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Title: Fundamental mechanisms in flue gas conditioning. Quarterly report, January 1993--March 1993

Abstract

Our recent laboratory efforts were primarily directed toward the determination of the effects of adsorbed water on the tensile strength of powders and the development of apparatus for Experiment 3.5. As suggested by our literature review, our data indicate that water adsorption depends on particle morphology and on surface chemistry. Our measurements of tensile strength show that, for many of the samples we have analyzed, a relative minimum in tensile strength exists for samples conditioned and tested at about 30% relative humidity. Under Experiment 3.5, which began during this last quarter, we have been developing a system capable of conditioning selected samples with (NH{sub 4}){sub 2}SO{sub 4}, NH{sub 4}HSO{sub 4}CaCl{sub 2}, organosiloxane, and SO{sub 3}.

Authors:
;
Publication Date:
Research Org.:
Southern Research Inst., Birmingham, AL (United States)
Sponsoring Org.:
USDOE, Washington, DC (United States)
OSTI Identifier:
10164245
Report Number(s):
DOE/PC/90365-T10; SRI-ENV-93-350-7375-Q7
ON: DE93016928
DOE Contract Number:
AC22-91PC90365
Resource Type:
Technical Report
Resource Relation:
Other Information: PBD: 20 Apr 1993
Country of Publication:
United States
Language:
English
Subject:
01 COAL, LIGNITE, AND PEAT; 20 FOSSIL-FUELED POWER PLANTS; FLY ASH; SORPTIVE PROPERTIES; TENSILE PROPERTIES; SCANNING ELECTRON MICROSCOPY; PROGRESS REPORT; WATER; ADSORPTION; 010600; 200202; PROPERTIES AND COMPOSITION; NOXIOUS GAS AND PARTICULATE EMISSIONS

Citation Formats

Snyder, T.R., and Vann Bush, P. Fundamental mechanisms in flue gas conditioning. Quarterly report, January 1993--March 1993. United States: N. p., 1993. Web. doi:10.2172/10164245.
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Snyder, T.R., & Vann Bush, P. Fundamental mechanisms in flue gas conditioning. Quarterly report, January 1993--March 1993. United States. doi:10.2172/10164245.
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Snyder, T.R., and Vann Bush, P. Tue . "Fundamental mechanisms in flue gas conditioning. Quarterly report, January 1993--March 1993". United States. doi:10.2172/10164245. https://www.osti.gov/servlets/purl/10164245.
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@article{osti_10164245,
title = {Fundamental mechanisms in flue gas conditioning. Quarterly report, January 1993--March 1993},
author = {Snyder, T.R. and Vann Bush, P.},
abstractNote = {Our recent laboratory efforts were primarily directed toward the determination of the effects of adsorbed water on the tensile strength of powders and the development of apparatus for Experiment 3.5. As suggested by our literature review, our data indicate that water adsorption depends on particle morphology and on surface chemistry. Our measurements of tensile strength show that, for many of the samples we have analyzed, a relative minimum in tensile strength exists for samples conditioned and tested at about 30% relative humidity. Under Experiment 3.5, which began during this last quarter, we have been developing a system capable of conditioning selected samples with (NH{sub 4}){sub 2}SO{sub 4}, NH{sub 4}HSO{sub 4}CaCl{sub 2}, organosiloxane, and SO{sub 3}.},
doi = {10.2172/10164245},
journal = {},
number = ,
volume = ,
place = {United States},
year = {Tue Apr 20 00:00:00 EDT 1993},
month = {Tue Apr 20 00:00:00 EDT 1993}
}
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Technical Report:
View Technical Report (0.84 MB)
DOI:  10.2172/10164245
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  • This project is divided into four tasks. We developed our Management Plan in Task 1. Task 2, Evaluation of Mechanisms in FGD Sorbent and Ash Interactions, focused on characteristics of binary mixtures of these distinct powders. Task 3, Evaluation of Mechanisms in Conditioning Agents and Ash, was designed to examine effects of various conditioning agents on fine ash particles to determine mechanisms by which these agents alter physical properties of ash. We began Tasks 2 and 3 with an extensive literature search and assembly of existing theories. We completed this phase of the project with publication of two special Topicalmore » Reports. In our literature reviews reported in Topical Reports 1 and 2, we emphasized the roles adsorbed water can have in controlling bulk properties of powders. During the next phase of the project we analyzed a variety of fly ashes and fine powders in the laboratory. The experiments we performed were primarily designed to define the extent to which water affects key properties of ashes, powders, and mixtures of sorbents and ashes. We have recently completed a series of pilot-scale tests designed to determine the effects that adsorbed water has on fabric filtration and electrostatic precipitation of entrained fly ash particles in actual flue gas environments. Under Task 4 we will issue our Final Report that will summarize the results of our laboratory and pilot-scale work and will also include a model of flue gas conditioning. In addition to a few measurements performed on Bell Ayr Powder River Basin coal ash (ID No. 4118) collected during our most recent pilot-scale test, our efforts during this reporting quarter have been directed toward production of the Draft Final Report and the Flue Gas Conditioning Model.« less

  • ; ;
    This project is divided into four tasks. The Management Plan was developed in task 1. Task 2, Evaluation of Mechanisms in FGD Sorbent and Ash Interactions, focuses on the characteristics of binary mixtures of these distinct powders. Task 3, Evaluation of Mechanisms in Conditioning Agents and Ash, is designed to examine the effects of various conditioning agents on fine ash particles to determine the mechanisms by which these agents alter the physical properties of the ash. Tasks 2 and 3 began with an extensive literature search and the assembly of existing theories. This phase of the project is now complete.more » During the past quarter, initial preparations of laboratory equipment for laboratory testing have been made. A plan for initial laboratory tests has been submitted to the Project Manager for review. Laboratory testing will commence once these laboratory plans have been formally approved. The results of the work performed under task 2 and 3 will be included in a Flue Gas Conditioning Model that will be issued under task 4. The Final Report for the project will also be prepared under task 4.« less

  • We are currently performing a series of pilot-scale tests designed to determine the effects that adsorbed water has on fabric filtration and electrostatic precipitation of entrained fly ash particles in actual flue gas environments. We are investigating two key phenomena in our pilot-scale tests. The first is the ability of flue gas humidification to increase ash cohesivity through the creation of liquid bridges between particles collected in a fabric filter. Increasing cohesivity through the development of liquid bridges was demonstrated in our laboratory measurements of tensile strength and uncompacted bulk porosity, and in filtration studies performed for DOE/PETC under anmore » earlier contract. With the range of coals that will be fired in Southern Research Institute`s Coal Combustion Facility (CCF), filtration tests should verify how different fly ashes react to water conditioning in actual flue gas environments. The CCF provides a valuable test location for our studies. The second phenomenon we plan to study is the electrostatic reentrainment of previously collected ash particles in an ESP. We have prepared a small ESP for use in our pilot-scale tests. Our laboratory studies have shown the effects that relative humidity can have on the forces that hold the collected ash on the grounded ESP plate.« less

  • We are investigating two key phenomena in our pilot-scale tests. The first is the ability of flue gas humidification to increase ash cohesivity through the creation of liquid bridges between particles collected in a fabric filter. Increasing cohesivity through the development of liquid bridges was demonstrated in our laboratory measurements of tensile strength and uncompacted bulk porosity, and in filtration studies performed for DOE/PETC under an earlier contract. With the range of coals that will be fired in Southern Research Institute`s Coal Combustion Facility (CCF), filtration tests should verify how different fly ashes react to water conditioning in actual fluemore » gas environments. The CCF provides a valuable test location for our studies. We are drawing a slipstream of flue gas and entrained fly ash particles during several different CCF tests. During the first six months of 1994, the CCF will be burning (in fuel evaluation tests and corrosion tests) a number of different coals. The variety of coals that will be burned at the CCF represents a valuable opportunity to compare the effects of adsorbed water on the behavior of different types of fly ashes. The second phenomenon we plan to study is the electrostatic reentrainment of previously collected ash particles in an ESP. We have prepared a small ESP for use in these examinations. Our laboratory studies have shown the effects that relative humidity can have on the forces (resistivity, cohesivity, and tensile strength) that hold the collected ash on the grounded ESP plate. Our laboratory studies, literature review, and our review of field experiences indicated that severe reentrainment can occur when these three forces have been modified by changes in flue gas temperature and/or water content. Therefore we will be intentionally modifying these factors in order to induce this type of electrostatic reentrainment.« less

  • The experiments we have been performing are primarily designed to define the extent to which water affects key properties of ashes, powders, and mixtures of sorbents and ashes. We have included selected data from prior quarterly reports in this report for the sake of completeness, and for comparisons with newly-acquired data. In several places in this report samples are referred to by their identification (SID) numbers. Table I provides a brief description of all the samples we have used in this project along with their SID numbers. As suggested by our literature review, our data indicate that water adsorption dependsmore » on particle morphology and surface chemistry. Our recent laboratory efforts were primarily directed toward the determination of the effects of adsorbed water on the tensile and cohesive strengths of powders, the development of apparatus for SO{sub 3} and organosiloxane conditioning, and the conditioning of powders and ashes with organosiloxane.« less