scholarly journals Optimization of the Process of Abies Wood Peroxide Delignification in the Medium “Formic Acid-Water” in the Presence of TiO₂ Catalyst

2019 ◽  
pp. 522-535
Author(s):  
Natalya V. Garyntseva ◽  
Irina G. Sudakova ◽  
Anna I. Chudina ◽  
Yuri N. Malyar ◽  
Boris N. Kuznetsov
Keyword(s):  
Molecular Weight ◽  
Formic Acid ◽  
Lignin Content ◽  
Average Molecular Weight ◽  
Mathematical Optimization ◽  
Acid Water ◽  
Water Medium ◽  
Residual Lignin ◽  
Acetic Acid Water ◽  
Peroxide Delignification

The experimental and mathematical optimization of abies wood peroxide delignification process in the formic acid – water medium in the presence of TiO₂ catalyst was carried out. It was established that in the temperature range 70-100 °С the rate constants of the delignification process vary between 0.4 and 3.2 · 10-4 min-1. The optimal parameters for the production of cellulose product with a residual lignin content of ≤ 3 wt.% were determined (temperature 100 °С, concentration Н₂О₂ 10 wt.%, НCOOН 38 wt.%, LWR 15, time 4 h). The features of abies wood peroxide delignification processes in the presence of TiO₂ catalyst in “ formic acid – water” and “acetic acid – water” were compared. It was shown the possibility of abies wood fractionation in the medium “ formic acid-water” to high-quality cellulose with the yield of 94 wt.% (the content of residual lignin 2.3 wt.%) and to low molecular weight lignin with the yield of 21 wt.% (average molecular weight 1854 g/mol and polydispersity 1.65). The obtained chemically active lignin can be used for the production such valuable products as enterosorbents, nanoporous carbon materials, aerogels

scholarly journals Study of Regularities and Optimization of the Process of Fir Wood Peroxide Delignification in the Medium of “Acetic Acid – Water” in the Presence of Sulfuric Acid Catalyst

2019 ◽  
pp. 590-603
Author(s):  
Olga V. Yatsenkova ◽  
Andrei M. Skripnikov ◽  
Boris N. Kuznetsov
Keyword(s):  
Acetic Acid ◽  
Lignin Content ◽  
Reaction Medium ◽  
Acid Catalyst ◽  
Acid Water ◽  
High Yield ◽  
Process Conditions ◽  
Residual Lignin ◽  
Acetic Acid Water ◽  
Peroxide Delignification

The work describes a one-stage method of cellulose obtaining from fir wood based on peroxide delignification of wood under mild conditions (100 °C, atmospheric pressure) in the presence of acetic acid, water and catalyst of 2% wt. H2SO4. The possibility of obtaining cellulose with a residual lignin content <1% wt. at a low concentration of hydrogen peroxide (3% wt.) in the reaction medium was established. The optimal concentrations of reagents (Н2О2 – 3% wt., CH3COOH – 38.9% wt.) and the duration of the process (4 h) were determined by experimental and calculation methods. This conditions provide a high yield of cellulose product (≥45% wt.) with a low content of residual lignin (<1% wt.). The composition and structure of fir cellulose was studied by chemical analysis and by FTIR and SEM methods. The cellulosic product which was obtained in optimal process conditions is high-quality cellulose

scholarly journals Numerical Optimization of the Process of Cellulose Isolation by Peroxide Delignification of Birch Wood in Acetic Acid-Water Medium in the Presence of TiO₂ Catalyst

2021 ◽  
Vol 14 (1) ◽  
pp. 120-132
Author(s):  
Natalya V. Garyntseva ◽  
◽  
Irina G. Sudakova ◽  
Anna I. Chudina ◽  
Boris N. Kuznetsov
Keyword(s):  
Acetic Acid ◽  
Numerical Optimization ◽  
Acid Water ◽  
Process Conditions ◽  
Water Medium ◽  
Cellulose Content ◽  
Birch Wood ◽  
Optimal Conditions ◽  
Acetic Acid Water ◽  
Peroxide Delignification

The possibility of isolation of high-quality cellulose by peroxide delignification of birch wood in an acetic acid-water medium in the presence of a TiO2 catalyst at a temperature of 100 °C was shown. The influence of the process conditions (concentration of hydrogen peroxide and acetic acid, liquid/wood ratio (LWR)) on the yield and composition of cellulose products was established. Numerical optimization of the process was carried out using a full factorial experiment. The optimal conditions for isolation from birch wood a cellulose product with residual lignin content of ≤ 1 wt.% are: СН3СООН concentration 23.8 wt.%, Н2О2 concentration 4.9 wt.%, LWR14.9, temperature 100 °C, time 4 h. Under these optimal conditions, the yield of a cellulose product with a cellulose content of 92.5 wt.% was 49.9 wt.%

scholarly journals The Fractionation of the Nitrogen Compounds of Wheat Flour on Sephadex Collumns

1968 ◽  
Vol 21 (5) ◽  
pp. 1077 ◽  
Author(s):  
HPC Galluse ◽  
AC Jennings
Keyword(s):  
Molecular Weight ◽  
Acetic Acid ◽  
Wheat Flour ◽  
Trichloroacetic Acid ◽  
Acid Water ◽  
Nitrogen Compounds ◽  
Low Molecular Weight ◽  
Acetic Acid Water

Bagdasarian et al. (1964) have discussed the difficulties in separating compounds of low molecular weight from proteins, and the advantages of using a volatile solvent, such as phenol~acetic acid~water (1 : 1 : 1, w/v/v) (referred to as solvent A in the remainder of this paper), to achieve this separation. Trichloroacetic acid is also efficient in effecting this separation (Bagdasarian et al. 1964), but it dissolves glycoproteins (Bell 1963; Stenzel et al. 1964 ; Jennings and Watt 1967) and some of the wheat flour proteins (Bell 1963) and is difficult to remove from solutions.

Recovering ultraclean lignins of controlled molecular weight from Kraft black-liquor lignins

2015 ◽  
Vol 51 (64) ◽  
pp. 12855-12858 ◽  
Author(s):  
A. S. Klett ◽  
P. V. Chappell ◽  
M. C. Thies
Keyword(s):  
Molecular Weight ◽  
Acetic Acid ◽  
Black Liquor ◽  
Acid Water ◽  
Liquid Equilibrium ◽  
Kraft Black Liquor ◽  
Acetic Acid Water

By operating in a region of liquid–liquid equilibrium, hot acetic acid–water mixtures can be used to simultaneously clean, fractionate, and solvate Kraft black-liquor lignins.

Selective oxidation of p-chlorotoluene with Co(OAc)2/MnSO4/KBr in acetic acid–water medium

2007 ◽  
Vol 8 (8) ◽  
pp. 1279-1283 ◽  
Author(s):  
An-Jun Hu ◽  
Chun-Xu Lü ◽  
Hai-Ying Wang ◽  
Bin-Dong Li
Keyword(s):  
Acetic Acid ◽  
Selective Oxidation ◽  
Acid Water ◽  
Water Medium ◽  
Acetic Acid Water

scholarly journals PEROXIDE DELIGNIFICATION OF THE VEGETATIVE PART OF JERUSALEM ARTICHOKE IN THE MEDIUM ACETIC ACID-WATER

2020 ◽  
pp. 351-358
Author(s):  
Tat'yana Vasil'yevna Ryazanova ◽  
Vladimir Sergeyevich Fedorov ◽  
Ekaterina Vyacheslavovna Kharyanova ◽  
Sergey Redzhinal'dovich Loskutov ◽  
Aleksandra Vasil'yevna Kournikova
Keyword(s):  
Chemical Composition ◽  
Jerusalem Artichoke ◽  
Dicarboxylic Acids ◽  
Raw Material ◽  
High Yield ◽  
Residual Lignin ◽  
Technological Parameters ◽  
Vegetative Part ◽  
Acetic Acid Water ◽  
Peroxide Delignification

The purpose of this work was to evaluate the vegetative part of Jerusalem artichoke as a raw material for the production of cellulose using redox-organosolvent delignification in the medium "CH3СOOН – H2O2 – H2O". The chemical composition of the vegetative part of Jerusalem artichoke and the influence of technological parameters of the delignification process on the yield and properties of the cellulose product were studied. It was found that the vegetative part of Jerusalem artichoke collected in October (stems without leaves) with a chemical composition of more than 50 wt.% of polysaccharides in which presented the Kurshner-Hoffer cellulose more than 90 wt.% was more promising for processing. Experimental methods have been used to determine the parameters of the process of delignification of the vegetative part of Jerusalem artichoke, which provide a high yield of cellulose (42.1 wt.%) with a low content of residual lignin (1.1 wt.%): content of H2O2 – 6.5 wt.%, CH3COOH – 23.4 wt.%, GM 15, duration – 2.5 h, catalyst H2SO4 – 0.2 wt.%. It is shown that pre-extraction of the vegetative part of Jerusalem artichoke with a 0.3% solution of dicarboxylic acids at a temperature of 80 °C with a liquid modulus of 10 for 3 hours reduces the content of residual lignin in the cellulose product to 0.5 wt.% and obtain an extract whose yield is – 7.8 wt.%, including a PB of 4.2 wt.%, which makes it promising for biochemical processing. The obtained results expand the areas of use of the vegetative part of Jerusalem artichoke and show the prospects for further more depth research to optimize the process of delignification and study the properties of the cellulose product.

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