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2000 Progress Report: RealTime, Ultrasensitive Measurement of Process Emissions for Pollution Prevention
EPA Grant Number: R826730Title: RealTime, Ultrasensitive Measurement of Process Emissions for Pollution Prevention
Investigators: Senkan, Selim M.
Institution: University of California - Los Angeles
EPA Project Officer: Karn, Barbara
Project Period: October 1, 1998 through September 30, 2001
Project Period Covered by this Report: October 1, 1999 through September 30, 2000
Project Amount: $350,000
RFA: Technology for a Sustainable Environment (1998)
Research Category: Pollution Prevention/Sustainable Development
Description:
Objective:Real time measurement of process emissions is important for undertaking rational pollution prevention and risk reduction strategies. The selective measurement of gaseous species at trace levels in a complex background mixture is a particular concern because many toxic pollutants are present at parts per trillion (ppt) to parts per million (ppm) levels in process effluents. Consequently, there is a growing need for the development of highly sensitive and selective techniques to continuously monitor the concentrations of a broad range of compounds. In this proposal we would like to exploit recent advances made in resonance enhanced multiphoton ionization (REMPI) and time of flight (TOF) mass spectrometry (MS) for the development of real time and ultrasensitive detection techniques to monitor a wide range of pollutant molecules in the gas phase. An important and challenging chemical reaction process where REMPI-TOF/MS should have a major impact is in combustion. The development of REMPI-TOF/MS technology to monitor emissions in harsh combustion conditions should readily be adaptable to chemical manufacturing processes, such as the catalytic cracking of petroleum and other catalytic processes, that operate under milder conditions. Progress Summary:
Progress has been made in several fronts. First, a high-temperature pulsed valve system has been designed and fabricated to feed gases into the TOF chamber at elevated temperatures. The valve system is constructed entirely from metal parts to ultimately operate at temperatures as high as 500?C, limited by the softening point of the plunger. To date, we have successfully used this valve to deliver polycyclic aromatic hydrocarbon (PAH) laden gases to the TOF-MS system at 350?C. However, although all-metal pulse valves can operate at higher temperatures than valves with plastic plungers, their operational life times are much shorter due to the mechanical wear of the plunger and/or the seat. Consequently, we are exploring different materials of construction to increase the operational life times of these high-temperature valves. Second, research on the application of REMPI to the real time detection of products of combustion as well as catalytic reactions also were pursued under the program. In the combustion area, earlier research involved the measurements of the concentrations of PAH in flames using GC/MS in order to quantify levels of these species for subsequent REMPI work. In catalytic reaction systems, we have used atmospheric pressure REMPI to determine reaction products in real time. Finally, we demonstrated the feasibility of using REMPI as a viable diagnostics tool in glow discharge plasmas. Future Activities:
We will continue our research program in assessing the applicability and limitations of REMPI as a real time, ultrasensitive diagnostics tool.
Journal Articles on this Report: 5 Displayed | Download in RIS Format
| Other project views: | All 6 publications | 6 publications in selected types | All 5 journal articles |
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Eastman JL, Coughenour MB, Pielke RA. The effects of grazing and CO2 at regional spatial and seasonal temporal scales using a dynamically-coupled meteorological and plant modeling system. Journal of Hydrometeorology 2000 (submitted for publication). |
R826730 (2000) R825412 (Final) |
not available |
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Olten N, Senkan SM. Formation of polycyclic aromatic hydrocarbons in an atmospheric pressure ethylene diffusion flame. Combustion and Flame, August 1999;118(3):500-507. |
R826730 (2000) R825412 (Final) |
not available |
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Olten N, Senkan SM. On-line measurements of the polycyclic aromatic hydrocarbons (PAH) in counter-flow ethylene diffusion flame. Combustion Science and Technology 2000;159():1-15 |
R826730 (2000) |
not available |
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Olten N, Senkan S. Effect of oxygen addition on polycyclic aromatic hydrocarbon formation in 1,3 butadiene counter-flow diffusion flames. Combustion and Flame 2001;125(1-2):1032-1039. |
R826730 (2000) R828193 (2002) R828193 (Final) |
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Senkan S, Ly A. Resonance enhanced multiphoton ionization as a diagnostic tool in glow discharge plasmas. Journal of Vacuum Science and Technology B 2000;8:1364-1368. |
R826730 (2000) |
not available |
resonance ionization, time of flight mass spectrometry, air toxics, pollution prevention. , Industry Sectors, Sustainable Industry/Business, Scientific Discipline, RFA, Technology for Sustainable Environment, Sustainable Environment, Manufacturing - NAIC 31-33, Environmental Engineering, Environmental Chemistry, mass spectrometry, cleaner production, hydrocarbons, hazardous emissions, real time measurement, risk reduction strategies, innovative technology, ultrasensitive measurement, chemical manufacturing, emission controls, pollution prevention, laser diagnostics
Relevant Websites:
http://www.seas.ucla.edu/~senkan
Progress and Final Reports:
Original Abstract