Control of metal radial profiles in alumina supports by carbon dioxide

In this work, mathematical models of carbon dioxide (CO2) absorption by monoethanolamine amine (MEA) in a falling film contactor are developed. The proposed models aim to predict conversion of the gas–liquid reaction along the contactor, gas–liquid interface temperature profile (axial and radial), liquid film thickness along the contactor length, axial and radial concentration profiles of reactants in liquid film, and axial and radial profiles of velocity in the liquid film. A code written in MatLab was used to obtain these profiles based on multi grid method through programming of kinetic and thermodynamic equations and physical properties of the absorption system. The mathematical model is validated by an experimental measurement based on absorption of CO2 gas by MEA solution. Four parameters are studied as independent variables namely, mole fraction of carbon dioxide in gaseous mixture, molar concentration of absorbent (MEA, volumetric flow rate of MEA, and its temperature. It is found that the entrance effect of the falling film contactor is related to axial distance from the contactor entrance exponentially: E=B0exp(−B1y) An optimization technique based on minimization of the sum of the squared error between the experimental and predicted composition of absorption process is used to obtain B0 and B1. It is found that reaction between carbon dioxide and MEA is instantaneous, and the axial conversion of carbon dioxide in the gas phase varies exponentially with the contactor length.

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Spatial Emission Characteristics of a Capillary-Burner Excitation Source for a Flame Infrared Emission (FIRE) Radiometer

Applied Spectroscopy ◽

10.1366/0003702914335102 ◽

1991 ◽

Vol 45 (10) ◽

pp. 1684-1694 ◽

Cited By ~ 4

Author(s):

S. Ravishankar ◽

David C. Tilotta ◽

Kenneth W. Busch ◽

Marianna A. Busch

Keyword(s):

Carbon Dioxide ◽

Carbon Number ◽

Vertical Axis ◽

Infrared Emission ◽

Aliphatic Hydrocarbons ◽

Number Density ◽

Particulate Carbon ◽

Complete Mapping ◽

Diffusion Controlled ◽

Radial Profiles

A complete mapping of the lateral and radial intensities of the 4.4- μm emission (antisymmetric CO2 stretch) resulting from the direct introduction of carbon dioxide, a homologous series of aliphatic hydrocarbons, and benzene into a hydrogen/air combustion flame supported on a capillary burner has been carried out. Both concentrated (99% methane, ethane, propane, and butane) and dilute (1% methane, ethane, propane, and benzene) hydrocarbons were studied. Flame profiles produced by the introduction of carbon dioxide were used to indicate the effects of local variations in source temperature and carbon dioxide number density in the absence of combustion. The radial profiles produced by the introduction of carbon dioxide and the hydrocarbons revealed a considerable amount of off-axis emission, believed to result from a zone of low temperature along the central vertical axis of the burner. Combustion of analyte appeared to be a diffusion-controlled process. For aliphatic hydrocarbons, combustion produced nearly quantitative amounts of carbon dioxide, provided the flame was not overloaded. For benzene, combustion produced particulate carbon, and the resulting blackbody emission was not strictly related to analyte concentration or carbon number. Blackbody emission may also result from the incomplete combustion of longer chain aliphatic hydrocarbons (propane and butane), if the burner is overloaded.

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Flame Structure and Pollutant Emission Characteristics of a Burning Kerosene Spray With Injection of Diluents

Journal of Energy Resources Technology ◽

10.1115/1.2905943 ◽

1992 ◽

Vol 114 (3) ◽

pp. 209-215 ◽

Cited By ~ 4

Author(s):

S. R. Gollahalli ◽

R. Puri

Keyword(s):

Nitric Oxide ◽

Carbon Dioxide ◽

Carbon Monoxide ◽

Flame Structure ◽

Flame Length ◽

Pollutant Emissions ◽

Pollutant Emission ◽

Radiation Emission ◽

Radial Temperature ◽

Radial Profiles

An experimental study of the effects of diluent gas injection on the structure and pollutant emissions of a kerosene spray from a twin fluid atomizer is presented. Nitrogen and carbon dioxide were used as the diluents. Flame length, radiation emission, axial and radial temperature profiles, and the radial profiles of carbon monoxide, oxygen, nitric oxide, and soot in flame gas samples were studied. The emission index, defined as the mass ratio of the rate of the species emitted to the fuel input rate, was determined from the experimental data. Results show, at a diluent injection rate approximately equal to the atomizing air flow rate, nitrogen was more effective than carbon dioxide in reducing flame length, flame radiation, and the emission indices of carbon monoxide and soot. Although both diluents increased nitric oxide emission, the effect of carbon dioxide was weaker.

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Electron Cytochemical Study of Carbon Dioxide Laser Effect on Rhesus Monkey Cornea

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s042482010005113x ◽

1974 ◽

Vol 32 ◽

pp. 224-225

Author(s):

K. C. Tsou ◽

J. Morris ◽

P. Shawaluk ◽

B. Stuck ◽

E. Beatrice

Keyword(s):

Carbon Dioxide ◽

Electron Microscope ◽

Rhesus Monkey ◽

Carbon Dioxide Laser ◽

Cytochemical Study ◽

Laser Effect

While much is known regarding the effect of lasers on the retina, little study has been done on the effect of lasers on cornea, because of the limitation of the size of the material. Using a combination of electron microscope and several newly developed cytochemical methods, the effect of laser can now be studied on eye for the purpose of correlating functional and morphological damage. The present paper illustrates such study with CO2 laser on Rhesus monkey.

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The Critical Point Drying Method Applied to Scanning Electron Microscopy of L-929 Cells

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100068382 ◽

1970 ◽

Vol 28 ◽

pp. 278-279

Author(s):

Charles TurnbiLL ◽

Delbert E. Philpott

Keyword(s):

Electron Microscopy ◽

Carbon Dioxide ◽

Surface Tension ◽

Critical Point ◽

Freeze Drying ◽

Attractive Alternative ◽

Crystal Formation ◽

Critical Point Drying ◽

Time Required ◽

Scanning Electron

The advent of the scanning electron microscope (SCEM) has renewed interest in preparing specimens by avoiding the forces of surface tension. The present method of freeze drying by Boyde and Barger (1969) and Small and Marszalek (1969) does prevent surface tension but ice crystal formation and time required for pumping out the specimen to dryness has discouraged us. We believe an attractive alternative to freeze drying is the critical point method originated by Anderson (1951; for electron microscopy. He avoided surface tension effects during drying by first exchanging the specimen water with alcohol, amy L acetate and then with carbon dioxide. He then selected a specific temperature (36.5°C) and pressure (72 Atm.) at which carbon dioxide would pass from the liquid to the gaseous phase without the effect of surface tension This combination of temperature and, pressure is known as the "critical point" of the Liquid.

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