Wood Residues Research Articles

Carbon Fixation and Soil Aggregation Affected by Biochar Oxidized with Hydrogen Peroxide: Considering the Efficiency of Pyrolysis Temperature

Biochar, as a carbon-rich material, may have a notable influence on carbon balance, especially that in soil mediums. The oxidation of biochar modifies the biochar’s effects on the soil’s carbon dynamics. To evaluate the alteration in soil carbon storage, biochars derived from wheat straw (WS) and wood residues (WR) produced at 350, 450, and 550 °C (marked BWS350, BWS450, BWS550, BWR350, BWR450, and BWR550) were oxidized with hydrogen peroxide (H2O2) and applied on a loamy soil (2% d.m.) for a 180-day greenhouse incubation period. The highest organic carbon (OC) concentration and carbon pool index (CPI) were obtained from the oxidized BWS550, with 154% and 70% increases, respectively, compared to the unamended control. For both the WS and WR biochars, applying oxidation significantly improved the soil’s aggregation indices, i.e., the mean weight diameter (MWD), water stable aggregates (WSA), and fractal dimension (D). BWS350, BWS450, and BWS550 showed significantly higher WSAs, with percentages of 68, 74, and 76% compared to the control (41%). The fractal dimensions decreased with an increasing pyrolysis temperature in both the biochar types. All the biochar treatments significantly decreased the soil bulk density (BD), while for both the pristine and oxidized biochars, the lowest BD was related to the biochars produced at high temperatures. The structural qualities of the biochars were enhanced by oxidation, particularly their specific surface areas and porosities, and this had a substantial impact on the soil structure and carbon status. The wheat straw biochar was more effective than the wood residue biochar and a higher pyrolysis temperature was more effective than lower ones for supporting the enhancement of the soil carbon pool.

Effects of ball milling on biochar adsorption of contaminants in water: A meta-analysis

Reckless release of contaminants into the environment causes pollution in various aquatic systems on a global scale. Biochar is potentially an inexpensive and environmentally friendly adsorbent for removing contaminants from water. Ball milling has been used to enhance biochar's functionality; however, global analysis of the effect of ball milling on biochar's capacity to adsorb contaminants in aqueous solutions has not yet been done. Here, we conducted a meta-analysis to investigate the effects of ball milling on the adsorption/removal capacity of biochar for contaminants in aqueous solutions, and to investigate whether ball milling effects are related to biochar production, ball milling, and other experimental variables. Overall, ball milling significantly increased biochar adsorption capacity towards both inorganic and organic contaminants, by 69.9% and 561.9%, respectively. This could be attributed to ball milling increasing biochar surface area by 2.05-fold, pore volume by 2.39-fold, and decreasing biochar pH by 0.83-fold. The positive adsorption effects induced by ball milling varied widely, with the most effective being ball milling for 12 to 24 h at 300 to 400 rpm with a biochar:ball mass ratio of 1:100 on biochars produced at 400–550 °C from wood residues. Based on this meta-analysis, we conclude that ball milling could effectively enhance biochar's ability to remove organic and inorganic contaminants from aquatic systems.

Forestry products as renewable energy sources

Forestry products as renewable energy sources

Experiments and design of concrete-filled steel tubes with timber chips under axial compression

This study includes experimental and analytical sections, which discuss the structural response of concrete-filled steel tubes (CFST). In the experimental section, the authors investigate the CFST columns with different proportions of recycled redwood timber chips embedded inside the concrete. An analytical investigation was also carried out in this paper, which puts together equations proposed by four design codes of Eurocode-4, AISC-LRFD, the Chinese code of DL/T, and ACI to predict the axial capacity.The idea of embedment of timber inside aggregates was inspired due to the significant compression strength of timber compared to concrete. In addition, environmental and sustainability concerns advocate substituting conventional aggregates with recycled natural material. In this study, 18 stub columns (in two groups with different steel tubes) were tested under pure axial compression with various compositions of the aggregates. The failure, capacity, weight, and energy absorption of the specimens were studied to evaluate the effect of the weight reduction as a result of timber embedment into the concrete. The results showed that embedding waste timber inside concrete is promising in upcycling wood residue into a commercially viable product. An equation is developed in this paper that takes into account the effect of confinement based on the assumptions that have been made in the literature. 100 test samples were extracted from the literature with a relatively wide range of geometry and material features, and then the capacity of these columns was calculated by the four standards and the proposed equation in this study. The results of the comparisons were analysed and it was found that the proposed equation predicts the capacity accurately.

Flue gas condensation of solid fuel fired heating plant

In the Czech Republic, increasing trend exists in utilization of biomass as a fuel in heating and power plants. This is preferred solution by EU Climate plans, and it is connected with some economic benefits (e.g. green bonuses, guaranteed purchase price), on the other hand the combustion of fossil fuels is penalized (EU ETS – Emission Trading System). There are many types of biomass with different parameters but one of the most discussed are wooden resides because of its quantity. There are big differences between quality parameters, especially in moisture content, which is decreasing the LHV. There are some technologies which can decrease moisture. Dryer technologies could be simple so-lution, but final decreasing of moisture is quite low. More effective is application of flue gas condensation. This technology is well known for gas-fired boilers but nowa-days is still more often build by new solid fuels-fired plants. This deals with design of condensation technology for existing heating plant in Mladá Boleslav. The fuel mixture is based on wood residues (70 %) and pelletized plant biomass (30 %). The calculation was done for three boilers for soild fuels – two same CFBs (steam production 100 t·h-1) and one BFB (steam production 80 t·h-1). Moisture content was calculated for two cases of wooden residues with moisture content 35 and 50 %. System of condensation include three step water scrubber, heat ex-changer, heat pump and humidifier of combustion air. The final designed output of unit for BFB is 12.7 MW (19 MW for each CFBs), but from these the output of heat pump is 5 MW (7.5 MW). The source of heat for heating pumps is steam, which can be used in current heater, so the final net output from condensation is 7.7 MW (11.5 MW). These parameters are only for 50 % of moisture content in wooden residues. The application of these system is not cost-effective for moisture content of fuel around 35 %. It is possible to build this technology for 50 % of fuel moisture content, but technology will not raise the temperature parameters of hot water. There are two differences between Mladá Boleslav heating plant and Finnish Vuosaari power plant in Helsinky, where the similar unit is already built. First of them is moisture content of fuel more than 50 %. Second one is temperature of hot water system 60 °C, however in Mladá Boleslav is at least 80 °C, sometimes it could be more than 110 °C. The decreasing of this temperature is problem because the most of heating systems were designed by current standards with temperature 80 °C. The only possible solution is to build two steps scrubber and the waste heat utilize as preheater of hot water.

Energy Recovery Analysıs of A Biomass Type of Installed Waste Water Treatment Plant

Energy production can also be obtained from plant, animal or sometimes human material, referred to be the biomass technology. The biomass raw material can be obtained from purposely grown energy crops, waste from food crops, wood or forest residues, horticulture, animal farming, food processing, or human waste from sewage plants. In this study, energy recovery analysis of an installed waste water treatment plant was conducted. The physical and chemical analyses of energy recovery that can be obtained from waste water treatment plant were clarified. In this regards, parameters including daily wastewater inlet water flow rate, wastewater inlet water 24 hourly average temperature, wastewater inlet water 24 hourly pH average, wastewater inlet water 24 hourly conductivity average, gas generator daily gas consumption, diesel generator daily energy generation, daily energy consumption from the city line, gas generator energy generation, total energy consumption of the water treatment plant, and daily gas generation of the treatment plant were identified. The plant has the duty of providing water treatment, so it is certain that noteworthy energy consumption in the plant can occur is an expected situation. However, the point that how much of the energy can be regained by the biomass technology provided by the burning processes conducted on the human waste is important. Namely, it is reported in this study that 78.29% of the total energy consumed by the plant was regained by these processes occurred in the treatment facility. On the other hand, this amount of recovered energy was reported to correspond a total of 14.200 GWh in this installed plant of Turkey. Apart from the amount of the recovered energy, the discharge of the amount of the methane gas which is responsible of the biomass energy generation was also analyzed according to the considered physical and chemical parameters. For instance, the analyses have shown that the increase of the waste water temperature causes decrease on the amount of the methane gas generation. On the other hand, the conductivity and the degree of acidity increase resulted the increase of the amount of the methane gas production.

Neolithic wood use at the Scheldt river banks in Bouchain (France)

Archaeological sites in wetlands or under waterlogged conditions provide excellent preservation conditions for organic material, particularly wood, and therefore constitute one of the most important prehistoric sources for dendroarchaeological studies available.The site of Bouchain in the North of France, is located on the bank of a palaeochannel close to the Scheldt River, a North Sea tributaty. Regular floods of varying intensity led to formation of peat and waterlogged site conditions, providing vast amounts of wooden artefacts sampled for dendroarchaeological analyses within an interdisciplinary research effort, further involving palynological, malacological and anthracological studies. Here we present a study on a total of 1858 individual wood objects, including architectural elements (posts, stakes and planks), tools and hunting weapons (axe handles, arrow shafts and bows, throwing sticks, slingshot balls), tableware, production waste from woodworking (chips) and finally two log boats. In addition, natural wood residues from peat and alluvial layers have been collected and analysed to obtain a more comprehensive picture of the Neolithic forest vegetation on-site. After an early occupation of the site during the Mesolithic period, the archaeological sequence is placed between the Middle Neolithic and the end of the Late Neolithic (∼4200–2700 BCE). However, the main occupation is in the Late Neolithic, broadly between 3400 BCE and 2950 BCE.The interdisciplinary approach allows to specify the nature of the forest stands on the periphery of the site as riparian forest of alder type, associated with a mixed forest and heliophilous vegetation.The dendroarchaeological investigations enabled precise tree-ring dating and provides important insights into the selection and processing of wood in Neolithic times in the context of weaponry production, shipbuilding and food consumption.

Combining Rock-Eval® thermal analysis and thermochemolysis to evaluate the influence of forest management on soil organic matter quality and stability

The effect of forest management practices on carbon quality is poorly documented. To assess changes in the quality and stability of soil organic carbon (SOC) of a temperate forest upon human activities, we investigated soil from forests (i) developed following natural regeneration after clearcutting 20 and 40 years ago, (ii) developed following afforestation on an abandoned crop area 40 years ago and (iii) in an area where regular clear-cut (with wood residues input) was conducted 40 years ago. Topsoil and subsoil layers were collected (0–20 cm and 50–80 cm). Soil organic matter (OM) was characterized by elemental analysis (total carbon and total nitrogen), thermal analysis (Rock-Eval®) and thermochemolysis (i.e., Py-GC/MS in the presence of tetramethylammonium hydroxide (TMAH)). In addition, a size fractionation to separate the labile coarse fraction (50–2000 μm) from the fine fraction (<50 µm) was performed. These fractions were analyzed by thermal analysis.Despite no measurable differences in carbon and nitrogen contents, the characterization of the OM by thermal analysis, and the relative quantification of OM compounds revealed differences in the composition in OM for the topsoil layers. The thermal analysis clearly distinguished sites with inputs of woody residues (higher HI) with a higher relative contribution of lignin and cutin/suberin compounds. However, the OM thermal stability seems mainly controlled by the organo-mineral interactions rather than chemical composition. Combination of Rock-Eval® thermal analysis and Py-GC/MS suggests that thermal stability cannot be used as an indicator of stability in specific contexts where pedogenetic processes are deeply modified by regular and extensive anthropogenic inputs of woody residues.

Saproxylic Hymenoptera in dead wood retained on clear cuts, relation to wood parameters and their degree of specialisation

Intensive forestry is a threat to biodiversity, and therefore actions are made to mitigate this loss. The actions are, however, designed based on available knowledge about the requirements of species, and for saproxylic insects this concerns mainly Coleoptera, while the diverse but poorly known Hymenoptera has contributed less. In this paper we therefore asked whether the substrate requirements of Hymenoptera (divided as parasitoids and non-parasitoids) are similar to those of Coleoptera and Diptera. We used an insect material reared from logging residue wood for the comparison. Theoretically parasitoid Hymenoptera should be less specialised than Coleoptera and other host species as they belong to a higher trophic level. However, we found no such difference and even an opposite trend, that parasitoids were more specialised than beetles. Parasitoids had significantly more species in newly dead wood of fine diameter (1–4 cm, compared to coarse wood of 8–15 cm) compared to other groups. This is probably due to that many of them have bark beetles as hosts. The non-parasitoids were less specialised than the other groups and more confined to old wood (4–5 years), which is in line with that many of them are aculeate wasps building nests in emergence holes from other insects.Implications for insect conservationThe habitat requirements of Hymenoptera suggest that the conservation actions designed for the well known groups are also applicable for them. The parasitoids’ association to trivial substrates (fine wood) suggest a good supply of breeding habitat, whereas their high specialisation in combination with higher trophic level suggest they contain an even higher proportion of threatened species than Coleoptera. How this is traded off needs further studies.

Avantium and Origin Materials to accelerate mass production of FDCA and PEF for advanced chemicals and plastics

On February 21, Avantium N.V. (“Avantium”), a technology company in renewable chemistry, and Origin Materials, Inc. (“Origin” and “Origin Materials”), a sustainable materials company based in the USA, announced a partnership to accelerate the mass production of FDCA and PEF for use in advanced chemicals and plastics. The partnership aims to bring the technology platforms of both companies together in order to produce FDCA from sustainable wood residues on an industrial scale.

Novel Hot Vapor Filter Design for Biomass Pyrolysis.

Fast pyrolysis is a mature technology for the conversion of solid biomass into a liquid intermediate, fast pyrolysis bio-oil (FPBO). FPBO has so far been used mainly as heating fuel, but the target is to use it for the production of sustainable fuels and chemicals in the future. In the pyrolysis process, inorganic materials (ash) from the biomass are mostly sequestered in char particles, which can be separated with cyclones. Small particles (<10 μm) escape the cyclones and condense with vapors. In bio-oils, these solid materials are unfavorable because they can cause erosion, corrosion, and blockages at injection nozzles in power generation systems and deactivate the catalyst in bio-oil upgrading. Hot vapor filtration using either moving bed or barrier filters has been tested on a small scale for the removal of fine particles from the pyrolysis vapors. The challenges with these filter types have been the increased pressure drop across the filter with time, inefficient solid removal, and loss in organics. A new hot vapor filter combining both a barrier filter and a moving bed filter was constructed and tested to overcome these problems. In this filter system, the filter elements are inserted in a vessel, where hot sand flows through to continuously remove the cake over filter candles. The filter was successfully tested with stem chips, contaminated wood, and forest residue for 6-8 h without any pressure increase. The organic liquid yield decreased in the best case only by 3 wt % using the lowest filtration temperature and shortest residence time. The oil properties were slightly affected by cracking of the sugar fraction, which decreased the oxygen content, microcarbon residue, and carbonyl content but increased the acidity. Only minor improvements in metal removal were seen due to the high detection limits of metal analysis.

Emission factors of industrial boilers burning biomass-derived fuels

ABSTRACT Boilers are combustion devices that provide process heat and are integral to many industrial facilities. Historically, outside of the pulp and paper industry, most boilers burned fossil fuels, although interest in decarbonization has been leading to an increased use of renewable fuels in boilers. These boilers, including those in the biorefineries, are often large sources of air pollutant emissions, and the characterization of these emissions is critical to obtaining air permits and ensuring protection of the surrounding air quality. Several industrial boilers and new biorefineries allow utilization of biomass-derived fuels (e.g. wastewater sludge, lignin, etc.) produced during their operation as a fuel for the boiler to meet process energy needs. However, there is limited empirical data on emission factors for the burning of unconventional fuels, such as solid-gas mixtures containing biomass residues. To fill this gap, we carry out a comprehensive data survey, collecting information on emission factors for boilers burning either a single or a mixture of solid and gaseous biomass-derived fuels. We review multiple hard-to-obtain and unconventional data sources, such as air permit applications, stack test data, and industry-sponsored data collection efforts, to compile emission factors for biomass-derived fuels. We then compare this data with wood residue emission factors from the U.S. Environmental Protection Agency’s AP-42 emission factor database. Our results indicate that the emission factors for boilers burning unconventional fuels vary widely depending on the fuel composition, boiler type, and fuel characteristics. Overall, we find that median emission factors of selected biomass-derived fuels are typically lower than those of wood residue boilers in AP-42. The information collected herein could be useful to permitting agencies and industries utilizing boilers who may want to reduce the carbon impact of their facilities by combusting biomass-derived wastes for process energy needs, for more accurate emission estimation for permitting. Implications: Emission factors are often used for air permitting, specifically for emission estimation purposes. This study carries out a comprehensive data survey of emission factors burning unconventional biomass-derived fuels from underutilized sources such as air permits, stack test data, and industry-led efforts, and compare the results to EPA’s wood residue emission factor database. The results from this study can be used can be used by multiple stakeholders such as air permitting agencies, industries burning biomass-derived fuels, and biorefineries, that utilize more advanced boiler technologies. The findings can help mitigate risks to industry owners and operators and helps to avoid delays in obtaining the required air permits that arise due to inappropriate emission estimates in permit applications.

Design of Decorative Wooden Wall Panels from Sliced Pedunculate Slavonian Oak (Quercus robur L.) from Veneer Production Residue

The growing awareness of nature conservation encourages producers, engineers, and designers to contribute to the rational and innovative use of raw materials. Sustainable development is imperative, symbolizing the balance between meeting the needs of the present generations without compromising the needs of future ones. The aim of this paper is to investigate the production process of cut veneer of Pedunculate Slavonian oak (Quercus robur L.) and which parts of the logs are lost or thrown in the production of cut veneer, to analyze the increase in the use of veneers that currently represent residue in processing, and to propose directions of designing a new product from the analyzed residue—decorative wall panels. The research was conducted in the company Spačva Ltd. in Vinkovci, Vukovar-Srijem County, Croatia, in 2021/2022. The findings emphasize that the vast majority of unused veneers, considered technologically unacceptable in the production process, can be decoratively and visually desirable due to their natural appearance in the design of a new product. By analyzing and applying the design principles and elements, natural phenomena were applied to the veneers that represent the basic motif of the new decorative wall panels. The initial solutions of the decorative wall coverings made of veneer with a natural appearance and the solution from other wood residues from production are shown. The results of this study have potentially far-reaching implications for wood product manufacturers and demonstrate the importance of applying design in wood technology to reduce residue, demonstrating that residue from standard production can be designed into an innovative, sustainable product that reduces environmental damage.

A Study on the Co-Combustion Characteristics of Coal and Bio-SRF in CFBC

Bio-SRF based on livestock waste has low heating value and high moisture content. The concentration of toxic gases such as SOx, NOx, and HCl in the flue gas is changed according to the composition of fuel, and it has been reported. Therefore, the study of fuel combustion characteristics is necessary. In this study, we investigated combustion characteristics on the blended firing of coal and Bio-SRF (bio-solid refused fuel) made from livestock waste fuel in CFBC (circulating fluidized bed combustor). The raw materials for manufacturing Bio-SRF include agricultural waste, herbaceous plants, waste wood, and vegetable residues. Bio-SRF, which is formed from organic sludge, has a low heating value and a high moisture content. Bio-SRF of livestock waste fuel is blended with different ratios of coal based on heating values when coal is completely combusted in CFBC. In the result of experiment, the combustor efficiency of calculated unburned carbon concentration in the fly ash shows 98.87%, 99.04%, 99.64%, and 99.71% when the multi co-combustion ratio of livestock waste fuel increased from 100/0 (coal/livestock waste) to 70/30 (coal/livestock waste). In addition, the boiler efficiency is shown to be 86.23%, 86.30%, 87.24% and 87.27%. Through the experimental results, we have identified that co-combustion of livestock waste fuel does not affect boiler efficiency. We have systematically investigated and discussed the temperature changes of the internal combustor, compositions of flue gases, solid ash characteristics, and the efficiency of combustion and of the boiler during co-combustion of coal and Bio-SRF.

Sustainable Valorization of Wood Residue for the Production of Biofuel Materials Via Continuous Flow Hydrothermal Liquefaction

When forests are extensively cleared for infrastructure and agricultural purposes, over half of the wood generated is regarded as waste. To minimize the negative consequences and successfully use renewable energy sources, further applications must be investigated. Biomass has the potential to be converted into biofuels using a process known as hydrothermal liquefaction (HTL). The conversion of wood residue under continuous flow, subcritical HTL, under both untreated and alkaline pretreated conditions was examined in this study. According to the results, pretreatment with 4% NaOH sped up recovery times compared to using raw wood and increased glucose production by 1.8 times (equivalent to 90 g/L) in comparison to using raw wood. Additionally, the fluid's pH was raised from 6.1 to 3.5 due to the alkaline pretreatment, which also switched the hydrolysis of arabinose and cellobiose to rhamnose at 0.2 MPa. The average Net Energy Ratio (NER) for glucose during liquefaction reached values as high as 63%, while the energy output from glucose during the pretreatment reached 246 kJ. The move to green energy transition toward net zero will be aided by these findings, which will usher in new waste conversion techniques to produce sustainable biofuels using continuous flow HTL.Graphical Abstract

The use of biochar made from biomass and biosolids as a substrate for green infrastructure: A review

Biochar made from biomass and biosolids can be used in substrates suitable for urban green infrastructure, especially green roofs, green parking lots, and green walls. The properties of biochar depend on the feedstock and pyrolysis conditions. Biochar made from different feedstocks, e.g., sludges, biomass, food waste, wood, and plant residues, has different physicochemical properties that affect the availability of nutrients, absorption of pollutants and harmful gases, carbon sequestration, and improvement of pH of amended soil. This paper reviews and summarizes various feedstocks for biochar production, pyrolysis technology and conditions, and physicochemical properties of selected types of biochar. Since biochar has a positive influence on plant growth, fertilizer efficiency, and rainwater capture, showing its use as a stable organic component of the substrate is the main objective of this research paper. Conclusion of the review considers the usage of biochar as a substrate for green infrastructure in pursuance of its characteristics, limiting pollutants concentration, potential benefits and risks for the environment, water sources and occurring climate change. The review is based on the analysis of selected papers on existing research and case studies related to the use of biochar and the evaluation of the impact of biochar on the characteristics of growing medium.

Feedstock and pyrolysis conditions affect suitability of biochar for various sustainable energy and environmental applications

Currently, the substitution of continuously depleting coal, a predominant source of global energy, and the treatment of contaminated soil and water bodies with sustainable means are the major concerns. Accordingly, biochars derived from slow pyrolysis of wood and rice residues (400–1000 °C) were observed to improve their properties over related feedstocks, among noticeable characteristic variations depending on the biomass type and pyrolysis temperature. Low-temperature pyrolysis produced high-yield biochars, and high-temperature pyrolysis produced low-yield, higher-C, and higher-HHV biochars. Wood residue biochars had higher HHV (21.25–24.05 MJ/kg) and lower H/C and O/C atomic ratios (0.643–0.201 and 0.326–0.084) than rice residue biochars (16.61–18.60 MJ/kg) and (1.22–0.259 and 0.720–0.558), respectively. Thus wood residue biochar, because of its substantially higher HHV than the threshold for an adequate solid fuel, have the potential for energy applications. The wood residue biochars (600–1000 °C) have higher C (>85%) than expected for pulverized coal injection (PCI, 75%C); and for coke, coke breeze, and recarburiser (85%C), together with much less ash and S content than required for blast furnace (BF). It can be utilized as PCI in BF (100%); as sintering solid fuel and BF nut-coke (50–100%); as BF carbon/ore briquette and steelmaking recarburiser (0–100%); and as a coal blend (2–10%) for coke-making, together with reduced onsite emissions. Wood residue biochars from 400 °C have the characteristic potential to replace 22.8% PCI and as a blend with lignite in existing coal-fired power plants. Wood residue biochars (600–1000 °C), with less H/C and O/C atomic ratios and a similar polarity index to pulverized fuel combustion coal, can be well applied in power-generating systems. Rice residue biochars (400–1000 °C), with poor persistence (O/Corg ratio, 1.228–0.799), higher alkali and alkaline earth metals content, and less HHV than the threshold for an adequate solid fuel, have weak prudence for fuel applications. But with other adaptable properties viz., higher pH, ash, (O/C and N/C) atomic ratios, polarity index, surface functional groups, plant nutrients, and moderate surface areas, can be selectively and judiciously utilized for soil amendment, soil-remediation, C-sequestration, wastewater treatment, and other pollutant abatements. Decision tree approaches, based on the characteristic pertinence of these biochars with literature values, have been developed for their various sustainable energy and environmental usages; and associated environmental concerns and needs to promote them to industrial-level applications have been discussed.

Efficient preparation and properties of wood fiber transparent materials with powdered wood

At present, since wood resources are in short supply, it is of great significance to utilize wood residues to prepare bio-composites for sustainable developments. Compared with the preparation of traditional transparent materials using solid wood, making transparent materials using wood fibers (WF) can utilize wood residues (such as wood chips, wood strips, sawdust, etc.) as the raw material sources, which can help the environmental protection and promote energy saving features of transparent fiber wood (TFW). Currently, the method of making TFW usually uses simple chopped wood residues with the removal of lignin. The transparent composites using WF were prepared by impregnating pre-polymerized polymers. Therefore, this study adopted a method of wood powders (WPF) screening to solve this problem. The wood residues were smashed into a certain mesh size of WPF, and then the epoxy resin (EP) was impregnated into the delignified WPF to successfully prepare the wood powder-reinforced transparent wood (TCWP), which effectively optimized the preparation process and improved the efficiency. The preparation efficiency is greatly improved by more than 50%. The effects of length-diameter ratio and mass fraction of WPF on optical properties, mechanical properties and thermal conductivity of TCWP were further investigated in this study. The comprehensive analysis showed that, when the WPF size was 80 mesh and the fiber mass fraction was 5%, it had the best optical, thermal, and mechanical properties. In addition, the laser scattering experiments showed TCWP can be used as an optical screen and architectural glass in the engineering practice and became a transparent composite material with high added value, because of the uniformity of WPF dispersion in EP, resulting in more uniform light passing rate and increased haze.

An Investigation into the Strength Properties of Three Reclaimed Structural Timber Joist Within the University of Ibadan Community

Background and Objective: The investigation presents the results of selected test assessment on physico-mechanical properties of three selected wood residues within the University of Ibadan Campus, Oyo State, Nigeria. Often, reclaimed planks were considered as useful material for heating and energy production, hence, potential re-usability of these residues for plate rack production were determined. Materials and Methods: Four planks of the selected three wood samples each were collected from the University of Ibadan community. The 12 pieces wood samples were cleaned, plained, and converted into required dimension; samples were dried to about 12%moisture content before tests. Selected physico-mechanical properties test (moisture content, volumetric shrinkage, modulus of elasticity, and modulus of rupture were carried out according to ASTM standards. The data obtained were subjected to analysis of variance (ANOVA). Results: The results of mean density show that <i>Gliricidia sepium, Milicia excelsa </i>and <i>Funtumia elastica </i>had 1032±0.97kg/m³, 548±0.57kg/m³ and 613±0.33kg/m³, respectively. The mean value for moisture content of <i>G. sepium, M. excelsa and F. elastica</i> ranges from 12.47±1.21, 20.84±1.21 and 18.13±1.21, respectively. While, volumetric shrinkage of <i>G. sepium, M. excelsa and F. elastica </i>ranged from 20.55±2.79, 7.48±2.79 and 11.43±2.79. The <i>G. sepium, M. excelsa and F. elastica </i>had MOE values of 8793.13±643.43 N/mm², 8083.64±643.43 N/mm² and 4299.54±643.43N/mm². The mean values for MOR of <i>G. sepium, M. excelsa and F. elastica </i>ranges 404.69±12.362 N/mm², 434.27±12.36N/mm² and 388.34±12.36N/mm². Conclusion: <i>Gliricidia sepium </i>wood had the highest mean density, low shrinkage value and modulus of elasticity. Therefore, it was found most suitable wood slab for plate rack production from reclaimed wood joist.

A bibliometric analysis on the agricultural use of biochar in Brazil from 2003 to 2021: research status and promising raw materials

Abstract Biochar is considered a promising option for the development of sustainable agroecosystems, due to its diverse agronomic and environmental benefits. In this context, the aim of this study was to carry out a bibliometric analysis on biochar research in Brazil within an agricultural context, including investigating the raw materials most employed for its production in the country. The analysis was conducted based on a search for scientific articles (peer-reviewed papers) at the Web of Science database (WoS Core Collection) from 2003 to 2020 specifically in Brazil. A performance analysis was carried out by applying a descriptive and metric approach concerning research constituents (authors, institutions, countries and keywords) and science mapping to clarify scientific collaborations and cognitive and intellectual structure patterns regarding the biochar domain in Brazilian research, using the VOSviewer software. The obtained studies were also analyzed individually to classify the different raw materials employed in biochar production. A total of 261 scientific articles met the screening criteria, indicating that the beginning of biochar publications in Brazil took place in 2003, increasing until 2015 and peaking in 2021. Institutions and authors with the highest publication contributions were the Brazilian Agricultural Research Corporation (EMBRAPA) (Novotny E.), São Paulo University (USP) (Cerri C.) and Federal Lavras University (UFLA) (Melo L.). The United States, Spain, Australia, Germany and the Netherlands present the most collaborations on biochar research with Brazil. The biochar domain was highly associated with the following keywords: biochar, pyrogenic carbon, pyrolysis, charcoal, immobilization, black carbon, soil fertility and soil and characterization. Raw materials of plant origin were the most employed in biochar research in Brazil, with wood residues being the most studied and residues originated from the sugar-energy industry (straw, bagasse and filter cake) identified as exhibiting high potential for future studies. Poultry litter is the most promising animal waste for biochar production, while the use of biosolids can be innovative, contributing to the consolidation of biochar as an option for serious urban waste sanitary management problems.