scholarly journals Gas sensing technologies in combustion: A comprehensive review

2020 ◽  
Vol 10 (2) ◽  
pp. 103-110
Author(s):  
Ulrich Guth ◽  
Pavel Shuk ◽  
Chad McGuire
Keyword(s):  
Gas Sensing ◽  
Glass Production ◽  
Tunable Diode Laser ◽  
Chemical Plants ◽  
Combustion Gases ◽  
Diode Laser Spectroscopy ◽  
Intelligent Sensors ◽  
Paper Fabrication ◽  
Combustion Processes

Irrespective of the change in kind of energy to renewables there are many processes in which combustion of conventional fuels and biofuel are necessary. For cement and glass production, paper fabrication and air traffic it is absolutely essential to control the combustion processes by intelligent sensors in order to maximize the efficiency and to minimize the emission of harmful substances such as NOx and CO. Mainly oxygen sensors based on solid electrolytes and calorimetric sensors using the heat formation by catalytic combustion of CO and hydrocarbons with two resistance temperature detectors (RTD) are utilized. Recently, tunable diode laser spectroscopy (TDLS) became attractive in chemical plants. Several analytical companies are offering in-situ or extractive laser analyzers for combustion gases.

Gaseous Contaminant Measurement for Semiconductor Processing by Diode Laser Spectroscopy

1995 ◽  
Vol 38 (5) ◽  
pp. 22-29
Author(s):  
James McAndrew ◽  
Ronald Inman ◽  
Benjamin Jurcik
Keyword(s):  
Diode Laser ◽  
Fluid Dynamic ◽  
Air Separation ◽  
Tunable Diode Laser ◽  
Laser Absorption ◽  
Diode Laser Spectroscopy ◽  
Diode Laser Absorption ◽  
Gaseous Contaminant

Tunable diode laser absorption spectroscopy (TDLAS) is a novel tool for purity measurement in microelectronic process gases and environments. It is compatible with any matrix gas and extremely sensitive. This paper describes the application of a laboratory TDLAS instrument to measurement of CO, CO2, and H2O with sub-ppb sensitivity, including determination of a CO level of 0.35± 0.2 ppb in nitrogen samples from an air separation plant. Fluid dynamic simulation was used to optimize the design of the cell used for H20 measurements. TDLAS lends itself to the study of contamination sources in situ. As examples, measurements of CO generation in sampling vessels and of CO2 outgassing in an electropolished stainless steel chamber are briefly discussed.

scholarly journals In-situ laser spectroscopy of CO, Ch4, and H2O in a particle laden laboratory-scale fluidized bed combustor

2002 ◽  
Vol 6 (2) ◽  
pp. 13-27 ◽  
Author(s):  
Maximilian Lackner ◽  
Gerhard Totschnig ◽  
Gerhard Loeffler ◽  
Hermann Hofbauer ◽  
Franz Winter
Keyword(s):  
Laser Beam ◽  
Fluidized Bed ◽  
Diode Laser ◽  
Laser Spectroscopy ◽  
Tunable Diode Laser ◽  
Char Combustion ◽  
Diode Laser Spectroscopy ◽  
Fuel Particles ◽  
Fluidized Bed Combustor

The pyrolysis, devolatilization and char combustion of bituminous coal and biomass (beechwood, firwood) were investigated in a laboratory-scale fluidized bed combustor by tunable diode laser spectroscopy. Individual fuel particles were suspended in the freeboard of the unit. The bed temperature was 800 ?C, the oxygen partial pressure 0 to 20 kPa (0-10 vol.%). Two Fabry Perot type tunable near infrared diode lasers were deployed for quantitative in-situ species concentration measurements. CH4 and CO were measured simultaneously during devolatilization and char combustion in-situ 10 mm above the surface of the fuel particles as well as H2O using laser spectroscopy. Sand particles were passing the probing laser beam path. Besides the resonant absorption of the laser light by CO, CH4 and H2O severe and strongly transient non-resonant attenuation by partial blocking of the beam and beam steering effects occurred. By wavelength tuning the two laser sources, species concentrations could be determined. The measured absorbances had to be corrected for the real temperature measured at the position of the probing laser beam. In addition, CO, CO2 and O2 were determined ex-situ by con ventional methods. A spatial profile inside the FBC of major species (CH4, CO, CO2, O, H, OH) was calculated using a chemical kinetics program for a single fuel particle in a plug flow reactor geometry. The results were compared to the experimental findings. Good agreement was found. Tunable diode laser spectroscopy was found to be an apt method of determining quantitative species concentrations of multiple gases in a high temperature multi phase environment.

In Situ Growth of Metal–Organic Framework Thin Films with Gas Sensing and Molecule Storage Properties

Langmuir ◽  
2013 ◽  
Vol 29 (27) ◽  
pp. 8657-8664 ◽  
Author(s):  
Wei-Jin Li ◽  
Shui-Ying Gao ◽  
Tian-Fu Liu ◽  
Li-Wei Han ◽  
Zu-Jin Lin ◽  
...  
Keyword(s):  
Thin Films ◽  
Gas Sensing ◽  
Metal Organic Framework ◽  
In Situ Growth ◽  
Metal Organic ◽  
Storage Properties ◽  
Organic Framework

Measurements of CH 4 and N 2 O fluxes at the landscape scale using micrometeorological methods

1995 ◽  
Vol 351 (1696) ◽  
pp. 339-356 ◽  
Keyword(s):  
Eddy Covariance ◽  
Arable Land ◽  
Temperature Response ◽  
Mean Value ◽  
Tunable Diode Laser ◽  
Hudson Bay ◽  
Flux Footprint ◽  
Relaxed Eddy Accumulation ◽  
Diode Laser Spectroscopy ◽  
Emission Fluxes

Flux gradient, eddy covariance and relaxed eddy accumulation methods were applied to measure CH 4 and N 2 O emissions from peatlands and arable land respectively. Measurements of N 2 O emission by eddy covariance using tunable diode laser spectroscopy provided fluxes ranging from 2 to 60 µ mol N 2 O m -2 h -1 with a mean value of 22 µ mol N 2 O m -2 h -1 from 320 h of continuous measurements. Fluxes of CH 4 measured above peatland in Caithness (U.K.) during May and June 1993 by eddy covariance and relaxed eddy accumulation methods were in the range 70 to 120 µ mol CH 4 m -2 h -1 with means of 14.7 µ mol CH 4 m -2 h -1 and 22.7 µ mol CH 4 m -2 h -1 respectively. Emissions of CH 4 from peatland changed with water table depth and soil temperature; increasing from 25 |Amol CH 4 m -2 h -1 at 5% pool area to 50 p.mol CH 4 m -2 h -1 with 30% within the flux footprint occupied by pools. A temperature response of 4.9 (xmol CH 4 m -2 h -1 °C -1 in the range 6-12 °C was also observed. The close similarity in average CH 4 emission fluxes reported for wetlands in Caithness, Hudson Bay and Alaska in the range 11 to 40 jamol CH 4 m -2 h -1 suggests that earlier estimates of CH 4 emission from high latitude wetlands were too large or that the area of high latitudes contributing to CH 4 emission has been seriously underestimated.

Porous Iron Molybdate Nanorods: In situ Diffusion Synthesis and Low-Temperature H2S Gas Sensing

2013 ◽  
Vol 5 (8) ◽  
pp. 3267-3274 ◽  
Author(s):  
Yu-Jin Chen ◽  
Xin-Ming Gao ◽  
Xin-Peng Di ◽  
Qiu-Yun Ouyang ◽  
Peng Gao ◽  
...  
Keyword(s):  
Low Temperature ◽  
Gas Sensing ◽  
Porous Iron ◽  
Iron Molybdate ◽  
In Situ Diffusion
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