Gas-Phase Reactions of the [(PHOX)IrL2]+ Ion Olefin-Hydrogenation Catalyst Support an IrI/IrIII Cycle

2004 ◽  
Vol 43 (41) ◽  
pp. 5513-5516 ◽  
Author(s):  
Rolf Dietiker ◽  
Peter Chen
Keyword(s):  
Gas Phase ◽  
Catalyst Support ◽  
Hydrogenation Catalyst ◽  
Gas Phase Reactions ◽  
Olefin Hydrogenation

scholarly journals Escaping undesired gas-phase chemistry: Microwave-driven selectivity enhancement in heterogeneous catalytic reactors

2019 ◽  
Vol 5 (3) ◽  
pp. eaau9000 ◽  
Author(s):  
A. Ramirez ◽  
J. L. Hueso ◽  
M. Abian ◽  
M. U. Alzueta ◽  
R. Mallada ◽  
...  
Keyword(s):  
Gas Phase ◽  
Solid Phase ◽  
Catalyst Support ◽  
Accurate Estimation ◽  
Gas Phase Reactions ◽  
Catalytic Reactors ◽  
Heterogeneous Catalytic ◽  
Catalyst Composition ◽  
Heterogeneous Catalytic Processes ◽  
Phase Chemistry

Research in solid-gas heterogeneous catalytic processes is typically aimed toward optimization of catalyst composition to achieve a higher conversion and, especially, a higher selectivity. However, even with the most selective catalysts, an upper limit is found: Above a certain temperature, gas-phase reactions become important and their effects cannot be neglected. Here, we apply a microwave field to a catalyst-support ensemble capable of direct microwave heating (MWH). We have taken extra precautions to ensure that (i) the solid phase is free from significant hot spots and (ii) an accurate estimation of both solid and gas temperatures is obtained. MWH allows operating with a catalyst that is significantly hotter than the surrounding gas, achieving a high conversion on the catalyst while reducing undesired homogeneous reactions. We demonstrate the concept with the CO2-mediated oxidative dehydrogenation of isobutane, but it can be applied to any system with significant undesired homogeneous contributions.

scholarly journals Gasification of Nickel-Preloaded Oil Palm Biomass with Air

2016 ◽  
Vol 11 (3) ◽  
pp. 262 ◽  
Author(s):  
Syed Shatir A. Syed-Hassan ◽  
Siti Nor Izuera Nor-Azemi
Keyword(s):  
Gas Phase ◽  
Oil Palm ◽  
Catalyst Support ◽  
Reduction Process ◽  
Gas Phase Reactions ◽  
Syngas Production ◽  
Nickel Particles ◽  
Oil Palm Biomass ◽  
Tar Reduction ◽  
Nickel Species

<p>This study experimentally investigates the gasification of nickel-preloaded oil palm biomass as an alternative catalytic approach to produce clean syngas. To eliminate the use of catalyst support, nickel was added directly to the oil palm mesocarp fiber via ion-exchange using an aqueous solution of nickel nitrate. Nickel species was found to disperse very well on the biomass at a nano-scale dispersion. The presence of the finely dispersed nickels on biomass enhanced syngas production and reduced tar content in the producer gas during the air gasification of biomass. It is believed that nickel particles attached on the biomass and its char promote the catalytic cracking of tar on their surface and supply free radicals to the gas phase to enhance the radical-driven gas-phase reactions for the reforming of high molecular weight hydrocarbons. The unconsumed nickel-containing char shows great potential to be re-utilised as a catalyst to further enhance the destruction of tar components in the secondary tar reduction process. Copyright © 2016 BCREC GROUP. All rights reserved</p><p><em>Received: 12<sup>nd</sup> September 2015; Revised: 10<sup>th</sup> January 2016; Accepted:16<sup>th</sup> January 2016</em></p><p><strong>How to Cite</strong>: Syed-Hassan, S.S.A., Nor-Azemi, S. (2016). Gasification of Nickel-Preloaded Oil Palm Biomass with Air.<em> Bulletin of Chemical Reaction Engineering &amp; Catalysis</em>, 11 (3): 262-272 (doi:10.9767/bcrec.11.3.566.262-272)</p><p><strong>Permalink/DOI</strong>: <a href="http://doi.org/10.9767/bcrec.11.3.566.262-272">http://doi.org/10.9767/bcrec.11.3.566.262-272</a></p>

Gas-Phase Reactions

1981 ◽  
Author(s):  
Victor N. Kondratiev ◽  
Evgeniĭ E. Nikitin
Keyword(s):  
Gas Phase ◽  
Gas Phase Reactions

Influence of Gas Mixing and Heating on Gas-Phase Reactions in GaN MOCVD Growth

2012 ◽  
Vol 1 (1) ◽  
pp. P46-P53 ◽  
Author(s):  
Ran Zuo ◽  
Haiqun Yu ◽  
Nan Xu ◽  
Xiaokun He
Keyword(s):  
Gas Phase ◽  
Gas Mixing ◽  
Gas Phase Reactions ◽  
Mocvd Growth

Gas Phase Reactions Activated by Nuclear Processes

1957 ◽  
Vol 79 (17) ◽  
pp. 4609-4616 ◽  
Author(s):  
Adon A. Gordus ◽  
John E. Willard
Keyword(s):  
Gas Phase ◽  
Gas Phase Reactions ◽  
Nuclear Processes

Nanocomposite ceramic powder production by laser-induced gas-phase reactions

1993 ◽  
Vol 168 (2) ◽  
pp. 177-181 ◽  
Author(s):  
E Borsella ◽  
S Botti ◽  
R Alexandrescu ◽  
I Morjan ◽  
T Dikonimos-Makris ◽  
...  
Keyword(s):  
Gas Phase ◽  
Ceramic Powder ◽  
Gas Phase Reactions ◽  
Powder Production

Methylene. III. Gas phase reactions with 1-chloropropane

1969 ◽  
Vol 312 (1509) ◽  
pp. 141-161 ◽  
Keyword(s):  
Gas Phase ◽  
Rate Constants ◽  
Hydrogen Abstraction ◽  
The Other ◽  
Gas Phase Reactions ◽  
Other Hand ◽  
Chlorine Substituent ◽  
High Degree ◽  
Singlet Methylene

The work described in this and the following paper is a continuation of that in parts I and II, devoted to elucidation of the mechanism of the reactions of methylene with chloroalkanes, with particular reference to the reactivities of singlet and triplet methylene in abstraction and insertion processes. The products of the reaction between methylene, prepared by the photolysis of ketene, and 1-chloropropane have been identified and estimated and their dependence on reactant pressures, photolysing wavelength and presence of foreign gases (oxygen and carbon mon­oxide) has been investigated. Both insertion and abstraction mechanisms contribute significantly to the over-all reaction, insertion being relatively much more important than with chloroethane. This type of process appears to be confined to singlet methylene. If, as seems likely, there is no insertion into C—Cl bonds under our conditions (see part IV), insertion into C2—H and C3—H bonds occurs in statistical ratio, approximately. On the other hand, the chlorine substituent reduces the probability of insertion into C—H bonds in its vicinity. As in the chloroethane system, both species of methylene show a high degree of selectivity in their abstraction reactions. We find that k S Cl / k S H >7.7, k T Cl / k T H < 0.14, where the k ’s are rate constants for abstraction, and the super- and subscripts indicate the species of methylene and the type of atom abstracted, respectively. Triplet methylene is discriminating in hydrogen abstraction from 1-C 3 H 7 Cl, the overall rates for atoms attached to C1, C2, C3 being in the ratios 2.63:1:0.

Sign in / Sign up

Export Citation Format

Share Document