Carbochlorination of Fly Ash in a Fused Salt Slurry Reactor

1986 ◽  
Vol 86 ◽  
Author(s):  
M. S. Dobbins ◽  
G. Burnet
Keyword(s):  
Mass Transfer ◽  
Fly Ash ◽  
Gas Flow ◽  
Mixed Oxides ◽  
Batch Reactor ◽  
Coal Fly Ash ◽  
Pure Alumina ◽  
Higher Temperature ◽  
Liquid Mass Transfer ◽  
Temperature Oxide

ABSTRACTCarbochlorination of the metal oxides in fly ash by suspending the solid reactants in a NaCl-AlCl3 melt at 530–850°C and then sparging chlorine into the melt has been investigated. A mechanically agitated, semi-batch reactor was used to test the effects of temperature, oxide and carbon loading, salt composition and gas flow on the reaction rate. The process was modeled using the carbochlorination of pure alumina, the rate of which was found to be chemical reaction controlled at temperatures below about 650°C and gas-liquid mass transfer controlled at higher temperature. The carbochlorination rate of the mixed oxides in coal fly ash was also mass transfer controlled at higher temperatures when aluminum recoveries were less than about 50%. At higher aluminum recoveries, the overall rate was limited by the rate of ash dissolution into the melt.

Biofuel preparation from waste chicken fat using coal fly ash as a catalyst: Optimization and kinetics study in a batch reactor

2019 ◽  
Vol 7 (3) ◽  
pp. 103155 ◽  
Author(s):  
Phorndranrat Suchamalawong ◽  
Suthasinee Pengnarapat ◽  
Prasert Reubroycharoen ◽  
Tharapong Vitidsant
Keyword(s):  
Fly Ash ◽  
Batch Reactor ◽  
Coal Fly Ash ◽  
Kinetics Study ◽  
Chicken Fat

Utilization of Fly Ash with Higher Loss on Ignition for Geopolymer Mortar

2015 ◽  
Vol 1129 ◽  
pp. 614-620
Author(s):  
Yasutaka Sagawa ◽  
Shu Ota ◽  
Koji Harada ◽  
Takeyoshi Nishizaki ◽  
Hiroki Goda
Keyword(s):  
Compressive Strength ◽  
Fly Ash ◽  
Coal Fly Ash ◽  
Drying Shrinkage ◽  
Silicate Material ◽  
Loss On Ignition ◽  
Heat Curing ◽  
Higher Temperature ◽  
Curing Condition ◽  
Class F Fly Ash

In this study, utilization of coal fly ash with higher loss on ignition (LOI) for geopolymer mortar was investigated. The fly ash with approximately 9% of LOI was compared with Class F fly ash. Relationship between heat curing condition and strength was clarified. As the results, although compressive strength of geopolymer mortar with higher LOI was 30-50% smaller, it was available for geopolymer mortar as an alumina silicate material. The higher temperature and the longer period for initial curing, the higher strength was obtained. In order to decrease drying shrinkage, the higher temperature and the longer period for heat curing were required.

Effect of Gas Flow Rate on Degradation of 2,4-D with O3 and O3/H2O2

2012 ◽  
Vol 433-440 ◽  
pp. 221-226
Author(s):  
Lan Chen ◽  
Yu Heng Quan
Keyword(s):  
Hydrogen Peroxide ◽  
Mass Transfer ◽  
Production Rate ◽  
Flow Rate ◽  
Gas Flow ◽  
Batch Reactor ◽  
Gas Flow Rate ◽  
Transfer Condition ◽  
Flow Rates ◽  
2,4 Dichlorophenoxyacetic Acid

The effect of gas flow rate on degradation of chlorinated phenoxy acetic acids herbicide 2,4-D(2,4-dichlorophenoxyacetic acid) in aqueous solution with O3 or O 3/H 2O2 process was investigated in a bubbling semi-batch reactor. The experiments were conducted to study the degradation rate constant, mass transfer condition, ozone consumption and formation of byproduct hydrogen peroxide at different gas flow rates. The results show that gas flow rate is a complicated parameter in the process. The contact time of gas and liquid phase varies with different gas flow rate, consequently ozone mass transfer condition changes with different gas flow rates. The production rate of ozone, amount of ozone in the end gas and ozone consumption during the degradation with ozonation and O 3/H2O2 process vary with different of gas flow rates. Hydrogen peroxide is a byproduct during the ozonation or O3/H2O2 process of 2,4-D. The production rate of hydrogen peroxide is also affected by the gas flow rate. In general gas flow rate has both positive and negative effect on the 2,4-D degradation.

Time-Dependent Deposition Characteristics of Fine Coal Fly Ash in a Laboratory Gas Turbine Environment

2012 ◽  
Vol 135 (2) ◽  
Author(s):  
Robert G. Laycock ◽  
Thomas H. Fletcher
Keyword(s):  
Fly Ash ◽  
Surface Temperature ◽  
Gas Turbine ◽  
Gas Flow ◽  
Coal Fly Ash ◽  
Time Dependent ◽  
Gas Temperature ◽  
Brigham Young University ◽  
Fine Coal ◽  
Two Samples

Time-dependent deposition characteristics of fine coal fly ash were measured in the Turbine Accelerated Deposition Facility (TADF) at Brigham Young University. Two samples of subbituminous coal fly ash, with mass mean diameters of 3 μm and 13 μm, were entrained in a hot gas flow with a gas temperature of 1288 °C and Mach number of 0.25. A nickel-based, superalloy metal coupon approximately 0.3 cm thick was held in a hot particle-laden gas stream to simulate deposition in a gas turbine. Tests were conducted with deposition times of 20, 40, and 60 min. Capture efficiencies and surface roughness characteristics (e.g., Ra) were obtained at different times. Capture efficiency increased exponentially with time, while Ra increased linearly with time. The increased deposition with time caused the surface temperature of the deposit to increase. The increased surface temperature caused more softening, increasing the propensity for impacting particles to stick to the surface. These data are important for improving models of deposition in turbines from syngas flows.

Experimental Research for SO2 Absorption in Bubbling Stirring Reactor

2010 ◽  
Vol 113-116 ◽  
pp. 339-342
Author(s):  
Su Min Lu ◽  
You Guang Ma ◽  
Shu Hua Shen ◽  
Chun Ying Zhu
Keyword(s):  
Mass Transfer ◽  
Citric Acid ◽  
Removal Efficiency ◽  
Residence Time ◽  
Experimental Research ◽  
Gas Flow ◽  
Buffer Action ◽  
So2 Removal ◽  
Liquid Mass Transfer ◽  
So2 Absorption

The effect of different parameters on SO2 absorption was investigated in a semi-batchwise bubbling stirring reactor. From the experimental results, an increase of the gas flow, which substantially decreased the residence time of the gas in liquid, led to a quick reduce of the time of 100% removal efficiency of SO2. The addition of CaCO3 increased the removal efficiency of SO2 significantly. With increasing the concentration of CaCO3, the time of SO2=100% was almost increased linearly. The increase of the stirring speed prolonged the time of SO2=100% at first, but when beyond a certain value, no further effect of the stirring speed was observed, which showed that the mass transfer of SO2 in slurry was controlled by both gas and liquid mass transfer. Citric acid displays a good buffer action on SO2 absorption. The addition of citrate prolonged the time in which the SO2 removal efficiency remained high valves.

Toluene removal in a biofilm reactor for waste gas treatment

1997 ◽  
Vol 36 (1) ◽  
pp. 69-76 ◽  
Author(s):  
Anne R. Pedersen ◽  
Erik Arvin
Keyword(s):  
Mass Transfer ◽  
Gas Flow ◽  
Biofilm Reactor ◽  
Biological Degradation ◽  
Gas Treatment ◽  
Waste Gas ◽  
Filter Performance ◽  
Liquid Mass ◽  
Toluene Removal ◽  
Liquid Mass Transfer

A lab-scale trickling filter for treatment of toluene-containing waste gas was investigated. The filter performance was investigated for various loads of toluene. Two levels of the gas flow were examined, 322 m d−1 and 707 m d−1. The gas inlet concentrations were varied in the range from 0.6 to 4.0 g m−3. The toluene elimination increased linearly with increasing load, and at maximum load the elimination was 50 g m−3 h−1 (70% purification efficiency). This was in accordance with reported values for toluene removal in trickling filters. The removal was determined by the gas/liquid mass transfer and the biological degradation as well. An analytical model described the toluene removal as a half-order removal by use of two sets of parameters for the gas/liquid mass transfer and the biological degradation due to the two different gas flows. The mass transfer coefficients and the surface removal rates estimated by parameter fitting corresponded to previously observed values. The effect of the gas flow on the mass transfer coefficient and the biological removal rate may be explained by different flow patterns of the gas and the liquid phases. A characterisation of the biofilm showed an almost even biofilm growth over the filter height, which was in accordance with a constant liquid concentration throughout the column.

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