Exchange of Oxygen Atoms among Carbon Dioxide, Carbon Monoxide and Oxide Catalysts of Spinel Type

1958 ◽  
Vol 80 (17) ◽  
pp. 4503-4507 ◽  
Author(s):  
Yukio Yoneda ◽  
Shoji Makishima ◽  
Katsuyoshi Hirasa
Keyword(s):  
Carbon Dioxide ◽  
Carbon Monoxide ◽  
Oxide Catalysts ◽  
Spinel Type ◽  
Oxygen Atoms

THE DECOMPOSITION OF CARBON DIOXIDE BY Hg 6(3P1) AND Hg 6(3P0) ATOMS

1961 ◽  
Vol 39 (11) ◽  
pp. 2244-2250 ◽  
Author(s):  
Otto P. Strausz ◽  
Harry E. Gunning
Keyword(s):  
Carbon Dioxide ◽  
Carbon Monoxide ◽  
Light Intensity ◽  
Chemical Method ◽  
Direct Evidence ◽  
Mercury Vapor ◽  
Maximum Effect ◽  
Electronically Excited ◽  
Oxygen Atoms

Carbon dioxide has been shown to decompose into carbon monoxide and oxygen atoms, when exposed to radiation at 2537 Å, in the presence of mercury vapor. The rate rises steeply with decreasing substrate pressure, and varies directly with the 1.8 ± 0.1 power of the light intensity. The proposed mechanism attributes reaction to the collision of electronically excited CO2 molecules with Hg 6(3P1) atoms. The suppression of reaction at higher substrate pressures is readily explained in terms of collisional deactivation of the excited CO2 species. Nitrogen was found to increase the rate of CO formation; the maximum effect was obtained for a mixture of 7.4 mm nitrogen and 3.74 mm carbon dioxide, in which case the rate was 1.58 times that for pure substrate. It is shown that nitrogen serves to generate metastable Hg 6(3P0) atoms, which can sensitize the decomposition. The reaction might serve as a chemical method for monitoring Hg 6(3P0) atoms. For CO2–N2 mixtures, the rate was found to rise when the reacting system was exposed to radiation at 4047 Å. This is taken as direct evidence of sensitization by higher states of mercury, generated by stepwise excitation, since radiation at 4047 Å converts Hg 6(3P0) to Hg 7(3S1).

PRELIMINARY STUDY OF PHOTOCHEMICAL BEHAVIOR IN THE SYSTEM NITROGEN DIOXIDE – ETHANE

1955 ◽  
Vol 33 (5) ◽  
pp. 843-848
Author(s):  
T. M. Rohr ◽  
W. Albert Noyes Jr.
Keyword(s):  
Nitric Oxide ◽  
Carbon Dioxide ◽  
Carbon Monoxide ◽  
Nitrogen Dioxide ◽  
Room Temperature ◽  
Reverse Reaction ◽  
Primary Process ◽  
Photochemical Behavior ◽  
Preliminary Study ◽  
Oxygen Atoms

The addition of ethane to nitrogen dioxide either during exposure to radiation transmitted by pyrex, or afterwards, reduces the amount of oxygen formed. At room temperature this is apparently due to the effectiveness of ethane in promoting the reverse reaction of nitric oxide and oxygen to form nitrogen dioxide. At temperatures over 100° there is a reaction which uses oxygen atoms produced in the primary process. Nitroethane (or nitrosoethane) is formed along with carbon monoxide, carbon dioxide, and some methane. The results suggest that acetaldehyde is an intermediate, but acetaldehyde could not be detected because it would react thermally with nitrogen dioxide. It is not possible to give a complete explanation of the results, but suggestions can be made which might form the basis for later work.

THE REACTION OF OXYGEN ATOMS WITH METHANE

1938 ◽  
Vol 16b (6) ◽  
pp. 203-209 ◽  
Author(s):  
E. W. R. Steacie ◽  
N. A. D. Parlee
Keyword(s):  
Carbon Dioxide ◽  
Activation Energy ◽  
Carbon Monoxide ◽  
Discharge Tube ◽  
Oxygen Atoms

The reaction of oxygen atoms, produced by the discharge tube method, with methane has been investigated at temperatures from 30° to 330 °C. The products of the reaction are carbon monoxide, carbon dioxide, and water. Ethane is absent. The activation energy is approximately 8 Kcal. It is concluded that either(a) The reaction postulated by Norrish[Formula: see text]does not occur to any great extent, or(b) The reaction[Formula: see text]has an activation energy greater than 11 to 12 Kcal.

scholarly journals Controlled atmosphere GMAW welding of transportation vehicles and production machines parts made from 30MnB5 steel

2018 ◽  
Vol 216 ◽  
pp. 03001 ◽  
Author(s):  
Evgeny Ivanayskiy ◽  
Aleksei Ishkov ◽  
Aleksandr Ivanayskiy ◽  
Iakov Ochakovskii
Keyword(s):  
Mechanical Properties ◽  
Carbon Dioxide ◽  
Carbon Monoxide ◽  
Chemical Composition ◽  
Controlled Atmosphere ◽  
Shielding Gas ◽  
Reducing Atmosphere ◽  
Metal Composition ◽  
Gmaw Welding ◽  
Welding Materials

The paper studies the influence of shielding gas on the composition and the structure of weld joint metal of 30MnB5 steel applied in essential parts of automobiles and tractors. The welding was performed in inert, oxidizing and reducing atmospheres. It was established that TIG welding with argon used as shielding gas did not provide the required mechanical properties when using conventional welding materials. Carbon dioxide during MAG welding caused partial burning of alloying elements. Carbon monoxide used as shielding gas was proved to form reducing atmosphere enabling to obtain chemical composition close to the base metal composition. Metallographic examinations were carried out. The obtained results provided full-strength weld, as well as the required reliability and durability of welded components and joints.

Low-Carbon Monoxide Hydrogen by Sorption-Enhanced Reaction

2003 ◽  
Vol 1 (1) ◽  
Author(s):  
Douglas P Harrison ◽  
Zhiyong Peng
Keyword(s):  
Carbon Dioxide ◽  
Carbon Monoxide ◽  
Hydrogen Production ◽  
Proton Exchange Membrane ◽  
Primary Energy ◽  
Proton Exchange ◽  
Raw Material ◽  
Impurity Level ◽  
Low Carbon ◽  
Enhanced Production

Hydrogen is an increasingly important chemical raw material and a probable future primary energy carrier. In many current and anticipated applications the carbon monoxide impurity level must be reduced to low-ppmv levels to avoid poisoning catalysts in downstream processes. Methanation is currently used to remove carbon monoxide in petroleum refining operations while preferential oxidation (PROX) is being developed for carbon monoxide control in fuel cells. Both approaches add an additional step to the multi-step hydrogen production process, and both inevitably result in hydrogen loss. The sorption enhanced process for hydrogen production, in which steam-methane reforming, water-gas shift, and carbon dioxide removal reactions occur simultaneously in the presence of a nickel-based reforming catalyst and a calcium-based carbon dioxide sorbent, is capable of producing high purity hydrogen containing minimal carbon monoxide in a single processing step. The process also has the potential for producing pure CO2 that is suitable for subsequent use or sequestration during the sorbent regeneration step. The current research on sorption-enhanced production of low-carbon monoxide hydrogen is an extension of previous research in this laboratory that proved the feasibility of producing 95+% hydrogen (dry basis), but without concern for the carbon monoxide concentration. This paper describes sorption-enhanced reaction conditions – temperature, feed gas composition, and volumetric feed rate – required to produce 95+% hydrogen containing low carbon monoxide concentrations suitable for direct use in, for example, a proton exchange membrane fuel cell.

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