Isolation, Study and Application of Organosolv Lignins (Review)

Кузнецов, Б.Н.; Malyar, Yuriy N.; Кузнецова, Светлана А.; Grishechko, Lyudmila I.; Kazachenko, Аleksandr S.; Levdansky, Alexander V.; Pestunov, Andrey V.; Celzard, Alan

doi:10.17516/1998-2836-2016-9-4-454-482

Cited by 9 publications

(4 citation statements)

References 52 publications

(67 reference statements)

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“…The unique structure of lignin makes it a good candidate for chemical processing into valuable products, for example, in the production of phenolic and aromatic chemicals and liquid fuels [ 1 , 2 , 3 , 4 , 5 ]; however, its processing techniques are underdeveloped, in contrast to the case of polysaccharides.…”

Section: Introductionmentioning

confidence: 99%

Sulfation of Wheat Straw Soda Lignin with Sulfamic Acid over Solid Catalysts

et al. 2022

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Soda lignin is a by-product of the soda process for producing cellulose from grassy raw materials. Since a method for the industrial processing of lignin of this type is still lacking, several research teams have been working on solving this problem. We first propose a modification of soda lignin with sulfamic acid over solid catalysts. As solid catalysts for lignin sulfation, modified carbon catalysts (with acid sites) and titanium and aluminum oxides have been used. In the elemental analysis, it is shown that the maximum sulfur content (16.5 wt%) was obtained with the Sibunit-4® catalyst oxidized at 400 °C. The incorporation of a sulfate group has been proven by the elemental analysis and Fourier-transform infrared spectroscopy. The molecular weight distribution has been examined by gel permeation chromatography. It has been demonstrated that the solid catalysts used in the sulfation process causes hydrolysis reactions and reduces the molecular weight and polydispersity index. It has been established by the thermal analysis that sulfated lignin is thermally stabile at temperatures of up to 200 °C. According to the atomic force microscopy data, the surface of the investigated film consists of particles with an average size of 50 nm. The characteristics of the initial and sulfated β-O-4 lignin model compounds have been calculated and recorded using the density functional theory.

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Section: Introductionmentioning

confidence: 99%

Sulfation of Wheat Straw Soda Lignin with Sulfamic Acid over Solid Catalysts

et al. 2022

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“…One of the main advantages of organosolv delignification processes is their higher environmental safety as compared to sulfate and sulfite technologies. Organosolv lignins do not contain sulfur, have a rather narrow molecular weight distribution and a relatively small molecular mass (Torre MJ et al 2013;Lindner A et al 1988;Kuznetsov BN et al 2016). They are chemically more active than technical lignins; they have high solubility in organic solvents, which facilitates their further chemical processing.…”

Section: Introductionmentioning

confidence: 99%

Optimization of the process of abies ethanol lignin sulfation by sulfamic acid–urea mixture in 1,4-dioxane medium

et al. 2020

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The new process of abies ethanol lignin sulfation by a low-toxic mixture of sulfamic acid and urea in 1,4dioxane medium was optimized and the structure of sulfated ethanol lignin was studied. The process of lignin sulfation is described by a first-order equation in the temperature range 70-100˚C. The value of the rate constants are weakly dependent on the ratios of lignin and sulfating complex (SC-sulfamic acid-urea mixture). The activation energy of the sulfation process decreaseses from 95 kJ / mol to 24 kJ / mol with an increase in the content of the sulfating complex. The optimal conditions for sulfation of abies ethanol lignin with a high yield of water-soluble sulfated lignin ((100% of mass) with sulfur content of 7.9%) where found: temperature 95-100°С, L / SC ratio 1: 2,3-1:2,9 and the 2-hour duration of the process. The composition and structure of water-soluble sulfated ethanol lignin were proven by elemental analysis, FTIR spectroscopy, two-dimensional NMR spectroscopy and gel permeation chromatography. It was shown that only alcoholic OH-groups of ethanol lignin react with sulfation complex. Sulfated ethanol lignin has a higher molecular weight and a lower degree of polydispersity compared to the initial ethanol lignin .

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“…Однако разрабатываемые в последние годы новые способы получения целлюлозы, основанные на процессах органосольвентной варки древесины в присутствии различных органических растворителей [5,6], более экологически безопасны по сравнению с сульфитными и сульфатными технологиями. Кроме того, получаемые органосольвентные лигнины не содержат серы, обладают относительно небольшой молекулярной массой [7][8][9], более химически активны, чем технические лигнины, хорошо растворяются в органических растворителях, что облегчает их дальнейшую химическую переработку.…”

Section: Introductionunclassified

Numerical Optimization of the Abies Ethanol Lignin Sulfation Process with Sulfamic Acid in 1,4-Dioxane Medium in the Presence of Urea

Васильева

Levdanskii

Kazachenko

et al. 2020

Journal of Siberian Federal University. Chemistry

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The process of abies ethanol lignin sulfation with sulfamic acid in 1,4-dioxane medium in the presence of urea was optimized by calculation methods. The influence of such factors, as the ratio of lignin/sulfating complex (L/SC), temperature and time of the sulfation process on the sulfur content in the resulting sulfated ethanol lignin and its yield, has been established. The variance analysis of the obtained mathematical models testifies their good predictive properties. The optimal conditions of abies ethanol lignin sulfation process, which provide the formation of water-soluble sulfated lignin with a high yield (to 100 % wt.) and sulfur content (up to 7.9 % wt.), have been established. They are: temperature of 95-100 °C, the ratio L/SC 1:2,3-1:2:9 and the time of the process 119-137 minutes

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Isolation, Study and Application of Organosolv Lignins (Review)

Cited by 9 publications

References 52 publications

Sulfation of Wheat Straw Soda Lignin with Sulfamic Acid over Solid Catalysts

Sulfation of Wheat Straw Soda Lignin with Sulfamic Acid over Solid Catalysts

Optimization of the process of abies ethanol lignin sulfation by sulfamic acid–urea mixture in 1,4-dioxane medium

Numerical Optimization of the Abies Ethanol Lignin Sulfation Process with Sulfamic Acid in 1,4-Dioxane Medium in the Presence of Urea

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