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Abstract  

Theoretical consideration has been made of the non-isothermal kinetics of consecutive reactions based on the superposition principle. In the model the first reaction product reacts to form the final product and the two reactions proceed independently. The amount of the first reaction product and the production rate of the final product have been obtained as a function of time for isothermal cases and as a function of the reduced times for non-isothermal cases.

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Abstract  

The transformation equation for the thermokinetics of consecutive first-order reactions has been deduced, and a thermokinetic research method of irreversible consecutive first-order reactions, which can be used to determine the rate constants of two steps simultaneously, is proposed. The method was validated and its theoretical basis was verified by the experimental results.

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loss. Several models were tested and the initial values of the parameters of E a and log A were optimized. As shown in Fig. 6 , a two-step consecutive reaction model was the most-probable one. The first step for dehydration process of hydrogen

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can be split into two rate equations derived for the one consecutive reaction with steps shown in Fig. 7 . The rate constants of each step in the m -dinitrobenzene hydrogenation were evaluated: m -nitroaniline formation ( k 1 ) and m

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equal to 10 5 –10 9 M −1 s −1 [ 22 – 24 ]. This process leads to the appearance of a dibenzoazepine radical, which dimerizes and is oxidized to a blue–colored dimeric radical dication, (TCA •+ ) 2 , in the two consecutive reactions between the S 2 O 8

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Abstract  

Slow pyrolysis of walnut shell which is a cheap and abundantly available solid waste was carried out using thermogravimetric analysis. The effects of raw material heating rate on the pyrolysis properties and kinetic parameters were investigated. A two-step consecutive reaction model were used to simulate the pyrolysis process. The kinetic parameters were established by using the pattern search method. Comparison between experimental data and the model prediction indicated that the two-step consecutive reaction model can better describe the slow pyrolysis of walnut shell as the formation of an intermediate during the pyrolysis process was taken into account.

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Abstract  

Reactions with large negative enthalpy changes are often encountered in the chemical industry. Sometimes they give rise to technical dangers and hazards, including explosions. This investigation concentrates on examination of adiabatic temperature-time-curves and gives non-linear optimization procedures for obtaining kinetic parameters of simple decompositions,e.g. o-nitrobezaldehyde, two types of autocatalysis, consecutive reactions and competitive consecutive reactions. The advantage of this computing method is that only differential kinetic equations are needed.

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