QUANTITATIVE GAS CHROMATOGRAPHY OF REACTION PRODUCTS FROM THE CATALYTIC OXIDATION OF ETHYLENE

1959 ◽  
Vol 37 (4) ◽  
pp. 708-713 ◽  
Author(s):  
C. H. Amberg ◽  
E. Echigoya ◽  
D. Kulawic
Keyword(s):  
Carbon Dioxide ◽  
Gas Chromatography ◽  
Water Vapor ◽  
Quantitative Analysis ◽  
Ethylene Oxide ◽  
Catalytic Oxidation ◽  
Reaction Products ◽  
Gas Chromatograph ◽  
Large Excess ◽  
Two Stage

A simple two-stage gas chromatograph is described which employs only one detector for both effluent streams. It was designed specifically for the routine quantitative analysis of mixtures of ethylene oxide, carbon dioxide, and ethylene in the presence of water vapor and a large excess of air, and for concentrations down to 0.2% by volume of individual components.

THE CATALYTIC OXIDATION OF ETHYLENE TO ETHYLENE OXIDE

1949 ◽  
Vol 27b (11) ◽  
pp. 813-827 ◽  
Author(s):  
F. L. W. McKim ◽  
A. Cambron
Keyword(s):  
Ethylene Oxide ◽  
Catalytic Oxidation ◽  
Atmospheric Pressure ◽  
Reaction Rate ◽  
Ethylene Dichloride ◽  
Complete Oxidation ◽  
Large Excess ◽  
Ethylene Concentration ◽  
Silver Catalysts ◽  
Flow Experiments

The catalytic oxidation of ethylene to ethylene oxide was investigated in flow experiments over silver catalysts at atmospheric pressure between 260° and 350 °C. Calcium oxalate and stannous oxide were used as catalyst promoters. Close temperature control was provided by mounting the catalyst on a silver support. At 270 °C. the selectivity increased from about 25%, with ethylene in large excess, to about 55%, with oxygen in large excess. With air constant and in large excess, the over-all reaction rate was found to be proportional to the square root of the ethylene concentration. With ethylene constant and in large excess, the reaction rate was found to be roughly proportional to the oxygen concentration. The presence of methane, ethane, or propane promoted the complete oxidation of ethylene to carbon dioxide and water. In the absence of paraffins the addition of traces of ethylene dichloride only served to poison the catalyst.

scholarly journals Identification of Aroma Differences in Refined and Whole Grain Extruded Maize Puffs

Molecules ◽  
2020 ◽  
Vol 25 (9) ◽  
pp. 2261 ◽  
Author(s):  
Kenneth Smith ◽  
Devin G. Peterson
Keyword(s):  
Mass Spectrometry ◽  
Gas Chromatography ◽  
Quantitative Analysis ◽  
Descriptive Analysis ◽  
Analytical Data ◽  
Gas Chromatography Mass Spectrometry ◽  
Maillard Reaction Products ◽  
Reaction Products ◽  
Whole Grain ◽  
Whole Grain Flour

Differences in the aroma profiles of extruded maize puffs made from refined grain and whole grain flour were investigated. Gas chromatography/mass spectrometry/olfactometry (GC/MS/O) analysis reported 13 aroma compounds with a flavor dilution (FD) value ≥16. Quantitative analysis identified eight compounds as statistically different, of which seven compounds were higher in concentration in the whole grain sample. Sensory recombination and descriptive analysis further supported the analytical data, with higher mean aroma intensities for cooked, corn chip, roasted, and toasted attributes for the whole grain sample. Generally, the compounds responsible for perceived differences in whole grain maize extruded puffs were associated with increased levels of Maillard reaction products, such as 2-ethyl-3,5-dimethylpyrazine and 2-acetyl-2-thiazoline.

Determination of Serum and Urinary Phenylalanine by Gas Chromatography

1973 ◽  
Vol 19 (5) ◽  
pp. 496-498 ◽  
Author(s):  
Z K Shihabi ◽  
G K Summer
Keyword(s):  
Gas Chromatography ◽  
Quantitative Analysis ◽  
Nitrous Acid ◽  
Gas Chromatograph ◽  
Phenyllactic Acid ◽  
Mild Conditions ◽  
Amino Acid Analyzer ◽  
Urine Specimens ◽  
Serum And Urine

Abstract Phenylalanine in serum and urine was determined by gas chromatography after it was converted, by action of nitrous acid, to the corresponding hydroxy acid, phenyllactic acid. After extraction with ether, the phenyllactic acid was derivatized with bis(trimethylsilyl)trifluoroacetamide under mild conditions, and the product was injected directly into the gas chromatograph. The precision of the method was verified by recovery studies and by comparison with the results of quantitative analysis of phenylalanine on an amino acid analyzer. Urine specimens from normal infants and children and from patients with phenylketonuria were analyzed by this method to show that the procedure is applicable to diagnosis of the disorder.

scholarly journals The mechanism of the catalytic oxidation of ethylene - I. Experiments using a flow system

1946 ◽  
Vol 188 (1012) ◽  
pp. 92-104 ◽  
Keyword(s):  
Carbon Dioxide ◽  
Ethylene Oxide ◽  
Catalytic Oxidation ◽  
Flow System ◽  
Oxidation Reactions ◽  
Direct Oxidation ◽  
Rate Of Reaction ◽  
Reaction Proceeds ◽  
Products Of Reaction ◽  
Kinetics Of

Experiments have been made using a flow system to determine the mechanism of the catalytic oxidation of ethylene on a silver catalyst. The effects of time of contact of the gases with the catalyst, gas concentration, and temperature have been investigated. The products of reaction are ethylene oxide, and carbon dioxide and water. There appear to be two processes whereby the carbon dioxide is formed: (1) by direct oxidation of the ethylene not via ethylene oxide, and (2) by the further oxidation of the ethylene oxide. The isomerization of ethylene oxide to acetaldehyde by the catalyst in the absence of any oxygen has also been examined. By comparison with the oxidation of ethylene oxide, it has been shown that this latter reaction proceeds to a large extent, and possibly entirely, through a preliminary isomerization of the ethylene oxide to acetaldehyde. The rate of oxidation of acetaldehyde is extremely rapid and no trace of acetaldehyde is found during the oxidation of ethylene or of ethylene oxide. Ethylene oxide forms on the catalyst an involatile deposit, which is oxidized away by oxygen, so that during oxidation reactions the quantity of it on the catalyst is kept low. The kinetics of the oxidation of ethylene, i.e. rate of reaction proportional to the oxygen concentration and slightly dependent on the ethylene pressure, are consistent with the view that ethylene reacts with oxygen adsorbed on the catalyst and that the slowest step in the whole series of reactions is the rate of adsorption of the oxygen. An energy of activation of about 27 kcal. was found for the production of ethylene oxide, and slightly less for the production of carbon dioxide and consumption of oxygen.

Reactivity of Nitrogen Oxides Towards Sodium Carbonate and Hydrogencarbonate Based Solid Sorbents

1996 ◽  
Vol 61 (12) ◽  
pp. 1709-1714
Author(s):  
Erich Lippert ◽  
Pavel Bach ◽  
Květoslava Stejskalová ◽  
Emerich Erdös ◽  
Karel Mocek
Keyword(s):  
Carbon Dioxide ◽  
Water Vapor ◽  
Nitrogen Oxides ◽  
Nitrogen Dioxide ◽  
Sodium Carbonate ◽  
Nitrogen Monoxide ◽  
Reaction Products ◽  
Solid Sorbents ◽  
Lower Reactivity ◽  
Technological Interest

The reactivity of nitrogen oxides towards sodium carbonate and hydrogencarbonate based solids was measured within a range of variables which is of technological interest. The reactivity is significant at lower temperatures only and is not affected by the presence of carbon dioxide or oxygen. Water vapor acts as a catalyst. Nitrogen dioxide is more reactive than nitrogen monoxide. The reactivity of the solid depends substantially on its origin and way of preparation. As compared with SO2 or HCl, nitrogen oxides exhibit a lower reactivity, presumably because the solid is blocked by the reaction products.

Potentials of gas chromatography in the determination of reaction products in the catalytic oxidation of ammonia to nitrogen(II) oxide

2007 ◽  
Vol 62 (12) ◽  
pp. 1170-1175
Author(s):  
V. I. Zheivot ◽  
T. A. Nikoro ◽  
V. N. Krivoruchko ◽  
L. I. Panina ◽  
L. G. Pinaeva ◽  
...  
Keyword(s):  
Gas Chromatography ◽  
Catalytic Oxidation ◽  
Reaction Products ◽  
Oxidation Of Ammonia

THE ROLE OF REACTION PRODUCTS IN THE SILVER-CATALYZED OXIDATION OF ETHYLENE

1960 ◽  
Vol 38 (11) ◽  
pp. 2256-2268 ◽  
Author(s):  
Kenneth E. Hayes
Keyword(s):  
Carbon Dioxide ◽  
Ethylene Oxide ◽  
Initial Rate ◽  
Flow System ◽  
Oxygen Exchange ◽  
Reaction Products ◽  
Exchange Reactions ◽  
Kinetics Of ◽  
Catalyzed Oxidation

Initial-rate studies of the kinetics of the silver-catalyzed oxidation of ethylene oxide and carbon dioxide in a flow system have been made. It was found that, using carefully purified reactants, the effect of added carbon dioxide was to suppress the formation of ethylene oxide only. The initial rate of the formation of ethylene oxide is given by the equation[Formula: see text]where r0 is the initial rate in the absence of CO2; m, n, and k are constants with m + n = 1.These results together with the results of oxygen exchange reactions between O18 and C2H4O16, CO216 and H2O16 are interpreted mechanistically.

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