The reaction of methanol vapour with silver(I) oxide

1964 ◽  
Vol 17 (5) ◽  
pp. 529
Author(s):  
JA Allen
Keyword(s):  
Carbon Dioxide ◽  
Thermal Decomposition ◽  
Carbon Monoxide ◽  
Gas Phase ◽  
Kinetic Data ◽  
Kcal Mole ◽  
Collision Model ◽  
Temperature Range ◽  
Methanol Vapour ◽  
The Mean

The reaction of methanol with silver(I) oxide has been studied in the temperature range 56.5-78.4�. For complete reduction of the oxide at 78.4�, the available oxygen is fully accounted for by the products, formaldehyde, formic acid, carbon monoxide, carbon dioxide, and water. In the temperature range 56.5-70.2� the net measured rates of formation of these products are expressed by equations of the form, ������������������ rate = Aexp(-E/RT), and the kinetic data are interpreted as the consecutive formation of the products on the surface without complete desorption to the gas phase between each step. For the dominant product, carbon dioxide, at the mean temperature the values of A and E are 1028.5 μg oxygen per minute and 41.3 kcal mole-1 respectively. The former is interpreted in terms of a simple collision model and the latter compared with values obtained for the thermal decomposition of the oxide.

Comparison of Emission Levels of Motor Cars, Motorcycles, and Tricycles Using Petrol Engines in Southwestern Nigeria

2021 ◽  
Vol 900 ◽  
pp. 183-187
Author(s):  
Odunlami Olayemi Abosede ◽  
Akeredolu Funso Alaba
Keyword(s):  
Carbon Dioxide ◽  
Carbon Monoxide ◽  
Carbon Dioxide Emissions ◽  
Mean Value ◽  
Southwestern Nigeria ◽  
Mean Values ◽  
Mobile Sources ◽  
Southwest Nigeria ◽  
The Mean ◽  
European Standards

The emissions of carbon monoxide, carbon dioxide, and hydrocarbon from four stroke-powered motorcars and two stroke-powered motorcycles and tricycles in Southwest Nigeria were examined using an automotive 4-gas analyer. Results show that tricycles produced more hydrocarbon and carbon monoxide emissions than motorcycles, while motorcycles emitted more of these pollutants than the gasoline fueled motor cars. (The gasoline fueled motorcars produced lowest hydrocarbon and carbon monoxide while the tricycles produced the highest hydrocarbon and carbon monoxide emissions). On the contrary, motor cars had the highest mean value of carbon dioxide followed by the motorcycles, while tricycles had the least. This could be attributed to the presence of the catalytic converters in some of the motor cars oxidizing carbon monoxide to carbon dioxide. The mean values of hydrocarbon, carbon monoxide and carbon dioxide emissions from motorcars are 630ppm, 10200ppm and 59900ppm. This is much higher than the NESREA (National Environmental standards and Regulations Enforcement Agency) standards as well as Euro II and Euro III (European standards) for vehicular emission. The mean values for hydrocarbon, carbon monoxide and carbon dioxide emissions from motorcycles and tricycles are (2150ppm, 21530ppm and 31200ppm) and (2820ppm, 24880ppm and 38710ppm) respectively. These results do not comply with Nigeria and European emission standards for hydrocarbon, and carbon monoxide. Tricycles and motorcycles account for higher concentrations of hydrocarbon and carbon monoxide pollutants from mobile sources, while they emit carbon dioxide minimally.

COMPARATIVE ANALYSIS OF THE CONTENT OF TOXIC SUBSTANCES IN THE GAS PHASE OF AEROSOL OF CIGARETTES AND HEATED TOBACCO STICKS FOR ELECTRIC TOBACCO HEATING SYSTEMS

2020 ◽  
Author(s):  
С.Н. МЕДВЕДЕВА ◽  
Т.А. ПЕРЕЖОГИНА ◽  
Е.В. ГНУЧИХ
Keyword(s):  
Thermal Decomposition ◽  
Carbon Monoxide ◽  
Comparative Analysis ◽  
Gas Phase ◽  
Control Sample ◽  
Toxic Substances ◽  
Heating Systems

Представлены результаты анализа содержания монооксида углерода, бензола, 1,3-бутадиена в газовой фазе аэрозоля (ГФА) образцов нагреваемых табачных палочек (стики) для электрических систем нагревания табака, пяти марок коммерческих сигарет, контрольной сигареты 3R4F с помощью тестирования на курительной машине в стандартном режиме прокуривания ISO и интенсивном ISO Intense. Установлено значительное снижение содержания монооксида углерода, бензола и 1,3-бутадиена в аэрозоле образцов стиков по режиму ISO Intense и ISO. Количество образующегося монооксида углерода в ГФА образцов стиков составляет 2% от его содержания в ГФА образца контрольных сигарет 3R4F, что подтверждает отсутствие процессов термического разложения (пиролиза) табака. Определено, что в ГФА образцов стиков содержится значительно меньше вредных и потенциально опасных соединений. Установлено снижение содержания бензола и 1,3-бутадиена более чем на 99% по сравнению с контрольным образцом 3R4F и пятью образцами популярных в России марок сигарет. The results of the analysis of the content of carbon monoxide, benzene, 1,3-butadiene in the aerosol gas phase (AGPh) of heated tobacco sticks for electric tobacco heating systems, five brands of commercial cigarettes, 3R4F control cigarette using testing on a Smoking machine in standard ISO smoking mode and ISO Intense are presented. A significant decrease in the content of carbon monoxide, benzene and 1,3-butadiene in stick aerosols according to the ISO Intense and ISO modes was found. The amount of carbon monoxide produced in the effluent AGPh is 2% of its content in the AGPh of 3R4F control cigarettes, which confirms the absence of thermal decomposition (pyrolysis) of tobacco. It was determined that the AGPh of verses contains significantly fewer harmful and potentially dangerous compounds. A decrease in the content of benzene and 1,3-butadiene was found by more than 99% compared to the control sample of 3R4F cigarettes and five brands of cigarettes popular in Russia.

The gas-phase photochemistry and thermal decomposition of glyoxylic acid

1985 ◽  
Vol 63 (2) ◽  
pp. 542-548 ◽  
Author(s):  
R. A. Back ◽  
S. Yamamoto
Keyword(s):  
Thermal Decomposition ◽  
Carbon Monoxide ◽  
Absorption Spectrum ◽  
Gas Phase ◽  
Singlet State ◽  
Glyoxylic Acid ◽  
Static System ◽  
First Order ◽  
Increasing Temperature ◽  
Homogeneous Formation

The photolysis of glyoxylic acid vapour has been studied at five wavelengths, 382, 366, 346, 275, and 239 nm, and pressures from about 1 to 6 Torr, at a temperature of 355 K. Major products were CO2 and CH2O, initially formed in almost equal amounts, while minor products were CO and H2. Except at 382 nm, the system was complicated by the rapid secondary photolysis of CH2O. Three primary processes are suggested, each involving internal H-atom transfer followed by dissociation.The absorption spectrum is reported and shows the three distinct absorption systems. A finely-structured spectrum from about 320 to 400 nm is attributed to a transition to the first excited π* ← n+ singlet state; a more diffuse absorption ranging from about 290 nm to a maximum at 239 nm is assigned to the π* ← n− state, while a much stronger absorption beginning below 230 nm is attributed to the π* ← π transition. Product ratios vary with wavelength and depend on which excited state is involved.The thermal decomposition was studied briefly in a static system at temperatures from 470 to 710 K and pressures from 0.4 to 8 Torr. Major products were again CO2 and CH2O, but the latter was always less than stoichiometric. First-order rate constants for the apparently homogeneous formation of CO2 are described by Arrhenius parameters log A (s−1) = 7.80 and E = 30.8 kcal/mol. Carbon monoxide and H2 were minor products, and the CO/CO2 ratio increased with increasing temperature and showed some surface enhancement at lower temperatures. The SF6-sensitized thermal decomposition of glyoxylic acid, induced by a pulsed CO2 laser, was briefly studied, with temperatures estimated to be in the 1100–1600 K range, and the CO/CO2 ratio increased with increasing temperature, continuing the trend observed in the static system.

Theoretical Study of the Kinetics and Mechanism of the Thermal Decomposition of 3-Oxetanone in the Gas Phase

2017 ◽  
Vol 42 (1) ◽  
pp. 36-43 ◽  
Author(s):  
Mohammad Khavani ◽  
Javad Karimi
Keyword(s):  
Thermal Decomposition ◽  
Carbon Monoxide ◽  
Ethylene Oxide ◽  
Gas Phase ◽  
Transition States ◽  
Decomposition Reaction ◽  
Kinetics And Mechanism ◽  
Methyl Radical ◽  
Decomposition Products ◽  
Concerted Mechanism

The kinetics and mechanism of the thermal decomposition reaction of 3-oxetanone in the gas phase were studied using quantum chemical calculations. The major products of this reaction are formaldehyde, ketene, carbon monoxide, ethylene oxide, ethylene and methyl radical. Formaldehyde, ketene, carbon monoxide and ethylene oxide are the initial decomposition products and other species are the products of ethylene oxide decomposition. The results of B3LYP and QCISD(T) calculations reveal that thermal decomposition of 3-oxetanone to ethylene oxide and carbon monoxide is more probable than to formaldehyde and ketene from an energy viewpoint. Moreover, quantum theory of atoms in molecules and natural bond orbital analysis indicate that 3-oxetanone decomposition to formaldehyde, ketene, carbon monoxide and ethylene occurs via a concerted mechanism and bonds that are involved in the transition states have a covalent character. Moreover, the calculated changes in bond lengths in the transition states reveal that bond breaking and new bond formation occur asynchronously in a concerted mechanism.

Using Amsorb to Detect Dehydration of CO2Absorbents Containing Strong Base

2002 ◽  
Vol 97 (2) ◽  
pp. 454-459 ◽  
Author(s):  
Erich Knolle ◽  
Wolfgang Linert ◽  
Hermann Gilly
Keyword(s):  
Carbon Dioxide ◽  
Carbon Monoxide ◽  
Water Content ◽  
Color Change ◽  
Anesthesia Machine ◽  
Strong Base ◽  
Carbon Monoxide Formation ◽  
The Mean ◽  
Indicator Dye

Background Because Amsorb changes color when it dries, the authors investigated whether Amsorb combined with different strong base-containing carbon dioxide absorbents signals dehydration of such absorbents. Methods Five different carbon dioxide absorbents (1,330 g) each topped with 70 g of Amsorb were dried in an anesthesia machine (Modulus CD, Datex-Ohmeda, Madison, WI) with oxygen (Amsorb layer at the fresh gas inflow site). As soon as a color change was detected in the Amsorb, the authors tested the samples for a change in weight and carbon monoxide formation from 7.5% desflurane or 4% isoflurane. In a different experiment with the five absorbents, Amsorb was layered at the drying gas outflow site. In further experiments, the authors tested for a color change in Amsorb from drying and rehydrating and from drying with nitrogen. Finally, they dried a mixture of Amsorb and 1% NaOH and examined it for color change. Results In the experiments with Amsorb layered at the inflow, the Amsorb changed color when the water content of the samples was only marginally reduced (to a mean 13.6%), and no carbon monoxide formed. With Amsorb layered at the outflow, it changed color when the mean water content of the samples was reduced to 8.8%, and carbon monoxide formation was detected to varying degrees. The color change was independent of the drying gas and could be reversed by rehydrating. Adding NaOH to Amsorb prevented a color change. Conclusions Dehydration in strong base-containing absorbents can reliably be indicated before carbon monoxide is formed when Amsorb is layered at the fresh gas inflow. The authors assume that the indicator dye in Amsorb changes color on drying because of the absence of strong base in this absorbent.

scholarly journals Gas-Phase Photocatalytic Oxidation of Dimethylamine: The Reaction Pathway and Kinetics

2007 ◽  
Vol 2007 ◽  
pp. 1-4
Author(s):  
Anna Kachina ◽  
Sergei Preis ◽  
Juha Kallas
Keyword(s):  
Carbon Dioxide ◽  
Gas Phase ◽  
Continuous Flow ◽  
Kinetic Data ◽  
Photocatalytic Oxidation ◽  
Reaction Pathway ◽  
Tubular Reactor ◽  
Order Process ◽  
First Order ◽  
Long Run

Gas-phase photocatalytic oxidation (PCO) and thermal catalytic oxidation (TCO) of dimethylamine (DMA) on titanium dioxide was studied in a continuous flow simple tubular reactor. Volatile PCO products of DMA included ammonia, formamide, carbon dioxide, and water. Ammonia was further oxidized in minor amounts to nitrous oxide and nitrogen dioxide. Effective at 573 K, TCO resulted in the formation of ammonia, hydrogen cyanide, carbon monoxide, carbon dioxide, and water. The PCO kinetic data fit well to the monomolecular Langmuir-Hinshelwood model, whereas TCO kinetic behaviour matched the first-order process. No deactivation of the photocatalyst during the multiple long-run experiments was observed.

THE THERMAL DECOMPOSITION OF PERACETIC ACID IN THE VAPOR PHASE

1963 ◽  
Vol 41 (7) ◽  
pp. 1819-1825 ◽  
Author(s):  
C. Schmidt ◽  
A. H. Sehon
Keyword(s):  
Thermal Decomposition ◽  
Vapor Phase ◽  
Dissociation Energy ◽  
Peracetic Acid ◽  
Kcal Mole ◽  
Temperature Range ◽  
Primary Reactions

The thermal decomposition of peracetic acid in a stream of toluene was studied over the temperature range 127–360 °C. The main products of the reaction were CO2, CH3COOH, C2H6, CH4, HCHO, O2, and traces of CO. Dibenzyl was also formed.The overall decomposition of peracetic acid was partly heterogeneous and was represented by the two parallel primary reactions[Formula: see text] [Formula: see text]The dissociation energy of the O—O bond in peracetic acid was estimated to be 30–34 kcal/mole.

The thermal decomposition of RDX at temperatures below the melting point. II. Activation energy

1970 ◽  
Vol 23 (4) ◽  
pp. 749 ◽  
Author(s):  
JJ Batten ◽  
DC Murdie
Keyword(s):  
Activation Energy ◽  
Thermal Decomposition ◽  
Melting Point ◽  
Kinetic Parameter ◽  
Arrhenius Equation ◽  
Kcal Mole ◽  
Decomposition Products ◽  
Sample Geometry ◽  
Temperature Range ◽  
Definition Of

The activation energy has been determined in the temperature range 170-198�. If the sample was spread the activation energy was independent of the definition of the kinetic parameter substituted in the Arrhenius equation and was 63 kcal mole-1. In the case of the unspread samples the activation energies of the induction, acceleration, and maximum rates were 49, 43, and 62 kcal mole-1 respectively. The effect that sample geometry has on the activation energy is attributed to gaseous decomposition products influencing the reaction.

scholarly journals RELAP5-3D Code Includes ATHENA Features and Models

2006 ◽  
Author(s):  
Richard A. Riemke ◽  
Cliff B. Davis ◽  
Richard R. Schultz
Keyword(s):  
Carbon Dioxide ◽  
Carbon Monoxide ◽  
Gas Phase ◽  
Molten Salts ◽  
Working Fluid ◽  
Hydraulic Systems ◽  
Sodium Potassium ◽  
Working Fluids ◽  
Noncondensable Gases ◽  
Magnetohydrodynamic Model

Version 2.3 of the RELAP5-3D computer program includes all features and models previously available only in the ATHENA version of the code. These include the addition of new working fluids (i.e., ammonia, blood, carbon dioxide, glycerol, helium, hydrogen, lead-bismuth, lithium, lithium-lead, nitrogen, potassium, sodium, and sodium-potassium) and a magnetohydrodynamic model that expands the capability of the code to model many more thermal-hydraulic systems. In addition to the new working fluids along with the standard working fluid water, one or more noncondensable gases (e.g., air, argon, carbon dioxide, carbon monoxide, helium, hydrogen, krypton, nitrogen, oxygen, sf6, xenon) can be specified as part of the vapor/gas phase of the working fluid. These noncondensable gases were in previous versions of RELAP5-3D. Recently four molten salts have been added as working fluids to RELAP5-3D Version 2.4, which has had limited release. These molten salts will be in RELAP5-3D Version 2.5, which will have a general release like RELAP5-3D Version 2.3. Applications that use these new features and models are discussed in this paper.

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