Sugarcane Bagasse Particles Research Articles

Evaluation of Thermophysical and Strength Properties of Composite Panels Produced from Sugarcane Bagasse and Waste Newspapers

Abstract Large quantities of waste newspapers and sugarcane bagasse are prevalently discarded by open burning or indiscriminate dumping, thereby posing severe danger to the environment and public health. This study sought to examine the feasibility of managing the wastes by recycling them into value-added products for building construction. Composite panels were fabricated using waste newspaper paste (WNP) with sugarcane bagasse particles (SBP) varied at 0, 25, 50, 75, and 100 % by weight of the composite mix. Epoxy resin was thoroughly mixed with its hardener and applied as binder. The samples were developed in triplicates per proportion of the SBP adopted and then dried completely before their thermophysical and strength properties were evaluated. It was observed that variations in mean values of water absorption (28.57 – 39.43 %), thickness swelling (6.21 - 8.33 %), specific heat capacity (1232 - 1312Jkg−1K−1) trended positively with increasing proportions of the SBP. Whereas nailability remained 100.0 % in all the cases, bulk density (689.4 - 640.5 kgm−3), thermal conductivity (0.1186 - 0.1163 Wm−1K−1), thermal diffusivity (1.396 - 1.384 x 10−7 m2s−1), and flexural strength (2.572 - 2.280 N/mm2) correlated inversely with the added fractions of the SBP. Generally, it was found that the samples could perform satisfactorily if applied as ceiling or partition elements in building design. Therefore, recycling of sugarcane bagasse and waste newspapers as described in this study could serve as a promising way of solving their disposal problems and also enhance achievement of low-cost and safe buildings.

Analysis of the performance and products in the torrefaction of sugarcane bagasse with different particle sizes

The torrefaction of sugarcane bagasse particles was evaluated using standard thermogravimetric equipment (TGA) and in a torrefaction reactor explicitly designed for this work. Different particle sizes (fine, large, and unground bagasse) were torrefied to examine any potential effect of particle type and size on the devolatilization process. The custom-designed reactor allowed measurement of the mass and temperature of the particle and the condensable volatiles captured through a condensation unit held at −12 °C during torrefaction. Final products of the process (liquids, solids, and gases) were measured and characterized to understand and analyze the processes occurring in the sugarcane biomass during torrefaction. A two-step kinetic model was fitted to experimental data on fine particles to get the kinetic parameters. A particle model was developed to understand the dynamics of biomass heating and conversion under isothermal conditions. Results of tests for large particles show an effect of particle size on the process of decomposition of the biomass. The large unground biomass showed the lowest mass loss among evaluated particles. The torrefaction process resulted in significant thermal impact for fine particles, having the highest center temperatures, devolatilization, and changes in the O-H group with FTIR tests.

Properties of particleboards made from sugarcane bagasse particles

The objective of this work was to evaluate the physical-mechanical properties and the density profile of panels produced with sugarcane bagasse particles with two sizes (0.50 and 0.85 mm) and with pre-treatment (particles treated in hot water at 70 °C for two hours) and without pre-treatment. The nominal density of the panels was 0.65 g cm-3. The cycle parameters were 35 kgf cm-2 of pressure, temperature of 180 °C and 10 min of pressing. The physical and mechanical tests were performed according to the requirements of NBR 14810-2006. The density profile of the particleboards was obtained by X-ray densitometry. The water absorption in two hours was higher in the panels produced with particles treated in hot water. The other physical and mechanical properties were not influenced by the evaluated factors. The apparent density varied along the thickness of the panels, with more pronounced peaks in the outer layers, thus presenting a vertical density gradient within the normal range for this type of panel. The physical-mechanical properties do not meet the minimum requirements by the NBR 14810 (2006) for nonstructural panels for indoor use in dry conditions (Type P2).

Trapezoidal core sandwich panel produced with sugarcane bagasse

The properties of traditional particleboards are limited by their flat shape. New shapes and configurations with alternative raw materials enable strength and stiffness gains without significantly increasing weight. In this context, the present work presents an investigation of the potential use of sugarcane bagasse particles agglomerated with castor oil-based polyurethane resin to produce trapezoidal core sandwich panels for building applications. Thickness swelling was analysed based on the Brazilian standard NBR 14810 and flexure tests were performed according to the standard ASTM C393. Maximum force at failure, bending stiffness (EI), maximum moment (FbS), maximum shear stiffness (U), and core shear modulus (G) were calculated. The obtained results were compared with specifications of the standard PS-2-10 – Performance Standard for Wood-Based Structural-Use, which provides values of bending stiffness and maximum moment requirements for OSB panels according to different classes of use. The evaluated sandwich panels presented bending properties (up to 2.1×106 N-mm2/mm for EI and 1199 N-mm/mm for FbS) similar to commercial OSB panels, showing potential for sealing, structural, and flooring applications. The castor oil polyurethane resin presented acceptable efficiency as the particle binder and as an adhesive for the face-core gluing of the low density sandwich panels (0.43 MPa), meeting the minimum requirements recommended by ABNT NBR 14810:2006.

Sieving process selects sugarcane bagasse with lower recalcitrance to xylan solubilization

AbstractBACKGROUNDSugarcane bagasse is a heterogeneous and organized material that needs a pretreatment to access the polysaccharides (cellulose and xylan). The particle size of a non‐milled bagasse can influence the xylan and xylose solubilization, as well as the enzymatic hydrolysis of the pretreated material. Using bagasse selected on 16‐, 30‐, 40‐ and 50‐mesh sieves: xylan solubilization was performed with hydrogen peroxide; xylose was solubilized with diluted sulfuric acid; and enzymatic hydrolysis was conducted for glucose yield evaluation.RESULTSThe xylose solubilized by acid pretreatment resulted in a maximum of 6.59 g L−1 with no influence of particle size. The solubilized xylan showed linear correlation with a variation of 36.18% (16‐mesh bagasse) to 71.43% (<50‐mesh bagasse). Pretreated material submitted to enzymatic hydrolysis revealed that particle size influenced the pretreatment, increasing the glucose yield.CONCLUSIONSThe results showed that non‐milled sugarcane bagasse particle size selection positively influenced the solubilization of xylan, improving the enzymatic hydrolysis of the pretreated material. © 2020 Society of Chemical Industry (SCI)

Characterization of sugarcane bagasse particles separated by elutriation for energy generation

Bagasse particle is used in energy generation, and the usual method for determining their size distribution is sieving. Traditional methods for measuring the bagasse particle size distribution, such as sieving, do not evaluate the effect of the irregular particle shape, producing results that are not always applicable to the prediction of fluid dynamic behavior. This work determined size distribution of bagasse particles considering their aerodynamic behavior. Physical-chemical characterization was performed in different particle sizes of the bagasse. A particulate elutriation and settling system was developed to determine the terminal velocity distribution of particles. Drag coefficients and terminal velocities measured were compared with literature correlations. Almost all the correlations analyzed showed significant deviations from the values obtained experimentally. Haider and Levenspiel’s correlation showed the smallest average deviation. Two types of particles were observed in bagasse: fibers and spongy pith. The apparent density of the particles depends on the particle size, and the ash concentration in smaller fractions is 3 times larger than the average. The method of aerodynamic separation for the characterization of bagasse particle allowed to obtain information that cannot be found by the traditional method of separation by sieving.

Coupling of bioaugmentation and biostimulation to improve lindane removal from different soil types

Lindane is an organochlorine pesticide that, due to its persistence in the environment, is still detected in different matrices. Bioremediation using actinobacteria consortia proved to be promising for the restoration of contaminated soils. Another alternative to remove xenobiotics is to use agricultural residues, which stimulates microbial activity, increasing its capacity to degrade organic pollutants. The present work studies the coupling of sugarcane bagasse biostimulation and bioaugmentation with the actinobacteria consortium composed of Streptomyces sp. A2, A5, A11 and M7 on lindane removal in different soil types. In this sense, factorial designs with three factors (proportion and size of sugarcane bagasse particles, and moisture content) were employed. A response optimizer identified the combination of factors levels that jointly allowed obtaining the maximum lindane removal in the evaluated conditions. In the optimal conditions, the effect of the bioremediation process on soil microbiota was studied by evaluating different parameters. The highest lindane removal percentages were detected in biostimulated microcosms bioaugmented with the microbial consortium, which were accompanied by a decrease in lindane half-life respect to the controls. Also, the bioaugmentation of biostimulated microcosms increased the microbial counts and enhanced soil enzymatic activities, corroborating the bioremediation process efficiency. The survival of the four actinobacteria at the end of the assay confirmed the ability of all Streptomyces strains to colonize amended soils. Bioremediation by simultaneous application of biostimulation with sugarcane bagasse and bioaugmentation with the actinobacteria consortium, in the optimized conditions, represents an efficient strategy to restore lindane contaminated soils.

Theoretical study of pneumatic separation of sugarcane bagasse particles

Sugarcane bagasse is a byproduct generated at sugarcane mills after sugarcane juice extraction. Studies on the enzymatic hydrolysis of fine pneumatic classified particles at ambient equilibrium moisture content have shown good cellulose to glucose conversion without any extra pretreatments as milling, enzymatic, acid or a combination of these, which is one of the current hydrolysis process bottlenecks. Avoid such pretreatments is extremely important for reducing process costs. Based on previous work, this study performed a theoretical investigation of bagasse particles' separation aiming a better understanding of this phenomena permitting development and improvement of equipment used for it. Numerical simulations were carried out using ANSYS Fluent® and Rocky® DEM software, which modelled separation experiments based on computational fluid dynamics and discrete element method, respectively. The comparison between simulation and actual experimental results showed that the model is predictive and can be extended to several processes that use the fluidisation of sugarcane bagasse, such as drying, pyrolysis, and gasification. The studied simulation models can also serve as a basis for fluidisation simulations of other biomasses.

THE EFFECT OF CELLULOSE NANOCRYSTALS IN SUGARCANE BAGASSE PARTICLEBOARDS OF PITH AND FIBERS

ABSTRACT The aim of this research was to investigate sugarcane bagasse (SCB) particleboards, using two kinds of particles, from pith and fibers, reinforced with cellulose nanocrystals (NCC). The NCCs were dispersed in the adhesive urea formaldehyde (UF) using a sonificator in two proportions (0 and 1%). The NCCs and UF were applied in the SCB particles using a rotary blender. The particleboards were produced in three layers using two kinds of particles: pith and fibers. After dispersion of the adhesive, the mixture was compressed to produce the particleboards, which were characterized by physical, mechanical and thermal properties. The anatomical and chemical features relating to pith and fiber were very similar. The particleboards made with and without NCCs did not differ statistically for most properties: modulus of elasticity (MOE), modulus of rupture (MOR), water absorption (WA) thermal conductivity (TC), and the volume heat capacity (VHC). Particleboards made only with fibers and without NCCs showed higher internal bond (IB). In the other hand particleboards made only with fibers in the face and pith in the core (without NCCs) showed lower thickness swelling after 24 hours (TS24h). Probably, the NCCs did not improve the particleboards performance, because less links were available for SCB to interact with the adhesive. For the others properties the particleboards made with pith and fibers did not showed statistical difference (MOE, MOR, TC, WA, TC and VHC), demonstrating that separation of pith and fiber are not significant and does not affect the final properties of particleboards.

PROPERTIES OF PARTICLEBOARD PANELS MADE OF SUGARCANE PARTICLES WITH AND WITHOUT HEAT TREATMENT

ABSTRACT The objective of this work was to determine the properties of particleboard panels made of “in natura” sugarcane bagasse particles, heated at 250 °C for 5 minutes. Various particle proportions were utilized to produce the panels and their properties were compared with that of a panel made of Pinus sp. The panels were produced with 8% tannin formaldehyde adhesive, and 0.5% paraffin emulsion, being pressed at 32 kgf.cm-2 for 10 minutes at 180 ° C. It was determined the basic density of the “in natura” and heat-treated particles, their chemical composition, as well as the compression ratio necessary to obtain panels with density equal to 0.75 g.cm-3. The basic density of the panels, hygroscopic equilibrium humidity, thickness swelling, linear expansion, water vapor adsorption, modulus of elasticity and rupture, perpendicular traction, screw pullout, and Janka hardness were determined. The basic densities of Pinus particles and sugarcane bagasse without and with heat treatment were 0.46, 0.27 and 0.30 g.cm-3, respectively. The average specific mass of the panels was 0.74 g.cm-3 with no significant difference between them. Generally, panels made of sugarcane particles were less hygroscopic and dimensionally more stable than panels made of Pinus particles. However, the perpendicular tensile strength, screw pullout and Janka hardness of these panels were higher than for the Pinus panels. The heat treatment of sugarcane bagasse particles resulted in better mechanical properties of perpendicular traction and Janka hardness. In general, the panels are within the limits set by ANSI A208.1. It is therefore possible to replace panels made of Pinus particles for the ones made of sugarcane bagasse, provided that at least 25% of the particles are heat treated for 5 minutes at 250 ° C.

Pelletizing of Colombian agro-industrial biomasses with crude glycerol

The effect of crude glycerol (G) on the pelletizing process and the quality of biomasses pellets were evaluated. Pellets were made of three types of agro-industrial biomasses typical of tropical countries: Sugarcane bagasse (SCB), Coffee Husk (CH) and Rice Husk (RH). Mixtures of water and glycerol were used as a binder. It was found that, with the addition of crude glycerin, the linkages between biomass particles for formation of pellets is made easier. However, this addition causes a reduction of the compaction degree since it acts as a lubricant between the biomass and the pelletization die, which produces the weakening of the solid to solid interaction. For CH and SCB particles, due to its shape and soft structure, pelletizing is not significantly affected by the biomass particle size variation, whereas in the case of small RH particles, the presence of a binder favors pelletizing. A brief dissertation about the aggregation mechanisms those were favored in each biomass type was carried out. A multi-criteria methodology was implemented by which it was possible to select the optimal conditions of pelletizing for each biomass.

Heat transfer in packed-beds of agricultural waste with low rates of air flow applicable to solid-state fermentation

Heat transfer studies were carried out in packed-beds (PBs) heated by the wall and percolated by low air flow rates. Porous media were composed by particles of sugarcane bagasse (SCB) and by a mixture of particles of SCB, orange pulp and peel (OPP) and wheat bran (WB) at proportion SCB:OPP:WB 1:2:2 w/w (composed medium), agricultural waste used as substrates in bioreactors of solid-state fermentation (SSF), an interesting biotechnological application of PBs. Once metabolic heat generated has to be dissipated, heat transfer studies and thermal parameters are required. Tube-to-particle diameter ratio was D/dp = 260, bed height ranged from L = 60 to 180 mm, while air flow rate ranged from 400 to 1200 L/h. Air temperature was 40 °C and wall temperature 65 °C. The outlet bed temperatures (TL) were measured by ring-shaped sensors and by aligned thermocouples. Average temperatures (Tavg) and global heat transfer coefficients (U) were calculated separately for central region of the beds and for wall-vicinity. Radial effective thermal conductivity (Λr) and wall-to-fluid convective heat transfer coefficient (αwall) have been estimated by means of the traditional two-parameters model. Radial temperature profiles at bed outlet were flattened in the central region and convergent at the edge of the packs. The two-regions approximation for U calculations showed to be appropriate for both packs. Global coefficient U, thermal conductivity Λr and convective coefficient αwall increased with increasing air flow rate and decreased with bed height. Λr tended to the stagnant value of the thermal conductivity and αwall were lower than 50 W/m2/°C, addressing the difficulty on removing metabolic heat from PBs of SSF.

Upregulation of genes encoding digestive enzymes and nutrient transporters in the digestive system of broiler chickens by dietary supplementation of fiber and inclusion of coarse particle size corn

BackgroundMeasures to improve bird performance have been sought due to the imminent phase out of in-feed antibiotics in poultry and continued demand for higher poultry feeding efficiency. Increasing grain particle size and dietary fibre may improve gizzard function, digestive efficiency and nutrient absorption. This study was conducted to evaluate the effect increased particle size of corn and inclusion of sugarcane bagasse (SB) on mRNA expression of genes encoding digestive enzymes and nutrient transporters in broilers.ResultsA total of 336 day-old Ross 308 males were assigned in a 2 × 2 factorial arrangement of treatments with corn particle size - coarse 3576 μm or fine 1113 μm geometric mean diameter, and SB - 0 or 2% inclusion. Feed conversion ratio (FCR), weight gain and feed intake were measured from d 0–10 and d 10–24. The relative gizzard weight and mRNA expression of genes encoding digestive enzymes and intestinal nutrient transporters were measured on d 24. During d 10–24, a particle size × SB interaction was observed for FCR (P < 0.01), where birds fed coarsely ground corn (CC) with 2% SB had lower FCR than those fed CC without SB. A particle size × SB interaction was observed for both expression of pepsinogen A and C (P < 0.01) which were negatively correlated with FCR on d 24. Addition of 2% SB upregulated pepsinogen A and C only in CC fed birds. Further, 2% SB also upregulated pancreatic amylase (AMY2A) and intestinal cationic amino acid transporter-1 (CAT1). Inclusion of dietary CC upregulated duodenal amino peptidase N (APN), jejunal alanine, serine, cysteine and threonine transporter-1 (ASCT1), and ileal peptide transporter-2 (PepT2).ConclusionThese results suggest that both SB and coarse particle size modulate expression of genes encoding important digestive enzymes and nutrient transporters and thus are directly related to bird performance. These findings provide insights into the combination effects of dietary fiber and particle size in the future management of broiler feeding.

Prediction of the minimum fluidization velocity of particles of sugarcane bagasse

This study refers to an experimental analysis of the fluid-dynamics of particles of sugarcane bagasse in a fluidization column with an internal diameter of 190 mm, which determined the minimum fluidization velocity of the particles with different characteristic diameters (0 < dp<9.5 mm), using air as fluidization means. The results have shown that the minimum fluidization velocity has a tendency to increase as the diameter of the particle increases. However, in a certain range of diameter (0.88 mm < dp<9.5 mm), where the particles have a high aspect ratio (length/diameter), it has not been possible to fluidize them. High superficial air velocities have been used, mainly due to the strong trend to interlace and to develop high adhesion forces in this type of particles, as well as the high porosity that is displayed. Based on the experimental results, two new models have been developed in order to determine the minimum fluidization velocity and the complete fluidization velocity of the sugarcane bagasse with diameters that range from 0.075 to 0.445 mm. The comparisons have been made by using correlations from the literature for the determination of the minimum fluidization velocity, and the experimental results have shown that the new suggested correlations finely predict this parameter, with a maximum error range of 6%, respecting the experimental values.

Fluid dynamic study of mixtures of sugarcane bagasse and sand particles: Minimum fluidization velocity

This paper is focused on the study of fluid-dynamic behavior of mixtures of the sugarcane bagasse particles and quartz sand in a transparent fluidized bed column. The minimum fluidization velocity (Vmf) was determined by different mean particle diameters and different mass fractions in the mixture compositions. The values of Vmf increased with amount of biomass in the mixture increased as well as with the size of the biomass particles in the range of 9.5 ≥ dpb > 0.225 mm. Binary mixtures with diameter ratios biomass/sand ≤1 had a (Vmf) almost constant as a function of mass fraction of biomass. It is suggested a practical upper limit of biomass fraction in the mixtures less than 5% of the overall bed mass to obtain a good mixing and uniform distribution in the bed. New correlations were developed to predict the values of (Vmf). It was found that the present proposed correlation predicted the (Vmf) for binary mixtures of sugarcane bagasse and sand particles more accurately than other correlations reported in the literature available.

Mixture and motion of sugar cane bagasse in a rotating drum

The mixture and motion of fibrous particles of sugar cane bagasse were experimentally investigated in a rotating drum, a configuration frequently used for bioreactors in solid-state fermentation processes. The rotational velocity, filling degree and presence of an inner tube amidst the particles were the controlled variables. The image analysis technique was used to evaluate the radial and axial mixtures. The numbers of rotations used to achieve radial and axial homogeneities were obtained and the radial particle motion described. The minimum numbers of rotations for radial homogeneity were 12, 15 and 17 for filling degrees of 0.3, 0.5 and 0.6, respectively and this number was not influenced by the presence of the inner tube and the rotation velocity. The radial motion was influenced by all the variables and the flow regimes observed were distinct from those previously described in the literature. The passive layer did not behave as a solid body under any of the experimental conditions tested in the absence of the inner tube. When the tube was inserted, stagnant and fast velocities were observed in its vicinity and a porosity profile was noted in the stagnant zone. For both configurations, agglomerates of particles flowed down the free surface rather than a steady flow of particles. The axial diffusion coefficient was experimentally obtained and the simulated tracer concentration presented good agreement with the experimental results.

Evaluation of mold growth on sugarcane bagasse particleboards in natural exposure and in accelerated test

The objective of this study was to investigate the performance of alternative sugarcane bagasse particle board (BCP) using castor oil polyurethane resin in comparison with commercial medium density wood particle board (MDP) under natural and accelerated test conditions. The particle boards were evaluated after 12 months of exposure to natural weathering in Pirassununga (21.9965° S, 47.4262° W), Brazil and by an accelerated mold growth test under laboratory conditions. The mold growth was quantified according to the Standards ASTM D 3273-12 (2012) and the results were evaluated by statistical analysis through the Proportional Chances Model (PCM). For both materials, the surface coating with castor oil based bi-component polyurethane resin was less colonized than the non-coated materials; independent of the particleboard type. Additionally, the bending test shows that the sugarcane bagasse particle boards presents better performance of module of elasticity (MOR) (7.7 MPa) in comparison with the commercial wood particle boards (3.6 MPa) after exposed to accelerated tests for mold colonization. The surface coating with castor oil based polyurethane resin reduces mold growth, therefore these results support the potential use of this alternative resin both as a binder and as a surface coating in these particulate materials. The particle boards fabricated with sugarcane bagasse and castor oil resin presented similar mold colonization compared to the commercial wood particle boards.

Performance of Agroindustrial Wastes for Removal of Disinfection By-products From Water

The aim of the present work was to use agroindustrial wastes as alternative adsorbents for the removal of trihalomethanes (THMs). SEM micrographs of sugar cane bagasse and coconut mesocarp samples showed a high degree of particle agglomeration, with particle sizes of 114.4 ± 74.0 μm, while the sugar cane bagasse particles were larger (557.3 ± 169.5 μm). The pyrogram obtained for sugar cane bagasse revealed the presence of many compounds with different functional groups containing oxygen atoms. In the case of the coconut mesocarp, the range of oxygenated functional groups was smaller. The adsorption processes showed fast kinetics, with equilibrium reached after around 240 min of contact. Adsorption tests revealed different selectivities of the biomass adsorption sites for the THMs. Adsorption percentages obtained with coconut mesocarp ranged from 49.2 ± 2.57 to 71.9 ± 1.88 %, while the values obtained for sugar cane bagasse were between 31.8 ± 1.08 and 67.4 ± 1.27 %. The orders of removal (significant at p CHBrCl2>CHBr2Cl>CHBr3 (using sugar cane bagasse) and CHBr2Cl>CHBrCl2>CHCl3>CHBr3 (using coconut mesocarp). Use of the sugar cane bagasse resulted in high removal percentages of chloroform (51.1 %) and dichlorobromoform (42.3 %) in the first 5 min of contact, showing that this biomass had greater affinity for trihalomethane compounds with more chlorine atoms in their structures. This finding has considerable environmental importance, given that these are the two commonest compounds found in water distribution networks.

Fluid-dynamic assessment of sugarcane bagasse to use as feedstock in bubbling fluidized bed gasifiers

The fluid bed gasification of a sugarcane bagasse is a promising option for the large-scale production of fuel gas in order to increase the energetic efficiency of the sugar industry. A fluid-dynamic and thermodynamic assessment of the use of sugarcane bagasse as feedstock for a bubbling fluidized bed gasifier was performed. It was determined the required range of sugarcane bagasse particles sizes to permit the use this biomass as feedstock in bubbling fluidized bed gasifiers and the main fluidization parameters for the range of diameters proposed, with good agreements with the experimental values reported for the same Geldart's type of particles. A range of particle sized between 0.8 and 1.21 mm was suggested. The producer gas composition was modeled using air as gasification agent, obtaining a theoretical LHV of 4.56 MJ/Nm3.

Combustion of single biomass particles in air and in oxy-fuel conditions

The combustion behaviors of four different pulverized biomasses were evaluated in the laboratory. Single particles of sugarcane bagasse, pine sawdust, torrefied pine sawdust and olive residue were burned in a drop-tube furnace, set at 1400 K, in both air and O2/CO2 atmospheres containing 21, 30, 35, and 50% oxygen mole fractions. High-speed and high-resolution images of single particles were recorded cinematographically and temperature–time histories were obtained pyrometrically. Combustion of these particles took place in two phases. Initially, volatiles evolved and burned in spherical envelope flames of low-luminosity; then, upon extinction of these flames, char residues ignited and burned in brief periods of time. This behavior was shared by all four biomasses of this study, and only small differences among them were evident based on their origin, type and pre-treatment. Volatile flames of biomass particles were much less sooty than those of previously burned coal particles of analogous size and char combustion durations were briefer. Replacing the background N2 gas with CO2, i.e., changing from air to an oxy-fuel atmosphere, at 21% O2 impaired the intensity of combustion; reduced the combustion temperatures and lengthened the burnout times of the biomass particles. Increasing the oxygen mole fraction in CO2 to 28–35% restored the combustion intensity of the single biomass particles to that in air.