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This paper explores the utilization of biomass resources derived from vineyard residues for producing densified solid biofuels in the Republic of Moldova, with the aim of quantitatively and qualitatively evaluating the residue from vine pruning, focusing on the feasibility of its use as raw material for the production of briquettes and pellets. The methodology includes the analysis of statistical data, as well as experimental investigations conducted at the Scientific Laboratory of Solid Biofuels of the Technical University of Moldova. Waste biomass samples were collected from various vineyards in the different districts of all three regions of the country, focusing on regions with significant plantations. Both quantitative and qualitative aspects of the biomass were assessed, considering the moisture content, calorific value, and ash content. It was found that about 1013 kg/ha of waste biomass is generated from the pruning of technical grape varieties with a net calorific value of 15.6 MJ/kg at a moisture content of 10 wt.% and about 1044 kg/ha with a calorific value of 16.4 MJ/kg from the table ones; both with an average ash content of 3 wt.%. The results indicated that vineyard pruning residues in the Republic of Moldova could provide a substantial biomass source, with an estimated total energy potential of approximately 370 TJ/y (80% located in the Southern region); they also highlighted the need for technological advancements and quality assurance procedures through which to ensure the efficiency and sustainability of biofuel production. The conclusions emphasize the numerous benefits of utilizing viticultural residue, both economically and ecologically, contributing to the sustainable development of the viticulture industry in the Republic of Moldova, as well as environmental protection. [ABSTRACT FROM AUTHOR]

Biomass waste energy recovery is a significant method for recycling energy from waste and capturing it for use in renewable energy sources. The abundance of brewing byproducts, such as brewery spent grain (BSG) and brewery wastewater sludge (BWWS), as well as their high carbon concentrations gives these wastes energy potential. With 20% molasses utilized as a binding agent to maximize the high caloric value of the briquette, this study sought to examine the quality of mixed briquettes made from BSG and BWWS. In order to make composite briquettes with a maximum caloric content of 19.94 MJ/kg, the ideal conditions were chosen, which included a temperature of 350°C, a production period of 60 min, and a 75% BSG mixing ratio. It can be compared to sawdust briquettes, which have a calorific value of 22.88 MJ/kg, by looking at the calorific value of densified with pressure 100 bar for mixed carbonized briquettes vs mixed noncarbonized briquettes (21.13 MJ/kg). The value of R2 was 0.9607 and indicated that 96.07% of the total validation in the calorific value correlation between experimental and predicted values. The finding of the study showed that the efficiency of the quadratic model in fitting the data would be higher under the conditions of the experiment. Based on ISO 17225‐6 fuel quality classes and specifications for graded nonwoody pellets, the study concluded that using BSG and BWWS as alternative energy sources meets those requirements. [ABSTRACT FROM AUTHOR]

As a by-product of wastewater treatment, sewage sludge can be used for natural, agricultural, or energy purposes. One method of preparing sludge for management and use is solar drying. To intensify the drying process, natural additives can be used to alter the structure of the sludge and accelerate the evaporation of water. This research aimed to evaluate the influences of different organic additives in sewage sludge mixtures on the physicochemical and energy parameters of briquettes. This research was carried out without thermal boosting in a 4 × 2.5 × 2 m plastic tunnel. The tunnel was equipped with three drying stations and control and measuring equipment. In two test series, sludge additives in the form of straw and lignocellulosic materials, sawdust, bark, woodchips, and walnut shells, were used. Briquettes were made from the resulting mixtures and then subjected to physical and chemical analyses. This research showed high variability in the contents of trace elements, nitrogen, and sulphur in relation to an increase in the amount of sludge in the briquettes, which, for the briquettes made from sewage sludge, was nearly twice as high as for the briquettes made from the mixtures. The results of the flue gas analysis for the briquettes with sawdust and wood chip additives were very similar. The briquettes made from sewage sludge with lignocellulosic materials (bark and wood chips) had fuel properties similar to woody biomass, with a calorific value and heat of combustion of 15–16 MJ/kg. Fibrous additives (straw) significantly increased the strength parameters of the briquettes, by more than 50% of the value. The compositions and properties of the mixtures affected the following briquetting parameters: temperature and compressive force. The briquettes made from sewage sludge and additives can be classified according to ISO 21640 as SRFs (solid recovered fuels). In most of the results, the net calorific value (NCV) was 3 to 4; the chlorine content (CL) was 2 to 1; and the mercury content (Hg) was 1. The sewage sludge mixtures facilitated the agricultural and energy use of the briquettes. [ABSTRACT FROM AUTHOR]

This work assessed some properties and effects of biocoal briquettes on environmental pollution compared with utilising coal alone. A mixture of coal fines and rice husks was prepared, with cassava starch gel as a binder, before compaction in a briquetting machine and drying with a solar dryer. Samples of the coal fines, rice husk, cassava flour and briquettes were analysed for their elemental and oxide concentrations via an energy-dispersive X-ray fluorescence analyser. The heat fuels were analysed for their thermal behaviour via thermogravimetric analyser (TGA), whereas the specific surface area, pore size and pore volume were determined using a Brunner–Emmett–Teller (BET) analyser. The conversion of the tested coals to biocoal briquettes resulted in a reduction in the level of arsenic in the briquettes. Additionally, the sulphur level decreased from 1.96 to 1.11% in the Okobo-Enjema briquettes and from 1.78 to 0.90% in the Onyeama briquettes. However, the levels of manganese increased from 0.04 to 0.22% in the Okobo-Enjema briquettes and from 0.04 to 0.21% in the Onyeama briquettes. Thermogravimetric analysis at different heating rates revealed that derivative weight loss increased with increasing heating rate, from 4.4% at 10 °C/min to 5.5% at 20 °C/min. BET analysis revealed that the briquettes had larger pore diameters, volumes and specific surface areas than did the coal samples. The coal samples have greater propensity to pollute the environment as the amount of potentially hazardous elements in the samples is greater than in their biocoal briquettes. [ABSTRACT FROM AUTHOR]

Alternative biomass for energy can reduce fossil fuel use and environmental impacts, providing energy security in semi-arid areas with shallow soils that are not ideal for agro-forestry. The densification of sorghum biomass (SB) brings its energetic characteristics closer those of wood. Higher heating value (HHV) represents the heat produced by a given quantity of fuel. This Brazilian research tested different mixtures of SB, eucalyptus wood (W), and eucalyptus bio-oil (Bo) as briquettes for HHV and least ash. Compressed mixtures of SB+B were compared to W+Bo and SB+W+Bo. The concentrations of bio-oil added to SB/W were 1%, 3%, 4%, and 5%. SB+W+Bo composites' W content was 0%, 25%, 50%, 75%, and 100%, with Bo as 3% of the weight. Sorghum biomass' HHV is equivalent to W at 3%Bo. Bo doses of 4% and 5% had the same HHV as 3%. Eucalyptus wood did not have a significantly greater HHV with any amount of Bo. SB+W+3%Bo had the same HHV as W when W was at least 50% of the mixture. At greater than 36%W, the ash content was lower than 3%, meeting the EN-B international standard. The optimal composite mixture was 64%SB+36%W+3%Bo for HHV and ash content. SB briquettes can be more widely adopted given sorghum's prevalence in semi-arid environments. [ABSTRACT FROM AUTHOR]

Efficient utilization of biomass requires conversion into forms that can be optimally applied in energy generation. Briquetting involves the compaction of biomass into solid blocks that are more efficient than raw biomass, and provides ease of transport and handling. These are improved when the briquettes possess a high density, shatter index, and compressive strength. Due to differences in nature and composition, it is imperative to define optimum conditions for the production of quality and durable briquettes for individual biomasses that are compacted into briquettes. This study investigated the effects of process variables on the strength, durability, and density of biomass briquettes produced using Abura sawdust. The lateral compressive strength and drop shatter index were investigated whilst varying the temperature (100–150 °C), pressure (9–15 MPa), and hold time (15–30 min). The compressive strength ranged between 2.06 and 5.15 MPa, whilst the shatter index was between 50 and 600. Briquette density was between 518.8 and 822.9 kg/m3. The pressure was significant to the determination of the compressive strength (p < 0.1) and the shatter index (p < 0.05). The pressure, temperature, and hold time are significant to the briquette density. Physical and mechanical characteristics of the binderless Abura sawdust briquettes can be improved by optimizing the densification variables during the briquetting process when moderate pressures are used for compaction. [ABSTRACT FROM AUTHOR]

Cardiovascular diseases (CVD) are one of the leading causes of death globally, and a major contributor to CVD mortality is ambient air pollution (AAP). This study aimed to evaluate associations between AAP and mortality from CVD, including ischemic heart diseases (IHD) and strokes. Data on daily mortality records, six criteria AAP and meteorology in the capital city of Mongolia were collected between 1 January 2016 and 31 December 2022. A time-stratified case-crossover design was analysed with distributed lag conditional Poisson regression to estimate the relative risk of CVD mortality. We found that for each interquartile range increase in PM2.5, PM10, SO2 and NO2 pollutants, the risk of CVD mortality increased by 1.5% (RR = 1.015; 95% CI: 1.005, 1.025), 4.4% (RR = 1.044; 95% CI: 1.029, 1.059), 3.1% (RR = 1.033; 95% CI: 1.015, 1.047) and 4.8% (RR = 1.048; 95% CI: 1.013, 1.085) at lag01, respectively. The association between all pollutants, except O3, and CVD mortality was higher in subgroups ≥ 65 years and male, during the cold season and after using a new type of coal briquettes. Despite using the new type of coal briquettes, Ulaanbaatar's ambient air pollution remained higher than the WHO's guidelines. Based on our findings, we recommend that efforts should be focused on adopting more efficient strategies to reduce the current pollution level. [ABSTRACT FROM AUTHOR]

Currently, enterprises producing crystalline silicon are facing the formation and accumulation of large volumes of microsilica, a technogenic dusty waste formed during the melting of silicon alloys. Due to its chemical composition, this waste can be a significant raw material for metallurgical production. Therefore, this study is aimed to solve the problem of recycling microsilica. For these studies, a technology for the combined briquetting of microsilica and a carbonaceous reducing agent was developed for the production of a pilot batch of briquettes. This paper presents the results obtained from the process of testing the melting of crystalline (technical) silicon from briquetted monocharge obtained from microsilica. The tests were conducted under large-scale laboratory conditions on a 200 kVA ore-thermal furnace, where 30, 50, and 100% replacements of the traditional charge mixture with briquettes were tested. The results of this study showed that briquettes in the melting process of technical silicon can be successfully used in the range of 0 to 50%. The use of briquettes can significantly improve the technological indicators. The maximum extraction of silicon (approximately 83%) was achieved at 30% replacement. The technical and economic indicators of the process also improved. In particular, an increase in productivity was observed in comparison with tests on a traditional charge. [ABSTRACT FROM AUTHOR]

The steel industry accounts, according to the International Energy Agency, for ~6.7% of global CO2 emissions, and the major portion of its contribution is from steelmaking via the blast furnace (BF) route. In the short term, a significant reduction in fossil CO2 emissions can be achieved through the introduction of bio-coal into the BF as part of cold bonded briquettes, by injection, or as part of coke. The use of bio-coal-containing residue briquettes was previously demonstrated in industrial trials in Sweden, whereas bio-coal injection was only tested on a pilot scale or in one-tuyere tests. Therefore, industrial trials replacing part of the pulverized coal (PC) were conducted. It was concluded that the grinding, conveying, and injection of up to 10% of charcoal (CC) with PC can be safely achieved without negative impacts on PC injection plant or BF operational conditions and without losses of CC with the dust. From a process point of view, higher addition is possible, but it must be verified that grinding and conveying is feasible. Through an experimentally validated computational fluid flow model, it was shown that a high moisture content and the presence of oversized particles delay devolatilization and ignition, lowering the combustion efficiency. By using CC with similar heating value to PC, compositional variations in the injected blend are not critical. [ABSTRACT FROM AUTHOR]

The objective of this study is to determine optimum conditions for producing briquettes fuel from biomass, examine the properties of the resulting briquette fuel and transfer the technology to target communities. The production process entails implementing a screwtype briquette press equipped with controlled temperatures through a molded pipe clamp electric heater for shaping the briquettes. This is an innovative approach that allows briquettes to be produced and ready for use in a single step, while other processes require the briquettes to be dried first. The production capacity was estimated to be 12 kg/hr. Bagasse, a byproduct of sugarcane processing, was the biomass used in the current research. For this study, four distinct temperatures were chosen for experimentation, 100, 110, 120, and 130°C. The proportions of bagasse, cassava flour, and water were investigated for briquette production utilizing two formulae: 1 kg bagasse to 0.1 kg cassava flour and 0.5 liters water, and 1 kg bagasse to 0.3 kg cassava flour and 0.5 liters water. The findings indicated that bagasse briquettes could be effectively manufactured at 120°C. The ideal proportion of bagasse particles, cassava starch, and water was 1 kg: 0.3 kg: 0.5 liters, respectively. The moisture content, volatile matter, ash, and fixed carbon were respectively 8.04, 70.20, 13.05, and 16.11 wt.% on a dry basis, based on the physical and chemical property tests of the briquette fuel. The material has a density of approximately 856.70 kg/m³, a compressive strength of 89.34 kg/cm², and a higher heat value (HHV) of 24.05 MJ/kg, with a longer burning time than regular charcoal. The research emphasizes using bagasse for innovative renewable energy production technologies and disseminating this technology in target communities in Thailand. [ABSTRACT FROM AUTHOR]

This study aims to provide an overview of the growing need for renewable energy conversion and aligns with the broader context of environmentally friendly energy, specifically through producing syngas from biomass. Unlike natural gas, which is mainly composed of methane, syngas contains a mixture of combustible CO, H2, and CnHm. Therefore, optimizing its production requires a thorough examination of various operational parameters such as the gasifying agent, the equivalence ratio, the biofuel type, and the state, particularly in densified forms like pellets or briquettes. As new biomass sources are continually discovered and tested, operational parameters are also constantly evaluated, and new techniques are continuously developed. Indeed, these techniques include different gasifier types and the use or non-use of catalysts during biofuel conversion. The present study focuses on these critical aspects to examine their effect on the efficiency of syngas production. It is worth mentioning that syngas is the primary gaseous product from gasification. Moreover, it is essential to note that the pyrolysis process (prior to gasification) can produce, in addition to tar and char, a mixture of gases. The common feature among these gases is their versatility in energy generation, heat production, and chemical synthesis. The analysis encompasses the resulting gas features, including the yield and composition, mainly through the hydrogen-to-carbon monoxide ratio and the carbon monoxide-to-carbon dioxide ratio, as well as the lower heating value and considerations of the tar yield. [ABSTRACT FROM AUTHOR]

Rice husks are not readily biodegradable making their disposal challenging due to the common disposal method of open burning which has negative environmental effects. Additionally, banana, sweet potato and cassava peelings form a large percentage of organic municipal solid waste. Therefore, this study developed rice husk biochar briquettes with organic municipal peelings waste as binders. Rice husks biochar was formed via carbonization processes in a step-down kiln at temperatures ranging between 400 and 500 °C. Organic binders were mixed with the rice husk biochar at different ratios of 10% and 15% before being compacted at a pressure ≤ 7 MPa into briquettes. Thermogravimetric results showed that the developed briquettes had high ash contents ranging from 44% to 47%. Rice husk biochar briquettes with the highest particle density were observed for briquettes with 15% cassava peel binder at 427.1 kg/m3. The highest HHV and maximum attainable flame temperature of 21.75 MJ/kg and 828.7 °C were obtained for rice husk biochar briquettes with 15% matooke peeling organic binder. For all rice husk biochar briquettes, increasing the organic peeling binder had a positive impact of reducing the ash content, while at the same time increasing the peak temperatures, thus contributing to their enhanced thermal stability. [ABSTRACT FROM AUTHOR]

The recovery of iron contained in mill scale rather than iron ore can be considered a promising valorization pathway for this waste, especially if carried out through reduction using biogenic carbon sources. Nevertheless, the physicochemical properties of the latter may hinder the industrial transferability of such a pathway. In this work, the mechanical and metallurgical behavior of self-reduced briquettes composed of mill scale and four biogenic carbons (with increasing ratios of fixed carbon to volatile matter and ash) was studied. Each sample achieved mechanical performance above the benchmarks established for their application in metallurgical furnaces, although the presence of alkali compounds in the ash negatively affected the water resistance of the briquettes. In terms of metallurgical performance, although agglomeration successfully exploited the reduction by volatiles from 750 °C, full iron recovery and slag separation required an amount of fixed carbon higher than 6.93% and a heat treatment temperature of 1400 °C. Finally, the presence of Ca-, Al-, and Si- compounds in the ash was essential for the creation of a slag compatible with steelmaking processes and capable of retaining both phosphorus and sulfur, hence protecting the recovered iron. [ABSTRACT FROM AUTHOR]

The Amazon region contains numerous areas dedicated to sustainable timber extraction. This operation has low yields and generates a large amount of waste. However, this waste can be repurposed for energy generation, providing income for locals and reducing reliance on non-renewable energy sources prevalent in the region. This study aimed to assess the impact of torrefaction on various wood residues for briquette production. Wood residues from Mimosa scabrella Benth (Bracatinga), Dipteryx odorata (Aubl.) Willd. (Cumaru), and Aspidosperma populifolium A.DC. (Peroba mica) were torrefied at temperatures ranging from 180 to 220 °C for sixty minutes under a nitrogen atmosphere. Briquettes were produced using laboratory equipment with loading pressures between 7 and 14 MPa. Torrefied particle properties were evaluated based on proximate composition and calorific value tests, while briquette quality was assessed for physical and mechanical properties. The results demonstrated the briquetting potential of different wood species before and after torrefaction, with optimal outcomes achieved by torrefaction at 220 °C due to its enhancement of energy density. Briquettes showed optimal characteristics at compression pressures of 14 MPa, resulting in increased density (between 1.10 and 1.24 g·cm−3) and compression strength (between 7.20 and 21.02 MPa). The ash values were low and met the requirements. The utilization of waste for briquette production offers a significant alternative for energy generation in economically disadvantaged communities, while also enabling the replacement of non-renewable energy sources. [ABSTRACT FROM AUTHOR]

Energy application potential from the abundant biomass residues is inadequately exploited. Over-dependence on forest trees, its negative environmental impacts, and ever-rising energy costs require alternative production technologies including briquetting. The physico-mechanical and combustion properties of binderless and bindered Alstonia boonei sawdust and Theobroma cacao (cocoa) pod briquettes, carbonized in a steel kiln (at 410±5°C, and a heating rate of 4°C/min from the ambient temperature of 25°C), piston-pressed at 9.0 MPa, were studied. The binders were starch, wax, and clay. Starch-bindered T. cacao pod briquettes recorded the maximum bulk density (640 kg/cm3), while basic density was greatest for sawdust/clay briquette (433 kg/cm3). Sawdust/wax briquette produced much Water Resistance Capacity (76.76%) with safer carbon monoxide (CO) emissions (0.67 ppm). A. boonei sawdust/starch briquettes recorded the greatest calorific value (24.023 MJ/kg), least specific fuel consumption (0.0483 kg/l), and slowest burning rate (0.0005 kg/min). All but T. cacao pod/starch and Sawdust/starch emitted CO below the safe air quality Standard of ≤ 6ppm (24h mean). Binderless sawdust, sawdust/starch and T. cacao pod/starch briquettes recorded 47.86, 20.95 and 11.40 μg/m3 particulate matter (PM2.5) respectively, which are below WHO Air Quality Standard safe for domestic uses. Binderless T. cacao pod produced more harmful CO and PM2.5 than its non-bindered A. boonei sawdust counterpart. Clay-bindered briquettes were the most durable. Briquetting, 'a waste-to-energy technology', enhances bio-residue management for domestic and industrial spaces in the global energy mix. [ABSTRACT FROM AUTHOR]

The combustion of briquettes made from organic and industrial residues in small boilers requires researchers to consider the characteristics of this type of fuel and methods of its combustion. For the efficient combustion of fuel briquettes, a layered combustion method with the ability to regulate the supply of combustion air is better suited. The purpose of this research is to study the thermal technical conditions of briquetted fuel combustion. In order to carry this out, a stand was created, which made it possible to determine the combustion efficiency of this type of fuel. Two types of briquettes were studied: one with 30% sunflower husks and 70% leaves, and one with and 70% sunflower husks and 30% coke breeze. The combustion results of the briquettes show that heat loss from chemical under-burning was no more than 6.25%. To determine the temperature distribution in the fuel layer, a model of unsteady heat transfer in a fixed layer was used. A calculation of the temperature fields in the layer of burned fuel briquettes was carried out, which showed that the most favorable conditions for burning briquettes were created with a layer about 15–20 cm thick for both burned briquette options. The temperature was in the range of 450–750 °C, which on the one hand corresponds to experimental data and on the other hand provides a combustion regime that occurs with a relatively low loss to the environment. This installation and mathematical model will help future studies based on the processes of other types of organic waste combustion with a grate system. [ABSTRACT FROM AUTHOR]

The production of cashew nuts has been increasing globally, leading to a greater volume of waste materials that require proper management. Nevertheless, cashew nutshells (CNS), currently considered waste by most processors, offer a noteworthy opportunity for alternative applications owing to their distinct physical, chemical, and thermal properties. This article reviews alternative applications for CNS that can leverage these properties, while evaluating research gaps. The potential uses are classified into three categories: material development, energy production, and substance absorption. In the materials segment, various examples are discussed where CNS serves as raw material to synthesize biopolymers, cementitious materials, and a broad range of composites. The energy production section discusses various processes that utilize CNS, including pyrolysis, gasification, and briquette production. The absorption section presents CNS and activated carbon derived from CNS as effective absorbents for liquid-phase and gas-phase applications. While this review highlights numerous research-level possibilities for CNS utilization, only a few of these options have been implemented within the industry. Consequently, further research is essential, particularly in CNS characterization, economic and environmental assessment, and real-life implementation, to broaden and enhance the integration of this biomass into applications that can contribute to the value of both its production and processing chain. [ABSTRACT FROM AUTHOR]

The fabrication of charcoal briquettes was considered using two distinct bases: palmyra palm and oil palm shells. The critical role of binders - namely tapioca starch, molasses, and termite mound clay (TMC) - were emphasized in influencing the properties of the briquettes. ANOVA results revealed that both the type of binder and charcoal significantly impacted various characteristics, such as proximate components like volatile matter content, and physical properties including combustion time. Briquettes made from palmyra palm shells notably demonstrated superior performance in terms of combustion time and onset time of saturation (OTS). Among the binders, tapioca starch was distinguished for contributing to the lowest ash content and the highest fixed carbon in the briquettes. Conversely, briquettes bound with TMC, despite having the lowest volatile matter percentage, also exhibited the highest ash content and fragility, in addition to the shortest combustion time. These findings highlight the importance of selecting appropriate binders to enhance the efficiency and sustainability of charcoal briquettes, aligning with the increasing demand for environmentally conscious energy solutions in the face of escalating global energy needs. [ABSTRACT FROM AUTHOR]

This study develops briquettes from fines generated in the processing of manganese ore from a strategic manganeferous district of Minas Gerais–Brazil. The briquettes were produced based on the following variables: compaction pressure (20 and 25MPa), curing time (7 and 28 days), percentage by mass of binder (5% and 10%), and replacement with tailings (0% and 10%). Technological tests evaluated the compressive, abrasion, impact strength and water absorption. The best conditions for briquette included 10% Portland cement, 10% Mn tailings, compaction pressure of 25MPa and 7 days of curing, as well as 10% Portland cement, compaction pressure of 25MPa and 28 days of curing. The briquettes primarily contained the spessartine, todorokite, quartz, and pyrolusite minerals. The storage time tests indicated that the briquettes responded satisfactorily to storage for three months in a dry environment and at room temperature. Through crackling tests, the briquettes have potential to be commercially used. [ABSTRACT FROM AUTHOR]

Worldwide, different strategies are being developed in order to ensure optimum conditions for the development and growth of economic competitiveness, as well as for increasing the quality of life and environmental protection. All these strategies are closely linked to the development and modernization of systems for producing energy from clean and renewable sources. In this context, the present paper presents the results of research regarding the evaluation of the sustainability of briquette production using biomass resulting from vine winter pruning as the raw material. An analysis of the scientific literature indicates that nearly 8 Mt of biomass would result from the over 7.4 million hectares of vine plantations in the world, biomass that could be valorized through densification in order to produce solid biofuels with a lower calorific value of more than 17 MJ/kg. This study examines the production of briquettes from vineyard winter pruning with consideration of two types of densification technologies: baling and natural drying of the tendrils, and collection, shredding, and artificial drying of the lignocellulose debris. The quality indices and energy consumption and energy efficiency of the briquettes were evaluated to determine their feasibility as an alternative fuel source. When designing the scientific endeavor, the following aspects were considered: defining the aim and objectives of the research; designing the research algorithm; collecting, preparing, and conditioning the biomass; conducting a chemical analysis of the briquettes; and evaluating the energy consumption and energy efficiency for producing the briquettes, taking into account two drying methods (natural and artificial drying). In the meantime, some specific laboratory equipment was designed and built for the artificial drying of biomass, evaluation of mechanical durability, measurement of energy consumption, etc. Analysis of the experimental data has led to the conclusion that the agricultural waste from vine pruning can constitute an important and sustainable source of energy in the form of briquettes that fulfill most of the requirements imposed by international standards. [ABSTRACT FROM AUTHOR]

The article discusses the potential for decarbonization in the global steel industry through the use of green steel technologies. It highlights the energy-intensive steps involved in steel production and the various technologies, such as blast furnaces and electric smelting furnaces, that can help reduce carbon emissions. The text emphasizes the importance of integrating decarbonization efforts from mining to steel production and explores innovative technologies like carbon capture and storage, hydrogen injection, and the use of low-carbon energy sources. Additionally, it addresses the need for increased energy efficiency, waste reduction, and technological innovation in the steel industry to achieve low-carbon steel production. [Extracted from the article]

This study analyzes the combustion of pellets and briquettes made of plant biomass in low-power heating devices powered periodically with fuel being placed on the grate, as well as after modification using an automatic fuel feeding system in the gutter burner. The use of herbaceous biomass in the form of pellets in low-power heating devices with automatic fuel feeding and combustion in a gutter burner is not widely promoted and popular. Therefore, this study used four types of herbaceous waste biomass (wheat straw, rye straw, oat straw and hay) and one type of woody waste biomass (birch sawdust) for testing. The basic chemical characteristics were determined for the raw materials. After appropriate preparation, the selected starting materials were subjected to briquetting and pelleting processes. Selected physical properties were also determined for the obtained biofuels. Biofuels made from birch sawdust had the lowest heat value (16.34 MJ·kg−1), although biofuels made from wheat, rye and hay straw had a slightly lower calorific value, respectively: 16.29; 16.28 and 16.26 MJ·kg−1. However, the calorific value of oat straw biofuels was only 15.47 MJ kg−1. Moreover, the ash content for herbaceous biomass was 2–4 times higher than for woody biomass. Similar differences between herbaceous and woody biomass were also observed for the nitrogen and sulfur content. To burn the prepared biofuels, a domestic grate-fired biomass boiler was used, periodically fed with portions of fuel in the form of pellets or briquettes (type A tests), which was then modified with a gutter burner enabling the automatic feeding of fuel in the form of pellets (type B tests). During the combustion tests with simultaneous timing, the concentration of CO2, CO, NO and SO2 in the exhaust gases was examined and the temperature of the supplied air and exhaust gases was measured. The stack loss (qA), combustion efficiency index (CEI) and toxicity index (TI) were also calculated. The research shows that the use of automatic fuel feeding stabilizes the combustion process. The combustion process is balanced between herbaceous and woody biomass biofuels. Disparities in CO2, CO and Tgas emissions are decreasing. However, during type B tests, an increase in NO emissions is observed. At the same time, the research conducted indicates that the combustion of herbaceous biomass pellets with their automatic feeding into the combustion chamber is characterized by an increase in combustion efficiency, indicating that when the combustion process is automated, they are a good replacement for wood biofuels—both pellets and briquettes. [ABSTRACT FROM AUTHOR]

Several types of waste are generated in the integrated steel industry, in particular from wet or dry LD (Linz-Donawitz) converter dedusting systems and blast furnace cleaning equipment. These wastes contain iron, carbon and, in some cases, zinc, which have been the subject of several studies and technological initiatives in recent decades. In this work, the fine (F) and coarse (C) residues generated in a dry dedusting system of the LD converter were used in the proportion of 50-50% and 70-30%, respectively, and to these proportions were added dust residues from the blast furnace (BF) collector. Previously, the C and F residues were hydrated for 3 and 4 days, respectively, and the mixture was agglomerated with Portland cement ARI (Alta Resistência Inicial) and water to produce self-reducing briquettes, in order to study their behavior in compression, metallization and mainly as an alternative cooling agent in liquid steel to control its final temperature. The results were analyzed considering the energy balance of the briquette-steel bath system and taking into account a thermodynamic sequence for the main reactions and oxygen potentials typical of steelmaking processes. The self-reducing agglomerates proved to cause a high cooling effect in the steel bath compared to iron ore scrap and pellets. Moreover, considering their high metallization degrees, self-reducing briquettes are an effective way to recover the metal (iron) contained in the waste. [ABSTRACT FROM AUTHOR]

The adaptation of lignocellulosic materials such as Cannabis sativa L. as a new renewable energy source is linked to the fact that the technology must be developed to be able to adapt to local market conditions. Bioenergy consumers are faced with this problem because, when it comes to the selection of briquettes and pellets for energy production, there are only individual standards in place. This research is intended to provide a better understanding of hemp product potential as a new material that can be used in the production of pellets and briquettes for biofuel purpose. Nevertheless, the anisotropic raw material interferes with the compaction process and may expose a poor durability of the pellets and briquettes. The research that was conducted evaluated the conditions of the biofuels by measuring the physical and chemical parameters. The ash content, compressive strength, and durability of the samples were examined. The statistical data analysis was performed after the strength tests on the prepared samples. [ABSTRACT FROM AUTHOR]

Biochar is the solid residual material obtained after carbonisation or slow pyrolysis of biomass in a controlled condition, typically at a temperature range of 450°C to 510°C in the absence of oxygen to remove water and other volatile constituents from the parent biomass in a closed vessel. The Agricultural Engineering College and Research Institute (AEC & RI), Trichy campus premises has more than 1500 teak trees and neem trees. Pruned twigs of these trees are collected and converted into biochar briquettes through pyrolysis and briquetting technology. The fixed carbon content was found to be 11.5% for teak twigs and 12.5% for neem twigs biomass. Pyrolysis of raw materials is carried out at a temperature range from 450°C to 510°C in a 100 kg capacity pyrolysis reactor. An average biochar yield of 25.7 % and 31.6 % were obtained for teak and neem twigs respectively. The fixed carbon content of 65 % and 68.20% is obtained for the biochar produced from teak and neem twigs respectively. Cow dung and rice gruel starch were used as binders for making biochar briquettes. Cow dung and rice gruel starch were mixed with the biochar with different proportions at 30%, 40%, 50% and 60%. Biochar briquettes were analysed for their thermal and physical properties. The biochar to cow dung ratio of 1:0.3 for both teak and neem twigs gives stable briquettes of 13 cm in length. The fixed carbon content of teak twig biochar briquette and neem twig biochar briquette is 71.96% and 73.47% respectively by using cow dung as binder whereas it was 71.30% and 70.60% respectively with rice gruel starch as binding material. [ABSTRACT FROM AUTHOR]

Agricultural waste recycling is crucial for sustainable farming operations and farming practices. Life cycle assessment has emerged as an innovative and comprehensive viewpoint that considers the entire recycling process to evaluate the potential and true implications of agricultural waste recycling. This study considered methods for recycling different agricultural waste streams, such as crop waste, animal manure, pruning materials, and by-products and subsequent uses. Furthermore, the life cycle assessment method was used to investigate the process of handling agricultural waste, from collection and recycling to final usage in the agricultural system. Environmental impact categories, including greenhouse gas emissions, energy usage, eutrophication, acidification, and land use, were evaluated to determine their potential effects on climate change, resource depletion, and ecosystem health. The results were compared with those of 31 studies that analyzed the potential environmental impacts of agricultural waste management. Various methods initially developed and implemented for agricultural waste landfilling methods have now changed to energy-generating sources, such as biochar, biogas, briquettes, and various energy production methods. Furthermore, composting, a popular method of recycling agricultural waste, significantly lowers greenhouse gas emissions and energy use compared to traditional waste disposal techniques. The study also examines cutting-edge technologies, such as anaerobic digestion and biomass-to-energy conversion, highlighting their potential to manage agricultural waste and being a sustainable energy source. These findings indicate potential environmental advantages in terms of decreased greenhouse gas emissions and fossil fuel consumption, leading to a circular economic approach for agriculture. When integrating agricultural waste, including composting, anaerobic digestion, and pyrolysis, biochar is highlighted as a waste recycling method that is promising for sustainable waste management. In addition to efficiently managing agricultural waste, these technologies help generate electricity and sequester carbon, thereby advancing the objectives of climate change mitigation and circular economy. Although life cycle assessment has been used to analyze several waste management strategies, including those specific to agricultural waste, certain significant gaps and discoveries still require attention for a more thorough analysis. It might be challenging to gather complete and accurate data to assess the entire lifecycle of agricultural waste management technology. The direct environmental effects of waste management are frequently the focus of life cycle assessment studies, but they may overlook secondary effects such as indirect land use change, habitat damage, and biodiversity effects. It is crucial to consider these secondary effects in a more comprehensive analysis. [ABSTRACT FROM AUTHOR]

Briquetted biomass, like sugarcane bagasse, a by-product of sugar mills, is a renewable energy source. This study aimed at the production and characterization of bagasse briquettes. The production of briquettes was carried out with different blending ratios (5, 10, and 15%) and average particle sizes (0.75, 2.775, and 4.8 mm) with various binders of cow dung, waste paper, and admixture (molasses and wastepaper). The bagasse underwent drying, size reduction, sieving, binder addition, and densification using a manual press during the briquetting process. Characterization of the physical and combustion parameters of briquettes, such as density, shatter resistance, proximate, and calorific value, followed the American Society for Testing and Materials procedures. The result shows that the maximum density of briquettes was 0.804 g/cm3, while shatter resistance varied from 83.051 to 94.975% (4.8mm, 5% cow dung and 0.75mm, 5% admixture binders respectively). ANOVA analysis showed that the factors and their interactions had a significant influence (p value < 0.05) on the physical properties. The optimum parameters of briquettes achieved were 14.953% admixture binder, 0.776 mm particle size, 0.805 g/cm3 density, and 95.811% shatter resistance. Bagasse briquettes with a 5% cow dung binder achieved a high calorific value of 39927.05 kcal/kg. The ultimate analysis revealed a composition of 47.49% carbon (C), 5.133% hydrogen (H), 1.557% nitrogen (N), 0.374% sulfur (S), and 45.446% oxygen (O). Therefore, bagasse has a high calorific value and can be used for briquetting to replace fossil fuel and firewood in different applications. In addition, due to its availability, utilizing as fuel source has economic advantage. [ABSTRACT FROM AUTHOR]

The paper presents the results of studying the use of iron ore concentrate as a component of the charge for briquetting finely dispersed dust generated during the production of ferrosilicon. Experiments were carried out on introducing iron ore concentrate into the mixture in the amount of 3 to 10 %. Liquid glass and water were used as a binder. It was shown that the use of 5-7 % by weight of iron ore concentrate with the iron and silicon content of about 65 % and 26 %, respectively, led to increasing strength and density of the briquette by an average of 20 % compared to the same characteristics of briquettes obtained without adding iron ore concentrate. It should be expected that improving such briquette characteristics as strength and density will provide higher safety of the product during transportation and loading and better conditions during deoxidation and alloying, which ultimately ensures an improved steel quality. [ABSTRACT FROM AUTHOR]

Investigation of the possibility of obtaining a complex master alloy used in the deoxidation of steel, smelted from substandard manganese-containing materials, briquettes, and high-ash coals in ore-thermal electric furnaces. Thermodynamic modeling was carried out using the HSC Chemistry software package to determine the optimal process parameters using a second-order rotatable plan (Box-Hunter plan). Thermodynamic modeling improves the understanding of physical and chemical processes, allows making predictions about the behavior of the system under various conditions, optimizing processes and saving time and resources necessary for experiments. Electric smelting of the briquette was carried out with coal and quartzite (to adjust the chemical composition and neutralize residual carbon) in an ore-thermal electric furnace with a power of up to 150 kV*A. The influence of temperature on the equilibrium distribution of silicon, manganese, and aluminum in the «briquette-coal-quartzite» system, the degree of transition of silicon and manganese into a complex ligature and the content of these metals in the alloy are determined by the method of thermodynamic modeling. As a result of experiments on ore-thermal electric smelting of a briquette with high-ash coal, a complex ligature was obtained with an average content of 45.92–53.11% silicon, 27.72–34.81% manganese and 5.60–6.91% aluminum. [ABSTRACT FROM AUTHOR]

As China's coal mines have transitioned to deep mining, the ground stress within the coal seams has progressively increased, resulting in reduced permeability and poor wetting ability of conventional wetting agents. Consequently, these agents have become inadequate in fulfilling the requirements for preventing washouts during deep mining operations. In response to the aforementioned challenges, a solution was proposed to address the issues by formulating a composite wetting agent. This composite wetting agent combines a conventional surfactant with a chelating agent called tetrasodium iminodisuccinate (IDS). By conducting a meticulous screening of surfactant monomer solutions, the ideal formulation for the composite wetting agent was determined by combining the monomer surfactant with IDS. Extensive testing, encompassing evaluations of the composite solution's apparent strain, contact angle measurements, and alterations in the oxygenated functional groups on the coal surface, led to the identification of the optimal composition. This composition consisted of IDS serving as the chelating agent and fatty alcohol polyoxyethylene ether (JFCS).Subsequent assessment of the physical and mechanical performance of the coal briquettes treated with the composite wetting agent revealed notable enhancements. These findings signify significant advancements in the field and hold promising implications. Following the application of the composite wetting agent, notable reductions were observed in the dry basis ash and dry basis full sulfur of coal. Additionally, the water content within the coal mass increased significantly, leading to a substantial enhancement in the wetting effect of the coal body. This enhanced wetting effect effectively mitigated the coal body's inclination towards impact, thereby offering technical support for optimizing water injection into coal seams and preventing as well as treating impact ground pressure. [ABSTRACT FROM AUTHOR]

In México, the utilization of fast-growing plant species for biomass production presents transportation-related issues such as freshness reduction, the transportation of large volumes with minimal weight due to low density, limited storage availability, and logistical challenges. To enhance understanding in this field, the research aimed to evaluate the densification potential of a variety of organic materials, with a specific emphasis on the biomass derived from eight species of rapidly growing plants, three animal species' manure, and concentrated feed. After conditioning, 100 g samples underwent particle size analysis and were categorized into seven sizes. Pellets and briquettes (40 g, 10% moisture, 15 MPa pressure, 5 min processing, 80 °C temperature) were produced and evaluated for bulk density (BD) and pellet (PD) and briquette durability (BDU). The predominant particle sizes were 0.850 mm and 0.425 mm. Original biomass bulk density (OBBD) varied notably, with ovine manure (0.50 g cm−3) and cattle feed (0.49 g cm−3) exhibiting the highest values. Caprine manure (0.83 g cm−3) and ovine manure (0.78 g cm−3) yielded the densest pellets at 1.76 and 1.84 g cm−3, respectively. Apple tree pellets achieved premium quality with the highest hardness (97.9%). Cattle manure (1.25 g cm−3) and cattle feed (1.25 g cm−3) had the densest briquettes, with notable BBD/OBBD ratios in pine sawdust (4.6) and corn (4.5). Caprine manure and Acacia biomass briquettes showed premium quality with the highest hardness (99.1%), emphasizing densification variations and the need for tailored approaches based on organic material characteristics. [ABSTRACT FROM AUTHOR]

Background: In Tanzania, firewood, charcoal, and agricultural waste play a crucial role in daily life as sources of cooking energy, especially in rural areas. Using these energy sources contributes to deforestation and the emission of harmful substances, leading to health problems. This study highlights the potential of faecal sludge briquettes as an innovative, environmentally friendly, and sustainable alternative to traditional energy sources to meet the increasing demand for cooking energy in Tanzania. The process involved sludge characterization, drying, sorting, carbonization, milling, briquette making, and characterization. Results: A study was conducted to assess the presence of zinc (Zn), cadmium (Cd), and lead (Pb) in faecal sludge collected from households. The results indicates that the levels of these metals were all within the acceptable limits set by the Tanzanian Standards (TZS) for sludge disposal and use in the environment, which are 5.00 mg/L, 5.00 mg/L, and 30.00 mg/L, respectively. Septic tanks and pit latrines sludge had a concentration of 0.5 mg/L and 0.5 mg/L for Zn, 0.55 mg/L, and 0.6 mg/L for Cd, and 10.01 mg/L and 4.87 mg/L for Pb, respectively. Adding 75% charcoal dust improved the gross and net heating values from 10.47 and 10.16 to 19.29 and 18.86 MJ/kg, respectively. Similarly, adding 50% charcoal dust improved the gross and net heating values to 19.24 and 18.78 MJ/kg. The emission of particulate matter (micrograms/m3) was reduced from 30.4 and 35 to 10.3 and 11.8 for PM2.5 and 7 and 8 for PM10, while carbon monoxide emission decreased from 51.2 to 19.7 ppm. Conclusion: The results strongly suggest that briquettes made of carbonized faecal sludge mixed with other biomass materials could offer an alternative to traditional solid fuels, with the added benefits of reducing greenhouse gas emissions, deforestation, and longer burning times. [ABSTRACT FROM AUTHOR]

CO2 blasting has been identified as a potent method for enhancing the permeability of coal seams and improving gas drainage efficiency. This study is focused on elucidating the deformation and fracture mechanisms of coal and rock during CO2 blasting and on identifying the precursor characteristics of these processes. To this end, a CO2 blasting-induced coal rock fracture pressure model and a gas pressure distribution model were developed. The research utilized a self-developed CO2 blasting test platform along with a non-contact full-strain field measurement analysis system. Briquette samples were subjected to CO2 blasting tests under controlled experimental conditions, which included an axial pressure of 1.0 MPa and variable gas pressures of 0.5, 1.0, and 1.5 MPa. This methodology enabled the capture of the principal strain field on the surface of the samples. The Gray Level Co-occurrence Matrix (GLCM) was employed to extract and analyze the grayscale and texture features of the strain cloud maps, facilitating a quantitative assessment of their evolution. The aim was to pinpoint the precursor characteristics associated with coal rock cracking and crack propagation. The results revealed that: (1) During the cracking and subsequent propagation of samples, the strain field's grayscale histogram underwent a transformation from a "broad and low" to a "narrow and high" configuration, with a consistent increase in peak frequency. Specifically, at 3 ms, a primary crack was observed in the sample, evidenced by a grayscale peak frequency of 0.0846. By 9 ms, as the crack propagated, the grayscale peak frequency escalated to 0.1626. (2) The texture feature parameters experienced their initial abrupt change at 3ms. Correlation with the gas pressure distribution model indicated that this was the crack initiation moment in the sample. (3) A secondary abrupt shift in the texture feature parameters occurred at 9ms, in conjunction with experimental phenomena, was identified as the crack propagation phase. Monitoring the grayscale and texture features of the principal strain field on the coal rock surface proved effective in recognizing the precursor characteristics of crack initiation and propagation. This research has the potential to reduce blasting costs in coal mines, optimize blasting effects, and provided theoretical guidance for enhancing gas extraction efficiency from deep and low permeability coal seams. [ABSTRACT FROM AUTHOR]

Briquetting is a compaction technology that has been used for many years to produce raw materials that are uniform in size and moisture content and are easy to process, transport and store. The physical and chemical properties of the raw material and the briquetting conditions also affect the density and strength of the briquettes. Nonetheless, assessing the quality of briquettes is challenging and extremely expensive, and necessitates lengthy laboratory investigations. In this study, a fast, cost-effective, and simple method using machine learning was used to evaluate the quality characteristics of briquette samples. The deformation energy, one of the most important briquette quality parameters, was predicted by machine learning methods, considering specific compression force, moisture content, compression resistance, briquette density, tumbler index, water resistance, shatter index and compression stress. For this purpose, Random Forest, Extreme Gradient Boosting, and CatBoost methods, which are among the ensemble learning methods, were used. The RMSE, MAE, MAPE, and R2 metrics were used to evaluate the models. With respect to the training data, the model created using the Extreme Gradient Boosting method was successful on all the metrics. However, for test data, the best RMSE (15.69), MAPE (0.0146), and R2 (0.9715) were obtained from the model established with the CatBoost method. The best MAE (10.63) was obtained from the model established with the Random Forest method. The metric results and the graphs obtained from the prediction values of the models revealed that machine learning methods were successfully able to predict briquette deformation energy. [ABSTRACT FROM AUTHOR]

This work examines biochar from carbonization of grape waste, and oat and buckwheat husks at 450°C. The main aspects of the work concern the analysis of the fixed carbon and ash content in accordance with the European Standard. Obtained results showed that biochar from oat and buckwheat husk can be used for barbeque charcoal and barbeque charcoal briquettes production, whereas biochar derived from grape waste can be used for the charcoal briquettes production. Thermogravimetric analysis showed that biochar from grape stalk is characterized by the highest ignition and burnout performance, but in relation to the remaining samples, combustion process occurs in a narrow range of time and temperature. Obtained results showed that biochar from oat and buckwheat husks has properties, as well as combustion stability and reactivity, similar to commercial charcoal. [ABSTRACT FROM AUTHOR]

Briquettes as a product of biomass compaction is considered a renewable product for replacing fossil fuels. Briquettes can be produced from several sources using the development of technology. In this study, the effect of walnut shells as an organic binder on the properties of biofuel briquettes made of industrial and garden wastes was investigated. Cylindrical briquettes from walnut shell flour with weight ratios of 5%, 10%, 15%, 20%, and 25% were prepared from industrial sawdust and ground garden residue with a weight ratio of 50/50. Briquettes were compacted under a temperature of 170 °C and pressure of 150 kg/cm2 for 30 s. Results indicated that the chemical analyses of compounds, compaction ratio, and density of the briquettes containing different proportions of walnut shells were not significantly different. The lowest fixed carbon was measured for briquettes containing 5% of walnut shell, and increasing the ratio of walnut shell significantly increased the compressive strength of the resulting briquette. [ABSTRACT FROM AUTHOR]

This document is an editorial introducing a special issue of the journal "Materials" titled "Advances in Thermal and Mechanical Properties of Polymeric Materials." The issue features papers on various topics related to the thermomechanical and electrical properties of polymers and their composites. The papers cover subjects such as the use of waste polyethylene in composites, predicting thermal comfort in sportswear, the impact of water temperature on viscoelastic pipes, and the effects of pressure and temperature on material density and thermal conductivity. Other papers discuss luminescent hybrid materials, behavior of plaster-based composites against water, properties of thermoplastic starch nanocomposites, decontamination of recycled polypropylene, mechanical properties of 3D-printed composites, combustion of fuels and waste materials, production of parts with varied transparency using polypropylene injection molding, and thermal conductivity of filaments used in fused deposition modeling. The editorial concludes by congratulating the authors and inviting scientists to contribute to future issues. It is important to note that the opinions and data presented in the document are those of the individual authors and contributors, and not of MDPI or the editor. MDPI and the editor disclaim responsibility for any harm caused by the ideas, methods, instructions, or products mentioned in the content. [Extracted from the article]

The significant energy need for alternative fuels is caused by the increasingly depleting fossil fuels. One alternative material that has the potential to be used as a substitute for fuel is agricultural waste. This research was conducted to determine the characteristics of briquettes by varying the composition of rambutan skin charcoal and coconut shell charcoal. Briquettes are made from coconut shells and rambutan skin. Molasses is used as a charcoal adhesive. Briquettes are made in the laboratory using a carbonization process using a furnace. Variations in the composition of rambutan skin and coconut shell charcoal are 10:90, 20:80, 30:70, 40:60, 50:50, 60:40, 70:30, 80:20, and 90:10. This article was conducted to study the calorific value, water content, ash content, and fixed carbon briquettes from coconut shell charcoal and rambutan skin. The results showed that mixing coconut shell charcoal and rambutan skin increased the calorific value and ash content. The best composition is 10:90 for rambutan skin and coconut shell charcoal with a calorific value of 6297.09 cal/gram. [ABSTRACT FROM AUTHOR]

Producing durable and efficient solid biofuels should be an important consideration in Nigeria's present economy due to the numerous advantages associated with it. It offers the benefit of energy generation, particularly in rural areas, and could potentially replace fossil fuels. However, the adoption and production of solid biofuels at commercial scale in Nigeria is limited by some challenges, including the lack of a developed supply chain structure, inadequate facilities, and air pollution. The present study summarizes the types of solid biofuel production technologies deployed in Nigeria as well as the biomass feedstock utilized in the production of fuel briquettes and pellets. While opportunities exist in the gasification of biomass in Nigeria, direct combustion is a readily applicable fuel conversion process that can be utilized to generate electricity from solid biofuel. The major challenges surrounding the full adoption of solid biofuel production and utilization in Nigeria are highlighted. Among others, promotion of clean energy alternatives, investments and financial incentives, sustainable renewable energy policy and energy transition plan, and legislative backing are identified as factors that could accelerate the commercial production and adoption of solid biofuel in Nigeria. [ABSTRACT FROM AUTHOR]

In order to obtain the characteristics of the effects of cyclic impact loading on the damage of coal-rock in the presence of a local static load constraint, the evolution of the damage factor and the fracture rate during the process and incremental cyclic impact on raw coal and briquettes has been studied. Experimental results show that the presence of local static load restraint improves the impact resistance of the coal-rock, and the damage factor of the coal-rock shows obvious zoning characteristics. When the coal-rock is in an elastic state, the partition with a larger static load restraint area has stronger impact resistance, when the coal-rock is in a plastic state, the partition with a larger static load restraint area has a weaker impact resistance. Increasing impulsive cyclic impacts have a higher damage efficiency to coal-rock than constant impulsive cyclic impacts. The difference in rock breaking efficiency between the two cyclic impact methods is mainly reflected in the partition with the largest constrained area. The crack propagation on the coal-rock surface is more consistent with the partition characteristics of the damage factor. When the static load constrained zone is in an elastic state, the static load has an inhibitory effect on the crack growth. When the static load confinement zone is in a plastic state, the cracks mainly propagate in the static load confinement zone, and the constrained zone mainly consists of tensile cracks that grow in the vertical direction, while the cracks in the non-constrained zone mainly grow in an oblique direction. Finally, fracture mechanics was applied to analyze the failure type of the sample. [ABSTRACT FROM AUTHOR]

The population has increased and resulted in an increase in the demand for energy sources and various types of waste. Palm oil fronds and stems are a type of solid waste which numbers are increasing rapidly due to the expansion of palm oil agriculture. Eco-energy can be used by knowing the water content and ash content. Therefore, the purpose of this study is to determine the water content and ash content of the fronds and stems of palm oil as eco-energy briquettes. The method of this research is an experimental research method starting from the collection of raw materials, drying, testing the water content and testing the ash content. From the results of the study it was found that with a ratio between fronds and palm oil stems, namely 1:1, the water content is 0.21% and the ash content iss 0.30%; a ratio of 1:2 means a water content of 0.23% and an ash content of 0.27%; a ratio of 1:3 means a water content of 0.20% and an ash content of 0.25%; a ratio of 2:1 means a water content of 0.22% and an ash content of 0.29%. All of the briquettes comply with SNI (Indonesian National Standard) where the water content of the briquettes according to SNI (SNI 01-6235-2000) is a maximum of 8% and a maximum briquette ash content of 8%. [ABSTRACT FROM AUTHOR]

This study utilized a combination of FLIC(1D3.2C) and FLUENT(2021R2) software to optimize the primary air distribution along the grate and the performance of a straw briquette combustion furnace of a 7 MW unit in China used to produce hot air for drying grain. Three air distribution modes, namely front-enhanced, uniform, and rear-enhanced modes, were analyzed to determine their effect on the flue gas components above the grate, the temperature field in the furnace, and the nitrogen oxide concentration at the furnace outlet. The results of the calculations showed that the NOx emissions for the front-enhanced, uniform, and rear-enhanced modes were 133.5 mg/Nm3, 104.4 mg/Nm3, and 76.6 mg/Nm3, respectively. It was found that the rear-enhanced mode can expand the biomass drying, devolatilization, and combustion zone, thus improving the furnace combustion performance and decreasing NOx emissions. These findings can provide useful guidance for optimizing biomass chain-grate-firing furnaces. [ABSTRACT FROM AUTHOR]

Indonesia needs energy to meet its needs. Energy sourced from waste is called biomass briquettes. The manufacture of briquettes is still done in a traditional way, so there are product quality problems. A computational approach has been taken to base the quality of the product on certain characteristics so that the types of briquettes that are made can be classified or sorted. The research objective of this work is to determine the quality of briquettes. The approach uses deep learning methods and convolutional neural network (CNN) architecture. Classification is based on good and bad briquette products, and testing is based on the level of performance accuracy. The dataset formed consists of 5,280 images. As training data, 85% of data is used and 15% is used as test data using 300 epoch parameters, 32 batch sizes, and learning speed up to 0.001. The results of testing and evaluating the performance of briquette products with the general CNN architecture have a level of accuracy that is not optimal. The optimization results of testing the MobileNetV2 architecture with a ratio of 70:30 obtains predictions with 0.99 as the highest accuracy value and 0.73 as the lowest. The average predicted value of the model is 0.95. The computational approach is able to provide traditional communities with solutions for the process of making briquettes. [ABSTRACT FROM AUTHOR]

Background: Uganda's energy relies heavily on biomass sources. This dependence on biomass for household and commercial purposes, driven largely by population increase, poses pressure on natural resources, such as forests. This study investigates the usage of some of the country's largely produced agricultural wastes for the production of biofuels. Methods: Pineapple peels (PP), banana peels (BP) and water hyacinth (WH_Eichhornia crassipes (Mart.) Solms) were used for generation of both carbonized and uncarbonized briquettes. Physical properties and calorific values for the developed briquettes were determined through thermogravimetric analysis and using a bomb calorimeter. Results: Pineapple peel carbonized briquettes had the highest calorific value (25.08 MJ/kg), followed by a composite of banana peels and pineapple peels (22.77 MJ/kg). The moisture content for briquettes ranged from 3.9% to 18.65%. Uncarbonized briquettes had higher volatile matter (ranging between 62.83% and 75.1%) compared to carbonized briquettes (ranging between 22.01% and 24.74%). Uncarbonized briquettes had a shorter boiling time (ranging between 27 and 36 min for 2.5 L of water) compared to carbonized briquettes (ranging between 26 and 41 min). Bulk density was highest in uncarbonized BP briquettes (1.089 g/cm3) and compressive strength was highest with carbonized BP + PP (53.22 N/mm2). When using water hyacinth alone, the produced carbonized briquettes show low calorific values (16.22 MJ/kg). However, the calorific values increased when they were mixed with banana (20.79 MJ/kg) or pineapple peels (20.55 MJ/kg). Conclusions: The findings revealed that agricultural wastes could be used to augment the energy sources pool to protect the environment and create social stability in the community. [ABSTRACT FROM AUTHOR]

In energy scarcity, particularly in Agri-based developing economies, bio-coal briquetting is the most suitable means of meeting sustainable energy needs utilizing agricultural waste. In this study, briquettes were made from an indigenously designed briquetting machine for investigating coal–biomass proportion blend using coal from Dara Adam Khel, Khyber Pakhtunkhwa in Pakistan, and pomegranate/olive waste to analyze their resulting calorific value, strength, and geochemical properties. A central composite design (CCD) and response surface methodology (RSM) were employed to design the experiments and analyze the data. Regression models were developed for each biomass type, demonstrating their adequacy and reliability for further analysis and prediction. Energy Dispersive X-ray Spectroscopy (EDX) analysis provided insights into the elemental composition of the coal briquettes. Mechanical analysis was performed to assess the strength of the briquettes, with varying compositions showing different levels of strength. Optimization using a composite desirability function yielded an optimal calorific value of 6728 kJ/kg. In summary, this study underscores the viability of bio-coal briquetting as a transformative solution to alleviate energy scarcity. Repurposing agricultural waste curtails resource depletion while mitigating waste disposal challenges. The optimized calorific value aligns with eco-friendly energy initiatives, advancing a greener path toward energy security. [ABSTRACT FROM AUTHOR]

In Indonesia, palm shells and plastic waste are quite abundant, and they have the potential to cause environmental pollution. Additionally, the availability of fossil fuels is dwindling, so other energy sources are needed. This study aimed to find a solution to these problems. In this study, briquettes based on dried palm shells (cangkang kelapa sawit or CKS) with the addition of polypropylene (PP) and polyethylene (PE) plastics were prepared and characterized. The briquettes were made using cassava starch adhesive, and the densification was carried out at a pressure of 1283.40 N/m² for 30 min. The briquettes were made with varying amounts of plastic added to the mixture: 1, 2, 3, and 4 % (w/w % of CKS). The produced briquettes were analyzed for their calorific values and mechanical compression properties. Calorific value is an important parameter related to the energy content of briquettes as fuel. A compression test is important since the briquettes must resist external compression load due to stacking during storage and transportation. The calorific values of the briquettes obtained from the experiments were found to be in the range of 27.14-27.7 MJ/kg, wherein the calorific value for briquettes containing PP is higher than that of the ones containing PE. From the compression testing, it was found that the higher the plastic content, the higher the compression modulus of elasticity and ultimate strength of the briquettes. As with the calorific values, the modulus of elasticity, and ultimate strength value of briquettes containing PP are higher than that of the ones containing PE with the same palm-to-plastic ratio. [ABSTRACT FROM AUTHOR]

A sequential two-step thermochemical process was studied for spent green tea waste (SGTW), involving an initial pyrolysis step followed by thermal or catalytic cracking. This process was carried out in two bench-scale reactors (fixed bed reactor and tubular reactor) serially coupled. At a fixed pyrolysis temperature of SGTW (550 °C), the application of high cracking temperatures (700 and 800 °C) positively affected both the yield and composition of the gas product. Consequently, it has the potential to be used for the production of diverse biofuels and chemicals, or to be partially recycled to optimize the process efficiency. Moreover, the use of inexpensive catalysts, particularly dolomite, was considered advantageous, since the syngas yield (56.5 wt%) and its potential were greatly enhanced, reaching a H2/CO ratio of 1.5. The homogenous biochar obtained, with a calorific value of 26.84 MJ/kg, could be harnessed as good-quality fuel for briquette applications and as a biofuel source for generating stationary power. Furthermore, catalytic cracking pyrolysis was examined for different types of coffee waste, revealing that this process is a simple and clean solution to valorize oxygen-rich lignocellulosic biomass and generate valuable gaseous by-products. [ABSTRACT FROM AUTHOR]

This research provides the results of large-scale laboratory and industrial tests on silicon electrothermy with silicon carbide and briquettes with quartz sand and petroleum coke added to the charge. It is shown that only replacement of petroleum coke for these ingredients in a standard charge is efficient. Substituting coal for them also deteriorates the process efficiency, which is explained by increased electrical conductivity of the charge. Recommendations to improve the electrothermy technology, including SolG Si preparation are formulated. [ABSTRACT FROM AUTHOR]

This paper presents a theoretical evaluation of the prices of mixed briquettes produced from coconut shells (CCS), banana peels (BNP), rattan waste (RWT), and sugarcane bagasse (SGC) and, on the other hand, an analysis of the economic viability of their use as a replacement for conventional household fuels (liquefied petroleum gas, fuelwood, and wood charcoal) in households in Cameroon. The investigation was carried out using the life cycle cost method on a typical household over a ten-year period with annual cooking energy requirements of 950 kWhth. The SGC–CCS and SGC–RWT mixed briquettes with ratios higher than 7.75% and 11.1%, respectively, have prices lower than EUR 0.063/kWhth. The Present Value of the Net Benefit is positive for the use of SGC–CCS and SGC–RWT mixed briquettes. The results show that by making the right mixes of residues, it is possible to obtain biomass briquettes that are less expensive than conventional fuels. [ABSTRACT FROM AUTHOR]