Investigation on the Combustion Rate of Carbon Particle in Pressurized Oxygen-Enriched Conditions

2011 ◽  
Vol 354-355 ◽  
pp. 380-384
Author(s):  
Chun Bo Wang ◽  
Jin Gui Sheng ◽  
Ming Lei ◽  
Jian Guo Wei ◽  
Xiao Fei Ma
Keyword(s):  
Particle Size ◽  
Combustion Rate ◽  
Carbon Particle ◽  
Enriched Environment ◽  
Carbon Particles

The combustion rates of carbon particle in pressurized oxygen-enriched environment were studied. The combustion rates of different diameter carbon particles were calculated in atmospheric as well as pressurized oxygen-enriched conditions. The effects of pressure and particle size on combustion rate of carbon particle were investigated. It shows that the combustion rate of carbon particle rise with the increase of the pressures in pressurized oxygen-enriched and pressurized air conditions. But, the combustion rate of carbon particle change little at higher pressure. When particle size increased from 50μm to 100μm，the combustion rate of carbon particle rising. When the particle size increased to 150μm, the combustion rate of carbon particle changed little.

Effect of Carbon Particle Feeding as Radiant Absorbent for Enhanced Heat Transfer

2021 ◽  
pp. 1-15
Author(s):  
Hamed Abedini ◽  
Nesrin Ozalp
Keyword(s):  
Heat Transfer ◽  
Particle Size ◽  
Temperature Profile ◽  
Energy Absorption ◽  
Carbon Particle ◽  
Carbon Particles ◽  
Solar Reactor ◽  
Simulation Results ◽  
Particle Feeding ◽  
Solar Receiver

Abstract Carbon particles can be used as catalyst in solar reactors where they serve as radiant absorbent and nucleation sites for the heterogeneous decomposition reaction. Unlike commonly used metal catalysts, carbon catalyst does not have durability problem and high cost. However, in order to achieve sustainable catalytic decomposition of feedstock over carbon catalysts at elevated temperatures, the surface area of the carbon particles must be maintained. A subsequent treatment of deactivated carbon samples with CO2 at about 1000 °C would increase the surface and would recover the original activity as catalyst. In a windowed solar reactor, carbon particles are directly exposed to the high flux irradiation providing efficient radiation heat transfer directly to the reaction site. Therefore, one of the key parameters to achieve higher conversion efficiencies in a solar reactor is the presence and transport of carbon particles. In this paper, a transient one-dimensional model is presented to describe effect of carbon particle feeding on energy transport and temperature profile of a cavity-type solar receiver. The model was developed by dividing the receiver into several control volumes and formulating energy balance equations for gas phase, particles, and cavity walls within each control volume. Monte Carlo ray tracing (MCRT) method was used to determine the solar heat absorbed by particles and cavity walls, as well as the radiative exchange between particles and cavity walls. Model accuracy was verified by experimental work using a solar receiver where carbon particles were injected uniformly. Comparison of simulation results with the experimentally measured temperatures at three different locations on cavity receiver wall showed an average deviation of 3.81%. The model was then used to study the effect of carbon particle size and feeding rate on the heat transfer, temperature profile, and energy absorption of the solar receiver. Based on the simulation results, it was found that injection of carbon particles with a size bigger than 500 µm has no significant influence on heat transfer of the system. However, by reducing the particle size lower than 500 µm, temperature uniformity and energy absorption were enhanced.

An Investigation of the Distribution of Trihalomethanes Within GAC Contactors

1987 ◽  
Vol 22 (3) ◽  
pp. 412-426
Author(s):  
R.C. Andrews ◽  
P.M. Huck ◽  
L. Gammie
Keyword(s):  
Particle Size ◽  
Drinking Water ◽  
Activated Carbon ◽  
Organic Carbon ◽  
Total Organic Carbon ◽  
Carbon Particle ◽  
Pilot Scale ◽  
Carbon Particles ◽  
Enhanced Adsorption ◽  
Different Sources

Abstract This study examined the loading distribution of trihalomethanes and total organic carbon within pilot scale granular activated carbon (GAC) contactors receiving finished drinking water and operating in the downflow mode. Three carbons originating from different sources were used for this comparison. Observed column loadings were compared to isotherms. As well, loadings were evaluated as a function of carbon particle size. Significantly higher loadings of trihalomethanes were found in the upper 10 cm (7%) of the GAC beds. Enhanced adsorption in this region was correlated with finer size carbon particles. Isotherms successfully predicted full bed depth trihalomethane loadings for two of the carbons but underestimated loadings in the top 10 cm. A replacement of the top 30 cm of the carbon in one of the beds resulted in a noticeable capacity increase for trihalomethanes.

Interfacial Thermal Resistance Between a Carbon Nanoparticle and Molten Salt Eutectic: Effect of Material Properties, Particle Shapes and Sizes

2011 ◽  
Author(s):  
Byeongnam Jo ◽  
Debjyoti Banerjee
Keyword(s):  
Particle Size ◽  
Thermal Resistance ◽  
Molten Salt ◽  
Thermal Power ◽  
Carbon Particle ◽  
Interfacial Thermal Resistance ◽  
Graphite Sheet ◽  
Carbon Particles ◽  
Different Shapes ◽  
Particle Shapes

The aim of this study is to estimate the interfacial thermal resistance between a carbon nano-particle and alkali molten salt eutectics using molecular dynamics simulations. Additionally the effect of particle shapes and sizes on the interfacial thermal resistance was investigated using three different shapes of the carbon nanoparticles. Transient heat transfer simulation between a carbon particle and molecules of a molten salt was performed with the lumped capacitance method. A carbonate salt eutectic which consists of lithium carbonate (Li2CO3) and potassium carbonate (K2CO3) in 62:38 molar ratio was used as a solvent medium for the nanoparticles. Three carbon particles of a single walled carbon nanotube (SWNT), a fullerene (C60), and a graphite sheet were used to represent different shapes of cylinders, a spheres, and disks, respectively. The interfacial thermal resistance was determined by a correlation with a specific heat of the carbon particle, their surface area, and the time constant of decaying particle temperature. The results show the interfacial thermal resistance values are independent of the particle size for SWNT and graphite particles. For three carbon particles with a similar particle size, similar resistances were obtained in our simulations. The purpose of this study is to design and develop novel high-temperature Thermal Energy Storage (TES) materials in order to improve the operational efficiencies for harnessing solar thermal power at cheaper costs for Concentrated Solar Power (CSP) systems.

Study on Properties of Carbon Particle Modified Silicon Carbide Composite Ceramics

2011 ◽  
Vol 311-313 ◽  
pp. 276-282 ◽  
Author(s):  
You Jun Lu ◽  
Hong Fang Shen ◽  
Yan Ming Wang
Keyword(s):  
Silicon Carbide ◽  
High Temperature ◽  
Carbon Particle ◽  
Composite Ceramics ◽  
Carbon Particles ◽  
High Temperature Mechanical Properties ◽  
Sic Ceramics ◽  
Carbide Composite ◽  
Application Fields ◽  
Different Content

High-temperature mechanical properties, machinability, oxidation resistance and thermal shock resistance of different content of carbon particles modified silicon carbide composite ceramics (Cp/SiC) prepared by pressureless sintering techniques were studied. Adhesion of Cp/SiC to melted glass under 1000°C was also observed. The results showed that 15-Cp/SiC had the optimum machinability and it also did not adhere to melted glass at high temperature. And flexural strength, hardness, and fracture toughness of 15-Cp/SiC is 136.5MPa, 274.6kgf/mm2, 2.58MPa•m1/2 respectively. The good performance of Cp/SiC made it possible to be used as high temperature glass fixture, which means that Cp/SiC can not only improve the service life of fixture materials, but also broaden the application fields of SiC ceramics.

Proteins Induced Formation of Hydrothermal Nitrogen Doped Carbons

2009 ◽  
Vol 1219 ◽  
Author(s):  
Niki Baccile ◽  
Maria-Magdalena Titirici
Keyword(s):  
Particle Size ◽  
Carbon Source ◽  
Nitrogen Sources ◽  
Model Compounds ◽  
Nitrogen Doped ◽  
Carbon Particles ◽  
Structural Order ◽  
Different Types

AbstractThis contribution illustrates the synthesis of nitrogen-containing hydrothermal carbon particles from a mixture of glucose, as carbon source, and different types of proteins, as nitrogen sources. Casein, ovalbumin, hemoglobin and gelatin were chosen here as model compounds. The particle size and the level of structural order could be tuned according to the protein type and the amount utilized.

Effect of Carbon Particle Size and Content on the Mechanical and Thermal Properties of Recycled SLS Glass Composite

2016 ◽  
Vol 694 ◽  
pp. 34-38
Author(s):  
Zaleha Mustafa ◽  
Zurina Shamsudin ◽  
Radzali Othman ◽  
Nur Fashiha Sapari ◽  
Jariah Mohd Juoi ◽  
...  
Keyword(s):  
Particle Size ◽  
Thermal Properties ◽  
Average Pore Size ◽  
Carbon Particle ◽  
Physical And Mechanical Properties ◽  
Waste Glass ◽  
Mechanical And Thermal Properties ◽  
Glass Composite ◽  
Average Pore ◽  
Glass Composites

Glass-composite materials were prepared from the soda lime silicate (SLS) waste glass; ball clay and charcoal powder were fired to temperature of 850 °C as an effort for recycling waste glass. Various carbon contents, i.e., 1, 5, 10, 20 and 30 wt.% C were used to evaluate the effect of carbon contents on the hardness and thermal properties of glass composites. In addition, five different particles size (d0.5) of 1, 5, 20, 40 and 75 μm were used to observe the influence of particle size on the physical and mechanical properties of the glass composites. Phase analysis studies revealed the presence of quartz (ICDD: 00001-0649, 2θ = 25.6° and 35.6°), cristobalite (ICDD 00004-0379, 2θ = 22.0° and 38.4°) and wollastonite (ICDD 00002-0689, 2θ = 30.1° and 26.9°). The results showed that the optimised properties is at 1 wt.% of carbon content containing average pore size of 10 μm, with lowest porosity percentage of 1.76 %, highest Vickers microhardness of 4.6 GPa and minimum CTE. The percentage of porosity and hardness value also increased with reduction in carbon particle size.

Carbon Particle Generation and Preliminary Small Particle Heat Exchange Receiver Lab Scale Testing

2013 ◽  
Author(s):  
Lee Frederickson ◽  
Kyle Kitzmiller ◽  
Fletcher Miller
Keyword(s):  
High Temperature ◽  
Heat Exchange ◽  
Natural Gas ◽  
Small Particle ◽  
Carbon Particle ◽  
Solar Flux ◽  
Gas Mixture ◽  
Solar Simulator ◽  
Spherical Cap ◽  
Carbon Particles

High temperature central receivers are on the forefront of concentrating solar power research. Current receivers use liquid cooling and power steam cycles, but new receivers are being designed to power gas turbine engines within a power cycle while operating at a high efficiency. To address this, a lab-scale Small Particle Heat Exchange Receiver (SPHER), a high temperature solar receiver, was built and is currently undergoing testing at the San Diego State University’s (SDSU) Combustion and Solar Energy Laboratory. The final goal is to design, build, and test a full-scale SPHER that can absorb 5 MWth and eventually be used within a Brayton cycle. The SPHER utilizes air mixed with carbon particles generated in the Carbon Particle Generator (CPG) as an absorption medium for the concentrated solar flux. Natural gas and nitrogen are sent to the CPG where the natural gas undergoes pyrolysis to carbon particles and nitrogen is used as the carrier gas. The resulting particle-gas mixture flows out of the vessel and is met with dilution air, which flows to the SPHER. The lab-scale SPHER is an insulated steel vessel with a spherical cap quartz window. For simulating on-sun testing, a solar flux is produced by a solar simulator, which consists of a 15kWe xenon arc lamp, situated vertically, and an ellipsoidal reflector to obtain a focus at the plane of the receiver window. The solar simulator has been shown to produce an output of about 3.25 kWth within a 10 cm diameter aperture. Inside of the SPHER, the carbon particles in the inlet particle-gas mixture absorb radiation from the solar flux. The carbon particles heat the air and eventually oxidize to carbon dioxide, resulting in a clear outlet fluid stream. Since testing was initiated, there have been several changes to the system as we have learned more about the operation. A new extinction tube was designed and built to obtain more accurate mass loading data. Piping and insulation for the CPG and SPHER were improved based on observations between testing periods. The window flange and seal have been redesigned to incorporate window film cooling. These improvements have been made in order to achieve the lab scale SPHER design objective gas outlet flow of 650°C at 5 bar.

Research on Mechanism of Electrical Transport of Carbon Aerogels

2010 ◽  
Vol 160-162 ◽  
pp. 1378-1382
Author(s):  
Ya Ning Feng ◽  
Rong Yang ◽  
Li Ling Ge ◽  
Bai Ling Jiang ◽  
Masaki Tanemura ◽  
...  
Keyword(s):  
Electrical Conductivity ◽  
Particle Size ◽  
Electrical Transport ◽  
Electrode Materials ◽  
Carbon Particle ◽  
Carbon Aerogels ◽  
Nano Structure ◽  
Power Battery ◽  
Chemical Conditions ◽  
Structure Lead

To have a fundamental understanding on the principle of carbon aerogels when it is used as electrode materials in power battery, the effects of density and structural properties on the electrical conductivity of carbon aerogels was investigated in this paper. Carbon aerogels with different density were prepared via adjusting the chemical conditions of the primary solution. The morphology of carbon aerogels were observed by field emission scanning electron microscopy (FE-SEM). Experimental results show that the electrical conductivity of carbon aerogels is ranged from 10-6 Ω/cm to 10 Ω/cm, and that not only the density but also the carbon particle size and porosity of carbon aerogels effect the transport property greatly. With the increasing of the density the electrical conductivity of carbon aerogels increases. This indicates that larger particle size and lower porosity of the nano-structure lead to higher conductivity.

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