Oxidation of hydrocarbons in a barrier discharge reactor

Kudryashov, S. V.; Щеголева, Г. С.; Сироткина, Е. Е.; Ryabov, A. Yu.

doi:10.1007/bf02761839

Cited by 21 publications

(30 citation statements)

References 2 publications

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“…The detailed mechanism for this observation is not clear at this stage, but presumably this is because radicals, such as hydroxyl radicals, show some selectivity in terms of the types of bonds with which they react, although this selectivity is in the context of a highly reactive and therefore relatively indiscriminate reactivity [18]. The oxidation products of hydrocarbons in DESI are consistent with those obtained using a discharge reactor [19], which also generates isomeric alcohols and ketones from short alkanes like hexane.…”

Section: Oxidation Induced By Discharge In Desisupporting

confidence: 71%

Ambient analysis of saturated hydrocarbons using discharge-induced oxidation in desorption electrospray ionization

Qian

Nefliu

et al. 2010

J. Am. Soc. Mass Spectrom.

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Saturated nonfunctionalized hydrocarbons can be oxidized in situ by initiating an electrical discharge during desorption electrospray ionization (DESI) to generate the corresponding alchohols and ketones. This form of reactive DESI experiment can be utilized as an in situ derivatization method for rapid and direct analysis of alkanes at atmospheric pressure without sample preparation. Betaine aldehyde was incorporated into the DESI spray solution to improve the sensitivity of detecting the long-chain alcohol oxidation products. The limit of detection for alkanes (C 15 H 32 to C 30 H 62) from pure samples is 20 ng. Multiple oxidations and dehydrogenations occurred during the DESI discharge, but no hydrocarbon fragmentation was observed, even for highly branched squalane. Using exact mass measurements, the technique was successfully implemented for analysis of petroleum distillates containing saturated hydrocarbons. (J Am Soc Mass Spectrom 2010, 21, 261-267) N on-polar hydrocarbons, the major constituent (90%) of petroleum distillates derived from crude oil [1], are difficult to analyze by mass spectrometry using atmospheric pressure ionization methods. Saturated hydrocarbons in particular, which lack functional groups and aromatic rings, can only be ionized by high voltage electron ionization (EI), chemical ionization (CI), field desorption (FD), or field ion-ization (FI). Among these methods, EI, and CI are not ideal for hydrocarbon mixture analysis due to significant fragmentation of molecular ions. As a result, FD and FI are the primary soft ionization methods used in petroleum analysis. However, heating the analytes during FD/FI can be problematic and may cause fragmentation of molecular ions, a problem that becomes acute for high boiling materials [2]. In addition, branched alkanes are easily fragmented in FD/FI, making quantitative measurement of isomeric paraffins very challenging [2, 3]. Atmospheric pressure photoionization (APPI) can be used to ionize nonpolar polycyclic aromatic hydrocarbons by producing a radical cation and/or a protonated molecule of the analyte, but it cannot be used to ionize saturated paraffins [4]. In spite of these difficulties, traditional hydrocarbon analysis in the petroleum industry continues to be an important subject. Recently, laser-induced acoustic desorption (LIAD) coupled with gas-phase ion/molecule reactions under vacuum has shown great potential to achieve efficient ionization of saturated hydrocarbons with little [1] or no [5] fragmentation. Direct analysis of hydrocarbons under ambient conditions remains highly desirable however, because it allows easy implementation on both commercial and portable mass spectrometers of on-site analysis and has the potential for high through-put screening. This paper introduces a new method that addresses this problem. Desorption electrospray ionization (DESI) is an ambient analysis method that shares some of the properties of the electrospray (ESI) technique [6]. In particular, oxidation artifacts of analytes have been reported in ...

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Section: Oxidation Induced By Discharge In Desisupporting

confidence: 71%

Ambient analysis of saturated hydrocarbons using discharge-induced oxidation in desorption electrospray ionization

Qian

Nefliu

et al. 2010

J. Am. Soc. Mass Spectrom.

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“…The primary event in the plasma oxidative cracking of hexane is the electron impact excitation of molecular oxygen yielding atomic oxygen radicals in the ground O( 3 P) and excited O( 1 D) states. 9,27 The Franck-Condon region for excitation from the ground state of O 2 is reported to favor a 6 eV and an 8.4 eV process leading to dissociation via electronic transitions to the Herzberg (A 3 Σ + u , A 3 ∆ u ,c 1 Σ u -) and Schumann-Runge (B 3 Σ -u ) systems 28 Figure 3. Effect of plasma and oxygen addition on the conversion of hexane at 600°C (a) (C 6 , 10 mL/min hexane + 90 mL/min helium in the absence of plasma; C 6 + O 2 , 10 mL/min hexane + 8 mL/min oxygen and 82 mL/min helium in the absence of plasma; C 6 + P, 10 mL/min hexane + 90 mL/min helium with plasma activation; C 6 + O 2 + P, 10 mL/min hexane + 8 mL/min oxygen and 82 mL/min helium with plasma activation); change in conversion of hexane with increasing concentration of oxygen (b), effect of increasing oxygen concentrations on product selectivities (c), effect of increasing oxygen concentrations on the yields of C 2 -C 5 olefins (d).…”

Section: Resultsmentioning

confidence: 97%

Pathway Study on Dielectric Barrier Discharge Plasma Conversion of Hexane

et al. 2010

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A plasma reactor based on dielectric barrier discharge has been developed for oxidative cracking of hexane to yield olefins at atmospheric pressure. Dissociation of hexane in the presence of oxygen with nonequilibrium plasma state represents complex chemistry, and both conversion and product selectivities differ significantly from the thermodynamic equilibrium state. In order to understand plasma chemistry initiated by electron impact processes, the Boltzmann equation is solved to determine the average electron energy and energy fractions in collision processes. Activation of oxygen in the plasma brings a new route with electron impact dissociation yielding atomic oxygen radicals and initiates oxidative cracking of hexane. Changes in certain features of the dissociation pattern of hexane to yield olefin products with varying parameters such as temperature, oxygen addition, and helium concentration are discussed.

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“…For example, by analogy with oxidation of alkanes with oxygen under the influence of the BD [8] the following set of reactions can be proposed for the formation of acrolein and allyl alcohol [21-23]:…”

Section: Discussion Of a Possible Mechanism For The Oxidation Of Propmentioning

confidence: 99%

“…More recently [8], to prevent the formation of polymer-like compounds, a method for efficient removal of products from the reactor discharge zone has been proposed using oxidation of liquid hydrocarbons as an example. The method consists in forming a liquid hydrocarbon film flowing down the reactor walls.…”

Section: Introductionmentioning

confidence: 99%

Oxidation of Propylene with Oxygen and Air in a Barrier Discharge in the Presence of Octane

Kudryashov

Очередько

Ryabov

et al. 2011

Plasma Chem Plasma Process

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Oxidation of propylene with oxygen, air and a mixture of nitrogen-oxygen in a barrier discharge is investigated. The selectivity towards formation of propylene oxide in pure oxygen is shown to be as high as 45 wt% and the propylene conversion ratio is found to be 12.9 wt%. In the oxidation with air, the propylene oxide selectivity is 23 wt%, while the conversion is 7.5 wt%. The values of propylene conversion and selectivity towards formation of propylene oxide in a barrier discharge are consistent with those obtained by the thermocatalytic methods for production of propylene oxide.

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Oxidation of hydrocarbons in a barrier discharge reactor

Cited by 21 publications

References 2 publications

Ambient analysis of saturated hydrocarbons using discharge-induced oxidation in desorption electrospray ionization

Ambient analysis of saturated hydrocarbons using discharge-induced oxidation in desorption electrospray ionization

Pathway Study on Dielectric Barrier Discharge Plasma Conversion of Hexane

Oxidation of Propylene with Oxygen and Air in a Barrier Discharge in the Presence of Octane

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