Detecting and Quantifying the Evolution of Hazardous Air Pollutants Produced During High Temperature Manufacturing: A Focus on Batching of Nitrate Containing GlassesEPA Grant Number: R828737C005
Subproject: this is subproject number 005 , established and managed by the Center Director under grant R830420
(EPA does not fund or establish subprojects; EPA awards and manages the overall grant for this center).
Center: Center for Environmental and Energy Research (CEER)
Center Director: Earl, David A.
Title: Detecting and Quantifying the Evolution of Hazardous Air Pollutants Produced During High Temperature Manufacturing: A Focus on Batching of Nitrate Containing Glasses
Investigators: Jones, Linda E. , Clare, Alexis G.
Institution: Alfred University
EPA Project Officer: Hahn, Intaek
Project Period: September 1, 2001 through August 31, 2003
RFA: Targeted Research Center (2000) Recipients Lists
Research Category: Targeted Research
Nitrogenoxide (NOx) emission from glass manufacturing presents a pollution concern. The sources of NOx emissions are thermal, prompt, fuel and in the case of glass, batch NOx. Batch NOx is the result of nitrate decomposition. The objective of this work is to accurately and sensitively identify and measure the concentrations of NOx, SOx, particulate and volatile alkali emissions in the effluent gas of a glass melt.
The investigators are developing the analytical technology necessary to accurately and sensitively measure air toxics produced during glass batching and melting of nitrate-containing glass. We are using a unique set of gas analysis tools in the form of combining Mass Spectroscopy and Fourier Transform Infrared Spectroscopy coupled to a high temperature thermodynamic calculations and thermogravimetric (TG/DSC) system. In the development of these tools and analytical techniques, they are investigating the mechanisms associated with the release of emissions during glass batching and melting of nitrate-containing glass compositions that are of critical importance for nuclear waste storage. They are focusing on the fining agent potassium nitrate.
Nitrates are deliberately added in glass batch as fining agents to lower the melting points, to decrease the viscosity of glass melts, and to act as strong oxidizing agents. However, even with all of these benefits, NOx emissions produced by nitrate decomposition from glass batch is an environmental problem. The on-going study addresses the mechanism connected with the decomposition of a common fining agent potassium nitrate.
This work addresses the complete sequential decomposition of potassium nitrate using TG/DSC experiments. The thermal calculation is performed using F*A*C*T (Facility for the Analysis of Chemical Thermodynamics) software package developed by A.D. Pelton and l’Ecole Polytechnique that employs Gibbs free energy minimization as the calculation method. The decomposition experiments are performed in a NETZSCH 409 CD TG/DSC system. It is coupled to a Fourier Transform Infrared (FTIR) for gas identification and quantification. Thermochemical calculations have identified the emission species and their dependence on temperature and processing atmosphere. The theoretical results agree quite well with the observations via thermochemical decomposition between room temperature and 1300°C.
Nitrate (NO3-) decomposes into the nitrite and evolves oxygen, then the nitrite undergoes two possible decomposition steps with solid oxide products. Nitrate may also decompose directly into oxide, peroxide, or superoxide. These reactions may occur simultaneously, consecutively, or overlap depending on the different experimental conditions.
There is remarkable commonality between the predicted chemistry and that observed experimentally. The sequence of supported decomposition events is as follows: (1) KNO3 in Ar undergoes an ordered KNO3 (s) to disordered KNO3 (s2) transition at 131.7 °C, ending at 144.2 °C; (2) KNO3 in Ar melts at 330.6 °C, ending at 339.7 °C; and (3) at 620. 2 °C, the KNO3 (s) begins to decompose. Decomposition ends at 872.9 °C.
FTIR spectra taken from the KNO3 decomposition in Ar at 500 °C, 700 °C, and 750 °C respectively, show that at 500 °C no NOx evolution occurs, at 700 °C, the emission includes NO (ν2 1876cm-1), NO2 (ν3 1621cm-1), and N2O (ν2 1299cm-1), and at 750 °C, NO2 has completely disappeared. This tells us that NO2 evolved only at the onset of the decomposition between 620 °C and 700°C.
Supplemental Keywords:NOx, SOx, alkali emissions, nitrates, nitrites, thermodynamic, thermogravimetric, glass melt effluent gas, mass spectroscopy, Fourier Transform Infrared Spectroscopy, FTIR, TG/DSC, thermochemical decomposition, potassium nitrate, Scientific Discipline, Air, air toxics, Environmental Chemistry, Air Pollutants, Environmental Monitoring, aerosol particles, mass spectrometry, gaseous effluent streams, Sox, air sampling, hazardous air pollutants (HAPs), nitrogen oxides (Nox), glass manufacturing
Progress and Final Reports:
Main Center Abstract and Reports:R830420 Center for Environmental and Energy Research (CEER)
Subprojects under this Center: (EPA does not fund or establish subprojects; EPA awards and manages the overall grant for this center).
R828737C001 Environmental Impact of Fuel Cell Power Generation Systems
R828737C002 Regional Economic and Material Flows
R828737C003 Visualizing Growth and Sustainability of Water Resources
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R828737C005 Detecting and Quantifying the Evolution of Hazardous Air Pollutants Produced During High Temperature Manufacturing: A Focus on Batching of Nitrate Containing Glasses
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R828737C009 Correlating Clay Mineralogy with Performance: Reducing Manufacturing Waste Through Improved Understanding
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R830420C002 Utilization of Paper Mill Waste in Ceramic Products
R830420C003 Development of Passive Humidity-Control Materials
R830420C004 Microarray System for Contaminated Water Analysis
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R830420C006 Interaction of Sealing Glasses with Metallic Interconnects in Solid Oxide and Polymer Fuel Cells
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