On the iron oxide neutral cluster distribution in the gas phase. I. Detection through 193 nm multiphoton ionization

2004 ◽  
Vol 120 (9) ◽  
pp. 4150-4156 ◽  
Author(s):  
D. N. Shin ◽  
Y. Matsuda ◽  
E. R. Bernstein
Keyword(s):  
Iron Oxide ◽  
Phase I ◽  
Gas Phase ◽  
Multiphoton Ionization ◽  
Neutral Cluster ◽  
Cluster Distribution ◽  
193 Nm

scholarly journals Water-cluster distribution with respect to pressure and temperature in the gas phase

1993 ◽  
Vol 48 (5) ◽  
pp. 3764-3770 ◽  
Author(s):  
Byung Jin Mhin ◽  
Sang Joo Lee ◽  
Kwang S. Kim
Keyword(s):  
Gas Phase ◽  
Water Cluster ◽  
Cluster Distribution

scholarly journals Experimental and ab initio studies of the reactive processes in gas phase i-C3H7Br and i-C3H7OH collisions with potassium ions

2014 ◽  
Vol 141 (16) ◽  
pp. 164310 ◽  
Author(s):  
E. López ◽  
J. M. Lucas ◽  
J. de Andrés ◽  
M. Albertí ◽  
J. M. Bofill ◽  
...  
Keyword(s):  
Phase I ◽  
Ab Initio ◽  
Gas Phase ◽  
Potassium Ions ◽  
Reactive Processes

Newly developed instrumentation for measuring highly oxidized molecules at atmospheric pressure

2021 ◽  
Author(s):  
Paap Koemets ◽  
Sander Mirme ◽  
Kuno Kooser ◽  
Heikki Junninen
Keyword(s):  
Gas Phase ◽  
Atmospheric Chemistry ◽  
Atmospheric Pressure ◽  
Chemical Ionization ◽  
Measurement Technology ◽  
Differential Mobility Analyzer ◽  
Neutral Cluster ◽  
Differential Mobility ◽  
Alpha Pinene ◽  
Ambient Measurements

<p>The Highly Oxidized Molecule Ion Spectrometer (HOMIS) is a novel instrument for measuring the total concentration of highly oxidized molecules (HOM-s) (Bianchi et al., 2019) at atmospheric pressure. The device combines a chemical ionization charger with a multi-channel differential mobility analyzer. The chemical ionization charger is based on the principles outlined by Eisele and Tanner (1993). The charger is attached to a parallel differential mobility analyzer identical to the ones used in the Neutral cluster and Air Ion Spectrometer (NAIS, Mirme 2011), but with modified sample and sheath air flow rates to improve the mobility resolution of the device. The complete mobility distribution in the range from 3.2 to 0.056 cm<sup>2</sup>/V/s is measured simultaneously by 25 electrometers. The range captures the charger ions, monomers, dimers, trimers but also extends far towards larger particles to possibly detect larger HOM-s that have not been measured with existing instrumentation. The maximum time resolution of the device is 1 second allowing it to detect rapid changes in the sample. The device has been designed to be easy to use, require little maintenance and work reliably in various environments during long term measurements.</p><p>First results of the prototype were acquired from laboratory experiments and ambient measurements. Experiments were conducted at the Laboratory of Environmental Physics, University of Tartu. The sample was drawn from a reaction chamber where alpha-pinene and ozone were introduced. Initial results show a good response when concentrations of alpha-pinene and ozone were changed. </p><p>Ambient measurements were conducted at the SMEAR Estonia measurement station in a hemiboreal forest for 10 days in the spring and two months in the winter of 2020. The HOMIS measurements were performed together with a CI-APi-TOF (Jokinen et al., 2012).</p><p> </p><p>References:</p><p>Bianchi, F., Kurtén, T., Riva, M., Mohr, C., Rissanen, M. P., Roldin, P., Berndt, T., Crounse, J. D., Wennberg, P. O., Mentel, T. F., Wildt, J., Junninen, H., Jokinen, T., Kulmala, M., Worsnop, D. R., Thornton, J. A., Donahue, N., Kjaergaard, H. G. and Ehn, M. (2019), “Highly Oxygenated Organic Molecules (HOM) from Gas-Phase Autoxidation Involving Peroxy Radicals: A Key Contributor to Atmospheric Aerosol”, Chemical Reviews, 119, 6, 3472–3509</p><p>Eisele, F. L., Tanner D. J. (1993), “Measurement of the gas phase concentration of H2SO4 and methane sulfonic acid and estimates of H2SO4 production and loss in the atmosphere”, JGR: Atmospheres, 98, 9001-9010</p><p>Jokinen T., Sipilä M., Junninen H., Ehn M., Lönn G., Hakala J., Petäjä T., Mauldin III R. L., Kulmala M., and Worsnop D. R. (2012), “Atmospheric sulphuric acid and neutral cluster measurements using CI-APi-TOF”, Atmospheric Chemistry and Physics, 12, 4117–4125</p><p>Mirme, S. (2011), “Development of nanometer aerosol measurement technology”, Doctoral thesis, University of Tartu</p>

Hydrogen Production via the Iron/Iron Oxide Looping Cycle

2011 ◽  
Author(s):  
A. Singh ◽  
F. Al-Raqom ◽  
J. Klausner ◽  
J. Petrasch
Keyword(s):  
Iron Oxide ◽  
Hydrogen Production ◽  
Gas Phase ◽  
Energy Content ◽  
Operation Conditions ◽  
Iron Oxide Reduction ◽  
Temperature Ranges ◽  
Iron Iron ◽  
Gas Phase Separation ◽  
Distinct Temperature

The iron/iron-oxide looping cycle has the potential to produce high purity hydrogen from coal or natural gas without the need for gas phase separation: Hydrogen is produced from steam oxidation of iron or Wustite yielding primarily Magnetite; Magnetite is then reduced back to iron/Wustite using syngas (CO+H2). A system model has been developed to identify favorable operation conditions and process configurations. Process configurations for three distinct temperature ranges, (i) 500–950 K, (ii) 950–1100 K, and (iii) 1100–1200 K have been developed. The energy content of high temperature syngas from conventional coal gasifiers is sufficient to drive the looping process throughout the temperature range considered. Temperatures around 1000 K are advantageous for both the hydrogen production step and the iron oxide reduction step. Simulations of a large number of subsequent cycles indicate that quasi-steady operation is reached after approximately 5 cycles. Comparison of simulations and experiments indicate that the process is currently limited by chemical kinetics at lower temperatures. Therefore, product recirculation should be used for a scaled-up process to increase reactant residence times while maintaining sufficient fluidization velocity.

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