Wood processing for energy use

Forest biomass has been used as an energy source since ancient times. Since then, several ways of using them have emerged, along with technologies to improve their energy quality. One can cite genetic improvement, thermal transformation through pyrolysis for charcoal and torrefied biomass production, and mechanical transformation through compaction, to produce pellets and briquettes and chipping for the production of chips. However, it is somehow difficult to find articles on these topics that are clearly and objectively presented, making it difficult to read them. The objective of this work was to search data on the ways of processing forest biomass and solutions for the better use of this biomass and its energy use. Therefore, Google Scholar was used as a database from which articles already recognized and others with less impact were obtained. The following search words were used: Eucalyptus, Pinus, wood chips, pellets, briquettes, charcoal, and torrefied wood. To filter the results obtained, the articles that appeared as the most relevant were selected first, then filtered for articles with less than five years from publication, and those at less than two years of publication. Next, the selected articles went through a verification of the data contained in them, and the necessary information was removed from each, which were the species, immediate analysis, extractives, HCV, etc. These data were organized in tables according to the type of processing, prioritizing the values of greatest interest in each analysis, along with the appropriate references. It was observed from the data obtained that the results are compatible among different researchers in their analyses. For samples processed without thermal treatment, the initial characteristics of the wood are maintained, and when going through pyrolysis or torrefaction, these characteristics are changed.

A metabolomics approach to evaluate the effect of lyophilization versus oven drying on the chemical composition of plant extracts

Lyophilization is the “gold standard” for drying plant extracts, which is important in preserving their quality and extending their shelf-life. Compared to other methods of drying plant extracts, lyophilization is costlier due to equipment, material and operational expenses. An alternative method is post-extraction oven-drying, but the effects of this process on extract quality are unknown. In this study, crude extracts from Arthrocnemum macrostachyum shoots were compared using three post-extraction drying methods (lyophilization and oven drying at 40 and 60 °C) and two extraction solvents (water and aqueous 50% ethanol). Untargeted metabolomics coupled with chemometrics analysis revealed that post extraction oven-drying resulted in the loss of up to 27% of molecular features when compared to lyophilization in water extracts only. In contrast, only 3% of molecular features were lost in aqueous 50% ethanol extracts when subjected to oven drying. That is to say, ethanol used as a solvent has a stabilizing effect on metabolites and enhances their resistance to thermal transformation in the oven. Collectively, oven-drying of extracts was as effective as lyophilization in preserving metabolites in extracts only when 50% ethanol was used as a solvent. The results presented in this paper demonstrate the value of selecting solvent-appropriate post-extraction drying methods.

Study of the Combustion , Pyrolysis Characteristics and Synergistic Effect of Co-hydrocharsation Products of Oil Shale and Rice HuskStudy of the Combustion , Pyrolysis Characteristics and Synergistic Effect of Co-hydrocharsation Products of Oil Shale and Rice Husk

Under the pressure of environmental problems and fossil energy shortage, countries all over the world are looking for fuel to replace fossil energy. Oil shale and rice husk are potential fuels, but they both have some problems, such as high ash content and low calorific value .In the present study,oil shale and rice husk were used as feedstock for the high quality fuel through hydrothermal approach,it provides a new way for the resource utilization of oil shale and rice.Thermogravimetric method was used to analyze the functional groups change and thermal transformation characteristics of mixed hydrochars prepared for oil shale(OS) and rice husk(RH) at different hydrothermal temperatures(150,200 and 250℃), including combustion and pyrolysis processes, and analyze the synergistic effects. Results showed that the co-hydrocharsization pretreatment had a significant effect on the thermal transformation behavior of oil shale and rice husk.On the one hand, the mixture of hydrocar has higher volatile content than its calculated value.On the other hand,a synergistic effect(promoting combustion and pyrolysis behavior) was found in both combustion and pyrolysis processes, and this effect was the most obvious when the hydrothermal temperature was around 200℃,and the characteristic peak of functional groups vibration was strong.Since the synergistic effect of pyrolysis process is lower than that of combustion process, co-hydrocharsation products are considered to be more suitable for combustion.These findings have positive significance of energy generation and utilization of organic waste by the combination of co-hydrocharsization modification and subsequent thermochemical process.

Mathematical modeling and analysis of operation of cylindric pyrolysis reactor with radial heating

The vector of development of solid-fuel energy is currently directed towards expanding the range of renewable fuels used. Along with the direct combustion of fuel, the processes of controlled thermal transformation of the raw biomass in an oxygen-free surrounding to obtain a new fuel based on it (liquid, solid, gaseous) are widely spread. A significant part of research in this sphere is related to the study of the formal kinetics of such processes, at the same time, the hardware design of the process is no less important, but less studied. Thus, development of mathematical models of pyrolysis equipment operation is relevant. A decisive difference approximation of these processes in the framework of an axisymmetric formulation of the problem is chosen as a mathematical basis for modeling physical and chemical transformations and transfer processes in the radial direction of a cylindrical pyrolysis reactor. The material constants of the processes are borrowed from the well-known literature references The authors studied the modes of reactor operation not covered by a full-scale experiment, using the previously proposed and verified one-dimensional mathematical model of a cylindrical pyrolysis reactor. The issues of the influence of the dimensionless kinetic function of the process (reaction model) on the thermal transformation of the material in the apparatus are considered. The significant influence of the chosen reaction model on the kinetic nature of the process is pointed out. The mutual influence of drying and pyrolysis the presence of which is due to the energy effects of the processes is considered. A significant spatial heterogeneity of the process is defined and the possibility of the existence of a non-trivial effect of advanced heating of the internal zones of the apparatus in comparison with the peripheral ones is specified. The paper shows that a computational experiment can help to detect non-trivial effects and identify the variability of the process implementation even within the framework of a single design and technological solution of the pyrolysis process. According to the authors, the results of the obtained numerical experiments indicate that mathematical modeling can be the basis of making technological solution. However, further research is also needed to determine reliably the material constants of the process.

Characterization of Sn–Sb–Ti Solder Alloy and the Study of Its Use for the Ultrasonic Soldering Process of SiC Ceramics with a Cu–SiC Metal–Ceramic Composite

The aim of this research was to characterize soldering alloys of the type Sn–Sb–Ti and to study the ultrasonic soldering of SiC ceramics with a metal–ceramic composite of the type Cu–SiC. The Sn5Sb3Ti solder exerts a thermal transformation of a peritectic character with an approximate melting point of 234 °C and a narrow melting interval. The solder microstructure consists of a tin matrix, where the acicular constituents of the Ti6(Sb,Sn)5 phase and the sharp-edged constituents of the TiSbSn phase are precipitated. The tensile strength of the soldering alloy depends on the Ti content and reaches values from 34 to 51 MPa. The average strength of the solder increases with increasing Ti content. The bond with SiC ceramics is formed owing to the interaction of titanium, activated by ultrasound, with SiC ceramics, forming the (Ti,Si)6(Sb,Sn)5 reaction product. The bond with the metal–ceramic composite Cu–SiC is formed owing to the solubility of Cu in a tin solder forming two phases: the wettable η-Cu6Sn5 phase, formed in contact with the solder, and the non-wettable ε-Cu3Sn phase, formed in contact with the copper composite. The average shear strength of the combined joint of SiC/Cu–SiC fabricated using the Sn5Sb3Ti solder was 42.5 MPa. The Sn–Sb–Ti solder is a direct competitor of the S-Bond active solder. The production of solders is cheaper, and the presence of antimony increases their strength. In addition, the application temperature range is wider.

Selective Thermal Transformation of Automotive Shredder Residues into High-Value Nano Silicon Carbide

Automotive waste represents both a global waste challenge and the loss of valuable embedded resources. This study provides a sustainable solution to utilise the mixed plastics of automotive waste residue (ASR) as a resource that will curtail the landfilling of hazardous waste and its adverse consequences to the environment. In this research, the selective thermal transformation has been utilised to produce nano silicon carbide (SiC) using mixed plastics and glass from automotive waste as raw materials. The composition and formation mechanisms of SiC nanoparticles have been investigated by X-ray diffraction (XRD), X-Ray-Photoelectron Spectroscopy (XPS) and Transmission Electron Microscopy (TEM). The as synthesised SiC nanoparticles at 1500 °C has uniform spherical shapes with the diameters of the fixed edges of about 50–100 nm with a porous structure. This facile way of synthesising SiC nanomaterials would lay the foundations for transforming complex wastes into value-added, high-performing materials, delivering significant economic and environmental benefits.

Simple and Rapid Synthesis of Calcium Acetate from Scallop Shells to Reduce Environmental Issues

The search for sustainable resources remains a subject of global interest. Calcium acetate used in many fields was prepared using waste scallop shell as a raw material, and its physicochemical properties were investigated. The waste scallop shells were transformed to calcium acetate compounds by reactions with four acetic acid concentrations at ambient temperature until the completely dried powder is obtained. The maximum yield of 87% with short reaction time at a low temperature was observed in the reaction of 60%w/w acetic acid with scallop shells. Thermal transformation reactions of all prepared calcium acetate samples revealed temperature conditions for heating to produce other advanced materials. FTIR and XRD results confirmed the purity and solid phase of all prepared calcium acetate samples, and they were compared with those of literatures and found to be well consistent. The obtained timber-like particles have different sizes depending on the acetic acid concentration. This work reports an easy and low-cost method with no environmental effect to produce cheap calcium products to be used in the industry.