Sample records for 2-methylpropene

  1. Electron collisions with 1-butene and 2-methylpropene molecules

    Lopes, A. R.; Freitas, T. C.; Bettega, M. H. F.


    In this paper we report integral and differential cross sections for the elastic scattering of low-energy electrons by C4H8 isomers, namely 1-butene and 2-methylpropene. The scattering cross sections were obtained using the Schwinger multichannel method with pseudopotentials, in the static-exchange and in the static-exchange plus polarization approximations, for energies of the incident electron ranging from 0.5 eV to 15 eV. Our calculations indicate that the 1-butene molecule has a resonance in the A″ symmetry at around 2.1 eV, in agreement with the experimental data of 2.3 eV as reported by Mozejko et al (2012 J. Phys. B 45 145203). The 2-methylpropene molecule has a resonance in the B2 symmetry, located at around 2.8 eV and also in good agreement with the experimental results of Mozejko et al around 2.4 eV. We also report differential cross sections around the energy of the broad structure present in the integral cross sections of both molecules, and discuss their oscillatory behavior in terms of the type of the molecular chain.

  2. Kinetics and Rate Law Determination of 2-Methylpropene Hydrogenation in a Packed-Bed Microreactor

    VAJGLOVÁ, Zuzana


    This study focuses on hydrogenation of C4 fraction, more specifically on development of the methodology of kinetic data collection and evaluation. The hydrogenation of 2- methylpropene on platinum catalyst was investigated as a model reaction.

  3. Assessment of the Kinetic Regime for 2-Methylpropene Hydrogenation in a Packed-Bed Microreactor

    Vajglová, Zuzana; Stavárek, Petr; Křišťál, Jiří; Kolena, J.; Jiřičný, Vladimír

    Budapest: Budapest University of Technology and Economics, 2014, s. 189-190. ISBN 978-963-05-9518-6. [International Conference on Microreactor Technology IMRET /13./. Budapest (HU), 23.06.2014-25.06.2014] Institutional support: RVO:67985858 Keywords : hydrogenation of 2-methylpropene * packed-bed microreactor * kinetic regime Subject RIV: CI - Industrial Chemistry, Chemical Engineering

  4. Improved direct production of 2,3-dimethylbutenes and 3,3-dimethylbutene from 2-methylpropene on tungsten hydride based catalysts

    Garron, Anthony


    2-Methylpropene in the presence of W-H/Ni 1%-Al 2O 3-(500) is transformed in high selectivity into a mixture of 2,3-dimethylbutenes (2,3-DMBs = DMB-1 and DMB-2) and neohexene. 2,3-DMBs arise from the unfavoured 2-methylpropene self-metathesis reaction whereas the neohexene originates from a cascade reaction: 2-methylpropene dimerisation followed by cross metathesis. © 2012 The Royal Society of Chemistry.

  5. Continuous Hydrogenation of 2-Methylpropene on Pt Catalyst in the Microreactor for Kinetic Studies

    Vajglová, Z.; Stavárek, Petr; Křišťál, Jiří; Kolena, J.; Jiřičný, Vladimír

    - : -, 2013, -. ISBN N. [European Congress of Chemical Engineering /9./. The Hague (NL), 21.04.2013-25.04.2013] Grant ostatní: GA MŠk(CZ) MŠMT:CZ.1.05/2.1.00/03.0071 Institutional support: RVO:67985858 Keywords : heterogeneous catalysis * microeractor * kinetic studies Subject RIV: CI - Industrial Chemistry, Chemical Engineering

  6. Kinetics and Rate Law Determination of 2-Methylpropene Hydrogenation in a Packed-Bed Microreactor

    Vajglová, Zuzana; Stavárek, Petr; Křišťál, Jiří; Kolena, J.; Jiřičný, Vladimír

    Prague: Orgit, 2014, s. 87. ISBN 978-80-02-02555-9. [International Congress of Chemical and Process Engineering /21./ - CHISA 2014 and Conference on Process Integration, Modelling and Optimisation for Energy Saving and Pollution Reduction /17./ - PRES 2014. Prague (CZ), 23.08.2014-27.08.2014] Institutional support: RVO:67985858 Keywords : fluid catalytic cracking * hydrogenation * microreactor Subject RIV: CI - Industrial Chemistry, Chemical Engineering

  7. Self-Sustained Oscillations of Temperature and Conversion in a Packed Bed Microreactor during 2-Methylpropene (Isobutene) Hydrogenation

    Stavárek, Petr; Vajglová, Zuzana; Křišťál, Jiří; Jiřičný, Vladimír; Kolena, J.


    Roč. 256, NOV 1 (2015), s. 250-260. ISSN 0920-5861. [InternationalCongress of Chemical and Process Engineering CHISA 2014 /21./. Prague, 23.08.2014-27.08.2014] Institutional support: RVO:67985858 Keywords : hydrogenation * microreactor * oscillation Subject RIV: CI - Industrial Chemistry, Chemical Engineering Impact factor: 3.893, year: 2014

  8. Electron collisions with methyl-substituted ethylenes: Cross section measurements and calculations for 2-methyl–2-butene and 2,3-dimethyl–2-butene

    We report electron-scattering cross sections determined for 2-methyl–2-butene [(H3C)HC = C(CH3)2] and 2,3-dimethyl–2-butene [(H3C)2C = C(CH3)2] molecules. Absolute grand-total cross sections (TCSs) were measured for incident electron energies in the 0.5–300 eV range, using a linear electron-transmission technique. The experimental TCS energy dependences for the both targets appear to be very similar with respect to the shape. In each TCS curve, three features are discernible: the resonant-like structure located around 2.6–2.7 eV, the broad distinct enhancement peaking near 8.5 eV, and a weak hump in the vicinity of 24 eV. Theoretical integral elastic (ECS) and ionization (ICS) cross sections were computed up to 3 keV by means of the additivity rule (AR) approximation and the binary-encounter-Bethe method, respectively. Their sums, (ECS+ICS), are in a reasonable agreement with the respective measured TCSs. To examine the effect of methylation of hydrogen sides in the ethylene [H2C = CH2] molecule on the TCS, we compared the TCS energy curves for the sequence of methylated ethylenes: propene [H2C = CH(CH3)], 2-methylpropene [H2C = C(CH3)2], 2-methyl–2-butene [(H3C)HC = C(CH3)2], and 2,3-dimethyl–2-butene [(H3C)2C = C(CH3)2], measured in the same laboratory. Moreover, the isomeric effect is also discussed for the C5H10 and C6H12 compounds

  9. Biogenic Emissions of Light Alkenes from a Coniferous Forest

    Rhew, R. C.; Turnipseed, A. A.; Martinez, L.; Shen, S.; De Gouw, J. A.; Warneke, C.; Koss, A.; Lerner, B. M.; Miller, B. R.; Smith, J. N.; Guenther, A. B.


    Alkenes are reactive hydrocarbons that play important roles in the photochemical production of tropospheric ozone and in the formation of secondary organic aerosols. The light alkenes (C2-C4) originate from both biogenic and anthropogenic sources and include C2H4 (ethene), C3H6 (propene) and C4H8 (1-butene, 2-butene, 2-methylpropene). Light alkenes are used widely as chemical feedstocks because their double bond makes them versatile for industrial reactions. Their biogenic sources are poorly characterized, with most global emissions estimates relying on laboratory-based studies; net ecosystem emissions have been measured at only one site thus far. Here we report net ecosystem fluxes of light alkenes and isoprene from a semi-arid ponderosa pine forest in the Rocky Mountains of Colorado, USA. Canopy scale fluxes were measured using relaxed eddy accumulation (REA) techniques on the 28-meter NCAR tower in the Manitou Experimental Forest Observatory. Updrafts and downdrafts were determined by sonic anemometry and segregated into 'up' and 'down' reservoirs over the course of an hour. Samples were then measured on two separate automated gas chromatographs (GCs). The first GC measured light hydrocarbons (C2-C6 alkanes and C2-C5 alkenes) by flame ionization detection (FID). The second GC measured halocarbons (methyl chloride, CFC-12, and HCFC-22) by electron capture detection (ECD). Additional air measurements from the top of the tower included hydrocarbons and their oxidation products by Proton Transfer Reaction Mass Spectrometry (PTR-MS). Three field intensives were conducted during the summer of 2014. The REA flux measurements showed that ethene, propene and the butene emissions have significant diurnal cycles, with maximum emissions at midday. The light alkenes contribute significantly to the overall biogenic source of reactive hydrocarbons and have a temporal variability that may be associated with physical and biological parameters. These ecosystem scale measurements