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Bananas are grown and consumed in large quantities in Uganda and have been a staple food that is socially and culturally important. Additionally, the leaves and fiber are used for various purposes such as cooking and fulfilling other daily necessities. Banana peels are used as a biomass briquette material in place of charcoal, which is currently used as the primary cooking fuel; this has been the case since the late 2000s in Kampala, the country's capital. This study examined the suitability of carbonized briquettes made from organic waste in a community where bananas are the main food source in Kampala. Through a fieldwork-based survey, production practices, material accessibility, and expansion of production are explored. It was discovered that briquette material is available all year long. Briquettes can be produced using widely available materials, and producers actively share production methods with each other. Since bananas and other steamed and stewed foods are common, briquettes are a convenient substitute to charcoal. With the rise of charcoal prices, briquette production and its use as fuel for cooking is expected to spread. Briquettes could become a new cooking fuel option or partial substitute and help reduce charcoal consumption and reliance on woodfuel., This article is based on my Japanese paper titled “Active use of household garbage as cooking fuel: A case study of biomass briquette production in Kampala, Uganda” published on pp. 41–60 on Asian and African Area Studies (Ajia Afurika Chiiki Kenkyu), No. 18-1 (2018).

The study aimed to determine the effects of adhesive content on rubber wood charcoal briquette characteristics. Wood charcoal was produced using a double-drum retort kiln at > 500°C. Wood charcoals were crushed into powder and then mixed with tapioca adhesive of 5%, 10%, and 15%. The charcoal-adhesive mix was then pressed using a hydraulic press machine. For comparison, rubber wood biomass briquettes were also produced using wood particle-adhesive mix with similar adhesive content. Biomass and charcoal briquettes characteristics as physical properties (density and water absorption), chemical properties (ultimate analysis, and FTIR analysis) and energy properties (calorific value) were evaluated. The results showed that density ranged between 0.52-0.56 g/cm3, water absorption of 6.54-7.47%, C content of 82.67-84.41%, H content of 3.28-3.60%, N content of 0.67%-0.74%, and calorific value of 30.76-32.86 MJ/kg. The results of FTIR analysis showed changes in the spectrum of the wave band on the functional groups OH, CH, C≡H, C=C, and C=O, indicating the decomposition of the chemical components of rubber wood due to pyrolysis. The results prove that increasing the adhesive content can reduce the quality of briquettes. Based on physical, chemical, and energy properties, charcoal briquettes with 5% adhesive showed better characteristics than briquettes with 10% and 15% adhesive content, showing water absorption of 6.54%, C content of 84.41%, H content of 3.28%, and heating value of 32.86 MJ/kg. Keywords: adhesive content, charcoal briquette, pyrolysis, rubber wood waste, tapioca starch

Deforestation remains a major ecological problem in most developing countries especially Pakistan which has a very high deforestation rate. Fuel-wood consumption is a determining socioeconomic factor for deforestation and degradation. Agroforest biomass utilization for energy production is an extreme value socioeconomic incentive towards the reduction in deforestation and degradation in Pakistan. This study was conducted at Basho forest valley Gilgit-Baltistan, Pakistan, in 2019. In this study, dried and milled forest waste (FW) including tree leaves and branches were briquetted (biofuel) to be used as an alternate of wood fuel and determined its physical properties regarding quality of the briquette. The screw extruder briquetting technology was employed. Dried (

This manuscript presents an experimental study on the combustion rate of biomass briquettes or logs in a domestic boiler, by monitoring the time decay of its mass and the temperature of the flame inside the boiler. Assuming close to steady state conditions, two combustion models were studied: the constant particle density-burning model and the constant particle diameter-burning model. For each model, the evolution of the global combustion resistance with the decay of the particle diameter was analyzed, and it was possible to conclude that the burning occurred approximately with constant particle size and that the heterogeneous C to CO reaction takes place at the surface of the inner carbonaceous core. The high values obtained for the Sherwood number revealed that there were significant convective effects inside the furnace and compare well with a previously developed Sherwood number correlation for a packed bed of active particles.

Biomass briquettes can be considered as an effective alternate source of energy for fossil fuels. The present study deals with the conversion of Sugarcane bagasse(S), Corn cob (C) and Rice husk (R) of various proportions into biomass briquettes. The characterization of the prepared biomass briquettes includes analysis of physical, thermal properties along with the burning capacity by means of water heater test. The physical properties of the briquettes have been analyzed by shatter resistance test, tumbling resistance test and water penetration test. Combustion, proximate and ultimate analysis have been carried out to evaluate the characteristics of the prepared biomass briquettes. A modified Harsha stove which has more efficiency than the conventional one has been fabricated in order to perform the combustion process. The physical and thermal characteristics of the prepared biomass briquettes have been compared with conventional wood charcoal briquettes. Proximate analysis of briquetted sample has been carried out to determine the moisture content, volatile matter, ash content and fixed carbon whereas ultimate analysis have been performed to determine the percentage of Carbon, Hydrogen and Nitrogen respectively.

Applying biomass energy for curing flue-cured/Virginia tobacco heating is the best way to realize green tobacco production. Aiming to satisfy the heating demand for flue-cured tobacco curing, a new heating device that uses biomass briquettes as fuel for curing tobacco is adopted the first time, which was developed using modern mature electromechanical and computer technology. The new device consists of automatic feeding, ash cleaning, ventilation, and ignition systems governed by an intelligent tobacco-curing controller designed for specific curing characteristics. The results of experiments conducted with an original direct combustion coal furnace, bulk curing barn, and controlled coal-fired heating indicated that the heat supply of the new device could satisfy the heat demand during the tobacco curing process, with a good performance-controlling difference of ?0.5?C between the actual and target dry-bulb temperature in the barn. With its unattended heating management and use of fully burning fuel, the new device sharply decreased the cost of manual operation and tobacco leaves required per kilogram compared to a coal furnace. Considering the shape of its structure, the new device could be used to heat homes or small-scale boilers if the chip procedure of the controller is altered.

Even though biomass is carbon-neutral renewable energy, the utilization of biomass results in sulfur oxides (SO x ), nitrogen oxides (NO x ) and particles emissions. Biomass briquetting and doping ...

The screw briquetting machine has problems which have been attributed to poor design. There are limited theoretical studies targeted at solving problems of biomass briquetting machines. The briquetting die determines the final shape and quality of the biomass briquettes. The performance of the screw briquetting machine is also dependent on the design of the briquetting die. In this paper, mathematical models were developed to study the die pressure using a plug flow theory. Effects of die entry angle, die reduction ratio, length of briquetting die, biomass compact yield strength and friction on the die pressure were investigated using the models. Increasing the die entry angle, reduction ratio, compact yield strength and friction coefficient resulted in increase in the die pressure. Increase in length of briquetting die and friction coefficient also resulted in increase in the die pressure. Optimum die entry angle was dependent on the yield strength of compacted material and the friction coefficient at the interface between the die and the compacted material. This study is useful in developing improved screw briquetting machines.

Water hyacinth is an aquatic plant that has a great reproductive potential. The propagation of water hyacinth in most water bodies have decimated the livelihoods of many and reduced the water quality, among other negative effects. Converting this invasive water hyacinth into briquettes will serve as a good measure for controlling its proliferation, and also as a strong strategy for the development of sustainable alternative energy sources. This study explored water hyacinth briquettes as alternative to the local wood fuels through mercerization process to enhance the qualities of a biomass briquette and encourage its use as a renewable energy source of fuel. The aim was to evaluate the combustion performance of treated water hyacinth (TWH) and water hyacinth (WH). After sample collection, preparation and treatment, the briquettes were produced using 20 g of starch prepared into slurry blended with 80 g of the sample to produce the briquettes. The proximate characteristics, physical properties, combustion properties, the morphologies and structural changes in the briquettes were determined. The results obtained showed that both samples have good energy potentials. The outcome indicates that the alkaline treatment removed the hemicelluloses in the biomass and in turn reduced the moisture content of the briquettes. Consequently, the physical and combustibility properties of the briquettes got improved. The calorific value also improved from (30.58 MJ/Kg) in WH to (34.22 MJ/Kg) in TWH, The scanning electron microscopy analysis showed a rough surface which enhanced bonding of the sample particles while the FTIR showed a structural change in the OH groups which indicates that the hemicelluloses have been removed.

Study on production of briquettes from two invasive forest weeds, i.e., Lantana camara and Prosopis juliflora was carried out. The experiments were carried out using a 90 mm industrial briquetting unit. The optimum moisture content for briquetting was found around 10–12%. L. camara and P. juliflora biomass briquettes were found to have high density (1.2 g cm−3) and high energy density (23.05 GJ m−3). In this study, fuel properties (calorific value, proximate and ultimate analysis), combustion characteristics and ash elemental composition of L. camara and P. juliflora biomass were investigated. Both the species are found to have less ash content. Further, high CaO content in ash (47–68%) gives added advantage to these species. In this study, we have also worked out the cost involved in briquetting. The emphasis was given to these species because of the huge biomass they produce. These species are widely present in different agro-climatic zones of India and can play a major role in future bioenergy schemes.

In recent decades there has been a considerable global increase in urban population, industrial productivity, energy demand, waste generation, and the emission of greenhouse gases from energy conversion. The agricultural, forestry, textile and food sectors generate large amounts of waste and their environmental impact has become a major cause for concern in societies around the world. Current efforts are concerned with maximization of combustion efficiency and energy-related processes in general by making use of industrial residues and reducing particulate matter. The present review addresses the availability of different types of biomass that can be used to produce renewable energy and focuses on agricultural, forestry, urban and industrial residues. It also provides a description of the physical and calorific characteristics of the various raw materials available for the manufacture of briquettes and other fossil fuel alternatives.

A large amount of waste biomass is produced during agricultural processes, which is a promising renewable energy source, but, to date, there are no effective ways of realizing industrial applicatio...

The effects of the briquetting temperature, briquetting pressure and hydrothermal pretreatment (HT) on the physicochemical properties of the resulted briquettes prepared from one herbaceous biomass, cotton stalk (CS) and one woody biomass, Chinese pine wood sawdust (WS) were mainly addressed in the paper. The apparent density, compressive strength and combustion characteristics of the resulted briquettes (CS/WS-Bs and CS/WS-HT-Bs) were investigated to evaluate their feasibility as the biomass briquette fuels. The results showed that the increase of briquetting temperature and pressure was beneficial to the densification of CS/WS-Bs. Compared with CS/WS-B, the hydrothermal pretreatment significantly improved the physical properties of the resulted biomass briquettes. As the hydrothermal pretreatment temperature increased, the heating values of the resulted CS/WS-HT-Bs increased, the content of fixed carbon increased and the yields of volatiles decreased. Furthermore, HT promoted the combustion characteristics. In addition, the Mad and heating values of all CS/WS-HT-Bs meet the Sweden Standard (SS18 7120). The most cost effective CS/WS-HT200/230-Bs were prepared from the cotton stalk and wood sawdust hydrothermal pretreated at 200 °C and 230 °C under the briquetting conditions of 75 °C and 80 MPa. However, the changes in the physical and chemical properties of the briquettes prepared from CS and WS followed different trends.

In Nasarawa state, over 70% of the population are involved in subsistence farming. Varied agricultural resources are produced in millions of tons annually. Large quantity of residues is generated that are either left to rot on farmlands or disposed of by burning in open air. In many rural areas, the residues are also used in their raw form for cooking purposes which is inefficient. The disposal and use of the residues cause pollution in the environment which affects human health. Residues can provide a source of clean and renewable energy in the form of solid biofuel called briquettes through densification. Briquetting is a densification technology that converts residues with a low heating value per unit volume into high density and energy concentrated fuels. This paper offers a perspective on the potentials of agricultural residues in Nasarawa state to produce briquettes as an alternative clean and sustainable domestic cooking fuel. The paper concludes that briquettes could be economically and environmentally friendly alternative to fuelwood. The use of biomass briquettes would reduce dependence on fuelwood, environmental pollution and the amount of time spent on cooking. Adopting the briquetting technology will enhance access to clean and affordable energy in line with the 7th goal of the United Nation’s Sustainable Development Goals.

The safe and sound disposal of vegetable market waste (VMW) is a major concern of India today. VMW is being produced in millions of tonnes in urban areas, which are often deposited in dumpsites, left untreated, or burned in open fires. A potential remedy for these waste disposal and high fuel dependence on wood as fuel is the conversion of this biomass into high-density briquettes. This paper presents an experimental exploration of fuel properties of bio-briquettes made from a combination of VMW and sawdust (SD). In the present work, binary briquettes have been made from VMW in combination with SD in a ratio of 25, 50, 75, and 100% by weight using bentonite clay as a binder. Furthermore, a comparative study between the VMW based biomass briquettes with firewood, coal, and conventional sawdust briquettes are also included in this study. Raw green vegetable wastes were collected from markets and were kept for open sun drying. The dried matter was then transformed into a pulverized form and eventually converted to briquettes. The percentage of moisture content, percentage volatile matter content, ash content percentage, fixed carbon content, and calorific values of the briquettes were investigated. The results showed that the composite briquettes had improved combustion characteristics like higher calorific value and more volatile matter content compared with pure VMW briquettes. The percentage volatile matter content of VMW briquette enhanced from 71.72% to 83.2% for the composite briquette of VMW and SD with the highest percentage at the proportion 25:75 (VMW: SD). The calorific value of bio-briquettes ranges from 14.002 to 15.721 MJ/kg and the highest heating value was obtained for the composite briquette of VMW and SD with proportion 25:75. Even though lignin contents of vegetable market waste were lesser (3.23–5.51%) compared to other ligno-cellulosic biomass, good quality biomass briquettes were produced.

Biomass briquettes are an alternative to fossil energy. Biomass briquette material has a large capacity and is easily available in the surrounding environment. The purpose of this study was to determine the value of water content, value of ash content, value of volatile matter content, value of bound carbon content and calorific value of mixed briquettes of peanut shell and rice husk with three different percentages. First a mixture of 30% peanut shell and 70% rice husk, second a mixture of 50% peanut shell and 50% rice husk, third a mixture of 70% peanut shell and 30% rice husk. From the results of the research data, it can be seen that the lowest water content is in a mixture of 70% peanut shells and 30% rice husks of 14.225. The lowest value of ash content was found in a mixture of 70% peanut shell and 30% rice husk at 13.873%. The lowest value of volatile substances was found in a mixture of 30% peanut shell and 70% rice husk at 36.712%. The highest value of bound carbon content was found in a mixture of 30% peanut shell and 70% rice husk at 27.028% and the highest calorific value was found in a mixture of 70% peanut shell and 30% rice husk at 5834.60 cal / g.

Bencana bajir besar di Provinsi Sulawesi Selatan telah terjadi pada tanggal 22 dan 23 Januari 2019. Peristiwa ini merupakan salah satu bencana yang cukup parah bagi Kota Makassar dan sekitarnya. Kejadian ini mendorong tim pengabdian melakukan pengabdian kepada masyarakat. Kegiatan pengabdian kepada masyarakat UNHAS-Program Kemitraan Masyarakat (PPMU-PK-M) telah bermitra dengan salah satu unit usaha (UD Prima Teknik) yang bergerak di bidang pengelasan pagar dan kebutuhan pembesian untuk bangunan. UD Prima Teknik tersebut berlokasi di Kelurahan Antang, Kecamatan Manggala, Kota Makassar. UD Prima Teknik merupakan mitra yang telah membantu tim pengabdian dalam melakukan desain kompor mobile berbahan bakar briket batubara dan biomassa. Kompor yang didesain tersebut telah disosialisasi dan dimanfaatkan untuk kebutuhan masak-memasak dalam memenuhi kebutuhan pangan di daerah-daerah yang mengalami bencana alam. Kompor ini didesain dari besi, kuat, tahan banting, dan mudah dibawa kemana-mana (khususnya ke daerah yang mengalami bencana alam). Bahan bakar yang digunakan pada kompor tersebut berupa briket batubara, kayu atau arang kayu (biomassa). Pemilihan bahan bakar tersebut, selain mudah dibawa dalam perjalanan, juga resiko bahayanya sangat rendah jika dibandingkan dengan kompor gas yang kebanyakan digunakan oleh masyarakat pada saat ini. Bila dalam kondisi terbatasnya bahan bakar briket dan arang kayu, maka kompor ini dapat juga menggunakan bahan bakar kayu yang ada di sekitar wilayah bencana. Dalam kondisi bencana pada suatu daerah, kesulitan yang sering dialami oleh masyarakat adalah sulitnya pasokan/bantuan pangan yang siap saji karena terbatasnya fasilitas dapur (alat untuk memasak).

The aim of the study was to assess the selected physical characteristics of the briquettes of English ryegrass waste biomass and its mixtures with waste components from the agri-food industry: pea husks and oat middlings. The raw materials used for the tests are characterized by high calorific value and low ash content. Among the tested raw materials, the most favorable values were recorded for oat middlings in this respect. The produced briquettes were characterized by high volumetric density and very diverse mechanical durability. At the same time, the results of the tests on the mechanical durability of briquettes indicated that the use of components of ryegrass mixtures selected for testing brought unsatisfactory results, as compared to other analyzed physical and energy features.

Reference mass spectra are routinely used to facilitate source apportionment of ambient organic aerosol (OA) measured by aerosol mass spectrometers. However, source apportionment of solid-fuel-burning emissions can be complicated by the use of different fuels, stoves, and burning conditions. In this study, the organic aerosol mass spectra produced from burning a range of solid fuels in several heating stoves have been compared using an aerosol chemical speciation monitor (ACSM). The same samples of biomass briquettes and smokeless coal were burnt in a conventional stove and Ecodesign stove (Ecodesign refers to a stove conforming to EU Directive 2009/125/EC), while different batches of wood, peat, and smoky coal were also burnt in the conventional stove, and the OA mass spectra were compared to those previously obtained using a boiler stove. The results show that although certain ions (e.g., m/z 60) remain important markers for solid-fuel burning, the peak intensities obtained at specific m/z values in the normalized mass spectra were not constant with variations ranging from < 5 % to > 100 %. Using the OA mass spectra of peat, wood, and coal as anchoring profiles and the variation of individual m/z values for the upper/lower limits (the limits approach) in the positive matrix factorization (PMF) analysis with the Multilinear Engine algorithm (ME-2), the respective contributions of these fuels to ambient submicron aerosols during a winter period in Dublin, Ireland, were evaluated and compared with the conventional a-value approach. The ME-2 solution was stable for the limits approach with uncertainties in the range of 2 %–7 %, while relatively large uncertainties (8 %–29 %) were found for the a-value approach. Nevertheless, both approaches showed good agreement overall, with the burning of peat (39 % vs. 41 %) and wood (14 % vs. 11 %) accounting for the majority of ambient organic aerosol during polluted evenings, despite their small uses compared to electricity and gas. This study, thus, accounts for the source variability in ME-2 modelling and provides better constraints on the primary factor contributions to the ambient organic aerosol estimations. The finding from this study has significant implications for public health and policymakers considering that it is often the case that different batches of solid fuels are often burnt in different stoves in real-world applications.

Improvements on energy density of loose biomass such as sugarcane feedstock is crucial in the technology of biomass energy conversion and generation. South Africa is one of the producers and refiners of sugarcane. High energy density of sugarcane bagasse biomass through separation and briquetting is imperative in developing adequate streams and quality energy generation from sugarcane upstream milling processes. Unseparated bagasse and separated fractions of fiber and pith possess energy contents of about: 16.14 MJ/kg, 17.73 MJ/kg and 15.74 MJ/kg respectively. Fiber fractions have high energy content than bagasse and pith which demonstrates that pith fraction from bagasse lowers energy density. However, the use of starch and PVA (Polyvinyl Alcohol) as binders during briquetting contributed no significant difference in the overall energy density of the biomass briquettes produced. In the same vein, the addition of 50% charcoal as the hybrid component significantly improves the energy density and the physical properties of briquettes, biomass fractions of bagasse, fiber and pith to: 19.43 MJ/kg, 19.57 MJ/kg and 18.37 MJ/kg respectively. Fiber fraction remains the biomass fraction with highest energy content as compared to other fractions. After briquetting and drying of briquettes to moisture content below 12%, there was a significant improvement on the burning rate, briquetting, binder, hybridization which does improve the biomass briquettes characteristics. Separation of bagasse is crucial under certain conditions since there are no significance differences in the energy density of bagasse fractions. However, the use of PVA and charcoal does pose the necessity of bagasse separation from its fractions for briquetting.

Biofuel briquettes were prepared using banana peels, rattan waste, coconut shells and sugarcane bagasse through a conventional method that involved drying, carbonizing, crushing, mixing with cassava starch as binder, compacting and drying. Briquettes produced were evaluated by proximate analysis using American Society for Testing and Materials (ASTM) standard and European Committee for Standardization (CEN) standard. Results of mass reduction study show that the losses are more important for banana peels (97.98%) and sugarcane bagasse (96%). Bulk density of briquettes produced is in the range 0.470–0.851 cm3/g; results of proximate analysis show that high calorific values of briquettes produced are 16.98, 30.07, 32.16 and 25.93 MJ/kg for banana peels, rattan waste, coconut shells and sugarcane bagasse respectively; of the four different residues used, volatile matters are slowly lower to the recommendation of literature, ash content has values in the range 7.44–11.95%, and moisture content is relatively higher than other agricultural residues especially banana peels and sugarcane bagasse.

The decreasing availability of fuel wood coupled with the increasing prices of kerosene and cooking gas in Nigeria has drawn attention on the need to consider alternative sources of energy for domestic and industrial use in the country. The study was undertaken to evaluate the combustion properties (percentage volatile matter, percentage ash content, percentage fixed carbon, heating value) of briquette produced from coconut husk and male inflorescence of Elaeis guineensis. The experiment was laid down using the Randomized Complete Block Design (RCBD). The study involves three particle sizes (2 mm each) of coconut husk, male inflorescence of oil palm tree and cassava starch used as binder. The coconut husk and male inflorescence of Elaeis guineensis were varied into (25:30:40:50:60) respectively and bound together with starch at same ratio. Proximate analysis was carried out to determine the constituent of the briquettes which include ash content, percentage fixed carbon, percentage volatile matter and experimental test to determine the heating value was also determined. All processing variables in this study were significantly different except for heating value at P>0.05. From the result of the percentage ash content, briquette produced from coconut husk, male inflorescence and starch at (20:20:60) has the least fixed carbon (6.5%) with better performance. The highest percentage volatile matter 74.6% was obtained from coconut husk, male inflorescence and starch at (20:20:60) while low fixed carbon (18.8%) was obtained from male inflorescence and starch at (60:40). In conclusion, large quantities of wastes generated in terms of coconut husk and male inflorescence which are disposed indiscriminately can be utilized to produce briquette with enhanced performance.

Fossil fuels are a non-renewable energy source and their existence will be depleted. An alternative is needed that can reduce fossil fuels by using biomass. Biomass waste in the form of bagasse and coconut shell can be used as an alternative fuel in the form of biobriquette. This study aims to analyze the quality value of briquettes from the proximate test of the composition of bagasse and coconut shell produced with briquette quality standards that refer to SNI 01-6235-2000 about wood charcoal briquettes. The variables in this study consisted of five variables. The variables in this study were mass ratio coconut shells to bagasse were 90%: 10%, 80%: 20%, 70%; 30%, 60%: 40% and 50%: 50% respectively. The results of the test of water content, ash content, and volatile matter of the best quality briquettes of five variables were 90% coconut shell and 10% bagasse.

To investigate the influence of alkali and alkaline earth metals (AAEMs: K, Na, Ca, and Mg) on the co-pyrolysis of municipal solid waste (MSW) and biomass briquettes (CSBs), the pyrolysis properties and products distribution for the blends of pretreated CSBs and MSW were studied by thermogravimetric analysis with Fourier-transform infrared spectroscopy under N2 and CO2 atmospheres. Results showed that the AAEM salts were effective at reducing the initial temperature during pyrolysis process. The presence of AAEM salts inhibited the volatile release rate of the first pyrolysis stage of the blend, while the alkali and alkaline earth salts separately enhanced the volatile release rates of the second and third pyrolysis stages under both atmospheres. Replacement of N2 with CO2 caused lower residual masses of the blend, which were further reduced by the catalytic effect of the AAEM salts. The CO2 yields were enhanced by adding AAEM salts under the N2 atmosphere. Ca had the most obvious catalytic effect on the CO production in the third pyrolysis stage. Different AAEM salts added to the samples displayed different effects on the emissions of alkyl and carbonyl groups.

This study assessed the fuel characteristics of briquettes made from oil palm mesocarp fibre and sawdust of Ceiba pentandra at room temperature, using low compacting pressure without a binder. Properties of briquettes studied included stability in diameter and length, relaxed density, compressive strength, impact resistance index, gross calorific value, volatile matter, ash content and elemental composition. These properties were determined using standard laboratory methods. The results show that briquettes with better relaxed density, compressive strength and impact resistance index could be produced from a blend of C. pentandra sawdust and oil palm mesocarp fibre at low compacting pressure and room temperature without a binder. The relaxed density of briquettes produced ranged from 377 kg/m3 to 586 kg/m3 which could be classified as medium-density briquettes. The result further indicates that compacting pressure 40 MPa or more could be used to produce briquettes with adequate compressive strength in cleft and impact resistance index from the blend of C. pentandra sawdust and oil palm mesocarp fibre at low compacting pressure and room temperature without a binder. At 5% level of significance, the compacting pressure and mixing proportion had significant effect on the physical and mechanical properties of briquettes produced. The gross calorific values of Ceiba pentandra sawdust and oil palm mesocarp fibre were found to be 20.33 MJ/kg and 19.50 MJ/kg respectively. Even though most of the elemental compositions of the oil palm mesocarp fibre were not adequate, a blend with Ceiba pentandra sawdust could make it suitable to be used as an environmental friendly material for biomass briquettes production.

Briquettes are widely used as a renewable energy material for solving the problem of dependency and over-consumption of wood fuel as a source of energy for human use. However, their performance depends on the types and nature of binders used during the preparation and densification process. Most of the performance-related problems such as low yield and energy content can be significantly improved with the use of binders in right proportions. This review discusses the state-of-the-art of fuel briquettes and the influence of binder’s properties on the combustion characteristics, energy content, mechanical durability, and density of fuel briquettes. The compatibility between the binders and the fuel briquettes to obtain a better yield is also discussed with the resulting mechanical and combustion properties. The mechanical durability of fuel briquettes can be improved by reducing the content of lignin, fat, and other extractives in the binder, as well as improving the binder’s variables such as the particle size, texture, and quantity. By using binders mixed with phosphorus-based additives such as Ca(H2PO4)2 and NH4H2PO4, the combustion rate of fuel briquettes can be enhanced and the pollutant emissions during the combustion process can be reduced to the minimum. In addition, the higher the binders’ compacting pressure and processing temperature, the higher the density and energy content per unit volume of fuel briquettes.

Temperature is important to the quality of biomass briquettes in hot-forming. In this paper, a heat transfer model based on plastic deformation was constructed in the EDEM by discrete element method at the grain scale. The prediction performance of the model was validated by comparing the temperature evolution in simulation with the experimental values. The influences of process parameters on heat transfer including the amount of compression, heating temperature, diameter of mold, moisture content and dwell time were discussed. The rate of heat transfer increased with the briquetting conditions of higher compression, higher heating temperature, lower diameter of the mold, higher moisture content and longer dwell time. It is expected that the new heat transfer model will help in getting enhanced briquettes quality in addition to improved utilization of biomass energy such as bio-refinery, biogasification and other biotechnologies.

Fossil fuel combustion is related to the increased global warming challenge. Coal was identified first as a fossil fuel historically in China dating back to 4000 before Christ (BC). Since then, 96 % of energy extraction was through coal until 2000 when other energy sources became more dominant. Coal dependency has since declined by 30 % but remains the most deployed fuel today. To mitigate the negative effects of continued coal combustion, the need has been identified to introduce more carbon neutral fuels such as biomass. Biomass is the only energy source that has enough carbon reserves to replace coal today. Biomass is carbon neutral due to its renewable nature hence offers significant environmental benefits. The use of inorganic fertilizers in the production of some loose agricultural and forestry residues that can be harnessed for energy poses pollution challenges. This work conducts a comparative study of the combustion and emissions behaviour of loose biomass briquettes produced from agricultural and forestry residues bonded by cow dung and cactus. The aim is to characterise emission content, particulate matters and the gases emitted during combustion. This provides a basis of comparison with coal-based emissions. Cactus bonded briquettes were found to have low emissions on CO2, CO, NOx and SO2 and cow dung bonded briquettes were found to have higher emissions compared to cactus briquettes.