Effects of Incubation Time on the Fractionation and Characterization of Lignin During Steam Explosion Pretreatment

2012 ◽  
Vol 51 (6) ◽  
pp. 2704-2713 ◽  
Author(s):  
Kun Wang ◽  
Jian-Xin Jiang ◽  
Feng Xu ◽  
Run-Cang Sun
Keyword(s):  
Incubation Time ◽  
Steam Explosion ◽  
Steam Explosion Pretreatment

scholarly journals Characterization of Cellulose Microfibrils Obtained from Hemp

2013 ◽  
Vol 2013 ◽  
pp. 1-5 ◽  
Author(s):  
Anna Šutka ◽  
Silvija Kukle ◽  
Janis Gravitis ◽  
Laima Grave
Keyword(s):  
Steam Explosion ◽  
Microfibrillated Cellulose ◽  
Cellulose Microfibrils ◽  
Fibre Size ◽  
Steam Explosion Pretreatment ◽  
Hemp Fibres ◽  
Before And After ◽  
Cellulose Fibrils ◽  
Scanning Electron

Microfibrillated cellulose was extracted from hemp fibres using steam explosion pretreatment and high-intensity ultrasonic treatment (HIUS). The acquired results after steam explosion treatment and water and alkali treatments are discussed and interpreted by Fourier transform infrared spectroscopy (FTIR). Scanning electron microscopy (SEM) was used to examine the microstructure of hemp fibres before and after each treatment. A fibre size analyser was used to analyse the dimensions of the untreated and treated cellulose fibrils. SEM observations show that the sizes of the different treated fibrils have a diameter range of several micrometres, but after HIUS treatment fibres are separate from microfibrils, nanofibres, and their agglomerates.

Preparation and Characterization of Liquefaction Polyol of Wheat-Straw Lignocellulose

2012 ◽  
Vol 472-475 ◽  
pp. 2828-2833
Author(s):  
Yan Qiao Jin ◽  
Yi Zhuan Zhang ◽  
Xian Su Cheng
Keyword(s):  
Sulfuric Acid ◽  
Reaction Time ◽  
Wheat Straw ◽  
Steam Explosion ◽  
Acid Value ◽  
Hydroxyl Value ◽  
Peg 400 ◽  
Steam Explosion Pretreatment ◽  
Liquefaction Temperature

In this study, wheat-straw lignocelluloses were liquefied in liquefaction solvents. Polyethyleneglycol 400 (PEG 400) and ethylene glycol (EG) were used as main liquefaction solvents. The effect of liquefaction time and liquefaction solvents on the properties of liquefied products was investigated. As the reaction time increased, the hydroxyl value, residue content and viscosity decreased, and the acid value decreased gradually in the previous period of time then increased. The optimum liquefaction conditions were as follows: wheat-straw lignocelluloses with steam-explosion pretreatment, the main liquefaction reagent of PEG 400, auxiliary liquefaction solvents of glycerin, catalyst of sulfuric acid, liquefaction temperature of 150°C, liquefaction time of 4 h. The hydroxyl value of liquefaction product was 206 mgKOH/g, the residue content was 0.19% and the viscosity was 88 mPa•s.

Extraction and characterization of lignin from corncob residue after acid-catalyzed steam explosion pretreatment

2019 ◽  
Vol 133 ◽  
pp. 241-249 ◽  
Author(s):  
Xin Zhang ◽  
Jiadeng Zhu ◽  
Lu Sun ◽  
Qipeng Yuan ◽  
Gang Cheng ◽  
...  
Keyword(s):  
Steam Explosion ◽  
Steam Explosion Pretreatment ◽  
Acid Catalyzed

scholarly journals An extensive parameter study of hydrotropic extraction of steam-pretreated birch

2021 ◽  
Author(s):  
Johanna Olsson ◽  
Michael Persson ◽  
Mats Galbe ◽  
Ola Wallberg ◽  
Ann-Sofi Jönsson
Keyword(s):  
Residence Time ◽  
Steam Explosion ◽  
Room Temperature ◽  
Initial Step ◽  
Parameter Study ◽  
Hydrothermal Degradation ◽  
Steam Explosion Pretreatment ◽  
Lignin Extraction ◽  
Extraction Step ◽  
Lignin Recovery

AbstractEfficient fractionation of lignocellulosic biomass is an important step toward the replacement of fossil-based products. However, the utilisation of all of the components in biomass requires various fractionation techniques. One promising process configuration is to apply steam explosion for the recovery of hemicelluloses and a subsequent hydrotropic extraction step for the delignification of the remaining solids. In this work, the influence of residence time, temperature and biomass loading on lignin recovery from birch using sodium xylene sulphonate as a hydrotrope was investigated. Our results show that residence time, temperature and biomass loading correlate positively with lignin extraction, but the effects of these parameters were limited. Furthermore, when steam explosion was implemented as the initial step, hydrotropic extraction could be performed even at room temperature, yielding a lignin extraction of 50%. Also, hydrothermal degradation of the material was necessary for efficient delignification with sodium xylene sulphonate, regardless of whether it occurs during steam explosion pretreatment or is achieved at high temperatures during the hydrotropic extraction.

Estimating time to onset of swine influenza symptoms after initial novel A(H1N1v) viral infection

2010 ◽  
Vol 139 (9) ◽  
pp. 1418-1424 ◽  
Author(s):  
B. D. M. TOM ◽  
A. J. VAN HOEK ◽  
R. PEBODY ◽  
J. McMENAMIN ◽  
C. ROBERTSON ◽  
...  
Keyword(s):  
Incubation Time ◽  
Time Distribution ◽  
Age Groups ◽  
Swine Influenza ◽  
Interval Censoring ◽  
Limited Data ◽  
History Of ◽  
Influenza Case ◽  
Time To Onset

SUMMARYCharacterization of the incubation time from infection to onset is important for understanding the natural history of infectious diseases. Attempts to estimate the incubation time distribution for novel A(H1N1v) have been, up to now, based on limited data or peculiar samples. We characterized this distribution for a generic group of symptomatic cases using laboratory-confirmed swine influenza case-information. Estimates of the incubation distribution for the pandemic influenza were derived through parametric time-to-event analyses of data on onset of symptoms and exposure dates, accounting for interval censoring. We estimated a mean of about 1·6–1·7 days with a standard deviation of 2 days for the incubation time distribution in those who became symptomatic after infection with the A(H1N1v) virus strain. Separate analyses for the <15 years and ⩾15 years age groups showed a significant (P<0·02) difference with a longer mean incubation time in the older age group.

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