Water-soluble azo derivatives of lignin were synthesized by the azo coupling reaction using organosolv ethanol lignin and diazonium salts based on sulfanilic acid and p-nitroaniline. The structure of azo derivatives of lignin were studied by nuclear magnetic resonance, Fourier-transform infrared spectroscopy, and gel permeation chromatography. It was found that the azobenzene bonds formed in the azo coupling reaction of macromolecules impart the photosensitive properties to the synthesized polymers via cis–trans photoisomerization of the diazobenzene group. It was shown experimentally that the synthesized polymers exhibited good solubility both in the aqueous media in a wide (2–12) pH range and in DMSO and THF organic solvents, which opens up new prospects for their application.

The influence of mass transfer intensity on the kinetics of the catalytic oxidation of flax shives with oxygen in alkaline media to aromatic aldehydes and pulp was studied. The process was carried out in two autoclaves, with moderate stirring (stirrer engine of 8 W) and intense stirring (stirrer engine of 200 W). The oxidation of flax shives into vanillin, syringaldehyde, and pulp was shown to proceed as a completely diffusion-controlled process under the studied conditions, both moderate and intense stirring. Depending on the process conditions, it can be limited by stages of oxygen transfer through the diffusion boundary layer near the gas–liquid interface (low intensity of mass transfer) as well as by reagents’ inner diffusion in the porous and solid matter of the flax shive particle (high intensity of mass transfer). The results on the influence of the stirring speed and volume of the reaction mass on the rates of oxygen consumption and vanillin accumulation were obtained. They were described using a known simple model connecting the intensity of mass transfer and the stirring power density in the bulk of the liquid phase in terms of algebra equations.

Agrotechnical wastes from processing herbaceous plants consist of lignin and polysaccharides, which can be processed into monomers – phenols and carbohydrates. The prospects of chemical processing of several agrotechnical waste types with a high lignin content (flax shives, sunflower seed husks and buckwheat husks) into vanillin, pulp, and glucose by oxidation and acid hydrolysis were studied. It has been shown that despite the distant phylogenetic relationship of the studied plants, their lignins have a similar structure: they contain a similar amount of methoxyl groups (10–13 wt.% per lignin) and give close yields of aromatic aldehydes upon oxidation with nitrobenzene (17–19%) and oxygen (14–16%). In general, the suitability of agrotechnical wastes for oxidation to aromatic aldehydes determines by the lignin content. Among the studied wastes, flax shives are the most promising feedstock for chemical processing into vanillin and glucose. Cellulose-containing solid residues of oxidation process are more easily hydrolyzed compared to the initial lignocellulosic biomass. The inversion of glucose oligomers during the hydrolysis of cellulose with H2SO4 is limited by the hydrolysis of the tetra- and octamers.

Ксилитол является важным продуктом переработки ксилана — основной гемицеллюлозы древесины березы и осины. Ксилитол получают прямым гидрированием ксилозы, в данном исследовании субстрат – ксилоза, был получен кислотным гидролизом ксилана древесины березы. Промышленным катализатором процесса получения ксилитола является никель Ренея. Пирофорность, склонность к спеканию, выщелачивание Ni и загрязнение продукта являются актуальными проблемами его применения. Нами разработаны новые нанесенные рутениевые катализаторы гидрирования ксилозы на основе мезопористого силиката SBA-15, допированного оксидом циркония (5Zr-SBA-15). Предложенный способ модификации SBA-15 допированием оксидом циркония улучшает гидротермальную стабильность носителя. Нанесенный Ru присутствует в виде высокодисперсных частиц RuO₂ и распределен равномерно. Катализаторы стабильны и безопасны, а их высокая каталитическая активность позволяет вести процесс в очень мягких условиях – в чистой воде при температуре 70 °С и давлении 5.5 МПа H₂, при этом катализаторы сохраняют селективность по основному продукту на уровне 96–99%. Внедрение в производство ксилитола разработанных катализаторов позволит сократить производственные затраты на очистку продукта, снизить энергетические затраты, тем самым улучшая эколого-экономические показатели процессов глубокой химической переработки растительного сырья.

The growth-promoting activity of lignoacids (LA), byproducts of the catalytic oxidation of pine and aspen wood to vanillin and cellulose, was studied. The use of LA opens the possibility of recycling wastewater from the catalytic processing of wood. The growth-promoting activity of LA was assessed on radish seeds Raphanus sativus var. radicula under laboratory conditions during germination on filter paper; germination energy, germination rate, and root and hypocotyl lengths were determined. The growth-promoting activity of LA was compared to radish seed germination in water and potassium bicarbonate solutions. It was shown that LA isolated during pine wood oxidation at concentrations of 5–40 mg/L exhibited a more pronounced growth-promoting effect compared to lignoacids isolated from aspen wood oxidation reaction solutions. It has been established that the growth-promoting effect increases in the order LCOsins < Pine LKS < Flax shives. This corresponds to a decrease in the content of methoxyl groups in various lignins. Lignoacids released during the oxidation of lignins from herbaceous plants and agricultural waste appear more promising for use as growth stimulants.

The mining, transportation, and processing of coal involve the formation and emission of significant amounts of particulate matter, which includes coal dust. The most commonly employed method for controlling coal dust in an air is water spray dust suppression (hydrodedusting). This method is founded on water’s capacity to moisten dust particles and bond them to both each other and the surfaces where the dust settles. One notable limitation of this method is the coal’s hydrophobic nature, which hinders water from wetting coal dust particles. In order to overcome this, surfactants are introduced into the water to increase the wettability of the hydrophobic coal particle surface. In this paper, we proposed a dust suppressant composition consisting of oleic acid, sodium hydroxide, and linseed oil in water. We examine its properties and evaluated its ability to enhance the wettability of coal dust. We have identified the most effective concentration, resulting in a working solution that improves the wettability of coal dust by 87 % compared to water, surpassing the wettability of most known reagents. The proposed composition contains 140 mg/L oleic acid, 100 mg/L sodium hydroxide, and 70 mg/L linseed oil in water. The simplicity of this composition, its minimal impact on the environment and human health, and its negligible influence on the further use of coal raw materials make this wetting agent composition highly promising for application in coal industry technologies of water spray dust suppression.