Analysis on residue formation during wood liquefaction with polyhydric alcohol

Kobayashi, Masahiko; Asano, Toshiyuki; Kajiyama, Mikio; Tomita, Bunichiro

doi:10.1007/s10086-003-0596-9

Cited by 110 publications

(92 citation statements)

References 6 publications

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“…Lignin degradation has been studied using phenol as solvent (Lin et al 1997): guaiacol and phenolated derivatives are produced, resulting from the cleavage of β-O-4 linkages. In wood, the behaviour of lignin and polysaccharides cannot be studied separately, as shown by Kobayashi et al (2004), who found that wood lignin was converted to N,N-dimethylformamide (DMF)-soluble compounds in the early stage, followed by cellulose dissolution into DMF and later by condensation reactions between the depolymerized and degraded compounds from cellulose and lignin, resulting into DMF-insoluble compounds. Polycondensation reactions only occur between polysaccharides and lignin derivatives and not by themselves (Kobayashi et al 2004).…”

Section: Introductionmentioning

confidence: 99%

“…In wood, the behaviour of lignin and polysaccharides cannot be studied separately, as shown by Kobayashi et al (2004), who found that wood lignin was converted to N,N-dimethylformamide (DMF)-soluble compounds in the early stage, followed by cellulose dissolution into DMF and later by condensation reactions between the depolymerized and degraded compounds from cellulose and lignin, resulting into DMF-insoluble compounds. Polycondensation reactions only occur between polysaccharides and lignin derivatives and not by themselves (Kobayashi et al 2004). A higher amount of low weight polyalcohols such as glycerol has been shown to significantly reduce polycondensation reactions.…”

Section: Introductionmentioning

confidence: 99%

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Cork Liquefaction for Polyurethane Foam Production

et al. 2017

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aCork is one of the most important forest products in Portugal. The cork processing industry is highly resource-efficient, and the only residue is cork powder, which is too small for agglomerate production. This work studied the usage of cork powder for the production of added-value products via polyol liquefaction. Liquefactions were performed in a reactor using a mixture of polyethylene glycol (PEG 400) and glycerol as solvents, which were catalyzed by the addition of sulphuric acid. Several cork-tosolvent ratios, reaction temperatures, and reaction times were tested. Polyurethane foams were prepared by combining polyol mixtures with a catalyst, surfactant, blowing agent, and polymeric isocyanate. Mechanical tests of the produced foams were conducted, and compressive modulus of elasticity and compressive stress at 10% deformation were determined. The results show that the best conditions for obtaining high liquefaction yields are as follows: 160 °C for 1 h; glycerol-to-PEG 400 ratio of 1:9; corkto-solvent ratio of 1:6; and 3% H2SO4 catalyst addition. The Fourier Transform Infrared (FTIR) spectra indicated that the lignocellulosic fractions of the cork were more selectively dissolved during acidified polyol liquefaction than the suberin. With liquefied cork powder using these optimized conditions, it is possible to produce polyurethane foams with desired properties.

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Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Cork Liquefaction for Polyurethane Foam Production

et al. 2017

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“…The polysaccharides are supposed to be firstly converted to its congener glycosides which are then hydrolyzed to levulinic glycosides [11,12]. The reaction pathway of lignin depolymerization is not known but it was shown that the presence of lignin plays a major role in the post-liquefaction re-condensation reactions, leading to insoluble precipitates [13].…”

Section: Introductionmentioning

confidence: 99%

Microwave-assisted Liquefaction of Cork - From an Industrial Waste to Sustainable Chemicals

RG¹,

Mateus²

2015

Ind Eng Manage

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Cork wastes and by-products were used as raw materials to access sustainable biopolyols in a fast and clean manner. Contributing for the mitigation of a residue recorded as industrial residues in the European waste catalogue and hazardous waste list reducing, therefore, its environmental impact. Cork powder resulting from the cork industry as a waste and/or by-products with no commercial value was subjected to liquefaction in 2-ethyl hexanol/DEG in the presence of p-toluene sulfuric acid. Microwave radiation was used as the heating source. Pulsed microwaves from 150-300 W power were applied for 5-20 min. This alternative energy source was successfully applied leading to a high conversion of cork powder into liquid biopolyols. The efficiency of liquefaction increased with higher microwave power and shorter reaction time. This study evidenced that cork powder can be liquidized via microwave. ATR experiments indicated that microwave led to a more intense oxidized cleavage of the lignocellulosic material and more extensive liquefaction reaction when compared to the conventional procedure.

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“…Condensation reaction occurred when the charge ratios were 2 and 4, but it was not observed at the larger charge ratios such as 6 and 10 [22]. Condensation did not occur in the process of cellulose and lignin liquefaction independently [13,20]. However, the longer reaction time, one of the signifi cant conditions, could lead to condensation reaction during cellulosic liquefaction due to the special molecular arrangement of cellulose, which was different from that of lignin and hemicellulose [14].…”

Section: Gel Permeation Chromatography Analysismentioning

confidence: 96%

“…However, condensation reaction had occurred due to a change in the experimental conditions such as solvent/ cellulose addition ratios in the study of cellobiose liquefaction [12]. A previous study reported that an insoluble residue was formed when cellulose and lignin coexisted [13]. However, the mechanism of formation of condensed residues still needs to be clarifi ed [14] and is driving the research to overcome the limitations of physical and mechanical properties of resin products [15].…”

Section: Introductionmentioning

confidence: 99%

Process analysis of the waste bamboo by using polyethylene glycol solvent liquefaction

Wang¹,

Chen²,

Qiao³

et al. 2014

Int. J. SDP

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Solvent liquefaction process is one of the promising techniques for the effective utilization of waste woody biomass. In the liquefaction process, waste woody biomass such as waste bamboo could be converted to liquid reactive materials for developing biomass-based materials since waste bamboo has an advantage of providing the liquefi ed products with a small range of variances. The components of liquefi ed waste bamboo released during the liquefaction reaction with the polyethylene glycol 400 (PEG 400) solvent is highly acidic in the presence of mineral acid catalysts. Therefore, this study was carried out for analyzing the behavior of the liquefi ed residues (LRs) from waste bamboo during the solvent liquefaction process. The LRs produced during the liquefaction process were measured and related to different liquefi ed conditions. The change in the morphological surface of the liquefi ed waste bamboo samples was observed by a scanning electron microscope. The chemical changes in the functional groups were analyzed by a Fourier transform infrared spectrometer. The crystalline structure of liquefi ed waste bamboo samples was determined by X-ray diffraction. The chemical composition analysis and particle size distribution of liquefi ed waste bamboo samples were also carried out to confi rm the results. It was found that the effi ciency of liquefaction process can be improved by increasing the temperature and the amount of acid catalysts, although condensation reaction occurred under the liquefaction condition with high temperature. The liquefaction period of lignin was signifi cantly shorter than one of cellulose in the solvent liquefaction process with PEG 400. Moreover, it is indicated that the progress of liquefaction process may be prevented by smaller particle sizes of cellulose collected in liquefi ed bamboo.

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Analysis on residue formation during wood liquefaction with polyhydric alcohol

Cited by 110 publications

References 6 publications

Cork Liquefaction for Polyurethane Foam Production

Cork Liquefaction for Polyurethane Foam Production

Microwave-assisted Liquefaction of Cork - From an Industrial Waste to Sustainable Chemicals

Process analysis of the waste bamboo by using polyethylene glycol solvent liquefaction

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