title: The gas chromatographic analysis of the reaction products of the partial isobutane oxidation as a two phase process.
abstract: The partial oxidation of isobutane to t-butyl hydroperoxide (TBHP) has been studied analytically for the first time as a two-phase process in a capillary micro reactor. In order to obtain detailed information on products, yields, selectivities and reaction pathways, the products have been investigated by GC/MS. An Rxi-5ms column and a PTV-injector have been used to analyze the liquid products. TBHP, di-t-butyl peroxide (DTBP), t-butanol (TBA), and propanone as main products as well as further by-products e.g. methanal, isopropanol, isobutanol and isobutanal in minor quantities have been identified by MS. The liquid products have been obtained by quenching the reaction and vaporizing the isobutane afterwards by pressure reduction using a mass flow controller allowing a constant mass flow. For all liquid reaction products calibrations, a validation of the method including limits of quantification and detection as well as calculation of uncertainties has been performed. The results have been applied successfully for the investigation of the selectivities of the main products (TBHP, DTBP, TBA, propanone) of the isobutane oxidation. In the frame of the analytical investigation of this reaction a correlation coefficient of r(2)>0.999 for TBHP and DTBP, which is necessary to perform a validation, has been obtained for the first time. The gaseous phase has been analyzed using a GASPRO column, a DEANS switch, a mole sieve column and a TCD detector. Apart from the gaseous reactants, isobutene has been found.
authors.affiliation: Helmholtz-Zentrum Dresden-Rossendorf, Institute of Fluid Dynamics, Bautzner Landstraße 400, 01328 Dresden, Germany. Electronic address: t.willms@hzdr.de.
authors.forename: Thomas
authors.initials: T
authors.lastname: Willms
authors.affiliation: Helmholtz-Zentrum Dresden-Rossendorf, Institute of Fluid Dynamics, Bautzner Landstraße 400, 01328 Dresden, Germany.
authors.forename: Holger
authors.initials: H
authors.lastname: Kryk
authors.affiliation: Helmholtz-Zentrum Dresden-Rossendorf, Institute of Fluid Dynamics, Bautzner Landstraße 400, 01328 Dresden, Germany.
authors.forename: Uwe
authors.initials: U
authors.lastname: Hampel
mesh_terms: D002073:Butanes / Q000737:chemistry*; D000440:Butanols / Q000032:analysis / Q000737:chemistry; D008401:Gas Chromatography-Mass Spectrometry / Q000379:methods*; D005740:Gases / Q000032:analysis / Q000737:chemistry; D010084:Oxidation-Reduction; D010545:Peroxides / Q000032:analysis / Q000737:chemistry; D011312:Pressure; D011407:Propane / Q000031:analogs & derivatives / Q000032:analysis / Q000737:chemistry; D014835:Volatilization
chemical_list: D002073:Butanes; D000440:Butanols; D005740:Gases; D010545:Peroxides; C111570:di-tert-butyl peroxide; C046888:butane; C000602361:tert-butyl peroxide; D011407:Propane
keywords: Di-t-butyl-peroxide; GC/MS; Isobutane oxidation; Multiphase process; t-Butyl hydroperoxide