Density Of Briquettes Research Articles

Effect of torrefaction on the properties of briquettes produced from agricultural waste

In this study, briquettes produced from cassava rhizome, sugarcane bagasse and straw were torrefied at 250 °C for 90 min to verify the effects of the process on their structure and properties such as density, durability, energy content, and energy density. The briquettes had a relaxed density of 1270 kg/m3 for those produced from cassava rhizome, 1240 kg/m3 from sugarcane bagasse, and 1300 kg/m3 from sugarcane straw. The torrefaction procedure increased calorific value of the briquettes by 9–13-fold. However, changes in briquette strength were identified after torrefaction, with a longitudinal deformation of 12.9–26.6 % and cracks in its bodies. Consequently, fragments were produced after durability testing. Moreover, briquette density decreased by 36 % for cassava rhizome, 50 % for sugarcane bagasse, and 55 % for sugarcane straw. The produced cassava rhizome briquettes exhibited the highest energy yield when torrefied. Combining these technologies facilitates the use of residues from agriculture for energy generation.

Effects of Feeding Speed and Temperature on Properties of Briquettes from Poplar Wood Using a Hydraulic Briquetting Press

Biomass has a high potential to contribute towards resolving the energy deficit. Processing biomass into solid fuels enhances its use in various bioenergy conversion technologies. The quality of densified biomass depends on several variables. The investigation of the effect of densification parameters on briquette quality is necessary for process optimization. This study investigates the influence of die temperature (100, 120, 140 °C) and feeding speed (2.4, 2.9, 3.3 mm s−1) on the quality of briquettes produced from poplar using a hydraulic biomass briquetting machine. The density of the briquettes ranged between 746.7 and 916.8 kg m−3, the mechanical durability ranged from 97.4 to 98.4%, and the water resistance index was between 91.6 and 96.1%. The results show that the temperature was statistically significant (p < 0.05) on the density, mechanical durability and water resistance of biomass briquettes. The feeding speed was statistically significant (p < 0.05) on the density and water resistance. The interaction of temperature and feeding speed was statistically significant (p < 0.05) on all properties considered. The results obtained in this study are useful for optimizing the quality of briquettes produced using the hydraulic piston press.

Optimization of elephant dung green fuel briquette production using a low-pressure densification technique and its characterizations, and emissions

Elephant dung is densely packed with undigested fiber, complicating disposal. To manage this waste more efficiently, the dung was converted into biofuel briquettes. Four variables in the briquette production were investigated using three levels of optimization techniques, including a response surface and a central composite design with 95 % confidence. The results show that when compressing a 7:3:1 weight ratio of elephant dung, binder, and water at 40 bars, a briquette density of 613 kg/m3 or 9.09 GJ/m3 could be achieved. Although its dimensional stability was consistent and its shatter resistance was acceptable, its water resistance was poor. The briquettes had atomic ratios of 0.15 and 1.17 for H/C and O/C, respectively. It had a high heating value of 17 MJ/kg and could enhance the stove's overall thermal efficiency by 22 %. The emission study demonstrated that the combustion of the briquettes released mainly CO2 (5.49 × 104 ppm), whereas other gases were negligible.

高密度単一円柱バイオマスブリケットの燃焼時間に及ぼすバイオマス原材料の影響（人工的に調整したバイオマス原材料を用いた研究）

It is known that flaming combustion duration of highly densified single cylindrical biomass briquette is proportional to the product of the inverse square of the specific surface area and briquette density. It was suggested that the proportional constant Cf can be correlated with the mass percentage of holocellulose in the biomass. On the other hand, the char combustion duration is almost proportional to the product of the inverse square of the specific surface area and the fixed carbon content of the briquette. It was suggested that the proportional constant Cc can be correlated with the mass percentage of the ash content in the biomass. However, the individual influences of cellulose, hemicellulose and ash content on the flaming and char combustion durations, and thus on Cf and Cc, have not been clarified yet. In the present study, to investigate the effects of holocellulose content, ash content in raw materials, and cellulose (hemicellulose) content in holocellulose on Cf and Cc in detail, briquettes made of artificial raw materials adding cellulose, hemicellulose powder, cypress ash or rice husk ash to cypress or rice husk were burned in the hot air flow. It was confirmed that Cf increases with increasing the holocellulose content, however, there is less effect of the cellulose content in holocellulose, in the scope of this study. And it was suggested that low boiling component in briquette affects the Cf value. It was confirmed that increasing the ash content decreases 1/Cc, and the dependence decreases as the ash content increased. And it was confirmed that there is less effect of the holocellulose content, the cellulose content in holocellulose, ash type and low boiling point component on 1/Cc value.

Adaptation and Evaluation of Pellet Press Briquette Machine

A good substitute for coal, lignite, and firewood is briquetted fuel made from agricultural leftovers. Compared to loose agro-residues, which have a specific density of 60 to 180 kg/m3 , briquettes have a high (1200–1450 kg/m3 ). Briquettes are formed right where they are made, thus reducing air pollution. In this work, a sawdust and coffee husk briquetting machine is redesigned and built. In this work, briquettes (solid fuels) were made using a screw-type briquetting to compress sawdust and coffee husk at different ratios. An effective densification technique that is suitable for small-scale applications is being adapted by screw press briquetting. The equipment has been modified to generate briquettes at a rate of 187.62 kg per hour. Briquette density, power consumption per kilogram of briquette produced, and calorific value per kilogram of briquette have all been examined in relation to the effect of moisture content in agro-residues and binders utilized. Paper was used as the binding agent, and different biomass binder ratios of 100:10, 100:12.5, and 100:15 were tested to assess the briquette's physical characteristics. The binder level has a big impact on the briquette's physical characteristics. level.

Cleaner energy potential analysis for composite biomass residues from decentralized sawmills in Ghana- A case study for Oforikrom Municipality

The variation of wood species processed in sawmills in developing countries generates composite waste which presents treatment challenges due to a lack of understanding of their physicochemical characteristics for proper planning for clean energy generation. Most of the waste is discarded or burnt openly which releases harmful gases into the environment. This study investigated the physicochemical characteristics of mixed sawdust generated from five wood species generated at a Ghanaian sawmill in Oforikrom Municipality for improving waste treatment. The particle size distribution (PSD), bulk density, proximate and ultimate values, thermogravimetric analysis (TGA) and structural analysis were used to characterize the composite sawdust for briquetting and gasification purposes. It was found that the net heating value (17.46 MJ/kg), some proximate and ultimate values meet briquette standard but high percentages of ash (2.95%), moisture (41.48%) and the possibility of nitrogen oxides emissions were notable challenges. PSD resulted in different high fine fractions which are unsuitable for densification. The increase of sieving amplitudes at 30, 50 and 80 rpm generated an average increase in sieve efficiency of fines by 4.22%. Mixing of fines (42.38–46.6%) and optimum particle size (53.40–57.62%) fractions was suggested as the best approach to enhance briquette density and durability. The FTIR spectra showed a range of peaks such as 1734.46 cm−1, 1620.48 cm−1, 1506.50 cm−1, 1462.02 cm−1, 1420.32 cm−1 etc. for functional groups identification. Composite sawdust spectra showed high absorbance with no shift of wavenumbers compared with temperate woods, however, it deviated massively when compared with industrial cellulose and organosolv lignin. TGA indicated that exact mixed wood pyrolysis temperatures, volatile and biochar fractions will always depend on sample compositions. The increase in heating rates yielded little significance to volatiles and char increments. Collection of clean sawdust and rooftop drying were recommended as a way of enhancing sawdust properties. Composite sawdust has a promising potential to support Ghana's activities for meeting the renewable energy generation targets. The understanding of these potential assessments is significant to boost the local municipality energy supply.

Development and Experimental Investigation of Briquetting Machine for Use in Rural Area

Biomass is an organic matter such as agricultural crop residues, forest plant materials and animal wastes used as animal fodder, domestic fuel energy source in India. The briquetting technology is the extrusion process of various biomass materials to produce briquettes as a biofuel substitute for fuel wood, coal and charcoal. Mahua (Madhuca Indica) seeds oil extraction plant have waste known as mahua deoiled cake (Doc) is major forest biomass and is locally available in southern parts of Gujarat. The development of an efficient and low-cost screw press type briquetting machine appropriate for rural peoples of developing countries was carried out. The four combinations with different proportions of raw biomass such as mahua seed deoiled cake, coal, rice husk and grass were used to produce briquette C1 (70:10:10:10), C2 (50:20:20:10), C3 (100:0:0:0), and C4 (50:0:50:0), respectively. The properties of briquettes were determined as the density of briquettes, shatter resistance, tumbling resistance, water retention test and calorific value. The highest resistance to water penetration was observed for combination C1 briquettes as 52.20% because mahua Doc has less porosity and high density. Combination C4 briquettes were observed for a maximum degree of densification and maximum energy density ratio as 31.37% and 1.1, respectively. Tumbler resistance and shatter resistance were observed maximum for combination C1 as 86.70% and 99.82%, respectively which comprises 70% mahua Doc, 10%, coal, 10% rice husk and 10% grass. A high calorific value was found 3946.43 kcal/kg in combination C3 (100:0:0:0) because briquette made of 100% mahua Doc. The addition of Mahua Doc matter in the briquette was found better results as an increase in calorific value, water retention, shatter and tumbling resistance.

A roller press parameter selection method taking account of the briquetted material characteristics

Introduction. Briquetting is an effective way to improve technological, environmental and economic indicators of waste utilization in various industries. Roller presses hold a special place among the aggregates for briquetting materials, since they are characterized by high reliability and productivity, as well as low energy consumption. It is known that the density of the source material conditions the compression force the press rollers apply to the material to obtain briquettes of the required quality. Thus, a press with given design parameters provides the required quality of briquettes in a certain range of the source material densities. However, there is currently no method for selecting the design parameters of a roller press depending on the density of the material to be briquetted. A discrepancy between the source material density and the roller press parameters can either result in the poor-quality of briquettes due to insufficient power, or in the employment of a press with excess capacity. Both alternatives are unacceptable, so the development of a method for choosing the roller press design parameters, depending on the density of the source material, can be considered relevant. Research objective is to develop a method for selecting the design parameters of a roller press depending on source material density. Methods of research. The paper considers the roller press pressing zone showing an increased density of the source material. The boundary of the pressing zone is determined by the pressing angle, which depends on the source material density and press roller radius. To determine the pressing angle value, a laboratory method has been developed, which consists in pressing batches of preheated source material in a special form at different force values. The quality indicators of the obtained briquettes are compared with the standard ones, and a briquette with the required values of quality indicators obtained with the least effort is selected. Then, the briquette density and compaction coefficient are determined by hydrostatic weighing. Based on the results obtained, the pressing angle is calculated. The values of the pressing force and the roller rotation resistance moment are obtained by employing the obtained pressing angle value, given roller press design parameters, as well as the pressed material physical and mechanical characteristics. Taking into account the obtained value of the resistance moment, as well as the specified operating speed of rollers rotation, the drive power required to obtain high-quality briquettes from a given source material is determined. Comparison of the calculated capacity and the nameplate capacity of the press indicates whether the considered roller press model can produce high-quality briquettes from the source material with a given density. Conclusions. The developed method allows to take into account specific production conditions when choosing a roller press model, and, consequently, reduce the expenditures for pressing equipment. The proposed method can also be used when designing new roller press models when determining rational design parameters of rollers.

Fluid Movement Law and Influencing Factors of Shredding on Rice Straw Briquetting Machines

The briquetting technology of rice straw could increase the bulk density of the straw, reduce transportation and storage costs, and improve resource utilization. This paper analyzed the working principle of the air-conveying integrated device in briquetting machines. High-speed photography technology was used to track and record the movement process of crushed straw material in the air-conveying cylinder area. It was compared with the simulation results of the average velocity of crushed straw material to verify the reliability of the simulation. The results showed that the flow of straw scraps in the straw-shredding and air-conveying integrated device was relatively stable when the impeller speed was 630 r/min, the number of blades was three, the blades were tilted back 15°, and the radius of curvature of the air-conveying tube elbow was 700 mm. At the same time, the speed distribution was uniform, and the highest throwing speed reached 4.5 m/s to 4.8 m/s. After optimization, the average increase rate of briquette density was 2.61% and the average increase rate of briquette productivity was 2.52%. The fluid movement law of the straw-shredding and air-conveying integrated device studied in this paper could be used to optimize the air-conveying device, improve the efficiency of straw briquetting and the utilization rate of straw resources.

THE EFFECT OF THE POROSITY OF HOT-BRIQUETTED IRON ON THE RELEASE OF HYDROGEN DURING SECONDARY OXIDATION WITH WATER OF DIFFERENT TEMPERATURES

During storage and transportation of the metallized product, moisture may enter it, resulting its oxidation occurring with the release of hydrogen. When delivering the product by sea, this can lead to fire and explosive situation. It is noted that the physicochemical properties of the metallized product, such as density, porosity, chemical composition, temperature, etc., have a great influence on the release of hydrogen. The purpose of this work is to determine the dependence of hydrogen release during iron oxidation in the metallized briquettes on their porosity and the temperature of the humidifying water. The results of study of the effect of porosity on the density of HBI are presented; the limits of changes in closed and open porosity and their effect on density were determined. It is shown that the bulk density of briquettes decreases with an increase in the porosity of HBI. The experiments were performed in order to determine the dependence of hydrogen release upon contact of briquettes with distilled water on the porosity and water temperature. It was found that with an increase in the open porosity of briquettes, their moisture saturation increases and the release of hydrogen increases. A change in the temperature of water that reacts with iron affects the release of hydrogen, but it practically does not affect the release rate within the parameters studied. When transporting the metallized briquettes it is recommended to take into account the effect of their open porosity on the intensity of hydrogen release in contact with moisture.

Empirical models for physical properties of abura (Mitragyna ciliata) sawdust briquettes using response surface methodology

Biomass densification is a complex process with each biomass having a unique set of variables from which briquettes of desirable quality can be produced. This study produced briquettes under different process conditions from Abura ( Mitragyna ciliata ) sawdust. The moisture content of the sawdust was 14.84%. Process variables considered were temperature, hold time and pressure. Predictive models were developed using response surface methodology and a Box-Behnken experimental design was adopted in the study. The study found that temperature, hold time, pressure, square term of pressure, and interaction of pressure and temperature were statistically significant (p < 0.05) in determining the density of the sawdust briquettes. Only linear terms of temperature and hold time were statistically significant (p < 0.05) for determining the water resistance of the sawdust briquettes. The response surface models developed had close prediction to experimental values. Surface plots showed how combination of the statistically significant terms within the model determine the quality of the sawdust briquettes.

PENGARUH VARIASI KADAR PEREKAT TAPIOKA TERHADAP KARAKTERISTIK BRIKET ARANG LIMBAH KAYU SENGON (Falcataria mollucana)

Biomass waste that has not been utilized properly is wood waste from Sengon (Falcataria moluccana). There is a high potential of these wastes to be used as solid fuel. The quality can be further improved by converting them into charcoal briquettes. This study aimed to determine the effects of adhesive content on the bioenergetic properties of charcoal briquette from Sengon wood wastes. The charcoal briquettes were produced by mixing charcoal powders with tapioca starch as an adhesive with a concentration of 5%, 10%, and 15%. Biomass briquette from Sengon wood particles (without pyrolysis) was also produced for comparison (control). The oven-dry density of briquettes of 0,23 – 0,25 g/cm3. Higher adhesive content increased the density of briquettes. The bioenergetic properties of the charcoal briquette were evaluated. The results showed that charcoal briquettes were more hydrophobic than biomass briquettes (control). The results of proximate analysis of charcoal briquettes showed volatile matter of 24,96–31,80%; ash content of 3,16–3,24%; and fixed carbon of 58,68–66.40%. Higher adhesive content increased the volatile matter, moisture content, and ash content of the charcoal briquettes and decreased the fixed carbon. The charcoal briquettes have a calorific value of 25,68-27,35 MJ/kg, which is remarkably higher than the control. Higher adhesive content tended to decrease the calorific value of the charcoal briquettes. Lower adhesive content will produce briquettes with good bioenergy characteristics. Sengon wood waste charcoal briquettes with 5% adhesive content has great potential to be developed as an alternative energy source.Keywords: Adhesive content, Charcoal briquettes, Pyrolysis, Sengon (Falcataria moluccana); Tapioca starch

Influence of rice straw forming factors on ring die wear and improved wear prediction model during briquetting

Briquetting is an effective way to ensure the comprehensive utilisation of straw. However, in the production of straw briquettes there can be problems of low productivity and high-power consumption caused by ring die wear. The working principle of briquetting machines and wear of the ring die wear studied to determine the relationship between different forming factors of straw briquette and ring die wear. The wear mechanism of the ring die was analysed by scanning electron microscope, and the pattern of wear on the inner wall of the ring die in the extrusion direction was studied. The friction and wear test of rice straw briquette was used to analyse the influence of different moulding factors on the friction coefficient. Results showed that the wear depth of the ring die module decreased slowly in the direction of extrusion. Deep scoring was found in the entrance section. Wear in the tail section was weak and mainly appeared in the form of spalling pits. The main wear mechanisms of the ring die were abrasion and fatigue. The main forming factors affecting friction coefficient were briquette density, moisture content and extrusion velocity. According to the comparison between the wear prediction model and the actual production, the maximum deviation between the calculated value and the simulated value was 12%, and the minimum deviation was 5%. The wear of circular ring die module was low, which could improve service life. • Wear mechanism of the ring die module is mainly the abrasive wear of micro-cutting. • Wear depth and total wear depth value of each step is calculated by ANSYS software. • Wear value data by wear prediction model is verified by actual briquetting production.

Experimental study of binderless briquetting process: effect of temperature on the fuel briquettes from rice husks

In developing countries’ socio-environmental background, fossil fuel use is evolving at the same time as deforestation, resulting in desertification and global warming. There is an urgent need to find alternative sustainable and environmentally friendly sources such as biomass briquettes. This study aims to analyse the effect of densification temperature on characteristics of biomass briquettes produced from rice husks. The densification temperatures applied to each production run varied from 0 to 350°C with an increment of 50°C in a heating screw press. Physical and proximal analysis of briquettes produced at each stage of temperature is done in order to determine bulk density, moisture content, Ash content, volatile matter according to NF standard. A statistical analysis was applied in order model the relationship between briquettes’ characteristics and densification temperature. Interpretation of correlation coefficients (0,98) shows that there is a strong correlation between densification temperature and briquette density. As temperature increases, density also increases. However, the correlation (r = 0,44) between densification temperature and ash content is very low, and there is no significant impact.

QUALITY EVALUATION OF COCONUT SHELL ACTIVATED CARBON AND ITS APPLICATION AS PRECURSOR FOR CITRONELLAL-SCENTED AROMATIC BRIQUETTE

Coconut shell, as a lignocellulosic material, has a great potential to be developed as a briquette for energy production. In this research, the aromatic briquette is obtained from a mixture of carbon and activated carbon from coconut shell waste using citronellal as an aromatic additive. A tremendous advantage can be gathered compared to the use of other briquettes. The methods used are carbonization and activation of coconut shell raw material followed by the production of briquette with carbon, activated carbon, adhesive, and aromatic addition. The activated carbon quality results meet all the requirements set by the Indonesian National Standard through a series of analysis procedures. Moreover, the briquette surface successfully adsorbs the citronellal aromatic group. The proximate analysis of briquette, consisting of moisture, ash content, volatile matter content, and fixed carbon, were 8-11%, 2-3%, 8-14.5, 82-87%, respectively. Meanwhile, the briquette's density, compressive strength, and calorific value were 0.7-0.8; 222-393 kg, and 6400- 6700 Kcal/kg. This green aromatic-functionalized briquette produced from a mixture of carbon and activated carbon offers an alternative energy source for a society that mainly gives an economic benefit

Processing and Characterisation of Charcoal Briquettes Made from Waste Rice Straw as A Renewable Energy Alternative

In Malaysia, waste paddy plant after rice harvesting were abundant and have no commercial value and significant usage. This paddy waste is commonly burnt on the landfilled which cause open firing and leads to environmental problem. This study determines the potential of rice straw waste for charcoal briquette production and study the effect of using different binders (corn and tapioca starch) in making the briquettes. Raw rice straws were combusted at 260°C for 4 hours in oven to form char powder. Corn starch and tapioca starch used as binder and each of them was mixed with char powder before compacted into briquettes. Each briquette was characterized in terms of their bulk density, moisture content, ash content, compressive strength and flammable characteristics. It was found that corn starch-charcoal briquette showed higher ash content, higher bulk density and compressive strength up to 68 MPa. Increased of both binders has increased the bulk density and compressive strength of briquettes. Both type of charcoal briquettes showed similar ignition time and burning characteristic, approximately at 18 minutes and 0.08 gm/min respectively.

Life Cycle Assessment Model for Biomass Fuel Briquetting

Previous Life Cycle Assessment (LCA) studies of biomass briquetting have shown wide variations in the LCA outcomes as a result of variations in LCA methodological parameters and briquetting technological parameters. An LCA model of biomass briquetting was therefore developed to enable transparent comparison of life cycle environmental impacts of briquetting with individual or blends of biomass feeds with a variety of technological options. The model was developed according to the standard LCA procedure of ISO14044. A comparative approach was utilised, and a set of integrated excel worksheets that describe process flows of material, energy and emissions across different units of the briquetting process was used in developing the model components. The main model components include materials and process inventory databases derived from standard sources, main process calculations, user inputs and results sections. The model is open-access in a user accessible format (Microsoft Excel). A representative case study with mixed rice husks and corn cobs was used in validating the model. Results showed that the briquetting unit made the largest contribution, 42%, to the total life cycle operational energy of the briquetting system. For all the blends of rice husks and corn cobs explored in this study, the total life cycle energy of briquetting was in the range 0.2 to 0.3 MJ/MJ. For the same blend ratios, a total life cycle energy of briquetting in the range 0.2 to 1.7 MJ/MJ was also obtained with change in other LCA input parameters, in a sensitivity test. An increase in rice husk content of the blend increased the environmental impact of briquetting in terms of global warming potential (kg CO2-eq), acidification potential (kg SO2-eq), human toxicity (kg 1,4-DB-eq), ozone layer depletion (kg CFC-11-eq), and terrestrial ecotoxicity (kg 1,4-DB-eq) per MJ briquette energy content, as it was associated with a lower briquette density, which increased the energy required for handling.

РЕЗУЛЬТАТЫ ЭКСПЕРИМЕНТАЛЬНЫХ ВЫДЕРЖЕК БРИКЕТИРОВАНИЯ ЛЕСОСЕЧНЫХ ОТХОДОВ В УСЛОВИЯХ ЛЕСНЫХ ТЕРМИНАЛОВ

About 100 million m3 of timber waste is generated at forest terminals in the Russian Federation, with a harvesting volume of about 500 million m3 of timber. Waste generated at the terminal can be used to produce generator gas, but this requires preliminary preparation of the raw materials. A homogeneous structure of raw materials is recommended for the efficient use of gas generating plants. It can be achieved, for example, by briquetting the waste after it has been crushed. At the same time, the process of briquetting waste at forest terminals will differ from briquetting in the conditions of specialized enterprises. Timber terminals, which are temporary warehouses for timber, usually do not have a centralized electricity connection. The use of internal combustion engines as power plants significantly increases the cost of the woodworking process, since the cost of fuel is quite high, and the efficiency of internal combustion engines is much lower than that of electric motors. In this regard, the search for the most optimal mobile power plants for power supply of forest terminals is a very urgent task. It is preferable to use lighter presses at terminals, since the requirements for density and strength of briquettes for gas-fired plants are lower than for biofuels intended for sale. Known studies are focused mainly on the production of fuel briquettes sold to third-party consumers with a density of more than 1000 kg/m3. The strength is sufficient at a density of briquettes up to 800 kg/m3 for feeding briquettes into gas generating plants. The deformation characteristics of the compacted material will be different in the indicated density range. It requires further experimental studies

Synergetic Effects of Feedstock Mixture and Torrefaction on Some Briquette Characteristics of Cornhusk and Sawdust Wastes

Agricultural waste management through energy recovery is one of the critical options that could drive the clean energy production industry and properly replace the use of coal in Nigeria if done sustainably. The objective of this work therefore is to study the synergetic effect of waste feedstock mixture and torrefaction pre-treatment on some physical and performance characteristics of briquettes from cornhusk (CH) and sawdust (SD) wastes. In this work, CH and SD wastes were processed raw and torrefied at 200 to 300 °C and were mixed in the ratios between 90/10 and 10/90 for briquette production using D-optimal crossed design. Cassava starch of 20 g to 100 g of the feedstock (w/w) was used as binder. The performance characteristics of CH/SD briquettes were evaluated using standard procedures while the generated data were processed using ANOVA, regression and pareto analysis. The thermal efficiency of 29.94% and water boiling time of 12 min were obtained for CH/SD briquette blend of ratio 10/90 torrefied at 300 °C. The maximum density and water resistance index of the torrefied briquettes at different blends respectively increased between 5.78–9.77% and 75.70–85.45% over those of the raw briquettes due to torrefaction and water preconditioning. Furthermore, the lowest value of burning rate was obtained for briquettes torrefied at 300 °C at 50/50 (CH/SD) ratio. ANOVA revealed that torrefaction and feedstock blending significantly influenced the characteristics of CH/SD briquette at p&lt;0.05. This study showed the potential use of torrefied briquettes from cornhusk and sawdust wastes as alternative for coal and forest wood and a new source of energy for heating applications.

Indirect Evaluation of the Porosity of Waste Wood Briquettes by Assessing Their Surface Quality

The briquette porosity is a quality characteristic known to be important for combustion analysis, heat and mass transfer processes during combustion stages, determination of effective thermal conductivity or other related properties. This paper describes a method to quantify the briquette porosity by some surface roughness parameters that can be useful for alternative, inexpensive and at hand evaluations. Porosity of briquettes manufactured with a hydraulic press from waste wood from secondary processing was calculated with three methods suggested in the literature for wood; of these, one was adapted here for a wet porosity model (called “general relation”) proposed for wood briquettes. Briquettes density was obtained by using two stereometric methods and a liquid displacement method. Correlations were examined between porosity, surface roughness parameters and density of briquettes. Very strong correlations with surface roughness were identified for porosity calculated with all three methods, when density was measured by one of the stereometric methods. These correlations can serve as a method to indirect evaluation of the briquettes porosity by assessing the surface quality.