scholarly journals Study of The Biomass, Sand, and Biochar Fluidization in A Typical Bed of Fast Pyrolysis

2021 ◽  
Author(s):  
David Vasconcelos ◽  
José Ferreira Júnior ◽  
George Simonelli ◽  
Luiz Carlos Santos ◽  
Carlos Augusto de Moraes Pires
Keyword(s):  
Particle Size ◽  
Room Temperature ◽  
Fast Pyrolysis ◽  
Ternary Mixtures ◽  
Biomass Pyrolysis ◽  
Particle Segregation ◽  
New Correlation ◽  
Large Particles ◽  
Series Of Experiments ◽  
Biomass Transformation

Abstract Biomass pyrolysis usually occurs in a fluidized bed reactor formed by sand, biomass, and biochar. Dynamics this fluidization differs from that of literature because the biomass is converted continually in biochar. In this study, a series of experiments have been carried out for ternary mixtures of sand, sisal residue, and biochar, varying the compositions and particle size. The tests were based on two simplification hypotheses (steady state and room temperature) due to fast biomass transformation in bed and low Van der Waals force to large particles. The dynamic characteristics determined included the bed pressure drop and bed fluctuation. The single and combined effects of particle size and composition on the final fluidization velocity (Uff) and particle segregation (S) have been analyzed using response surface (RSM). The Uff and S minimum values were found when the variables were in the smallest particle size and composition levels. New correlations were developed for predicting the values of Uff. The error from measured values when using the new correlation was 7.6%, while the literature equation was 9.7%. The present correlations predicted reasonably well predicted the Uff of ternary mixtures in the fast pyrolysis bed.

The Behaviour of Recycled Material with Particles of Various Sizes of Polyamide 6 to Micro Hardness

2015 ◽  
Vol 662 ◽  
pp. 225-228
Author(s):  
Vojtech Senkerik ◽  
Michal Stanek ◽  
David Manas ◽  
Miroslav Manas ◽  
Adam Skrobak ◽  
...  
Keyword(s):  
Particle Size ◽  
Room Temperature ◽  
Size Variation ◽  
Polyamide 6 ◽  
Melting Rate ◽  
Dust Particles ◽  
Micro Hardness ◽  
Large Particles ◽  
Plastic Parts ◽  
Recycled Material

Every manufacture of any plastic parts produces some waste, such as defective injects or cold runner system from injection molding technology. This waste can be directly used several times. But when size of this material is reduced, particles of different sizes are made. From large particles similar to the original granulate material, to dust particles. This size variation can cause problems during subsequent processing. These particles of different size have distinct melting rate. That can cause an inhomogeneity of a melt and diverse structure of solidified polymer. This research paper studies the influence of the particle size of recycled polymeric material on the micro harness properties of semi-crystalline polyamide 6 at room temperature.

scholarly journals Leaching of Manganese from Marine Nodules at Room Temperature with the Use of Sulfuric Acid and the Addition of Tailings

Minerals ◽  
2019 ◽  
Vol 9 (5) ◽  
pp. 289 ◽  
Author(s):  
Norman Toro ◽  
Manuel Saldaña ◽  
Jonathan Castillo ◽  
Freddy Higuera ◽  
Roxana Acosta
Keyword(s):  
Particle Size ◽  
Sulfuric Acid ◽  
Room Temperature ◽  
Sulfuric Acid Concentration ◽  
Future Research ◽  
Independent Variables ◽  
Series Of Experiments ◽  
Optimization Methodology ◽  
Cost Efficient

Based on the results obtained from a previous study investigating the dissolution of Mn from marine nodules with the use of sulfuric acid and foundry slag, a second series of experiments was carried out using tailings produced from slag flotation. The proposed approach takes advantage of the Fe present in magnetite contained in these tailings and is believed to be cost-efficient. The surface optimization methodology was used to evaluate the independent variables of time, particle size, and sulfuric acid concentration in the Mn solution. Other tests evaluated the effect of agitation speed and the MnO2/Fe2O3 ratio in an acid medium. The highest Mn extraction rate of 77% was obtained with an MnO2/Fe2O3 ratio of 1/2 concentration of 1 mol/L of H2SO4, particle size of −47 + 38 μm, and 40 min of leaching. It is concluded that higher rates of Mn extraction were obtained when tailings instead of slag were used, while future research needs to focus on determination of the optimum Fe2O3/MnO2 ratio to improve dissolution of Mn from marine nodules.

A correlation to predict the performance characteristics of centrifugal pumps handling slurries

1997 ◽  
Vol 211 (2) ◽  
pp. 147-157 ◽  
Author(s):  
K A Kazim ◽  
B Maiti ◽  
P Chand
Keyword(s):  
Experimental Data ◽  
Particle Size ◽  
Suspended Solids ◽  
Reduction Factor ◽  
Performance Characteristics ◽  
Centrifugal Pumps ◽  
Pump Performance ◽  
New Correlation ◽  
Effect Of Particle Size ◽  
The Individual

Centrifugal pumps are being used increasingly for transportation of slurries through pipelines. To design a slurry handling system it is essential to have a knowledge of the effects of suspended solids on the pump performance. A new correlation to predict the head reduction factor for centrifugal pumps handling solids has been developed. This correlation takes into account the individual effect of particle size, particle size distribution, specific gravity and concentration of solids on the centrifugal pump performance characteristics. The range of validity of the correlation has been verified by experiment and by using experimental data available from the literature. The present correlation shows better agreement with the experimental data than existing correlations.

Investigation on the arc erosion behavior of new silver matrix composites: Part I. Reinforced by particles

2003 ◽  
Vol 18 (4) ◽  
pp. 804-816 ◽  
Author(s):  
Shou-Yi Chang ◽  
Chia-Jung Hsu ◽  
Cher-Hao Hsu ◽  
Su-Jien Lin
Keyword(s):  
Particle Size ◽  
Erosion Resistance ◽  
High Viscosity ◽  
Matrix Composites ◽  
Particle Content ◽  
Arc Erosion ◽  
Erosion Behavior ◽  
Surface Areas ◽  
Large Particles ◽  
Silver Matrix

Static-gap, single-spark tests were used to investigate the arc erosion behavior of newly developed silicon carbide and alumina particle reinforced silver matrix composites (SiCp/Ag, Al2O3p/Ag). Craters and hills exist on the surfaces of eroded silver matrix composites, and their depths and sizes decrease as the particle content increases and the particle size decreases. Obvious melting, flow, severe splash of molten silver, and the segregation of particles are present on the surfaces of eroded composites containing low volume percents of large particles. Easier silver flow results in smooth surfaces and reduces the total surface areas of the eroded composites containing large particles. The flow and splash of silver decreased with increasing particle content and decreasing particle size, exhibiting a better erosion resistance to single-spark tests. The static-gap, single-spark erosion behavior of silver matrix composites is dominated by the flow and splash of molten composites. A high viscosity of the liquids provides the composites a good arc erosion resistance.

scholarly journals Carbon-supported Platinum Electrocatalysts probed in a Gas Diffusion Setup with Alkaline Environment: how Particle Size and Mesoscopic Environment influence the Degradation Mechanism

2020 ◽  
Author(s):  
Shima Alinejad ◽  
Jonathan Quinson ◽  
Johanna Schröder ◽  
Jacob J. K. Kirkensgaard ◽  
Matthias Arenz
Keyword(s):  
Particle Size ◽  
Degradation Mechanism ◽  
Active Phase ◽  
Active Surface ◽  
Carbon Support ◽  
Gas Diffusion ◽  
Active Surface Area ◽  
Electrochemical Cells ◽  
Co Stripping ◽  
Large Particles

In this work, we investigate the stability of four different types of Pt/C fuel cell catalysts upon applying accelerated degradation tests (ADTs) in a gas diffusion electrode (GDE) setup equipped with an anion exchange membrane (AEM). In contrast to previous investigations exposing the catalysts to liquid electrolyte, the GDE setup provides a realistic three-phase boundary of the reactant gas, catalyst and ionomer which enables reactant transport rates close to real fuel cells. Therefore, the GDE setup mimics the degradation of the catalyst under more realistic reaction conditions as compared to conventional electrochemical cells. Combining the determination of the loss in electrochemically active surface area (ECSA) of the Pt/C catalysts via CO stripping measurements with the change in particle size distribution determined by small-angle X-ray scattering (SAXS) measurements, we demonstrate that i) the degradation mechanism depends on the investigated Pt/C catalyst and might indeed be different to the one observed in conventional electrochemical cells, ii) degradation is increased in an oxygen gas atmosphere (as compared to an inert atmosphere), and iii) the observed degradation mechanism depends on the mesoscopic environment of the active phase. The measurements indicate an increased particle growth if small and large particles are immobilized next to each other on the same carbon support flakes as compared to a simple mix of two catalysts with small and large particles, respectively.

scholarly journals THE EFFECT OF CAVITATION TREATMENT ON THE EXTINGUISHING OF PARTICLES OF OILS IN FUEL BOILERS

2019 ◽  
Vol 20 (9-10) ◽  
pp. 52-59
Author(s):  
M. A. Taymarov ◽  
R. V. Akhmetova ◽  
S. M. Margulis ◽  
L. I. Kasimova
Keyword(s):  
Particle Size ◽  
Combustion Zone ◽  
Consumption Rate ◽  
Fuel Oil ◽  
Particle Sizes ◽  
Oil Consumption ◽  
Boiler Efficiency ◽  
Large Particles ◽  
Oil Particles

The difficulties of burning the watered fuel oil used at the TPP as a reserve fuel for boilers are associated with its preparation by heating to reduce viscosity and the choice of a method of spraying with nozzles into the combustion zone. The quality of the preparation of fuel oil for combustion affecting the boiler efficiency is estimated by the length of the flame, the presence of burning large particles of fuel oil, the injection of coke and unburned particles onto screen and other heat-receiving surfaces. One of the ways to prepare fuel oil for combustion is cavitation treatment, which results in an emulsion consisting of fine micronsized particles. Heating of fuel oil particles after the nozzle in contact with the combustion zone is due to the flow of radiation from the burning torch. Therefore, in this article, the values of the flux density from the torch during the combustion of fuel oil are experimentally determined. The influence of particle size on the burning rate of the fuel oil M100 with the different density of the thermal radiation of the flame. It is found that the effect of cavitation treatment of fuel oil on the combustion rate is most significantly manifested in particle sizes less than 10 microns. For this purpose, the use of hydrodynamic cavitators are preferred at high fuel oil consumption rate.

Sintering of Silver Nanoparticles at Room-Temperature for Conductive Ink Applications

2018 ◽  
Vol 775 ◽  
pp. 144-148 ◽  
Author(s):  
Bethel Faith Y. Rezaga ◽  
Mary Donnabelle L. Balela
Keyword(s):  
Particle Size ◽  
Ag Nanoparticles ◽  
Room Temperature ◽  
Average Diameter ◽  
Aqueous System ◽  
Ag Nanoparticle ◽  
Nacl Solution ◽  
Cellulose Acetate Film ◽  
Sintered Ag ◽  
Nanoparticle Ink

Silver (Ag) nanoparticles synthesized in an aqueous system was sintered at room temperature using NaCl solution. The Ag nanoparticles have an average diameter of about 24 nm. After dispersing the Ag nanoparticles in 50mM NaCl solution, a significant increase in particle size to about 206 nm was observed. On the other hand, the particle size was also increased to about 175 nm when the Ag nanoparticles were printed and then 50mM NaCl solution was dropped onto the printed Ag nanoparticles. The enlargement of particle size was accompanied by the increase in conductivity of the Ag nanoparticle ink. The resistance was reduced from 57.7 to 6.5 and 6.7 ohms for the as-prepared and sintered Ag nanoparticles using two different treatments, respectively. The sintered Ag nanoparticle ink formulation exhibit high conductivity when drawn on both cellulose acetate film and bond paper even after bending and folding of the substrates.

NANOEMULSIONS BASED ON LIPOIC ACID DERIVATIVES WITH VARIOUS ALCOHOLS: PRODUCTION AND INFLUENCE ON FUNCTIONAL ACTIVITY OF PLATELETS

2020 ◽  
pp. 461-464
Author(s):  
A. Sinebryukhova ◽  
A. Shipelova ◽  
E. Darnotuk ◽  
A. Chekanov ◽  
O. Baranova ◽  
...  
Keyword(s):  
Particle Size ◽  
Arachidonic Acid ◽  
Lipoic Acid ◽  
Encapsulation Efficiency ◽  
Room Temperature ◽  
Optimal Conditions ◽  
Pluronic F68 ◽  
Long Term Storage ◽  
Term Storage

The optimal conditions were selected for obtaining homogeneous nanoemulsions (NE) of lipoic acid conjugates (LA-conjugates) based on Pluronic F68 (1,8%) with a particle size not exceeding 400 nm, characterized by 97±2% encapsulation efficiency of substances in nanoparticles (NP). A heterogeneous NE (polydispersity index, PDI>0,3) with the derivative of LA and myo-inositol based on phosphatidylcholine (PC, C = 3 mg/ml) was also obtained consisting of 2 particle fractions: 20–70 nm (27%) and 122–212 nm (73%). The obtained NEs with LA-conjugates based on Pluronic F68 and PC were stable during long-term storage (more than 12 months) at room temperature. The effect of the obtained NEs of LA-conjugates on platelet aggregation (Pt) caused by arachidonic acid (AA) was determined, and a mechanism of their action was proposed.

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