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The processing of lignocellulose wastes is one of the urgent tasks in modern society. These wastes can be effectively used for the production of heat, electricity, fuels, and valuable chemicals. Catalytic pyrolysis can be considered the most effective way to convert waste into valuable products. In this work, the investigation of the pyrolysis process of the birch and pine sawdust was carried out in the presence of a zeolite-based catalyst. The synthesised zeolite-based catalyst is characterised by high porosity (the specific surface area of 350 m2 /g) and acidity (0.34 mmol/g). The use of the zeolite-based catalyst increases the yield of the gaseous and liquid products of pyrolysis by ca. 5 % in comparison with the non-catalytic one. Despite this increase seems to be negligible, the composition of the products was changed sufficiently because of the higher degree of feedstock decomposition. The addition of pure zeolite into the pyrolysis zone led to an increase in furanes and phenols yield for 3 times while the addition of Fe-ZSM-5 catalyst increased twice the yield of acids/esters, and hydrocarbons. [ABSTRACT FROM AUTHOR]

Flax shive is a highly lignified nonfibrous plant parts obtained from the scutching of straw flax to produce fibers. It is one of the multi-tonnage agricultural wastes. The use of the flax shive as a source for the valuable products is a promising way to solve the problem of the waste processing. This work is devoted to the study of composition and properties of the products of slow and fast pyrolysis of the flax shive. It was found that the slow pyrolysis results in a higher degree of the feedstock decomposition as well as in a higher yield of valuable gases and liquids. The gaseous product yield was found to be over 35 wt. % for the slow pyrolysis, and about 25 wt. % for the fast pyrolysis. For the gaseous products, methane concentration was found to be twice lower for the fast pyrolysis in comparison with the slow one. This decreases the calorific value of gases and leads to the low feasibility of the process. Interestingly, the fast pyrolysis resulted only 20 wt. % of liquids, while for the slow one, a twice increase (ca. 40 wt. %) of liquid yield was obtained. The liquid obtained in a fast mode contained the higher number of carboxylic acids and furanes, while the product obtained in a slow pyrolysis was characterised by the higher concentration of phenols, aldehydes and hydrocarbons increasing its further application. The solid residue obtained by the slow pyrolysis was found to have a higher porosity in comparison with the sample obtained by the fast mode. As the solid residue can be used as an adsorbent, the porosity is a critical parameter to choice the proper mode for flax shive thermal processing. [ABSTRACT FROM AUTHOR]

Carbon materials are widely used in catalysis as effective catalyst supports. Carbon supports can be produced from coal, organic precursors, biomass, and polymer wastes. Biomass is one of the promising sources used to produce carbon-based materials with a high surface area and a hierarchical structure. In this review, we briefly discuss the methods of biomass-derived carbon supported catalyst preparation and their application in biodiesel production, organic synthesis reactions, and electrocatalysis. [ABSTRACT FROM AUTHOR]

ZnO supported on hypercrosslinked polystyrene was developed for liquid-phase methanol synthesis. The synthesized catalyst was characterized using the low-temperature nitrogen physisorption, TEM, XPS, XAS, and CO DRIFT methods. The analysis showed that the catalyst has a high specific surface area (720 m2/g) and is characterized by the micro-mesoporous structure typical of the polymer used. The active phase is represented by ZnO species with a hexagonal wurtzite structure. ZnO-HPS showed high activity, selectivity, and stability in liquid-phase methanol synthesis in comparison with the industrial catalyst. The activity of the proposed catalyst was found to be 1.64 times higher than that of the conventional Cu/ZnO/Al2O3. [ABSTRACT FROM AUTHOR]

A novel screw‐type reactor for the fast pyrolysis of agricultural waste (flax shive) is described. A preliminary study on the influence of process parameters on the yield, composition, and properties of pyrolysis products was carried out. Based on the results obtained, the optimal conditions of fast pyrolysis of flax shive particles in terms of feedstock particle size, solid residence time, and process temperature were identified. Considering the construction, the developed reactor seems to be close to the screw fluidized bed and auger reactor and is characterized by a simple design and operation control. Moreover, the proposed reactor can be used for continuous pyrolysis without any significant modification. [ABSTRACT FROM AUTHOR]

This paper presents a study of the pyrolysis process of oil residues in the presence of catalysts based on natural and synthetic aluminosilicates. The process of fast thermal decomposition was studied in a continuous reactor at a residence time of feedstock in the reaction zone less than 20 s. The optimum temperature of oil-sludge decomposition was determined taking into account the yield of gaseous and liquid pyrolysis products. The optimal pyrolysis temperature for the studied feedstock was found to be 600 °C. The study of the effect of the aluminosilicates on the oil-sludge thermal decomposition showed that among the studied catalysts, zeolites were found to be the most active. The highest yield of gaseous and liquid products was observed In the presence of three-dimensional porous pentasil zeolite H-ZSM-5. H-ZSM-5 was found to provide the 40 wt. % yield of liquid and 13.5 wt/% of gaseous products during the fast oil-sludge pyrolysis at the optimal temperature. In order to reduce the cost of the catalyst used, a catalyst representing a mixture of zeolite H-ZSM-5 and bentonite clay was synthesized. This catalyst also showed high activity in the process of oilcontaining residue composition providing 36 w. % yield of liquid products and 10 wt. % of gaseous products. It is interesting to note, that in the presence of the mixed catalyst the highest yield of light liquid fraction (50 wt. %) was obtained. [ABSTRACT FROM AUTHOR]

A study of the structure and catalytic properties of the cobalt- and iron-containing catalysts synthesized by the subcritical deposition in the water medium was performed in the current work. The catalyst synthesis was carried out at a temperature of 200 °C and a total pressure of 7.5 MPa using silica as support. The catalytic activity of the synthesized materials was studied in the liquid-phase Fischer-Tropsch synthesis. The study of catalyst structure and composition showed that the use of silica as catalyst support allows the formation of Coand Fe-containing particles consisted of metal oxides. Testing of the synthesized catalysts in liquid phase Fischer-Tropsch synthesis showed that Co-based catalyst allowed the formation of gasoline-range hydrocarbons. It is noteworthy that Co/SiO2 showed higher selectivity towards the formation of linear C5-C8 hydrocarbons. In the case of Fe-containing catalyst, the formation of a significant amount of oxygenates (C3- C4 alcohols) was found. [ABSTRACT FROM AUTHOR]

In this paper, the results of the study on the influence of the addition of 10 wt.% of FeCl3, CoCl2, NiCl2, ZnCl2, SnCl2, and CuCl2 on the wheat straw pyrolysis process are presented. The studied chlorides were found to affect the pyrolysis process; however, the highest activity was observed while using CuCl2. The presence of the copper chloride led to the decrease in the temperature of the initial destruction of hemicellulose fraction of wheat straw by 64°С. Besides, the use of CuCl2 allowed increasing the yield of liquid and solid pyrolysis products as well as decreasing the molecular weight distribution of the volatiles. Moreover, the increase in the hydrogen and decrease in carbon dioxide concentration were also observed in the presence of copper chloride. The analysis of the solid residue obtained in the wheat straw pyrolysis in the presence of CuCl2 showed the increase in the specific surface area of the carbon residue from 24 up to 63.5 m2/g in comparison with that obtained for the noncatalytic process. [ABSTRACT FROM AUTHOR]