Bed Material Research Articles

ENHANCING 3D PRINTING THROUGH MATERIAL SELECTION

Additive manufacturing (AM) has revolutionized industries by enabling the layer-by-layer 3D printing of objects. Among the diverse materials employed in AM, polymers and their composites hold significant importance due to their wide-ranging applications in fields such as medicine, aerospace, and automotive engineering. Extensive research efforts have been dedicated to developing advanced polymer materials tailored for various AM techniques, encompassing vat photo-polymerization, material jetting, powder bed fusion, material extrusion, binder jetting, and sheet lamination. While previous reviews often focus on specific aspects, this comprehensive review offers a holistic overview of polymer material advancements in AM. The review explores notable breakthroughs in newly developed materials and their potential applications. Furthermore, it outlines the existing challenges in utilizing AM for polymer materials and identifies promising opportunities, aiming to stimulate further progress in this dynamic and transformative field. Keywords:Polymers,Composites,Vatphoto-polymerization,Additivemanufacturing,Powder bed fusion, Material jetting,Binder jetting,sheet lamination.

Field observations of wave-averaged suspended sediment concentrations in the inner surf zone with varying storm conditions

During extreme conditions, the transport of the wave-averaged suspended sediment concentrations in the inner surf zone affects dune erosion. Although large-scale laboratory experiments have provided insight in what drives these sediment concentrations, corresponding field data are lacking. To fill this gap, novel field observations of suspended sediment concentrations are compared to drivers that govern sediment suspension during storm conditions known from literature. A total of 128 time intervals of 20 min are analysed, spread over 10 different high water events with different hydrodynamic conditions. For each time interval, the wave-averaged (i.e. 20 min mean) suspended sediment concentration is computed and compared to three suspension drivers. The studied drivers are (1) bed shear due to near bed velocities that originate from mean currents in combination with wave-induced orbital flow, (2) the horizontal pressure gradients under steep wave fronts that increase the forces on the bed material, and (3) bore-induced turbulence that is generated at the free surface and reaches the bed. The derived bore-induced turbulence generates the greatest correlation with the mean suspended sediment concentrations (r = 0.74, p = 4.47E-23). Samples that deviate from this correlation correspond to time intervals with lower values of derived bore turbulence, less wave energy saturation in the inner surf zone, and stronger mean currents. The correlation with the mean suspended sediment concentrations increases when the shear stress originating from mean currents is used for these time intervals (r = 0.83, p = 1.63E-33). For time intervals during which more energetic conditions persist and the wave energy is saturated in the nearshore, bore turbulence was the dominant mechanism in stirring up sediment. The outcome of this study suggests that, based on the events analysed, dune erosion models may achieve more accurate results if computations of suspended sediment concentrations include a bore-induced turbulence term, or if already included, properly address the relative importance of bore-induced turbulence when compared to bed shearing.

CFD modeling of a fluidized bed with volatiles distributor for biomass chemical looping combustion

Achieving high volatiles conversion is crucial to biomass chemical looping combustion. Challenges arise from rapid devolatilization of biomass and limited biomass injection ports, resulting in volatiles with insufficient contact with oxygen carriers in fluidized beds. A concept called volatiles distributor (VD) has recently been proposed and investigated in a cold-flow fluidized bed, which shows excellent performance in achieving an even distribution of volatiles over the cross section. To deeply understand VD's impact on hydrodynamics behaviors, pioneering three-dimensional full-loop cold-flow CFD simulations were conducted using an Eulerian multiphase granular model. Three drag models, i.e., Gidaspow, Filtered, and two-step EMMS/bubbling, were evaluated against experimental data. While all models perform well in bubbling fluidization, the two-step EMMS/bubbling model excels in turbulent fluidization. Additionally, CFD simulations reveal improved mixing between volatiles and bed materials with VD, highlighting its efficiency in addressing incomplete conversion of high-volatile fuels like biomass in fluidized bed systems.

Effect of different bedding depths of rice hulls on growth performance and carcass traits of White Pekin ducks.

Duck meat is recognized as a healthier poultry product that contains higher amounts of unsaturated and essential fatty acids, iron, and excellent amounts of protein. It has been found to possess the ability to reduce low-density lipoprotein cholesterol and subsequently, blood pressure in the human body; and improve the immunity system. The current study investigated the appropriate bedding depths of rice hulls as a preferred bedding material by evaluating the growth performance and carcass traits of White Pekin ducks raised for 42 days. A total of 288 one-day-old White Pekin ducklings were randomly allotted to floor cages with one of four bedding depths at 4 cm, 8 cm, 12 cm, and 16 cm. Ducklings were fed standard duck starter (days 1-21) and finisher (days 22-42) diets. The birds were stocked at a rate of 6 birds/m2 with 6 replicates per treatment. Growth performance evaluation for the body weight, average daily gain, and average daily feed intake were measured to calculate the weekly feed conversion ratio. Breast, leg, and carcass yield were assessed as carcass traits. The muscle color and proximate composition were also analyzed for meat quality. Footpad dermatitis was also evaluated on day 42. Ducks reared on 16 cm bedding depth over the 42 days recorded higher (p < 0.05) body weight, average daily, average daily feed intake, and improved feed conversion ratios compared to other groups. The crude fat in breast meat also lowered (p < 0.05) in ducks reared at 16 cm (1.02%) when compared to ducks raised at 4 cm bedding depth (2.11%). Our results showed improved redness (p < 0.05) when the depth of bedding materials was elevated. Except for the breast meat fat, the dissimilar bedding depths did not affect (p < 0.05) the breast and leg meat composition, footpad dermatitis, and mortality for the current study. In conclusion, this study indicated that the bedding depths would directly or indirectly affect the growth performance and meat color of White Pekin ducks; and the bedding depth of rice hulls at 16 cm improved the growth performance of White Pekin ducks for 42 days.

CO2 conversion to CO by fluidized bed biomass gasification: Measuring CO2 utilization via stable carbon isotope ratios

Thermochemical conversion of CO2 in biomass gasification is a promising technology for utilizing CO2 as a feedstock to produce a CO-rich gas. Simultaneous decomposition reactions of biomass and various gas-solid and gas-gas reactions form the product gas in this process. The overlap in sub-processes makes it challenging to assess the conversion of feedstock CO2 with common methods like mass balancing. This work introduces stable carbon isotope ratio analysis (δ13C) to identify the sourcing of carbonaceous product gas components and determine the conversion of CO2. This methodology is applied to evaluate experiments conducted for one hour of continuous operation in a lab-scale fluidized bed gasifier. Softwood pellets and wood char are used as fuel, with Olivine as a bed material, a target heating temperature of 1000 °C and atmospheric pressure. Product gas with more than 80 vol% CO was generated when wood char was used as fuel. Stable carbon isotope measurements show that CO2 is converted at 48–93% in this process, underpinning the position of biomass CO2 gasification as carbon capture and utilization technology. These results were up to 25% higher than suggested by mass balancing, with higher discrepancies at lower CO2 conversions when using softwood as fuel. Therefore, stable carbon isotope ratio measurement can be a valuable tool for improving the process understanding of biomass CO2 gasification. The results can be used for carbon accounting and the technical development of gasifiers with high CO2 utilization efficiency.

Attrition and morphological analysis of CaCO3 corresponding to oxy-fuel circulating fluidized bed conditions

The specific surface area of CaCO3 has always been an essential parameter for various oxy-fuel combustion processes and chemical looping processes. However, the circulating of bed material through the furnace, cyclone and loop-seal in an oxy-fuel circulating fluidized bed (CFB) reactor may trigger the particle size changes as a result of rapid collisions among particles and friction with the inner refractory wall. Rather than considering only the effect of initial particle size, it is significantly important to emphasize on the change in limestone particle size due to in-reactor attrition. In addition, the changes are further enhanced with calcination reaction that occurred under high-temperature conditions. Herein an investigative account of limestone in a lab-scale CFB process was presented by using two types of fluidizing media (Air, CO2) to determine its attrition and morphological changes under simulated operating conditions for riser and loop-seal. A significant difference in attrition index was observed as calcination of limestone occurred at high temperature under air atmosphere which was not observed under CO2 condition. With similar cross-sectional area observed for both the tested (CO2 condition) and re-carbonated limestone, it was concluded that re-carbonation of calcined lime at high CO2 concentration in the loop-seal resulted in a comparable abrasion resistance that further improved desulfurization performance by reducing the amount of ultra-fine particles generated from limestone.

Acinetobacter in fresh faecal samples is related to sperm motility: A case report in Piétrain boars housed on different deep-litter bedding materials.

The swine gastrointestinal tract contains a great variety of microbes, forming a complex and dynamic ecosystem. Various internal and external factors (e.g. age, breed and diet) may influence its composition. This study aimed to investigate the gut microbial diversity of German Piétrain boars housed on different deep-litter bedding materials (regional wood shavings, linen, hemp, spelt husks, and wood shavings) via 16S-rDNA sequencing. Additionally, short-chain fatty acids were analysed using gas chromatography. Fresh faecal samples (n = 80) from 40 Piétrain boars were collected twice during the trial. Although it can be assumed that boars ingest bedding orally, no differences in the microbiome composition could be found. The main phyla were Firmicutes and Bacteroides. Acinetobacter was identified as a biomarker for sperm quality differences (total sperm motility) in breeding boars.

Composting Dairy Manure with Biochar: Compost Characteristics, Aminopyralid Residual Concentrations, and Phytotoxicity Effects

Aminopyralid (2-pyridine carboxylic acid, 4-amino-3, 6-dichloro-2-pyridine carboxylic acid) is an auxin herbicide that has been used widely to control broadleaf weeds in pasture and hay fields. With no post-application withdrawal time, aminopyralid absorbed into forage material can contaminate compost feed stocks such as hay, grass bedding material, and manure. Composts derived from such feed stocks raises concerns about after-effect injuries to sensitive crops by residual aminopyralids. Biochar (BC) additive may affect the composting process and immobilizes organic pollutants. This study examined the effect of composting dairy manure/sawdust 1:1 mixture containing 10 ppb (wet) of aminopyralid with 0%, 2%, 4%, and 10% (w/w) BC levels on chemical and biological characteristics of compost, residual aminopyralid concentration, and intensity of plant injury to tomato (Lycopersicon esculentum L.) plants after composting in 140 L plastic rotary drum reactors for two 6-month cycles. Biochar addition decreased organic matter degradation and intensified reduction in residual aminopyralid levels in a dose-dependent manner. Composting with BC concentrated more N, P, and K, caused mild plant injuries, and increased the above ground biomass compared to the no BC incorporation. Addition of BC for composting aminopyralid-contaminated dairy manure can increase the phyto safety level of compost while enhancing the key fertilizer values.

Stability of boulders on cobble streambeds

The placement of boulders in streams enhances aquatic habitat by increasing the heterogeneity of flow conditions. Practical design must ensure the stability of individual boulders, requiring calculation of their incipient movement conditions. The stability of a boulder on a cobble bed is shown experimentally to depend on its size, the bed material size, the degree of embedment of the boulder, the slope of the bed and the flow velocity and depth. An equation is derived through a pivoting analysis for predicting the relationship between the critical ambient depth-averaged velocity and the critical flow depth; this, together with a resistance equation, can be used to predict the flow conditions for boulder stability. The equation is used to develop a simpler form for unsubmerged spherical boulders and cobbles. The stability equation is tested against the experimental data, using an experimentally determined drag coefficient relationship.

MODELLING AND ANALYSIS OF CNC MILLING MACHINE BED WITH COMPOSITE MATERIALS

The materials utilized as a part of a machine device have an unequivocal part in deciding the efficiency and exactness of the part made in it. The regular basic materials utilized as a part of exactness machine apparatuses, for example, cast iron and steel at high working velocities create positional mistakes because of the vibrations moved into the structure. Quicker cutting rates can be procured just by structure which has high firmness and great damping attributes. We know that by experiences life of a machine is inversely proportional to the levels of vibration that the machine is subjected. The further procedure is completed to experience the distortion, normal recurrence and removal utilizing Static examination, Modal investigation and Harmonic individually. Since the bed in machine apparatus assumes a basic part in guaranteeing the exactness and precision in segments. Is a standout amongst the most critical apparatus structures which have a tendency to retain the vibrations coming about because of the cutting operation. To break down the bed for conceivable material changes that could build solidness, diminish weight, improve damping characteristics. In this paper constant load is applied on a bed with and without Nanocoating on the material and with composite materials. Graphene is used for coating basing on strength and thermal properties. Modelling of the bed was carried out in SolidWorks and ANSYS is used for structural analysis. By comparing the stress distribution and deformation in the bed by changing its material with the previous. Finally this thesis summarizes the suitable materials can be used as machine bed material. Key words: Machine Tool, Machine Bed, Stiffness, Damping, SOLID WORKS, Ansys

Using &lt;i&gt;Origanum vulgare&lt;/i&gt; L. in the floor management of chickens as an element of organic poultry farming

The article provides the results of the use of dried Origanum vulgare mass as an additional component of bedding material in chickens of the Hubbard Redbro M meat-and-egg cross. Origanum vulgare dried mass was added at the rate of 0.5 kg per experimental group daily from the age of 45 days after the transfer of chickens to floor management. The number of heads for each group was 35. The live weight advantage at the age of 2 months of the experimental group of chickens over the control group is 102.5 g, at 75 days of age is 216.5 g, at 90 days of age is 326.0 g and at the age of 105 days is 403.0 g. The SBA increased at the background of the S. aureus test culture: there was a significant suppression of colonies in the first five hours of exposure, and at the background of the E. coli test culture there was a suppression throughout the entire study period. The intensification of metabolic processes was noted in chickens of the experimental group, due to increased protein metabolism, liver and kidney enzymes of blood serum, which was also associated with an increased concentration of thyroid hormones. All these factors made it possible to raise significantly the gain in live weight by an average of 0.11 kg, which increased the slaughter weight by 8.4 %. Almost all indicators of the development of internal organs in chickens of group II are within significant limits of the difference compared with the control group.

Experimental and numerical investigation on the pyrolysis of oil shale particles in a bubbling fluidized bed

The efficient utilization of oil shale resource is beneficial to environment and the resource diversity. In this work, a bubbling fluidized bed (BFB) reactor was first used to pyrolyze Huadian oil shale experimentally, mainly focusing on the influence of fluidization flow rates. The yield of shale oil, char and non-condensable gas varies little at different fluidization flow rates, but the components in shale oil are different due to the secondary cracking, such as the fractions and species of aliphatic hydrocarbons, aromatic hydrocarbons and non-hydrocarbons. Then, the dense discrete phase model (DDPM) was used to track the trajectories of oil shale particles with different diameters in a bubbling fluidized bed. Population balance model (PBM) coupled Eulerian model was used to well describe the bubbling status of bed materials to characterize the hydrodynamic behaviors. Furthermore, a segmented kinetic model was compiled by UDF module to illuminate the pyrolysis of oil shale particles. The multi-phase reactive flow modeling clearly indicated the distribution of oil shale particles and gaseous products in BFB reactor, as well as pyrolysis time and the secondary cracking at different fluidization flow rates. In summary, this work provides a reference basis for complete pyrolysis of oil shale particles in a bubbling fluidized bed and generating shale oil with high yield and good quality.

Production and investigation of water absorbent fibre pellets from unutilised lignocellulosic biomass pre-processed in a twin-screw extruder

Organic livestock farming requires all resource input to be organic as well. Competition for raw materials as bedding increases the demand for alternative bedding materials. The production of absorbent fibre pellets from underutilized lignocellulosic plant material is therefore a research area that needs further attention. Precise research on processing methods and absorbent quantity is essential for the development of sustainable, high-quality absorbent bedding pellets. Twin-screw extruded fibre from eight different raw materials were processed into absorbent pellets. These pellets were investigated for physical properties including absorbency, mechanical durability, particle-size distribution and bulk density in accordance with relevant standards. Due to the absence of a standardised method for assessing absorbency, a testing method was devised. This involved submerging the produced pellets in deionized water for durations of 30 s, 300 s, and 1200 s. This research analysed various raw materials for suitability in absorbent pellet production. Poplar pellets performed good in absorbency (130 %, 172 %, 194 % respectively) and mechanical durability (95 %). As a result, larger quantities of absorbent pellets could be produced from poplar if needed since poplar wood chips are of higher availability due to existing short rotation coppices. This article emphasised producing absorbent bedding pellets, prioritising, using twin-screw extruded lignocellulosic fibre, revealing significant raw material influence on absorption properties.

Two-fold advancement in LDPE Pyrolysis: Enhancing light oil output and substituting sand with kaolin in a fluidized bed system

Low-density polyethylene (LDPE) is the second most prevalent waste plastic globally, followed by polypropylene. The pyrolytic conditions required to obtain light oil(≤C12) from LDPE are more stringent than those for polypropylene, water plastics, acrylonitrile, butadiene, styrene, and other materials. Consequently, numerous researchers have underscored the necessity of employing catalysts in LDPE pyrolysis. This study explored the pyrolysis characteristics of LDPE at various temperatures in a non-catalytic fluidized bed reactor. The experiments employed a mixture of sand + kaolin, one of the Si-Al catalysts, to investigate the pyrolysis of LDPE in a fluidized bed reactor at different temperatures. The findings demonstrated that using sand + kaolin as a fluidized bed material significantly enhances the yield of pyrolysis oil while concurrently reducing the gas yield compared to using sand alone. Moreover, a higher light oil fraction was obtained using kaolin (16.67 wt%) at 560 °C compared with 8.6 wt%. In addition, the study revealed that elevated temperatures (520 °C, 560 °C, and 600 °C) led to a reduction in olefins and paraffin, coupled with an increase in the formation of naphthenes, aromatics, and ketones in the pyrolysis oil. Overall, the findings underscore the promising potential of kaolin as an alternative to sand, facilitating the enhanced production of valuable light oil fractions. The insights garnered from this study are invaluable for devising effective waste management strategies.

Experimental investigation and modeling of the impact of random packings on mass transfer in fluidized beds

This study investigates the impact of two novel settings of bubbling fluidized beds equipped with random metal packings on the mass transfer. To do this, a comprehensive approach is applied that integrates experiments and modeling and explores the relevance of the different underlying mechanisms involved in interphase mass transfer in fluidized beds. Firstly, the mass transfer of water from moisturized silica gel particles to dry air is studied in both a packed-fluidized bed and a freely bubbling bed with no packing. The experimental set-up consists of a cylindrical bubbling fluidized-bed column with an inner diameter of 22 cm. Silica-gel particles with a mean particle diameter of 797 μm are used as bed material. The total bed amount ranges from 4 to 8 kg, while the fluidization number (F) varies between 1.7 and 2.3. Two types of packing, RMSR (stainless steel thread saddle rings) and Hiflow (stainless steel pall rings) are examined and compared to the reference case of a bubbling bed with no packing. The height of the packed section is maintained at 60 cm. The results show that, at all operating conditions, the use of packings enhances the amount of desorbed water in the fluidized bed. The increase is up to 17%, as compared to the bed without packing. The effect is believed to be inhibition of bubble growth in the packed-fluidized bed. To study this further, a mass-transfer model is introduced to analyze the different mass-transfer steps (intra-particle, particle surface to emulsion gas, and emulsion gas to bubble gas) in packed-fluidized beds compared to beds with no packing. TGA experiments are applied to describe the intra-particle mass transfer through a desorption kinetic model. Model analysis shows that the main resistance for mass transfer occurs across the bubble-emulsion boundary. The calculated value of the mass transfer coefficient for this, Kb, at reference conditions (6 kg of silica gel and F = 2.3) is 7.6e-5 s−1 with packings (in average) and 6.2e-5 s−1 without packings, i.e. a 23% improvement in the governing mass-transfer coefficient.

How do sleepwear and bedding fibre types affect sleep quality: A systematic review

SummarySleepwear and bedding materials can affect sleep quality by influencing the skin and body temperature and thermal comfort. This review systematically evaluates the impact of sleepwear or bedding of different fibre types on sleep quality. A systematic search was conducted in six data bases plus Google Scholar and manual searches. Original articles that compared human sleep quality between at least two fibre types of bedding or sleepwear were included, resulting in nine eligible articles included in the review. The fibre types included cotton, polyester, wool, and blended materials for sleepwear; cotton, duck down, goose down, polyester and wool for duvet; and linen and a combination of cotton and polyester for bedding. The interplay between fibre materials and sleep quality is complex. Blended sleepwear demonstrated potential benefits for specific populations. Wool sleepwear showed benefits for sleep onset in adults (cool conditions) and in older adults (warm conditions). Linen bedsheets improved sleep quality under warm conditions in young adults. Goose down‐filled duvets increased slow‐wave sleep under cool conditions in young adults. However, a systematic comparison of fibre types is challenging due to the diverse nature of the studies evaluating sleep quality. Further research employing standardised methodologies with standard fibre samples in different populations and in different temperature conditions is imperative to elucidate comprehensively the effects of fibre choices on sleep quality. Despite the limitations and heterogeneity of the included studies, this analysis offers valuable insights for individuals seeking to optimise their sleep experiences and for manufacturers developing sleep‐related products.

Experimental investigation of hydraulic jump characteristics in sloping rough surfaces for sustainable development

Understanding the intricate dynamics of hydraulic jumps in sloped channels holds pivotal importance in various engineering applications. This research explores the intricate relationship between the size of the bed material and the basic properties of hydraulic jumps, providing insight into the relative jump length, height, and energy efficiency. The goal of the research is to get important knowledge that will be useful for optimizing hydraulic systems and enhancing their overall efficiency in diverse engineering domains. This study used an open-channel flow arrangement with four-bed slopes (0° to 6°) and three irregularity heights (10 to 30 mm). During the investigation, the Froude number differed from 2.30 to 8.85 and the Reynolds number differed from 5450 to 25500. A novel instinctive technique was used to create correlations for different hydraulic jump characteristics in roughen-bed inclined channels. The study examines the combined effects of roughness and slope of the bed, and it was discovered that the relative jump height and efficiency of hydraulic jump increase by 19.37% and 8.44% respectively while the relative jump length decreases by 23.05% with an increase in bed slope from 0° to 6°. The relative jump height and efficiency of the hydraulic jump increase by 14.20% and 21.06% respectively while the relative jump length decreases by 29.09% with a rise in bed roughness from 0 to 30 mm.

Co-Gasification of Polyethylene and Biomass in Catalytic Bed Material

In this work, a simplified comprehensive three-dimensional numerical model is developed to study the effect of hydrogen production on co-gasification of biomass and low-density polyethylene (LDPE). CFD software AVL Fire 2020 inbuilt algorithms were employed to develop the gas phase while the solid phase was developed by user-defined FORTRAN subroutines. Solid hydrodynamics, fuel conversion, homogenous and non-homogenous chemical reactions, and heat transfer, including radiation, subroutines were defined and incorporated into AVL FIRE explicitly. Species concentrations of the syngas were analyzed for co-gasification of Beechwood and LDPE for three distinct types of bed materials (silica sand, Na-Y zeolite, and ZSM-5 zeolite). Then, the model is validated with experiment results available in the literature for a lab-scale fluidized bed reactor. The highest hydrogen production was observed in Na-Y zeolite followed by ZSM-5 zeolite and silica in both numerical and experimental analysis for the co-gasification of Beechwood and LDPE, providing a reasonable agreement between the numerical and the experimental results. Therefore, the current model predicts the enhancement of the quality of hydrogen-rich syngas through the application of co-pyrolysis within a fluidized bed reactor, incorporating a catalytic bed material.

Hydrodynamic Modeling and Comprehensive Assessment of Pier Scour Depth and Rate Induced by Wood Debris Accumulation

This study mainly investigates the impact of debris accumulation on scour depth and scour hole characteristics around bridge piers. Through controlled experiments with uniform sand bed material, the influence of various debris shapes (high wedge, low wedge, triangle yield, rectangular, triangle bow, and half-cylinder), upstream debris length, downstream debris extension, and debris thickness on scour depth and scour hole area and volume around the cylindrical pier were analyzed. The findings revealed that the shape and location of debris in the water column upstream of piers are key factors that determine the depth of scour, with high wedge shapes inducing the deepest scour and potentially the largest scour hole, particularly when positioned close to the pier and fully submerged. Scenarios in which triangle bow debris was submerged at full depth upstream of the pier closely resembled situations devoid of debris. Conversely, debris extension downstream of the pier was found to reduce local scour depth while concurrently enlarging the dimensions of the scour hole. The existing scour prediction equations tend to overestimate scour depth in scenarios involving debris, particularly when applying effective and equivalent pier width. This discrepancy arises because these equations were originally developed to predict scour depth around piers in the absence of debris. In response, a refined model for predicting scour induced by debris was proposed, integrating factors such as upstream debris length, downstream extension, obstruction percentage, and debris shape factor. This model demonstrated strong agreement with experimental data within the scope of this study and underwent further validation using additional experimental datasets from other research endeavors. In conclusion, this experimental study advances the comprehension of scour processes around cylindrical bridge piers, providing valuable insights into the role of debris characteristics and positioning.

Agglomeration behaviour of various biomass fuels under different air staging conditions in fluidised bed technology for renewable energy applications

The most common technology for thermochemical conversion of solid fuel through the process of gasification, such as coal, varieties of residues from biomass and agriculture are the bubbling fluidised bed or fluidised bed systems. However, there are some disadvantages within these systems including the formation of eutectic mixtures, increased process of melting and bed agglomeration. Hence, the current study aimed to evaluate the agglomeration behaviour of various biomass fuels. Characteristics of five biomass fuels (miscanthus, peanut, straw, domestic wood and industrial wood) in a bubbling fluidised bed (BFB) combustor were studied by SEM-EDX, XRD and XRF analysis of bed materials and ash samples. The influence of bed temperatures on the fuel ash composition and bed particles was evaluated, as well as fuel ash components, their interaction with the particles from the bed sand and morphology of the bed material. The combustion efficiency ranged from 95.5 to 99.5% with the highest value obtained for miscanthus under SA conditions. The peanut and straw had the highest K content, whereas the industrial wood ash contained the highest Ca content compared to other biomasses. The XRF results showed that most of the potassium (K) from the wheat straw biomass was converted to K2O with 19%. No bed agglomeration was noticed without staging-air (WSA) and with staging-air (SA) combustion conditions, even with temperatures up to 850 °C during the testing period. Overall obtained results demonstrated that agglomeration is unlikely expected to be a major problem during fluidised bed combustion of tested biomass fuels.