Kinetics of the thermal reactions of ethylene. Part II. Ethylene–ethane mixtures

1968 ◽  
Vol 46 (14) ◽  
pp. 2427-2433 ◽  
Author(s):  
M. L. Boyd ◽  
M. H. Back
Keyword(s):  
Free Radical ◽  
Product Formation ◽  
Radical Chain ◽  
Thermal Reactions ◽  
Temperature Range ◽  
Initiation Step ◽  
Chain Polymerization ◽  
Main Effects ◽  
Kinetics Of ◽  
Simplified Mechanism

Mixtures of ethane and ethylene have been pyrolyzed in the temperature range 563–600 °C and at pressures from 30–60 cm. The products were similar to those obtained from the pyrolysis of ethylene by itself, described m Part I, with a marked increase in the yields of the saturated products. The initial rates of product formation and the dependence of these rates on the concentration of ethane suggest that the initiation step is the same as that proposed in the pyrolysis of ethylene alone, viz.[Formula: see text]and that the reaction[Formula: see text]is not an important source of radicals. A simplified mechanism is outlined to account for the main effects of ethane on the free radical chain polymerization.

Kinetics of the thermal reactions of ethylene. Part I

1968 ◽  
Vol 46 (14) ◽  
pp. 2415-2426 ◽  
Author(s):  
M. L. Boyd ◽  
T-M. Wu ◽  
M. H. Back
Keyword(s):  
Activation Energy ◽  
Molecular Weight ◽  
Free Radical ◽  
Induction Period ◽  
Pressure Range ◽  
Kcal Mole ◽  
Radical Chain ◽  
Thermal Reactions ◽  
Chain Polymerization ◽  
Kinetics Of

The pyrolysis of ethylene has been studied in the temperature range 500–600 °C and the pressure range 15–60 cm. The main products were ethane, propylene, butene, butadiene, and a polymer of molecular weight corresponding to C8 or higher. Small amounts of methane, butane, unsaturated C5, unsaturated C6, and benzene were also measured. Of the main products, propylene, butene, and butadiene showed an induction period, as long as several minutes at the lowest temperature. The order with respect to ethylene of ethane, propylene, and butene was close to two and the activation energy of the rates was approximately 40 kcal/mole. The results have been interpreted in terms of a free radical chain polymerization. It is suggested that the polymer formed is unstable and decomposes to yield the products for which an induction period was observed.

Mechanism of the Pyrolysis of Acetylene

1971 ◽  
Vol 49 (13) ◽  
pp. 2199-2204 ◽  
Author(s):  
M. H. Back
Keyword(s):  
Free Radical ◽  
Chain Mechanism ◽  
Kinetic Characteristics ◽  
Radical Chain ◽  
Temperature Range ◽  
Decomposition Reactions ◽  
Radical Chain Mechanism ◽  
Initiation Reaction ◽  
Kinetics Of ◽  
Subsequent Addition

A free radical chain mechanism is presented to describe the kinetics of the pyrolysis of acetylene over the temperature range 700–2400 °K. The mechanism is based on the following initiation reaction[Formula: see text]and subsequent addition, abstraction, and decomposition reactions of the radicals involved are shown to account for the products observed and for the kinetic characteristics of the reaction.

THE KINETICS OF THE THERMAL REACTIONS OF ETHYLENE OXIDE

1963 ◽  
Vol 41 (12) ◽  
pp. 2956-2961 ◽  
Author(s):  
M. Lynne Neufeld ◽  
Arthur T. Blades
Keyword(s):  
Free Radicals ◽  
Free Radical ◽  
Ethylene Oxide ◽  
Thermal Reactions ◽  
Kinetics Of

The thermal reactions of ethylene oxide in the presence of an excess of propylene have been studied as a function of pressure and it has been found that there are two sets of products, acetaldehyde and free radicals, presumably methyl and formyl. These products are believed to arise from an excited acetaldehyde intermediate. Some evidence has been obtained for the occurrence of a surface-catalyzed rearrangement to acetaldehyde but the free radical products are uninfluenced by surface.

THE KINETICS OF THE THERMAL DECOMPOSITIONS OF THE LOWER PARAFFINS: V. THE NITRIC OXIDE INHIBITED DECOMPOSITION OF n-BUTANE

1940 ◽  
Vol 18b (1) ◽  
pp. 1-11 ◽  
Author(s):  
E. W. R. Steacie ◽  
H. O. Folkins
Keyword(s):  
Nitric Oxide ◽  
Thermal Decomposition ◽  
Free Radical ◽  
High Pressures ◽  
Free Radical Processes ◽  
Temperature Range ◽  
Radical Recombination ◽  
Radical Processes ◽  
Kinetics Of ◽  
Good Agreement

A detailed investigation of the inhibition by nitric oxide of the thermal decomposition of n-butane has been carried out over the temperature range 500° to 550 °C.In all cases it was found that inhibition decreased with increasing butane concentration. This suggests that radical recombination occurs in the normal decomposition by ternary collisions with butane molecules acting as third bodies.The activation energies of the normal and inhibited reactions have been determined. For high pressures the two values are in good agreement, viz., 58,200 and 57,200 cal. per mole respectively. The products of the inhibited reaction were also found to be the same as those of the normal reaction.It is concluded that free radical processes predominate, involving comparatively short chains.

Kinetics of Ionic and Free Radical Chain Reactions in Radiation Chemistry

1969 ◽  
Vol 6 (5) ◽  
pp. 466-473
Author(s):  
Donald H. Martin ◽  
Robert B. Taylor ◽  
Ffrancon Williams
Keyword(s):  
Free Radical ◽  
Radiation Chemistry ◽  
Radical Chain ◽  
Chain Reactions ◽  
Kinetics Of

scholarly journals Inhibiting oxidation and enhancing absorption characteristics of sodium sulfite for SO2 removal from the non-ferrous smelting flue gas

2020 ◽  
Vol 26 (2) ◽  
pp. 200043-0
Author(s):  
Yongpeng Ma ◽  
Dongli Yuan ◽  
Xiaojing Zhang ◽  
Zan Qu ◽  
Wenjun Huang
Keyword(s):  
Free Radical ◽  
Flue Gas ◽  
Absorption Capacity ◽  
Inhibition Mechanism ◽  
Radical Chain ◽  
Consumption Rates ◽  
Free Radical Chain Reaction ◽  
Kinetics Of ◽  
Radical Chain Reaction ◽  
Absorption Characteristics

In this work, we investigated the absorption characteristics of SO2 and the effect of inhibitors on the desulfurization performances of Na2SO3. The results showed that the NO2 had a competitive effect with SO2 on SO32- which resulted in a significant decrease in the absorption capacity of SO2. O2 in the flue gas could decrease the absorption capacity of SO2 due to the oxidation of Na2SO3. Besides, Na2S2O3 had more excellent inhibiting effect on the oxidation of SO32-; the inhibition mechanism is understood on the basis of the free radical chain reaction, whereby S2O32- combined with the sulfite free radical to form an inert substance, thus, quenching the reaction of free radical with the dissolved oxygen and invariably inhibiting the oxidation of SO32-. Furthermore, the intrinsic and the apparent oxidation kinetics of Na2SO3 oxidation process with Na2S2O3 were investigated to explain the relationships between consumption rates of SO32- and the absorption capacities of SO2 under different components in flue gas and absorption solution.

Sign in / Sign up

Export Citation Format

Share Document