birch wood
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2021 ◽  
pp. 345-350
Author(s):  
Andrey Aleksandrovich Spitsyn ◽  
Mariya Igorevna Minich ◽  
Dmitriy Andreyevich Ponomarev ◽  
Nikolay Ivanovich Bogdanovich

The sorption capacity of activated carbon obtained from various plant precursors – apple wood, birch wood, pine cones and cellolignin was studied. The plant material was first subjected to carbonation by heating to a temperature of 700 °C and further exposure at this temperature. The total heating time was 8 hours. Charcoal was then subjected to steam activation at a reactor temperature of 950 °C and an activation time of 40–45 minutes. The yield of activated carbon estimated on charcoal was 42–46%. The characteristics of the porous structure were determined by the method of low-temperature nitrogen adsorption. The total specific surface area according to the BET method was (m2/g) 674, 594, 552, 552, 622 for apple wood, birch wood, pine cones, cellolignin and an industrial sample of activated carbon, respectively. Determination of the adsorption capacity by iodine adsorption methods showed that this value, depending on the source of raw materials, falls in the order: birch wood > cellolignin ≈ apple wood > pine cones. The data on the sorption of benzene characterize approximately the same range of sorption capacity: birch wood > cellolignin > pine cones ≈ apple wood. The data on the sorption capacity show that unconventional plant raw materials can be used to produce activated carbon.


2021 ◽  
pp. 105-118
Author(s):  
Boris Nikolayevich Kuznetsov ◽  
Natal'ya Viktorovna Garyntseva ◽  
Irina Gennad'yevna Sudakova ◽  
Andrey Mikhaylovich Skripnikov ◽  
Andrey Vladimirovich Pestunov

For the first time, it was proposed to fractionate the main components of birch wood into microcrystalline cellulose, xylose and enterosorbents by integrating heterogeneous catalytic processes of acid hydrolysis and peroxide delignification of wood biomass. The hydrolysis of wood hemicelluloses into xylose is carried out at a temperature of 150 °C in the presence of a solid acid catalyst Amberlyst® 15. Then the lignocellulosic product undergoes peroxide delignification in a "formic acid – water" medium in the presence of a solid TiO2 catalyst to obtain microcrystalline cellulose (MCC) and soluble lignin. Under the determined optimal conditions (100 °С, Н2О2 – 7.2 wt.%, НСООН – 37.8 wt.%, LWR 15, time 4 h), the yield of MCC reaches 64.5 wt.% and of organosolvent lignin 11.5 wt% from the weight of prehydrolyzed wood. By the treatment of organosolvent lignin with a solution of 0.4% NaHCO3 or hot water the enterosorbents were obtained, whose sorption capacity for methylene blue (97.7 mg/g) and gelatin (236.7 mg/g) is significantly higher than that of the commercial enterosorbent Polyphepan (44 mg/g and 115 mg/g, respectively). The products of catalytic fractionation of birch wood are characterized by physicochemical (FTIR, XRD, SEM, GC) and chemical methods.


Materials ◽  
2021 ◽  
Vol 14 (24) ◽  
pp. 7616
Author(s):  
Georg Baumann ◽  
Reinhard Brandner ◽  
Ulrich Müller ◽  
Alexander Stadlmann ◽  
Florian Feist

In order to use wood for structural and load-bearing purposes in mechanical engineering, basic information on the impact behaviour of the material over a wide temperature range is needed. Diffuse porous hardwoods such as solid birch wood (Betula pendula) and solid beech wood (Fagus sylvatica) are particularly suited for the production of engineered wood products (EWPs) such as laminated veneer lumber (LVL) or plywood due to their processability in a veneer peeling process. In the frame of this study, solid birch wood and solid beech wood samples (300 × 20 × 20 mm3) were characterised by means of an impact pendulum test setup (working capacity of 150 J) at five temperature levels, ranging from −30 °C to +90 °C. The pendulum hammer (mass = 15 kg) was equipped with an acceleration sensor in order to obtain the acceleration pulse and deceleration force besides the impact bending energy. In both solid birch wood and solid beech wood, the deceleration forces were highest at temperatures at and below zero. While the average impact bending energy for solid birch wood remained almost constant over the whole considered temperature range, it was far less stable and prone to higher scattering for solid beech wood.


Author(s):  
Elena V. Tomina ◽  
Anna A. Pavlenko ◽  
Aleksandr I. Dmitrenkov ◽  
Sofiya A. Neminushchaya

The aim of the study was to synthesise a ZnO/silver birch wood (Bétula péndula) nanocomposite and evaluate its physical and mechanical properties in comparison with an unmodified natural polymer.Using the sol-gel method, we synthesised almost spherical impurity-free zinc oxide nanoparticles with a predominant particle size of about 20 nm. Amorphous hydrated Zn(OH)2 was impregnated into the wood material at the gel formation stage. It resulted in the reaction of zinc hydroxide decomposition with the formation of ZnO nanoparticles in the wood as a nanoreactor.The hydrophobic properties of the surface of ZnO/silver birch wood nanocomposite improved significantly (the contact angle of wetting doubled). Its moisture and water resistance decreased (2-5 times and 30%, respectively). The nanocomposite also showed less swelling in the radial (8-10 times) and tangential (2.6-10 times) directions in comparison with natural wood.


Catalysts ◽  
2021 ◽  
Vol 11 (11) ◽  
pp. 1362
Author(s):  
Boris N. Kuznetsov ◽  
Sergey V. Baryshnikov ◽  
Angelina V. Miroshnikova ◽  
Aleksandr S. Kazachenko ◽  
Yuriy N. Malyar ◽  
...  

For the first time, the fractionation of birch wood into microcrystalline cellulose, xylose and methoxyphenols is suggested based on the integration of alkali-acid pretreatments and hydrogenation in ethanol over a bifunctional Ru/C catalyst. It is established that removal of hemicelluloses during pretreatments of birch wood influences the yields of the liquid, gaseous and solid products of the non-catalytic and catalytic hydrogenation of pretreated samples in ethanol at 225 °C. The bifunctional Ru/carbon catalyst affects in different ways the conversion and yields of products of hydrogenation of the initial and acid- and alkali-pretreated birch wood. The most noticeable influence is characteristic of the hydrogenation of the acid-pretreated wood, where in contrast to the non-catalytic hydrogenation, the wood conversion and the yields of liquid products increase but the yields of the solid and gaseous products decrease. GC-MS, gel permeation chromatography and elemental analysis were used for characterization of the liquid product composition. The molecular mass distribution of the liquid products of hydrogenation of the initial and pretreated wood shifts towards the low-molecular range in the presence of the catalyst. From the GC-MS data, the contents of monomer compounds, predominantly 4-propylsyringol and 4-propanolsyringol, increase in the presence of the ruthenium catalyst. The solid products of catalytic hydrogenation of the pretreated wood contain up to 95 wt% of cellulose with the structure, similar to that of microcrystalline cellulose.


2021 ◽  
pp. 100874
Author(s):  
Seyedbehnam Hashemi ◽  
Prajin Joseph ◽  
Antoine Mialon ◽  
Størker Moe ◽  
Jacob J. Lamb ◽  
...  

2021 ◽  
Author(s):  
Nataliya Khodosova ◽  
A. Dmitrenkov ◽  
V. Zayats

The study of the surface tension of wood of various tree species impregnated with used sunflower oil was carried out. Samples of birch, pine and linden wood were used for oil treatment. Impregnation of wood materials was carried out by the method of “hot-cold baths”. As an impregnating material, used refined fryer oil was used. In more detail, the paper examines the effect of an impregnating composition based on used fryer oil, with a filler and a desiccant on birch wood. Wood flour of coniferous wood species and a metal salt-based drier were used as a filler. The surface tension for all images was determined by the edge angle of wetting. For this purpose, the method of a liquid drop on the surface of a solid body was used. It was found that the impregnation of untreated wood with deep-frying oil leads to an increase in the surface tension on all samples, to a greater extent this is typical for pine wood. The introduction of a 1% siccative in the impregnating composition together with wood flour reduces the drying time and improves the water-repellent properties of birch wood.


2021 ◽  
Author(s):  
Svetlana Snegireva ◽  
Anna Kurnikova

At present, due to the reduction of business wood stocks, the problem of using fast-growing soft hardwoods as industrial raw materials is of particular relevance. This wood has a number of disadvantages – low density, low strength indicators, which limit the scope of its application. It is possible to improve the quality of soft hardwood wood by pressing it (compacting). Compaction of wood has a great influence on the physical and mechanical properties of wood. The wide application of pressed wood is possible in the production of railway sleepers. Pressing wood significantly increases the performance properties of the sleeper beam. One of the advantages of wooden railway sleepers is their high damping properties. The presence of damping properties in wooden sleepers ensures high speed performance and a long service life of the rolling stock. In this connection, research that ensures the rational use of wood raw materials is relevant. The purpose of this study is to determine the nature of the change in the strength limit of pressed birch wood (Betula pendula) during local crumpling.


2021 ◽  
Vol 25 ◽  
pp. 85-96
Author(s):  
G.N. Kononov ◽  
◽  
A.N. Verevkin ◽  
Yu.V. Serdyukova ◽  
V.D. Zaitsev ◽  
...  

The article is devoted to the study of the component composition of mycologically destroyed wood. As a result of wood mycolysis under the action of wood-destroying fungi enzymes, so-called «rot» is formed with a chemical composition different from healthy wood. It is noted that the «brown rot» of wood is enriched with lignin components of wood and «white rot» with carbohydrate components of wood. The results of analyses of ligno-carbohydrate complexes of spruce wood «brown rot», birch wood «white rot» and a group study of low-molecular compounds isolated by extraction methods with various solvents are presented. It is noted that the content of lignin in the sample of «brown rot» wood is four times higher than in the sample of «white rot». It is shown that birch wood with «white rot» is significantly enriched with cellulose. The chemical nature of some groups of extractive substances has been revealed. In the extracts of mycologically destroyed wood, substances of phenolic, alcoholic and quinone nature were found. The presence of derivatives of aromatic and aliphatic carbonyl and carboxyl compounds is noted. Among the products of mycolysis, carbohydrates, flavanoids and terpenoids have been identified. Based on the analysis, an assumption is made that mycologically destroyed wood contains a wide range of phenolic and carbohydrate compounds contained both in the original wood and in the spores and hyphae of wood-destroying fungi themselves. The idea is substantiated that the study of extractive substances of mycologically destroyed wood makes it possible to predict possible directions of the prospective use of this raw material for obtaining target products. This article is the fourth in the cycle «Wood mycolysis, its products and their use», the previous ones were published in the journal «Forestry Bulletin», 2020, v. 24, no. 2, 6; v. 25, no. 1.


2021 ◽  
pp. 309-317
Author(s):  
Leysan Azatovna Mingazova ◽  
Yelena Vyacheslavovna Kryakunova ◽  
Zosia Albertovna Kanarskaya ◽  
Альберт Владимирович Kanarskiy ◽  
Igor' Vadimovich Kruchina-Bogdanov ◽  
...  

The aim of this work is to develop a technology for the preparation of neutral-sulfite liquors formed during the production of fibrous semi-finished products - cellulose from birch wood - for subsequent use as a nutrient medium for the cultivation of microorganisms. Acid hydrolysis was carried out at a temperature of 100 °С at a ratio of a 10% sulfuric acid solution to a liquor sample of 1 : 1. Enzymatic hydrolysis of neutral sulfite liquors was carried out with the enzyme preparations Accellerase XY and Accellerase XC at 50±2 °C and 60±2 °C. The end of hydrolysis was determined by the cessation of the increase in the content of reducing substances (RS) in the hydrolyzate. The original neutral sulphite lye contained 9.4% dry matter, 21.7 g/l of reducing substances, pH 5.3±0.2. It has been shown that as a result of enzymatic hydrolysis, the content of insoluble dry residue in the hydrolyzate decreases to 8.32% and 8.41%, respectively, and during acid hydrolysis – to 7.8%. The content of RS in neutral sulfite lye after acid hydrolysis increases by an average of 3 times, while after enzymatic hydrolysis - a maximum of 2 times. It was found by gas-liquid chromatography that pentoses predominate in the obtained hydrolysates. Microbiological processing of media with a similar carbohydrate composition is possible by a number of strains of microorganisms capable of assimilating pentoses, for example, yeast-like fungi of the Saccharomycetaceae family and bacteria of the Enterobacteriaceae family.


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