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In the last decades, the utilization of chitin-containing wastes has become an urgent task. The current work is aimed at studies on the use of chitosan (one of the main chitin components) for the preparation of magnetically separable biocatalysts. A multicomponent biocatalyst based on glucose oxidase (GOx) immobilized on Fe3O4 nanoparticles modified with chitosan and sodium tripolyphosphate was synthesized. The carboxyl groups of GOx were pre-activated with 1-Ethyl-3-(3-dimethylaminopropyl)carbodiimide hydrochloride (EDC) and N-hydroxysuccinimide (NHS). Fourier-transform infrared spectroscopy and low-temperature nitrogen physisorption proved successful modification of the magnetically separable support with a fine layer of chitosan. The presence of target functional groups on the support surface was also confirmed. The activity and stability of the biocatalyst were investigated in the oxidation reaction of D-glucose to D-glucono-d-lactone. The immobilized biocatalyst showed slightly lower activity than that for the native enzyme. However, the immobilized enzyme can be easily separated from the reaction mixture by an external magnet and reused practically without activity loss. The ratio of the biocatalyst components providing maximum activity and stability was determined. It has been shown that the immobilization of GOx by the method described above results in an expansion of the operating range of pH and temperatures by 15-20 % compared to the native enzyme. The synthesized biocatalyst can be used to produce gluconic acid and determine the concentration of D-glucose in various fluids.

The polymer can be effectively used as the supports for catalyst preparation. The main disadvantage of the polymer support is the absence of the acid-base sites on its surface. The modification of the polymeric support is one of the ways to solve this problem. In the current work, the modification of the surface of the hypercrosslinked polystyrene was carried out to apply the silicon oxide and provide the acid sites on the polymer. The effect of the silica deposition method and silica precursor was studied by the physics chemical analysis. The precipitation of the silica in subcritical water was found to provide the higher specific surface area of the resulting support (over 700 m2/g) in comparison with the wet-impregnation method. The use of ethoxysilanes, particularly 3-aminopropyltriethoxysilane, as a silica precursor was found to lead to the full deposition of Si. The synthesized modified support was used for the preparation of the catalyst for Fischer-Tropsch synthesis. Lewis acid sites on the catalyst support facilitate the CO adsorption and enhance the production of hydrocarbons via Fischer-Tropsch synthesis. The use of the catalysts on the silica-modified support showed a three-fold increase in CO conversion with an increase in the selectivity towards the oxygenates.

Reducing the density of building composites improves a number of performance properties of materials. Reducing the thermal conductivity, weight, and thickness of building products provides a solution to problems of energy and resource conservation and leads to a reduction in the consumption of natural resources and energy. To solve these problems, the work explores the possibility of using one of the fractions of fuel ash containing predominantly unburned organic residues of solid fuel. The structural features of unburned coal after high-temperature treatment can contribute to the transformation of the structure of mineral composites. The synthesis of modified gypsum with the addition of unburned coal fraction additionally leads to a reduction in the volume of gypsum binder used by up to 30 %. The purpose of the work was to determine the optimal additive content of this by-product according to the criteria of density and porosity. The results obtained demonstrate the effect of changing the content of additives on the synthesis of modified gypsum. It has been established that gypsum modified is superior to the control composition in all aspects of structural changes. First of all, this was manifested in the porosity characteristics. The radical change in the pore structure is confirmed by research and analysis of the results obtained using the mercury porosimetry method. The total pore volume increased more than 4 times. The achieved results on density and porosity open up new broad opportunities in the field of creating bio-positive materials for green construction.

Biochar is a carbonaceous product from biomass obtained by heat treatment of organic materials such as wood, by-products of wood processing, and plant residues. Biochar can be obtained as a result of thermal processing, which can be divided into three main processes: pyrolysis, torrefaction, and hydrothermal carbonization. The resulting biochar has different composition, structural and textural properties, strength, etc. Despite of numerous studies, the investigation of biochar production and properties are of great interest. Modification of carbonaceous products obtained from biomass is one of the actual tasks to produce the tailor-made materials. This article presents a comparison of the characteristics of biochar obtained by three methods: pyrolysis, torrefaction, and hydrothermal carbonization. Another task was the evaluation of the modifier addition to biochar to form materials with higher surface area and abrasion resistance for catalyst applications. The biochar obtained by the torrefaction from different lignocellulosic feedstock (hydrolysed and non-hydrolysed pine and birch sawdust) was found to have the highest carbonization degree, and the highest specific surface area. It was found that the additional modification of biochar with silica provides an increase its abrasion resistance, and higher porosity that allows the material obtained to be used for different purposes (as filler and binder for the construction materials, catalyst support etc.).

Biomass can be considered as a potential resource for the production of renewable fuels. Lignocellulose biomass is a widely available, renewable, biodegradable, and biocompatible resource that can potentially reduce the dependence of modern society on fossil resources. It is a potential feedstock for the production of heat, electricity, fuel, chemicals, and other bioderived products. Considerable attention of researchers is directed to the conversion of biomass into bioenergy through chemical, biochemical, or thermochemical processes. Hydrolysis is considered to be one of the important steps to convert biomass into valuable chemicals. During hydrolysis, liquid rich in sugars with a certain amount of dissolved lignin, usually called hydrolysate, is formed. In this paper, the influence of the catalyst type, temperature, catalyst concentration, and solvent type on the conversion and composition of hydrolysate was studied. The highest yield of hydrolysis products (hexoses and pentoses) reached up to 80 wt. % at a temperature of 220 °C in water medium in the presence of 1.5 wt. % of sulfuric acid.

The influence of ultrasonic treatment of flotation reagents on the yield of carbon concentrate and its carbon content, and the duration of flotation, was studied. It has been established that the effect of ultrasound on flotation reagents leads to almost complete dispersion and a 3-fold reduction in the consumption of collectors. It is shown that with an increase in the time of ultrasonic treatment of collectors, the volume fraction of collector droplets with a size of less than 1000 nm increases. In addition to reducing collector consumption, the yield of carbon concentrate increases by 20-30 %. The carbon content in the concentrate increases to 72-78 %. The resulting carbon concentrate corresponds to high-grade hard coals in terms of calorific value and can be used as fuel in power plants using solid fuels. Carbon-free ash contains less than 4% unburned carbon and can be used in the construction industry.

A control of a cement composite structure formation from modern positions should be carried out taking into account the synergistic effect of its components. The goal of the article is to study the combined effect of nanomodified basalt fiber (NBF) and bottom ash (BA) as structural elements of concrete using a two-factor analysis of variance ANOVA. The tasks for achieving this goal are the development of nanomodified basalt fiber bottom ash-cement concretes, as well as the study of their fresh, physical and mechanical properties (slump, slump flow, average density, compressive and flexural strength, elastic modulus and crack resistance) and durability performances (water, frost, and abrasion resistance). Nanomodified basalt-fiber-reinforced concretes (from 0 to 7 wt % NBF) have been developed, in which the economical Portland cement CEM I 32.5 N is replaced by up to 45 wt % mechanically activated bottom ash (400 m2/kg). Achieving uniform flowability of the compositions (slump 20–22 cm and slump flow 45–52 cm) was carried out by varying the dosage of an economical superplasticizer with a high water-reducing ability (35%). The joint effect of the BA and NBF provides control over the structure formation of cement materials, which ensures the redistribution of internal stresses from shrinkage deformations throughout the entire volume of the composite; during loading, the process of crack formation is retarded, stress concentration near structural defects is reduced, and stresses are redistributed in the microstructure of the cement composite between its components.High values of mechanical properties (compressive strength up to 59.2 MPa, flexural strength up to 17.8 MPa, elastic modulus up to 52.6 GPa, limit stress intensity factor 0.507 MPa m0.5) are explained by the complex effect of bottom ash and nanomodified basalt fibers. For the composition with 30 wt % BA and 5 wt % NBF, W18 water resistance grade, F400 frost resistance grade, and the abrasion resistance of 0.59 g/cm2 were achieved, which characterizes the high durability of the developed materials.

Platform chemicals, also known as chemical building blocks, are substances that serve as starting materials for the synthesis of various value-added products, which find a wide range of applications. These chemicals are the key ingredients for many fine and specialty chemicals. Most of the transformations of platform chemicals are catalytic processes, which should meet the requirements of sustainable chemistry: to be not toxic for humans, to be safe for the environment, and to allow multiple reuses of catalytic materials. This paper presents an overview of a new class of heterogeneous catalysts based on nanoparticles of catalytically active metals stabilized by a polymer matrix of hypercrosslinked polystyrene (HPS). This polymeric support is characterized by hierarchical porosity (including meso- and macropores along with micropores), which is important both for the formation of metal nanoparticles and for efficient mass transfer of reactants. The influence of key parameters such as the morphology of nanoparticles (bimetallic versus monometallic) and the presence of functional groups in the polymer matrix on the catalytic properties is considered. Emphasis is placed on the use of this class of heterogeneous catalysts for the conversion of plant polysaccharides into polyols (sorbitol, mannitol, and glycols), hydrogenation of levulinic acid, furfural, oxidation of disaccharides, and some other reactions that might be useful for large-scale industrial processes that aim to be sustainable. Some challenges related to the use of HPS-based catalysts are addressed and multiple perspectives are discussed.

Despite numerous works devoted to the cellulose hydrogenolysis process, only some of them describe reaction kinetics. This is explained by the complexity of the process and the simultaneous behavior of different reactions. In this work, we present the results of the kinetic study of glucose hydrogenolysis into ethylene- and propylene glycols in the presence of Ru@Fe3O4/HPS catalyst as a part of the process of catalytic conversion of cellulose into glycols. The structure of the Ru-containing magnetically separable Ru@Fe3O4/HPS catalysts supported on the polymeric matrix of hypercrosslinked polystyrene was studied to propose the reaction scheme. As a result of this study, a formal description of the glucose hydrogenolysis process into glycols was performed. Based on the data obtained, the mathematical model of the glucose hydrogenolysis kinetics in the presence of Ru@Fe3O4/HPS was developed and the parameter estimation was carried out. The synthesized catalyst was found to be characterized by the enhanced magnetic properties and higher catalytic activity in comparison with previously developed catalytic systems (i.e., on the base of SiO2). The summarized selectivity towards the glycols formation was found to be ca. 42% at 100% of the cellulose conversion in the presence of Ru@Fe3O4/HPS.

The article presents the results on the thermal processing of the samples of flax production - flax shive and the cellulose residue of flax shive. Experimental data on the conversion of selected samples of flax production waste obtained on a laboratory installation of slow pyrolysis in a temperature range of 500-750 ? are presented. The composition of gaseous pyrolysis products has been studied in detail and the main content of methane, hydrogen, and carbon oxides in the course of the process have been determined. Data on the composition of liquid products of pyrolysis of selected samples of plant biomass using the method of gas chromatography-mass spectrometry are presented. As part of the work, elemental analysis of samples of solid carbon-containing residues for the studied samples of flax and cellulose residue was carried out, and an analysis was carried out by the method of low-temperature adsorption of nitrogen.

Nitrobenzene hydrogenation is a widely used process applied for aniline production. Nitrobenzene hydrogenation kinetics greatly depends on catalyst properties and structure therefore, its study can shed light on process particularities and catalyst properties. The article is devoted to study of nitrobenzene hydrogenation kinetics for monometallic Ni (18.4 wt.%) containing hypercrosslinked polystyrene and bimetallic Pd(0.5 wt.%), Ni(17.9 wt.%) containing hypercrosslinked polystyrene. Nitrobenzene concentration and hydrogen partial pressure influence was studied in a variety of conditions. Nitrobenzene hydrogenation over monometallic sample shows the formation of essential amounts of side products - nitrozobenzene and phenylhydroxylamine while for bimetallic sample direct formation of aniline was noticed. Langmuir–Hinshelwood model was used to study reaction kinetics. A complex model including azobenzene, phenylhydrohylamine and aniline formation steps was developed for monometallic catalyst. The reaction model for bimetallic Ni, Pd catalyst contains only direct aniline formation reaction due to high process selectivity. Values of adsorption and reaction constants are higher for bimetallic catalyst that can explain its enhanced nitrobenzene hydrogenation rate.

Nowadays, the processes aimed at the deep conversion of heavy oil are of great interest. Polyaromatic and sulfur-containing compounds (such as anthracene and dibenzothiophene) are one of the main components of heavy oil fractions which are hard to process. Catalytic hydrotreatment of heavy petroleum fractions (vacuum gas oil, light gas oil, etc.) is widely used to improve the quality of the resulting products. As the hydrotreatment of oil fractions often requires the use of harsh process conditions and consumes a high amount of molecular hydrogen, the researchers’ interest is focused on the development of novel approaches including the use of supercritical fluids. In this work, the influence of solvent in the supercritical state on the conversion and product composition of cracking and desulfurization of polyaromatic and sulfur-containing compounds is described. The experimental results showed that the use of a supercritical solvent mixture composed of n-hexane and methanol allows the polyaromatic compounds to be effectively converted into monoaromatics providing a high conversion degree (up to 95 %).

Hydrocarbons synthesis using transformation of methanol/dimethyl ether is of particular interest in connection with the possibility of using synthesized hydrocarbons not only as fuel but as components for basic organic synthesis to obtain organic acids, polymers and pharmaceuticals. However, catalysts deactivation, based on surface coking and dealumination, can be considered as one of the main problems for the wide application of this technology. Deactivation kinetics modeling can play a leading role for economic assessment of this process and for development of methods for catalysts activity and stability improving. Article devoted to approval three deactivation models. Simple linear deactivation model showed the possibility of its usage only in the first parts of the deactivation process, where kinetic curves are linear. An extra operator addition to this model for determination of deactivation rate change allowed to improve model reliability. To enhance model correlation with reaction mechanism additional model was developed using chemical equations for catalysts surface deactivation. This model application allowed to improve results accuracy, however measurement of surface active sites quantity is needed for this calcula

Nowadays, the production of liquid motor fuel faces such problems as compliance of the final product with existing international standards (for the content of sulfur, oxygen and nitrogen) as well as the improvement of the feasibility of the existing technologies for fuel production. Biomass is one of the most perspective and widely spread sources for energy. The existing techniques for biomass conversion into the fuels are mainly based on the hydroprocessing and can be successfully applied in petroleum industry. The integrated processes involving both biofuel and oil conversion are of great interest. In this work, the novel hydrogen-free approach for co-processing of heavy oil fractions and bio-oil is described. The use of supercritical solvent mixture, which includes propanol-2 and n-hexane, allows full substrate conversion to be achieved for maximum 3 h. As a result, the hydrocarbon mixture consisting of aromatic and cyclic compounds was obtained with 99 wt. % yield.

A new Ru-containing catalyst based on Fe3O4-SiO2 particles that exhibit magnetic properties is proposed for the hydrogenolysis of cellulose to glycols and the hydrolytic hydrogenation of inulin to mannitol. Here, we also report utilisation of a magnetically recoverable catalyst in the inulin hydrolytic hydrogenation to mannitol. The effect of process parameters on the selectivity toward the main products is studied. In the hydrogenolysis of cellulose, the highest selectivities for EG (19.1 %) and PG (20.9 %) are achieved within 50 min under conditions of 255 °C, H2 60 bar. The conversion of cellulose is 100 %. In the hydrolytic hydrogenation of inulin, maximum mannitol selectivity (44.3 %) is reached within 45 min under conditions of 150 °C, H2 60 bar. The conversion of inulin is 100 %.The catalyst used in this work is stable under hydrothermal conditions of the process. It can be easily magnetically separated from the reaction mixture and reused without any loss of selectivity and activity, making this catalyst promising for practical applications in biomass conversion.

The selective oxidation of organic compounds to obtain vitamins is one of the key processes in chemistry and biotechnology. The use of toxic compounds such as chromium and manganese oxides for these purposes strongly affects the environment. We propose a novel bio-catalyst supported on magnetically separable nanoparticles based on the immobilized peroxidase. Biocatalysts based on immobilized enzymes received considerable attention due to important applications in syntheses of value-added chemicals, pharmaceuticals and drug intermediates with great catalytic efficiency and high yields of target molecules. In this work, we studied the oxidation of 2,3,6-trimethylphenol to 2,3,5-trimethylhydroquinone (an intermediate of vitamin E) using hydrogen peroxide. The effects of initial substrate concentration, temperature, and pH were studied. The optimum conditions for the process of oxidation 2,3,6-trimethylphenol in the presence of magnetically separable biocatalyst were found: initial substrate concentration – 1.5 mmol/L; temperature – 40 °C; pH – 6.5. The developed biocatalyst showed high activity and selectivity in 2,3,6-trimethylphenol oxidation to 2,3,5-trimethylhydroquinone.

Furfural (FF) is one of the main components of bio-oil obtained by the treatment of lignocellulose biomass. Furfural alcohol (FA) as the main product of the selective FF hydrogenation is a source of value-added chemicals. In this paper, the results of the study of ruthenium catalysts based on hyper-crosslinked polystyrene (PS) in the selective hydrogenation of FF to FA are presented. Two types of ruthenium catalysts: nanoparticles of RuO2 and Ru0 stabilized in the PS pores were synthesized and compared. The novelty of this work is in the comparison of the PS stabilized Ru0 and RuO2 nanoparticles were performed and differences in their catalytic properties were shown. The BET, TEM, and SAXS data showed the formation of Ru-containing nanoparticles similar in size and structure for both catalysts. The comparison of the catalytic properties of the Ru catalysts showed that the catalyst with Ru0 (Ru-PS) exhibits higher values of FF conversion (99 %) and selectivity to FA (96 %). It can be assumed that Ru0 nanoparticles are responsible for the formation of catalytically active sites of selective hydrogenation of FF to FA.

In this paper, a novel catalysts on the base of hypercrosslinked polystyrene (HPS) with magnetic properties are proposed for the one-pot processes of the cellulose conversion into ethylene glycol (EG) and propylene glycol (PG). Synthesized magnetically recoverable supports and catalysts were characterized by different physical-chemical methods. The magnetic properties of the supports Fe3O4/HPS MN270 and the corresponding catalysts were studied. The use of this catalyst in the process of microcrystalline cellulose hydrogenolysis in subcritical water allows PG and EG selectivities of 20.0 and 22.6%, respectively, at 100% of cellulose conversion.

Here, the novel method for the conversion of fatty acids into hydrocarbon fuel without hydrogen consumption is reported. The deoxygenation of stearic acid as a model compound was performed in the medium of supercritical n-hexane in the presence of Ni-containing catalysts synthesized by a hydrothermal deposition method. We studied the influence of the support as well as the metal loading on the yield of target products of stearic acid conversion into hydrocarbons. Ni was supported on the three different supports: anhydrous microporous silica, anhydrous alumina, and non-functionalized hypercrosslinked polystyrene. The hydrothermal synthesis of the catalysts leads to the changes in the porosity and structure of the supports increasing the number of mesopores. The active phase of the catalysts was found to be deposited on the internal surface of the supports as a thin layer of ?-NiOOH. Ni/HPS catalyst was found to be the most active in the stearic acid deoxygenation process in supercritical n-hexane. The study of the influence of the metal loading on the conversion of the substrate and the target product yield showed that 10 wt. % of Ni is more favorable for the production of high yield of C16-C17 hydrocarbons.

The article presents the results of the process of hydrogenolysis of lignin obtained from softwood sawdust using 5% Pt/MN270 and 3% Pt/MN270 catalysts. Depending on the desirable products 2-propanol was chosen as the solvent showing the highest substrate conversion and product yield. Pt polymer-based catalyst provides high substrate conversion compared to Pd catalysts. This can be due to the higher surface area and the higher active metal concentration on the catalyst surface. Also, it is notable, that Pt-containing catalyst results in the lowest formation of oxygen-containing products. The highest conversion (90%) and the highest selectivity towards the oxygen-free hydrocarbons (92%) were achieved while using 5% Pt catalyst based on HPS.

The work is devoted to the modification of H-ZSM-5 samples with sodium hydroxide and oxalic acid to provide the formation of the mesoporous structure of the zeolite and to obtain optimal Si/Al ratio. Moreover, zeolite active sites were modified with Co, Ni, Fe in order to decrease polyaromatic substances formation during methanol transformation into hydrocarbons. The testing of the samples was performed at 350 ºC in a flow reactor, the methanol feed rate was maintained at 0.16 g(methanol)/(g(Cat)*h). Dimethyl ether transformation rate into hydrocarbons was found to be 0.055-0.1 kg(DME)/(kg(Cat)*h) for investigated catalysts. Alkali treatment of H-ZSM-5 samples results in the formation of a mesoporous structure with a mean pore diameter of 5 nm. Formation of additional mesopores results in some increase of dimethyl ether to hydrocarbons transformation rate up to 0.09 kg(DME)/(kg(Cat)*h). Zeolite treatment with oxalic acid results in decreasing of Si/Al ratio from 0.76 to 0.41 that case some decrease of dimethyl ether transformation rate from 0.07 kg(DME)/(kg(Cat)*h) to 0.05 kg(DME)/(kg(Cat)*h), however considerable decrease of polyaromatic hydrocarbons concentration in reaction media was achieved for sample with lowest Si/Al ratio. Modification of H-ZSM-5 with Co, Fe, Ni results in some increase of dimethyl ether transformation rate up to 0.07-0.1 kg(DME)/(kg(Cat)*h) and a considerable decrease of polyaromatic hydrocarbons concentration in reaction media due to active sites modification.The ZSM-5-Ni-0.001M sample showed highest activity 0.1 kg(DME)/(kg(Cat)*h).

Basing on the experimental data the optimal parameters of the pyrolysis of heavy and residual hydrocarbons of oil were defined as follows: temperature of 500 °С; catalyst of CoCl2 with the catalyst loading 5% (wt.) of the substrate weight. Under the optimal conditions the kinetic investigation of the pyrolysis process was carried out using the thermogravimetric method. According to the investigation, it was found that the activation energy of the catalytic pyrolysis of oil-containing waste decreased by 20-30 kJ/mol in comparison to non-catalytic process.

This paper describes synthesis of Pd-containing catalysts of Suzuki cross-coupling based on amino-functionalized hypercrosslinked polystyrene. The investigation of the influence of a palladium concen-tration, solvent composition, temperature, type and concentration of base, and a type of a gas phase was carried out. It was shown that the catalyst developed allows achieving conversion of 4-bromoanisole higher than 98% for less than 1 h at mild reaction conditions and in the absence of a phase transfer agent. Catalyst reduction was found to result in formation of small Pd nanoparticles (about 3 nm in diameter) and a large number of Pd clusters, which are highly active in Suzuki-Miyaura cross-coupling (conversion of 4-bromoanisole reached 90.2% for 3 h). Copyright © 2015 by Authors, Published by BCREC Group. This is an open access article under the CC BY-SA License (https://creativecommons.org/licenses/by-sa/4.0).

This paper reports on ruthenium nanoparticles formation and stabilization by hypercrosslinked poly-styrene and the catalytic properties of the nanocomposites obtained. Hypercrosslinked polystyrene with functional groups and without them was used. The nanocomposites were characterized using low-temperature nitrogen physisorption, X-ray photoelectron spectroscopy and transmission electron mi-croscopy. It is established that the tertiary amine group of the support influences both formation of ru-thenium nanoparticles, and their catalytic properties in the selective hydrogenation of D-glucose. Copyright © 2015 by Authors, Published by BCREC Group. This is an open access article under the CC BY-SA License (https://creativecommons.org/licenses/by-sa/4.0).