Selective Removal of Methanol from Humid Air Streams Using a Water-Vapor-Purged Membrane Separator

2001 ◽  
Vol 40 (12) ◽  
pp. 2685-2692
Author(s):  
Arto Klug ◽  
Peter H. Pfromm ◽  
Mary E. Rezac ◽  
Peter Czermak
Keyword(s):  
Water Vapor ◽  
Selective Removal ◽  
Humid Air ◽  
Membrane Separator ◽  
Air Streams

scholarly journals Accurate measurements of carbon monoxide in humid air using the cavity ring-down spectroscopy (CRDS) technique

2012 ◽  
Vol 5 (5) ◽  
pp. 6493-6517 ◽  
Author(s):  
H. Chen ◽  
A. Karion ◽  
C. W. Rella ◽  
J. Winderlich ◽  
C. Gerbig ◽  
...  
Keyword(s):  
Carbon Monoxide ◽  
Water Vapor ◽  
Near Infrared ◽  
Infrared Region ◽  
Humid Air ◽  
Cavity Ring Down Spectroscopy ◽  
Carbon Dioxide Co2 ◽  
Air Streams ◽  
Line Interference ◽  
Cavity Ring Down

Abstract. Accurate measurements of carbon monoxide (CO) in humid air have been made using the cavity ring-down spectroscopy (CRDS) technique. The measurements of CO mole fractions are determined from the strength of its spectral absorption in the near infrared region (∼1.57 μm) after removing interferences from adjacent carbon dioxide (CO2) and water vapor (H2O) absorption lines. Water correction functions that account for the dilution and pressure-broadening effects as well as absorption line interferences from adjacent CO2 and H2O lines have been derived for CO2 mole fractions between 360–390 ppm. The line interference corrections are independent of CO mole fractions. The dependence of the line interference correction on CO2 abundance is estimated to be approximately −0.3 ppb/100 ppm CO2 for dry mole fractions of CO. Comparisons of water correction functions from different analyzers of the same type show significant differences, making it necessary to perform instrument-specific water tests for each individual analyzer. The CRDS analyzer was flown on an aircraft in Alaska from April to November in 2011, and the accuracy of the CO measurements by the CRDS analyzer has been validated against discrete NOAA/ESRL flask sample measurements made on board the same aircraft, with a mean difference between integrated in situ and flask measurements of −0.6 ppb and a standard deviation of 2.8 ppb. Preliminary testing of CRDS instrumentation that employs new spectroscopic analysis (available since the beginning of 2012) indicates a smaller water vapor dependence than the models discussed here, but more work is necessary to fully validate the performance. The CRDS technique provides an accurate and low-maintenance method of monitoring the atmospheric dry mole fractions of CO in humid air streams.

scholarly journals Accurate measurements of carbon monoxide in humid air using the cavity ring-down spectroscopy (CRDS) technique

2013 ◽  
Vol 6 (4) ◽  
pp. 1031-1040 ◽  
Author(s):  
H. Chen ◽  
A. Karion ◽  
C. W. Rella ◽  
J. Winderlich ◽  
C. Gerbig ◽  
...  
Keyword(s):  
Carbon Monoxide ◽  
Water Vapor ◽  
Near Infrared ◽  
Infrared Region ◽  
Humid Air ◽  
Cavity Ring Down Spectroscopy ◽  
Carbon Dioxide Co2 ◽  
Air Streams ◽  
Line Interference ◽  
Cavity Ring Down

Abstract. Accurate measurements of carbon monoxide (CO) in humid air have been made using the cavity ring-down spectroscopy (CRDS) technique. The measurements of CO mole fractions are determined from the strength of its spectral absorption in the near-infrared region (~1.57 μm) after removing interferences from adjacent carbon dioxide (CO2) and water vapor (H2O) absorption lines. Water correction functions that account for the dilution and pressure-broadening effects as well as absorption line interferences from adjacent CO2 and H2O lines have been derived for CO2 mole fractions between 360–390 ppm and for reported H2O mole fractions between 0–4%. The line interference corrections are independent of CO mole fractions. The dependence of the line interference correction on CO2 abundance is estimated to be approximately −0.3 ppb/100 ppm CO2 for dry mole fractions of CO. Comparisons of water correction functions from different analyzers of the same type show significant differences, making it necessary to perform instrument-specific water tests for each individual analyzer. The CRDS analyzer was flown on an aircraft in Alaska from April to November in 2011, and the accuracy of the CO measurements by the CRDS analyzer has been validated against discrete NOAA/ESRL flask sample measurements made on board the same aircraft, with a mean difference between integrated in situ and flask measurements of −0.6 ppb and a standard deviation of 2.8 ppb. Preliminary testing of CRDS instrumentation that employs improved spectroscopic model functions for CO2, H2O, and CO to fit the raw spectral data (available since the beginning of 2012) indicates a smaller water vapor dependence than the models discussed here, but more work is necessary to fully validate the performance. The CRDS technique provides an accurate and low-maintenance method of monitoring the atmospheric dry mole fractions of CO in humid air streams.

Dynamic behavior of single glycerol droplets in humid air streams

Langmuir ◽  
1989 ◽  
Vol 5 (1) ◽  
pp. 133-140 ◽  
Author(s):  
A. K. Ray ◽  
R. D. Johnson ◽  
A. Souyri
Keyword(s):  
Dynamic Behavior ◽  
Humid Air ◽  
Air Streams

scholarly journals CO Gas-Induced Resonance Frequency Shift of ZnO-Functionalized Microcantilever in Humid Air

2017 ◽  
Vol 2017 ◽  
pp. 1-7 ◽  
Author(s):  
Lia Aprilia ◽  
Ratno Nuryadi ◽  
Dwi Gustiono ◽  
Nurmahmudi ◽  
Arief Udhiarto ◽  
...  
Keyword(s):  
Carbon Monoxide ◽  
Zinc Oxide ◽  
Water Vapor ◽  
Resonance Frequency ◽  
Frequency Shift ◽  
Hydrothermal Method ◽  
Gas Flow ◽  
Humid Air ◽  
Resonance Frequency Shift ◽  
Co Gas

Resonance frequency shift of a zinc oxide- (ZnO-) functionalized microcantilever as a response to carbon monoxide (CO) gas has been investigated. Here, ZnO microrods were grown on the microcantilever surface by a hydrothermal method. The measurement of resonance frequency of the microcantilever vibrations due to the gas was carried out in two conditions, that is, gas flow with and without air pumping into an experiment chamber. The results show that the resonance frequency of the ZnO-functionalized microcantilever decreases because of CO in air pumping condition, while it increases when CO is introduced without air pumping. Such change in the resonance frequency is influenced by water vapor condition, and a possible model based on water-CO combination was proposed.

scholarly journals Development and verification of an in-flow water condensation model for 3D-CFD simulations of humid air streams mixing

2018 ◽  
Vol 167 ◽  
pp. 158-165 ◽  
Author(s):  
J.R. Serrano ◽  
P. Piqueras ◽  
R. Navarro ◽  
D. Tarí ◽  
C.M. Meano
Keyword(s):  
Cfd Simulations ◽  
Humid Air ◽  
Water Condensation ◽  
Condensation Model ◽  
Air Streams

The Varieties of Scrubbers, Tubing, and Tubing Connectors

2018 ◽  
pp. 221-231
Author(s):  
John R. B. Lighton
Keyword(s):  
Carbon Dioxide ◽  
Water Vapor ◽  
Correct Selection ◽  
Flow Rates ◽  
Intended Application ◽  
Metabolic Measurement ◽  
Air Streams ◽  
Selection Of ◽  
Selective Membranes

This chapter discusses several often-neglected areas of respirometry infrastructure. These include the correct selection of scrubber chemicals for removing water vapor and/or carbon dioxide from air streams, without undesirable interactions; chemical-free scrubbing techniques such as selective membranes, thermal condensing systems, and mathematical correction for water vapor dilution; selecting tubing for metabolic measurement; evaluating the different tubing chemistries in light of the intended application; selecting appropriate tubing diameters for the flow rates that will be used; selecting tubing connectors; maintaining connector gender conventions to minimize plumbing confusion; and other related topics.

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