocellulosics Publisher School of Chemical Technology Unit Department of Forest Products Technology Series Aalto University publication series DOCTORAL DISSERTATIONS 95/2011 Field of research Biorefineries Manuscript submitted 9 May ...

Kraft pulping is the dominant process currently used to produce chemical pulps, and has been applied for more than 130 years. A large number of studies have been conducted to gain a better understanding of the delignification kinetics as well as the reactions of the wood components being dissolved during the cooking process. Nevertheless, these remain far from being well understood in detail du...

A series of kraft pulps were prepared in which the level of calcium was selectively enriched and depleted. These pulps were then oxygen delignified, and the pulps were characterized according to kappa number and viscosity. The residual lignin samples were isolated via acid-hydrolysis and characterized by NMR techniques. The results indicated that the presence of nonprocess elements could impact...

Delignification is the process of breaking lignocellulose into lignin, cellulose, and hemicellulose. The presence lignin in lignocellulosic materials results limited utilization cellulose. This article discusses delignification process. There are various methods from literature study, namely physical, chemical, semi-chemical, mechanical, enzymatic.

BACKGROUND As a natural renewable biomass, the tea oil fruit hull (TOFH) mainly consists of lignocellulose, together with some bioactive substances. Our earlier work constructed a two-stage solvent-based process, including one aqueous ethanol organosolv extraction and an atmospheric glycerol organosolv (AGO) pretreatment, for bioprocessing of the TOFH into diverse bioproducts. However, the AGO ...

Kraft pulping of hydrolyzed green bamboo (Dendrocalamopsis oldhami) chips was performed under various conditions to determine the effects of process variables (alkali charge, sulfidity, cooking temperature, and cooking time) on the dissolution of the lignocellulosic components, i.e. lignin, pentosans, and cellulose. Meanwhile, the kinetics of kraft delignification of hydrolyzed bamboo was inves...

Hybrid poplar genetically engineered to possess chemically labile ester linkages in its lignin backbone (zip-lignin hybrid poplar) was examined to determine if the strategic lignin modifications would enhance chemical pulping efficiencies. Kraft pulping of zip-lignin and wild-type hybrid poplar was performed in lab-scale reactors under conditions of varying severity by altering time, temperatur...

A detailed study was undertaken to examine the color and chemistry changes of pine wood flour when its extractives are removed and when it is delignified. The solvent systems employed were toluene/ethanol (TE), acetone/water (AW), and hot-water (HW), while sodium chlorite/acetic acid were used for delignification (i.e., lignin removal (LR)). Samples were analyzed by attenuated total reflectance...

An integrated strategy was followed to valorise rice straw, one of the most relevant biomass feedstocks available worldwide, to selectively recover solubilised hemicelluloses and lignin. The pathway encompassed the use of autohydrolysis to hydrolyse the hemicelluloses and an ethanol-based organosolv process to solubilise lignin. Several autohydrolysis conditions were assayed with the best resul...

BACKGROUND In the biorefinery utilizing lignocellulosic biomasses, lignin decomposition to value-added phenolic derivatives is a key issue, and recently biocatalytic delignification is emerging owing to its superior selectivity, low energy consumption, and unparalleled sustainability. However, besides heme-containing peroxidases and laccases, information about lignolytic biocatalysts is still l...