Andrews, GE orcid.org/0000-0002-8398-1363, Slatter, DJF, Saeed, MA et al. (3 more authors) (2016) Flame development in pulverised biomass for fine and coarse particles. In: Proceedings of the 11th European Conference on Coal Research and Its Applications, 11th ECCRIA. 11th European Conference on Coal Research and Its Applications, 11th
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There is very little information on the combustion properties of pulverised biomass, particularly for agricultural wastes. This makes burner design and optimization difficult and also has implications on fire and explosion hazard protection, both in storage, milling and particle transport to burner. A modified Hartmann dust explosion tube was employed to determine the Minimum Explosible Concentration (MEC) and the flame speed for three Pakistani agricultural wastes: bagasse, rice husk and wheat straw. The MEC was influenced by the particle size distribution and there was a strong linear correlation between the MEC and the sum of the ash and moisture content of these and other biomasses. Comparison of the results was made with more conventional pulverized biomass. Peak flame speeds were approximately 2.5 m/s. The lean limits for these pulverised agricultural waste biomasses were comparable to pulverised wood but much leaner than those for coal and hydrocarbon fuels, which indicate that these biomasses are highly reactive.
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This work investigated the flame propagation characteristics of two biomass crop residues bagasse (B) and wheat straw (WS), which are abundantly available in Pakistan. The agricultural residues were coarse milled in Pakistan and then milled in Leeds to less than 63µm using an ultrafine grinder prior to their chemical characterization. An ISO 1m 3 dust explosion vessel was used, but the standard dust injection system using a ‘C’ ring disperser  would not pass the fibrous particles that occur in woody and plant biomass after milling. The ‘C’ ring will only pass spheric al type particles and nut dusts are a biomass that does operated with the standard dust injector . For woody biomass and plant based biomass a new disperser was required and a spherical grid injector was developed and calibrated , similar to an explosion suppressant injector . This would disperse woody and plant biomass milled to <63µm, but would not disperse larger particle sizes. A further problem with woody and plant pulverised biomass was the low bulk density, which resulted in the standard 5L external dust injection pot being too small to hold sufficient mass of biomass powder. To overcome this, a 10L external pot was developed and calibrated to give the same flame speed and K st as for the 5L pot with C ring
For HCO dusts the results are quite unusual, as the lean limit is much leaner in equivalence ratio terms than would be expected based on the results for alcohol vapours, which are very similar to hydrocarbons. For the four pure chemical HCO dusts, the lean limits in Table 1 vary between = 0.18 and 0.24, much leaner than for the pure hydrocarbon dusts. There is very sparse data for lean limits of naturally occurring HCO dusts such as wood dusts. Where the HCO dusts data is available the HCO composition of the dust is not given. Table 1 gives the stoichiometric mixture for a range of biofuels, for which the HCO composition is known but for which no lean flammability data has been reported. Table 1 includes the reported lean limit data for wood dust explosions, for which no HCO composition was given. These results in Table 1 indicate that the lean limit data is compatible with that for pure HCO chemicals and is around =0.2. There is an urgent need for more data on the dust explosion hazards of biofuels, as major plants are under construction for co-firing pulverised wood and straw with coal with no reliable published data on the explosion risk in the dust handling plant.
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Pulverised biomass and torrefied biomass present a few characteristics which pose challenges to the standard methods for determining explosion characteristics using the 1m 3 ISO vessel or the 20 L sphere. Wood biomass and some torrefied biomass materials can present very low bulk densities (c.a. 200-300 kg/m 3 ), therefore the standard dust holders cannot hold enough quantities of dust for a complete characterisation of the samples. The addition of another 5L volume dust holder used in parallel with the standard dust holder is mentioned for low bulk density dusts in the standard (BSI 2004). In addition, the fibrous nature of most biomass dusts prevents a correct dispersion of dust from external dust holders into the explosion vessel. Other researchers have previously recognised and tackled these issues, finding new dispersion methods and ensuring matching results with the standard methods (Wilén et al. 1999; Sattar 2013; Sattar et al. 2013).
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pulverised Colombian coal and Kellingley coal and compare with two pulverised biomass explosions. The laminar and turbulent flame speeds and burning velocities were determined. This is the essential data required in burner design to avoid flame flashback and blow-off. In addition residues collected after explosion tests were analysed in order to understand why roughly half of the coal or biomass injected did not participate in the flame propagation. This unburned coal or biomass was not in the flame zone and did not act as a heat sink; otherwise the adiabatic pressure rise could not be achieved. The work also examines the reason that coal and biomass reactivity are so variable, even when the chemical composition is similar.
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We worked with small colonies of massive Porites spp., a functional group with unresolved taxonomy (Forsman et al., 2009) that is ecologically important and common on shallow reefs throughout the Indo-Pacific (Done and Potts, 1992), and consists of P. lobata (Dana 1846) and P. lutea (Quoy and Gaimard 1833). We collected juvenile colonies (<40 mm diameter) of massive Porites spp. from the back reef (2 – 3 m depth) on the north shore of Moorea, French Polynesia. We collected corals twice, a few days prior to each trial, which began on 17 April 2010 (trial 1) and 8 May 2010 (trial 2). We chose massive Porites spp. for this study because: (i) members of this functional group have a thick tissue layer (Edmunds, 2009), and (ii) properties of coral tissue vary seasonally (Fitt et al., 2000) and are responsive to treatments including light, temperature and food supply (Edmunds, 2009, 2011). Therefore, we reasoned that starvation-induced changes in biomass would be relatively easy to
from/to the reaction sites are required between PAM and electrolyte. Difficulties in the movement of these reaction species may regulate the conversion process [1, 19]. In the present study, as illustrated in Fig. 5, the difference (phase composition and morphology) between the original 4BS and pulverised 4BS electrodes after formation may be due to three main reasons: (1) the branchy long crystalline rods of 4BS used as PAM cause less shrinkage, and make tight electric connection to the grid frame (Fig. 5a), while the pulverised 4BS particles cause much more shrinkage (Fig. 5b), leading to part of PAM loss the connectivity to grid frame, resulting in the poor electrochemical properties ; (2) during the soaking and formation process, 4BS will react with H 2 SO 4 to form PbSO 4 . While the branchy large
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Perspex flow cells (10 x 5 x 0.5 cm) were filled with either: quartz sand (Fisher, particle size 500-700 μm); Ordinary Portland Cement; or Pulverised Fly Ash/OPC cement (5:4). Cements were prepared with a w/s ratio of 0.37, cured at room temperature for 28 days, and crushed and sieved to a 1-2 mm size fraction. Compositions are given in Table 1. Flow cells were saturated with pH 5.7 de-ionised water and continuous flow was maintained in the cells, from top to bottom, at 0.33 mL min -1 using an 8-channel peristaltic pump, beginning 30 minutes prior to injection of the radiotracer, and for the duration of the experiment.
The threat of increased global warming has subjected the usage of fossil to be further researched for better alternatives. As a result, the utilisation of renewable and sustainable energy resources, such as biomass, for electricity production has become increasingly attractive. Co-firing biomass with low percentages in coal fired power plants will enable the use of sustainable fuels for power production without large investments. Co-firing can be seen as a method to mitigate the emissions of CO 2 as the
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Pulverised stem fibres of the natural sponge plant, SP, (Acanthus montanus) and stranded coconut fibre, CF, (Cocos nucifera) from the coir tree were used as reinforcements for thin cement sheets in this research work. The mixture of cement and pulverised waste paper, which formed the matrix, was maintained constant while the fibre mass concentration of both fibres were varied. The slurry formed by adding water to the mixture of the matrix materials and the reinforcement fibres, was poured into rectangular mould and consequently pressed to eject excess water. De-moulded samples were allowed to cure in the laboratory for twenty- eight days before flexural and compressive tests were carried out. The analysis of the experimental results established that sample coded as S4, with 30% CF and 70% SP, showed the most promising result. This implied that particulate reinforcement in cement matrix composite contributed to higher and improved flexural load bearing capacity and ductility when utilised in a higher proportion than long fibres.
Table 6. Effects of experimental treatments on biomass of the six most abundant sown species in the 2009/10 census. Analyses were based on biomass harvests in autumn 2009 (over-canopy species) and spring 2010 (under-canopy species). Mixed model F- values and significance levels are given. Only model terms significant (P < 0.05) for at least one species are shown.
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In this work, an experimental study on the utilisation of sweet potato peels (PTPS), an abundantly available agricultural residue for the removal of Cd(II) ions from aqueous solution was carried out. The effect of a number of parameters such as pH, contact time and initial metal ion concentration on the loading of the metal ion onto the adsorbent were determined. The results showed that the loading of Cd(II) ions (mgg -1 ) increased with increase in initial metal ion concentration, time and pH and the optimised pH range for adsorption was from 6.5 to 7. The kinetics of Cd(II) ion removal indicated an optimum contact time of 180 minutes via a two stage kinetic uptake profile(initial fast and subsequent slow equilibrium). Kinetic modelling of Cd(II) ion adsorption was carried out using the pseudo first order (PFO), pseudo-second order (PSO) and intraparticle diffusion models. The PFO and PSO were evaluated using a non-linear optimization procedure and the PFO described the kinetics better than the PSO order model. The results from the intraparticle modelling suggest that intraparticle diffusion mechanism was not the only rate controlling step for the sorption Cd(II) ions by the PTPS adsorbent. The physico-chemical, elemental and spectroscopic properties of the PTPS residue adsorbent were determined and the results obtained from the spectroscopic analysis using (FTIR analysis and EDAX) indicates that ion-exchange and adsorption- complexation mechanism may be involved in the loading of the Cd(II) ions onto the PTPS adsorbent. The equilibrium sorption studies of Cd(II) ions were modelled using the Langmuir and Freundlich isotherms using a non-linear optimization approach and the experimental data was described better by the Langmuir model. This indicates that the monolayer adsorption capacity of the PTPS adsorbent was 18.9 mgg -1 , and a Langmuir constant of 5.21× 10 -3 lmg -1 at 25 ° C implying that the adsorbent was effective for Cd(II) ion removal from an aqueous system as well as natural water bodies and effluents. The results of this study highlights the potential of using an agricultural waste residue as an adsorbent for Cd(II) ion adsorption and has also enabled comparisons to be made with similar adsorbents based on waste biomass.
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ABSTRACT: Demand for renewable energy is increasing day by day. Need of renewable source of energy is important now a days. Renewable energy sources have lower impact on environment as compared to conventional energy sources. For renewable source of energy agricultural residues are required , they are large in quantity . The main ingredients of biomass briquettes are agricultural waste product ( ex . Paper pulp, plant leaves, sugarcane , wheat powder etc) . Briquettes are very cheap in price cause they are manufactured from agricultural waste product. We are substituting the product which has large environment impact and also which leads to high pollution. Our experimental work is to produce machine which uses product manufactured from agricultural waste which avoid pollution to the environment. Also biomass briquettes machine is small scale business in rural areas .
also found that elevated Co 2 increased plant growth and allocation to foliar secondary metabolites, and the responses to Co 2 were strongly enhanced by increasing light availability. agrell et al. (2000) also found that effects of enriched Co 2 were strongest in high light, which resulted in an average increase of 79% in starch content, compared to an average increase of 66% in low light on paper birch. But, opposite results were also found in some studies. osborne et al. (1997) demonstrated that the rela- tive Co 2 effects may be particularly large in deep shade because higher Co 2 concentrations reduce photorespiration and, thus, decrease the light com- pensation point of photosynthetic carbon uptake. in line with this, Bazzaz and Miao (1993) also found the relative Co 2 -stimulation of biomass production was increased at low light levels in temperate forest tree seedlings. our research did not find the similar uptrend as the above study, but light environment needs to be considered when species are ranked ac- cording to their responsiveness to Co 2 concentration (Kerstiens 2001) and this magnitude of changes may differ among tree species (agrell et al. 2000).
In 2009 the German funding programme for “ Promoting Projects to Optimise the Use of Biomass for Energy Production ” ("Biomass for Energy ” ) has started and fostered a wide range of projects to combine sustainable energy supply and climatic protection. Certain projects are described to give an idea of the wide range of projects and the different aspects of sustainability which are addressed. Additionally a first product for the planned quality assurance of the results via a dedicated method handbook is given.
furnace employs three distinct banks of burners, each composed of three secondary air inlets interposed by two primary air inlets. The highest of these banks also incorporates a close- coupled over-fire air (OFA) inlet above. The OFA is injected into the boiler to give an opposite rotational direction of the fireball, in the recirculation zone, compared to the other inlets. The three banks are present in the four corners, which come 64 inlets, although these are not all operated simultaneously under the firing conditions in this study. The system provides the means for air staging and a recirculation zone above the burners. The cases studied are summarised in Table 1. A baseline test of typical operation of the furnace, firing coal only (Case 0), was first performed. Thereafter a battery of coal mills, used to supply the top primary air conveyers, was given over to biomass processing at 12 or 24 t/h (3.33 or 6.67 kgs -1 ; Cases 1 and 2, respectively). For comparison, the system used for the wheat straw is capable of handling approximately 9kgs -1 of coal. In the separate injection method of co- firing the co-fired fuels are mixed only upon entrance to the boiler. It is important to note that the power station was designed to burn only coal and that no modifications have been made to the hardware, except the biomass storage and onsite handling. This represents a simple and cheap retrofit co-firing configuration for many similar furnace designs that have burners with dedicated upstream fuel systems.
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Simulations using the previously exposed set of pa- rameters led to craters as the one in Fig. 7. In accor- dance with experimental observations, damage follows in- terfaces as only targeted Z-fiber and the adjacent mesocon- stituant are concerned. It appears that the zone where the parameter D = 1 encompass all the experimental crater pro- file (Fig. 8) with D=1 corresponding to a damaged state. The damage variable used in the model is quite simple as it only considers two possible states. Therefore, it can- not take into account all the phenomena happening dur- ing the shock. Due to the microstructure of the material, the predamage state and the complexity of the mesoscale structure, damaged material is not totally pulverised nor intact and a precise meaning of damage is not obvious. Still, we got a model that overall reproduces the totality of the experimental results on a laser energy domain from 13.8 J to 36 J. Actually, area where D = 1 furnish lower and upper limit of the experimental crater. However, dif- ficulties were met to get a good estimation of the crater diameter at surface as initial state surface and predamage significantly influence the results. Nevertheless, damage
Risto V Filkoski et. al  applied a method for handling two phase reacting flow for prediction of pulverised coal combustion in large scale boiler furnace and to assess ability of model to predict existing power plant data. This paper presents principal steps and results of numerical modeling of furnace. The CFD/CTA approach was utilised for creation of three dimensional model, including platen super heater in upper part of furnace. Standard k epsilon model was employed for description of turbulent flow. Radiation heat transfer is computed by means of simplified P-N model. Simulation results concerning furnace walls, thermal efficiency and combustion efficiency shows good results corresponding with plant data.