Consecutive reactions in the thermal decomposition of phenylalkyldiazirines

1977 ◽  
Vol 55 (20) ◽  
pp. 3596-3601 ◽  
Author(s):  
Michael T. H. Liu ◽  
Barry M. Jennings
Keyword(s):  
Thermal Decomposition ◽  
Kinetic Parameters ◽  
Diazo Compounds ◽  
First Order ◽  
Temperature Range ◽  
Decomposition Reactions ◽  
Consecutive Reactions ◽  
Rate Processes ◽  
Subsequent Decomposition

The thermal decomposition of phenyl-n-butyldiazirine and of phenylmethyldiazirine in DMSO and in HOAc have been investigated over the temperature range 80–130 °C. The intermediate diazo compounds, 1-phenyl-1-diazopentane and 1-phenyldiazoethane respectively have been detected and isolated. The decomposition of phenyl-n-butyldiazirine and the subsequent decomposition of its product, 1-phenyl-1-diazopentane, are an illustration of consecutive reactions. The kinetic parameters for the isomerization and decomposition reactions have been determined. The isomerization of phenylmethyldiazirine to 1-phenyldiazoethane is first order and probably unimolecular but the kinetics for the subsequent reactions of 1-phenyldiazoethane are complicated by several competing rate processes.

THE THERMAL DECOMPOSITION OF PERACETIC ACID IN AROMATIC SOLVENTS

1963 ◽  
Vol 41 (7) ◽  
pp. 1826-1831 ◽  
Author(s):  
F. W. Evans ◽  
A. H. Sehon
Keyword(s):  
Thermal Decomposition ◽  
Rate Constant ◽  
Peracetic Acid ◽  
First Order ◽  
Aromatic Solvents ◽  
Temperature Range ◽  
Polymeric Compounds

The thermal decomposition of peracetic acid in toluene, benzene, and p-xylene was studied over the temperature range 75–95°C. The main products of decomposition were found to be CH4, CO2, CH3COOH; small amounts of methanol, phenols, and polymeric compounds were also detected.The rate of the overall decomposition was first order with respect to peracetic acid, and the results could be explained by postulating the participation of the two simultaneous reactions:[Formula: see text] [Formula: see text]The rate constant of reaction (1) was independent of the solvent, whereas k2 was dependent on the solvent. The ratio k2/k1 was about 10.

scholarly journals Kinetic Analysis of the Thermal Decomposition of Polymer-Bonded Explosive Based on PETN: Model-Fitting Method and Isoconversional Method

2020 ◽  
Vol 2020 ◽  
pp. 1-12
Author(s):  
Trung Toan Nguyen ◽  
Duc Nhan Phan ◽  
Van Thom Do ◽  
Hoang Nam Nguyen
Keyword(s):  
Thermal Decomposition ◽  
Kinetic Parameters ◽  
Model Fitting ◽  
Isoconversional Method ◽  
Isothermal Tg ◽  
Decomposition Reactions ◽  
Model Free ◽  
Negative Effect ◽  
Adverse Influence ◽  
Vacuum Stability Test

This work investigates kinetics and thermal decomposition behaviors of pentaerythritol tetranitrate (PETN) and two polymer-bonded explosive (PBX) samples created from PETN (named as PBX-PN-85 and PBX-PP-85) using the vacuum stability test (VST) and thermogravimetry (TG/DTG) techniques. Both model-free (isoconversional) and model-fitting methods were applied to determine the kinetic parameters of the thermal decomposition. It was found that kinetic parameters obtained by the modified Kissinger–Akahira–Sunose method (using non-isothermal TG/DTG data) were close to those obtained by the isoconversional and model-fitting methods that use isothermal VST data. The activation energy values of thermal decomposition reactions were 125.6–137.1, 137.3–144.9, and 143.9–152.4 kJ·mol−1 for PBX-PN-85, PETN, and PBX-PP-85, respectively. The results demonstrate the negative effect of the nitrocellulose-based binder in reducing the thermal stability of single PETN, while the polystyrene-based binder seemingly shows no adverse influence on the thermal decomposition of PETN in our presented PBX compositions.

Thermal processing of sewage sludge by drying, pyrolysis, gasification and combustion

2001 ◽  
Vol 44 (10) ◽  
pp. 333-339 ◽  
Author(s):  
P. Stolarek ◽  
S. Ledakowicz
Keyword(s):  
Thermal Decomposition ◽  
Sewage Sludge ◽  
Kinetic Parameters ◽  
Thermal Processing ◽  
Combustion Process ◽  
Order Kinetic ◽  
Municipal Sludge ◽  
Pyrolysis Kinetics ◽  
Exponential Factor ◽  
First Order

Thermal processing of sewage sludge including drying, pyrolysis and gasification or combustion may be an alternative to other ways of utilising it. In this paper thermogravimetric analysis (TGA) was employed in the investigation of thermal decomposition of sewage sludge. The kinetic parameters of drying, pyrolysis and gasification or combustion of sewage sludge have been determined in an inert-gas (argon) and additionally some series of the sludge decomposition experiments have been carried out in air, in order to compare pyrolysis and combustion. The pyrolysis char has been gasified with carbon dioxide. A typical approach to the kinetics of thermal decomposition of a solid waste is to divide the volatile evolution into a few fractions (lumps), each of which is represented by a single first-order reaction. If these lumps are assumed to be non-interacting and evolved by independent parallel reactions the first-order kinetic parameters such as activation energy Ei and pre-exponential factor Ai can be determined from mathematical evaluation of TG or DTG curves. The object of our investigations was a municipal sludge from the two wastewater treatment plants (WTP) in Poland. The experiments have been carried out in the thermobalance Mettler-Toledo type TGA/SDTA851 LF, in the temperature range 30-1,000°C. Five different values of heating rate have been applied β = 2, 5, 10, 15 and 20 K/min. The values of Ei and Ai have been determined for all recognised lumps of gaseous products. The method employed has also revealed its usefulness for the determination of kinetic parameters for municipal sludge, that possess an undefined content. An alternative route to combustion of sewage sludge is its gasification, which significantly increases the gaseous product (pyrolytic gas + syngas). Besides pyrolysis kinetics, gasification or combustion process kinetics have also been determined.

ChemInform Abstract: Kinetic Parameters for the Thermal Decomposition Reactions of CrO3 in Air.

ChemInform ◽  
1989 ◽  
Vol 20 (35) ◽  
Author(s):  
Y. LAUREIRO ◽  
M. GAITAN ◽  
A. JEREZ ◽  
C. PICO ◽  
M. L. VEIGA
Keyword(s):  
Thermal Decomposition ◽  
Kinetic Parameters ◽  
Decomposition Reactions

scholarly journals Thermal decomposition of cobalt(III), nickel(II), copper(II), palladium(II) and platinum(II) complexes of N-allyl-N'-(4'-methylthiazol)-2ylthiourea

2011 ◽  
Vol 7 (3) ◽  
pp. 1395-1398 ◽  
Author(s):  
Naeema H. M. Yarkandi
Keyword(s):  
Thermal Decomposition ◽  
Kinetic Parameters ◽  
Structural Properties ◽  
Temperature Range ◽  
Mass Losses ◽  
Three Stages ◽  
Decomposition Stages ◽  
Dta Curves ◽  
Two Stages ◽  
Free Metal

Thermal decomposition of Co(III), Cu(II), Ni(II), Pd(II), and Pt(II) complexes of N-allyl-N'-(4'-methylthiazol)-2ylthiourea (AllMeTzTu), HL, have been studied by TG, DTG, and DTA curves. The complexes have the molecular formulae as CoL3.H2O, [Cu(HL)Cl2]0.5H2O and [CuL2(H2O)2]  a square for ML2 (M = NiII, PdII and PtII), and [Pd(HL)Cl2]. The TG curves show that the four-coordinate complexes decompose in two stages to yield a free metal  ,with exception  [Pd(HL)Cl2] which gives PdS, as a residue, while the two six-coordinate complexes CoL3.H2O, and [CuL2(H2O)2]  decompose in three stages to yield Co and Cu residues. The initial mass losses correspond to elimination of allylamine radical for all complexes in the same temperature range; and with MeTz when the temperature range extended beyond that range of the first stage  for Pd(II) and Pt(II) complexes. Kinetic parameters (E#, n, ΔH#, ΔS#, ΔG#) of the decomposition stages are determined and correlated with bonding and structural properties of the complexes. 

scholarly journals Kinetics of the thermal decomposition of pine needles

2015 ◽  
Vol 7 (1) ◽  
pp. 5-22 ◽  
Author(s):  
Alok Dhaundiyal ◽  
Jitendra Gangwar
Keyword(s):  
Thermal Decomposition ◽  
Kinetic Parameters ◽  
Pine Needles ◽  
Experimental Results ◽  
Pyrolysis Process ◽  
Order Model ◽  
Exponential Factor ◽  
First Order ◽  
Model Free ◽  
Good Agreement

Abstract A kinetic study of the pyrolysis process of pine needles was examined using a thermogravimetric analyser. The weight loss was measured in nitrogen atmosphere at a purge flow rate of 100 ml/min. The samples were heated over a range of temperature of 19°C–600°C with a heating rate of 10°C/min. The results obtained from the thermal decomposition process indicate that there are three main stages: dehydration, active and passive pyrolysis. The kinetic parameters for the different samples, such as activation energy and pre-exponential factor, are obtained by the shrinking core model (reaction-controlled regime), the model-free, and the first-order model. Experimental results showed that the shrinking model is in good agreement and can be successfully used to understand degradation mechanism of loose biomass. The result obtained from the reaction-controlled regime represented actual values of kinetic parameters which are the same for the whole pyrolysis process; whereas the model-free method presented apparent values of kinetic parameters, as they are dependent on the unknown function ϕ(C), on the sum of the parameters of the physical processes, and on the chemical reactions that happen simultaneously during pyrolysis. Experimental results showed that values of kinetic constant from the first-order model and the SCM are in good agreement and can be successfully used to understand the behaviour of loose biomass (pine needles) in the presence of inert atmosphere. Using TGA results, the simulating pyrolysis can be done, with the help of computer software, to achieve a comprehensive detail of the devolatilization process of different types of biomasses.

KINETICS AND MECHANISMS OF THE PYROLYSIS OF DIMETHYL ETHER: II. THE REACTION INHIBITED BY NITRIC OXIDE AND PROPYLENE

1963 ◽  
Vol 41 (8) ◽  
pp. 1993-2008 ◽  
Author(s):  
D. J. McKenney ◽  
B. W. Wojciechowski ◽  
K. J. Laidler
Keyword(s):  
Nitric Oxide ◽  
Thermal Decomposition ◽  
Dimethyl Ether ◽  
Chain Process ◽  
Maximal Inhibition ◽  
First Order ◽  
Temperature Range ◽  
Maximum Inhibition ◽  
A Chain

The thermal decomposition of dimethyl ether, inhibited by nitric oxide and by propylene, was studied in the temperature range of 500 to 600 °C. About 1.5 mm of nitric oxide gave maximal inhibition, the rate then being approximately 8% of the uninhibited rate. With propylene, approximately 70 mm gave maximal inhibition, the rate being slightly higher than that using nitric oxide (~12.5% of the uninhibited rate). In both cases the degree of inhibition was independent of the ether pressure. In the maximally inhibited regions both reactions are three-halves order with respect to ether pressure. As the pressure of nitric oxide was increased beyond 10–15 mm, the overall rate increased, and in this region the reaction is first order with respect to both nitric oxide and ether. A 50:50 mixture of CH3OCH3 and CD3OCD3, with enough NO to ensure maximum inhibition, was pyrolyzed. Even at very low percentage decomposition the CD3H/CD4 ratio was approximately the same as that in the uninhibited decomposition, proving that the inhibited reaction is largely a chain process. Detailed inhibition mechanisms are proposed in which the inhibitor is involved both in initiation and termination reactions.

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