&lt;title&gt;Jet-REMPI for process control in incineration&lt;/title&gt;

Oser, Harald; Thanner, R.; Grotheer, Horst-Henning; Walter, Robert A.; Richers, U.; Merz, Albert R.

doi:10.1117/12.274771

Cited by 14 publications

(15 citation statements)

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“…However, it is possible to increase the ionization and detection efficiencies, to 100 % in the extreme case, for analyte molecules within a detection volume in multiphoton ionization/mass spectrometry. The best detection limit reported so far is 3 pmol/mol for benzene, and the linear relationship between signal and concentration extends over almost six orders of magnitude [23]. Similar results are obtained for toluene and naphthalene.…”

Section: Sensitivitysupporting

confidence: 76%

Critical assessment: Use of supersonic jet spectrometry for complex mixture analysis (IUPAC Technical Report)

Imasaka¹,

Moore²,

Vo‐Dinh³

2003

Pure and Applied Chemistry

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Republication or reproduction of this report or its storage and/or dissemination by electronic means is permitted without theAbstract: When cooled to a temperature of a few K using supersonic jet expansion into a vacuum, a molecule exists in the lowest vibrational level of the ground electronic state and is isolated at collision-free conditions. The absorption or excitation/fluorescence spectrum is then greatly simplified, when transitions occur from this single vibrational level to a limited number of vibrational levels in the excited electronic state. This method, called supersonic jet spectrometry, is a powerful analytical technique because of its high selectivity, since the chemical species can be accurately identified and selectively quantified using the sharp spectral features even for large molecules. Supersonic jet spectrometry has distinct advantages over other low-temperature spectrometries, in that it can be combined with gas-phase separation and detection techniques such as chromatography or mass spectrometry. Therefore, this spectrometric technique can be used as a versatile analytical means, not only for basic research on pure substances, but also for practical trace analysis of chemical species in multicomponent samples (e.g., in biological monitoring or in environmental monitoring).

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Section: Sensitivitysupporting

confidence: 76%

Critical assessment: Use of supersonic jet spectrometry for complex mixture analysis (IUPAC Technical Report)

Imasaka¹,

Moore²,

Vo‐Dinh³

2003

Pure and Applied Chemistry

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“…[3][4][5][6][7][8] Laser ionization utilizes the resonanceenhanced multi-photon ionization (REMPI) method, which features molecular selectivity and enables fragment-free ionization. [3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18][19][20][21][22] The authors of the present report have developed an online monitoring method using ultrasonic jet-type laser ionization TOFMS (time of flight mass spectrometry), and have confirmed the usefulness of this method with respect to PCBs. 8 Because an extremely large number of molecules exist in environmental gas, the requirement is for a method that is for relatively large molecular selectivity in a short time, so as to enable the rapid analysis of trace concentrations.…”

Section: Introductionmentioning

confidence: 76%

Rapid Analysis of Polychlorinated Biphenyls in the Gas Phase with Resonance-enhanced Two-photon Ionization: Optimal Injection of Ions into the Ion-trap Storage/Time-of-flight Mass Spectrometer

et al. 2005

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“…To heat the inlet valve does not only result in starting from a higher initial temperature, it also reduces the cooling effect of the adiabatic expansion through a change of the Knudsen number leading to a higher end temperature. The same situation is met when TCDDs are sampled and the valve is heated to avoid their condensation (see [18]). These problems can only be overcome by a complete redesign of the inlet system.…”

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confidence: 95%

“…From the earlier literature [17], however, it was known that for a certain degree of chlorination the use of (1 + 1) REMPI would become impossible for PCDDs. We could show [18] that 2,3,7,8-TCDD and other isomers can indeed be measured with one-color REMPI and this was the first time that Seveso' dioxin was measured using REMPI.With regard to the second question, we used 2,7-DCDD as a model substance (see also [16]). The spectra in Fig.…”

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confidence: 99%

DLR-Jet REMPI - Ultrasensitive Monitor for Process Control in Thermal Processes

Oser¹,

Thanner²,

Grotheer³

1998

Chem. Eng. Technol.

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Process control requires sensitive and selective on-line monitors for species concentrations. This applies in particular if feeds of varying compositions are involved. Current REMPI (= Resonance Enhanced Multiphoton Ionization) mass spectrometers would be suitable instruments in terms of selectivity and on-line capability, their sensitivities, however, are generally too low. By contrast, the DLR-Jet REMPI geometry provides a major sensitivity improvement. An extended test series shows that this is achieved without paying a price in terms of selevtivity. The paper provides some of these results and lists up the development steps needed to make Jet REMPI an instrument suitable for industrial use. Process Optimization and Control for Emission AbatementCurrent pollutant abatement technologies for thermal plants have mostly been developed in the context of incineration. Air pollutant cleaning devices (APCs) consist of wet or dry scrubbers, beds of activated carbon or catalytic converters. They are generally simply added to the primary process in order to trap or destroy pollutants formed there. Hence, they are called end-of-the-pipe techniques. The complementary approach is given by head-end techniques aiming at the reduction of pollutant formation. This can be accomplished by optimizing the process through carefully tailoring its design and operation parameters. With hydrocarbon flames, chemical kinetic models and models dealing with transport of heat and matter are now sufficiently accurate to enable such tailoring. In incineration, however, kinetic mechanisms are still poorly understood so that modeling is widely replaced by empirism.The other problem quite often involved in incineration is that the composition of the feed is subject to rapid changes. This requires that such an optimization has to be based on time-resolved concentration measurements of relevant species in the process gas. With a suitable computer program, these signals can be used to drive control means (e.g., air distribution flaps) so as to continuously optimize the process. This type of process control could not be carried out in the past for lack of sufficiently sensitive monitors.Some examples are given to illustrate the present situation. One of the very rare exceptions from the more current end-of-the-pipe technologies in incineration has been presented recently in Japan [1]. In an attempt to reduce NO emissions the re-burn technology, which has been developed for hydrocarbon combustors, was adopted to an incinerator. To this end, a re-burn zone was established above the grate using an additional natural gas burner. It was found that this technique not only diminished the NO release but also led to a significant reduction of dioxins as measured further downstream. Obviously, fuel-staging had an advantageous effect on precursors to dioxin formation, such as chlorophenols. Consequently, by continuously monitoring these species it should be possible to control the process in a way as to minimize precursor concentrations and hence dioxin release...

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<title>Jet-REMPI for process control in incineration</title>

Cited by 14 publications

References 0 publications

Critical assessment: Use of supersonic jet spectrometry for complex mixture analysis (IUPAC Technical Report)

Critical assessment: Use of supersonic jet spectrometry for complex mixture analysis (IUPAC Technical Report)

Rapid Analysis of Polychlorinated Biphenyls in the Gas Phase with Resonance-enhanced Two-photon Ionization: Optimal Injection of Ions into the Ion-trap Storage/Time-of-flight Mass Spectrometer

DLR-Jet REMPI - Ultrasensitive Monitor for Process Control in Thermal Processes

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