Search Results (48)

Solid fuels are still widely used in household heating in Europe and North America. Emissions from boilers are released in proximity to people. Therefore, there is a need to minimise the toxicity of emissions affecting human health to the greatest extent possible. This study compares the genotoxic potential of the emissions of four boilers of modern and old design (automatic, gasification, down-draft, over-fire) operating at reduced output to simulate the real-life combustion fed by various fossil and renewable solid fuels (hard coal, brown coal, brown coal briquettes, wood pellets, wet and dry spruce). Organic emissions were tested for genotoxic potential by analysing bulky DNA adducts and 8-oxo-dG adduct induction. There was no consistent genotoxic pattern among the fuels used within the boilers. Genotoxicity was strongly correlated with polycyclic aromatic hydrocarbon (PAH) content, and even stronger correlation was observed with particulate matter (PM). In all measured variables (PM, PAHs, genotoxicity), the technology of the boilers was a more important factor in determining the genotoxic potential than the fuels burned. The highest levels of both bulky and 8-oxo-dG DNA adducts were induced by organics originating from the over-fire boiler, while the automatic boiler exhibited genotoxic potential that was ~1000- and 100-fold lower, respectively. Full article

This research analyzes the technical feasibility and implementation of an appropriate technology for the production of briquettes from Pinus spp. waste (sawdust and shavings) in a rural community in Michoacán, Mexico. The results indicate that local small-scale briquette production in the Pichátaro community has the potential to boost a local economy based on the manufacturing and marketing of densified solid biofuels. The design of the manual briquetting machine was developed through a participatory approach with community users. Structural simplicity and locally accessible maintenance were prioritized, the aspects that were addressed little in previous studies. The machine allows for the production of briquettes using a low-cost mixture composed of sawdust and Pinus spp. shavings, corn starch, and water. Based on local conditions and production needs, parameters such as reduced processing times and simplified manufacturing methods were identified as essential to establishing an efficient regional production and supply chain. Furthermore, the valorization of solid waste through the production of alternative biofuels contributes to the diversification of the energy matrix in rural residential sectors and small industries in communities in Mexico. The estimated cost of the machine is USD 75.44, and most of its components are easily replaceable, which favors its sustainability and prolonged use. This study demonstrates that the implementation of a low-pressure briquette system based on appropriate rural technologies represents a viable strategy for the use of wood waste and the promotion of sustainable energy solutions in rural communities. Full article

The aim of this paper is to carry out a rheological study of the pressing of pine wood sawdust, after which obtaining briquettes from the same wood material with a hydraulic installation and analyzing their properties. In order to know the rheological behavior during pressing, the fractions resulting from sorting the sawdust with 4 × 4, 3 × 3, 2 × 2, and 1 × 1 mm² sieves were used, respectively, six fractions (the fraction larger than 4 × 4 mm² and the smaller one of 1 × 1 mm² are added) and a specific pressing device, placed on a universal testing machine. The results obtained in the rheological study showed that the obtained density does not increase proportionally with the pressure, the best results (density of 1030 kg/m³) being obtained at a pressure of 180 MPa. Within the briquettes, higher densities were obtained for the sawdust fraction smaller than 1 × 1 mm², but the breaking strength was higher for the fraction larger than 4 × 4 mm². As a general conclusion, it was found that pine sawdust is easily compressible, and the briquettes obtained from it have good properties for use in combustion. Full article

This article aims to provide a comprehensive review of the use of logging residues in manufacturing briquettes, and to demonstrate their potential as a renewable energy source. Technical aspects of briquetting are examined, including wood properties, particle size, moisture content, and process temperature. Forest residues, such as branches and treetops, have a high energy potential with calorific values reaching up to 20 MJ∙kg⁻¹ after briquetting. Densifying these residues increases their energy density (achieving up to 1120 kg∙m⁻³) and reduces waste and greenhouse gas emissions. Briquetting processes were analyzed economically and environmentally, with studies showing that production costs can be reduced by 25% when using locally sourced residues. This review recommends optimizing production processes to improve briquette durability and quality. Future research directions focused on developing cost-effective briquetting technologies tailored for small- and medium-sized businesses are identified in the study. Rural and economically disadvantaged regions could benefit from these advancements in briquetting. This paper advocates improved collaboration with international organizations to standardize briquette quality, promoting market acceptance and trade. Technology such as briquetting has the potential to advance renewable energy systems and achieve global climate goals. Full article

This study aimed to determine the nutritional composition of Synodontis membranaceus, Clarias gariepinus and Labeo senegalensis smoked with firewood (FW), wood charcoal (WC) and charcoal briquettes (CBs) and also to investigate the efficiency, drying capacity and cost-effectiveness of the fuels. A sensory assessment of the smoked fish was conducted. Proximate analysis of the smoked fish was conducted for moisture, ash, crude lipids and crude proteins. Proximate values for smoked C. gariepinus were significantly different (p < 0.05) across the three fuels. Only moisture and crude protein were significantly different in smoked L. senegalensis, while in S. membranaceus, all proximate values were significantly different except ash (p > 0.05). Protein retention was higher in WC-smoked fish. CBs dried the fish moisture (84.85%) to the level required to halt deterioration within a reasonable time (15.6 h) and was cheaper (NGN 795) than FW and WC. CBs also had higher fuel efficiency (0.76) compared to FW and WC. The organoleptic properties of the fish smoked were generally acceptable. Full article

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. Full article

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. Full article

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. Full 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 T_gas 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. Full article

Fuel types are essential for the control systems of briquette biofuel boilers, as the optimal combustion condition varies with fuel type. Moreover, the use of coal in biomass boilers is illegal in China, and the detection of coals will, in time, provide effective information for environmental supervision. This study established a briquette biofuel identification method based on the object detection of fuel images, including straw pellets, straw blocks, wood pellets, wood blocks, and coal. The YoloX-S model was used as the baseline network, and the proposed model in this study improved the detection performance by adding the self-attention mechanism module. The improved YoloX-S model showed better accuracy than the Yolo-L, YoloX-S, Yolov5, Yolov7, and Yolov8 models. The experimental results regarding fuel identification show that the improved model can effectively distinguish biomass fuel from coal and overcome false and missed detections found in the recognition of straw pellets and wood pellets by the original YoloX model. However, the interference of the complex background can greatly reduce the confidence of the object detection method using the improved YoloX-S model. Full article

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 kWh_th. 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/kWh_th. 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. Full article

The development and utilization of wood briquettes is one of the efforts to reduce dependence on fossil fuels, including to fulfill overseas market need. This study aimed to evaluate the properties of wood briquettes made of the branches of three mangrove species and to analyze the effect of different wood species of mangrove branches, and the types of starch adhesive, on the quality of wood briquettes. The wood briquettes made in this study were 3 cm × 4 cm in a cylindrical shape using three wood species of mangrove branches, namely mata buaya (Bruguiera sexangula), buta-buta (Excoecaria agallocha), and bakau minyak (Rhizophora apiculata), while the adhesives used were tapioca starch, maize starch, and potato starch. The results showed that the moisture, ash content, and calorific value of the wood briquettes mostly met the ISO 17225-3:2-2020 class A2 standard and the specification and quality standards of wood briquettes for Grade A2 issued by the Korea Forest Research Institute, except the density. Wood briquettes made of mata buaya by using the three types of starch adhesives generally had better properties than all other types of wood briquettes. The interaction of mangrove wood species and the types of starch adhesive had a significant effect on the properties of wood briquettes, except for volatile matter and calorific value for which they had no significant effect. The use of wood briquettes from mangrove wood branches contributes to sustainable forest management and maintains the ecological function of mangrove forests while providing environmentally friendly alternative energy for households as a source of fuel/energy. Furthermore, future research is needed, such as investigating the optimal pressing pressure needed to achieve higher density of the wood briquettes. Full article

The present article focuses on pressed biofuel preparation from invasive herbaceous plants, and the quality indicators and properties were analyzed and determined. Two invasive herbaceous plants were chosen for this research: giant knotweed (Fallopia sachalinensis) and Sosnowsky’s hogweed (Heracleum sosnowskyi). For a control, pine wood biomass was utilized. After harvesting and drying, plant biomass was chopped and milled and later pressed into cylindrical pellets and briquettes. The research results for the pellets’ and briquettes’ physical and elemental properties showed that the density of the pellets (moisture 5–8%) reached 1145.60–1227.47 kg m⁻³, and the average density of the briquettes reached 615.60–867.31 kg m⁻³. The determined critical compressive strength of the pellets ranged from 420 N to 676 N, and the briquettes disintegrated under a significantly greater critical force of 783 N to 1219 N. The variation in pellet compressive strength with changes in their moisture content was also investigated. The determined lower caloric value of the pellets varied from 15.9 MJ kg⁻¹ to 18.6 MJ kg⁻¹. Harmful gas emissions during burning of the tested biofuel pellets were also evaluated and determined, and they were sufficiently low and did not exceed the permissible values. Finally, it can be stated that all of the pressed biofuels produced from invasive herbaceous plants met the most important requirements for the quality of pressed solid biofuel and can be used for burning in special boilers. Full article

Nitrocellulose (NC) is a conservative material that is used in a variety of applications, such as coating agents, biodegradable plastics, and propellant main charge. Nitrocellulose raw materials are easily obtained from lignocellulose sources, most notably cotton and wood pulp. The egg carton, a recycled paper waste designed for packaging and transporting eggs, is used in this study to make nitrocellulose in pulp form. The effects of different nitration durations (40, 50, and 60 min) from egg carton pulp bleached with various KOH concentrations (0.6 M, 1.0 M, and 1.5 M) on NC properties were evaluated. The accelerant properties of the NC of nitration time in 50 min were studied in a rice husk charcoal briquette. Rice husk charcoal briquettes are made in various ratios with nitrocellulose as an accelerant (97:3, 96:4, and 95:5). The NC was characterized using Fourier transform infrared (IR) spectroscopy and thermogravimetric (TG) analysis. 1.0 M of bleached egg carton pulp has the highest cellulose content (86.94%) with the presence of crystalline structure of cellulose at peak 1430 cm⁻¹ after the bleaching process. Meanwhile, different nitration times revealed that 50 min had the highest nitrogen content (7.97%) with a 1.23 degree of substitution (DS) value. Based on its TG analysis, NC 50 has met the requirements for use as an accelerant for briquettes, with an onset temperature of 91.60 °C and a weight loss of 62.60%. Infrared at peak 1640 cm⁻¹ confirmed the presence of NO₂ groups in nitrocellulose successfully formed by nitration. After the addition of nitrocellulose, the calorific value of the briquette increased from 13.54% to 15.47%. Fixed carbon and volatile matter showed the same pattern. The combustion of nitrocellulose-briquette has also been demonstrated by Td10% of degradation, which degraded between 310 and 345 °C. Full article

Nigeria has the potential to generate 12,522 MW of electricity, but can only dispatch 4000 MW, which is insufficient for a population of over 200 million people as of 2022. Therefore, Nigerians use solid fuels including firewood and charcoal as an alternative to insufficient electricity for domestic use. The consumption of firewood and charcoal in Nigeria is estimated at 23,745,458 tons and 4,828,689 tons, respectively in 2021, by far the most consumed domestic solid fuel sources in Nigeria. Although there are domestic solid fuel alternatives, such as dung, agricultural residues and coal, to firewood and wood charcoal, their sustainable adoption has been slow in Nigeria, indicating that there is insufficient knowledge of domestic solid fuel sources. This requires a review focused on assessing Nigeria’s national sources of solid fuels. This article presents an overview of the sources of domestic solid fuels in Nigeria, an exploration of different types of firewood and charcoal studies, the impact of solid fuels on climate change and the environment, health risks associated with solid fuel and biomass briquettes and pellets as domestic solid fuel alternatives to charcoal and firewood. The continued production and use of firewood and wood charcoal as domestic solid fuel sources encourage deforestation, desertification and greenhouse gas emission, which in turn pose a threat to a sustainable environment and good health. It is necessary to limit the felling of trees for firewood and charcoal production to curtail their negative impacts on the health of users and the environment. This review covered the thermal, mechanical and physical properties of briquette and pellet fuels as substitutions for firewood and charcoal. It was shown that employing briquettes and pellets as a source of solid fuel in the home will lessen the negative impacts that these fuels have on users’ health, the climate and the environment. Full article