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 ...

Two types of pure cellulose, Avicel PH-101 and Whatman filter paper, were treated with an acid-chlorite delignification procedure in the presence of varying amounts of incorporated lignin, and the molecular weight distributions and degrees of polymerization (DP) of derivatized cellulose were determined by gel permeation chromatography (GPC). Avicel samples with 0% added lignin showed a DP reduc...

The effects of sodium carbonate (Na(2)CO(3)) pretreatment on the chemical compositions and enzymatic saccharification of rice straw were investigated. The enzymatic digestibility of rice straw is enhanced after pretreatment since pretreated solids show significant delignification with high sugar availability. During pretreatment, an increasing temperature and Na(2)CO(3) charge leads to enhanced...

The present work is aimed to study the microstructural changes that occurred during the delignification process of agave fibers using microscopy techniques and image analysis (AI). Acetosolv kinetic was followed by chemical analysis and by light (LM), confocal laser scanning (CLSM), and scanning electron (SEM) microscopies, evaluating the micrographs by image analysis (IA). Kinetic studies show...

Fresh-harvested, air-dried rice straw was pretreated at a water content of 5 g H(2)O/g straw using sodium hydroxide (NaOH) and compared to pretreatment at 10 g H(2)O/g straw by hydrated lime (Ca(OH)(2)). Full factorial experiments including parallel wash-only treatments were completed with both sources of alkali. The experiments were designed to measure the effects of alkaline loading and pretr...

Red maple, sweet gum, trembling aspen, red alder, and Eucalyptus globulus samples were pretreated with dilute sulfuric acid and green liquor before enzymatic saccharification. Substrates showed different levels of delignification and sugar recovery, depending on the applied pretreatments and the syringaldehyde/vanillin ratio (S/V). Three major conclusions were drawn in this research. First, lig...

Studies about renewable energy are evolved continuously to decrease the needs of fuel oils that were diminished. One alternative sources can be is bioethanol due high amount oxygen component in it hence combustible and eco-friendly. Mesocarp farming trading waste Cocos Nucifera (Coconut) contains 40% lignin, 44,4% cellulose, 15% hemicellulose. Delignification a process removing lignin from mate...

Environmental regulations coupled to market pressures have forced the pulp and paper industry to explore alternatives to chlorine based bleaching practices for the production of bleached kraft pulp.Various technologies and bleaching chemicals have been suggested as answers to kraft pulp bleaching concerns, from which oxygen, ozone and peroxides are the leading candidates for chlorine replacemen...

Many kinetic studies of oxygen delignification have been reported in literature. In the past these studies were mostly performed in batch reactors whereby the caustic and dissolved oxygen concentrations are changing during the reaction. This makes it difficult to determine the reaction order of the different reactants in the rate expressions. Also the lignin content and cellulose degradation of...

A hardwood-based biorefinery process starting with hot-water extraction (HWE) is recommended in order to remove most of the hemicelluloses/xylans before further processing. HWE may be followed by delignification in acetone/water in the presence of oxygen (AWO) for the production of cellulose and lignin. In this study, the HWE-AWO sequence was evaluated for its effectiveness at removing lignin f...