Peroxyformic acid has been recently assuming a growing importance due to the versatile oxidizing properties in several applications in the chemical industry. However, quite surprisingly, a lack of data exists about the kinetics of formation of this compound, an even more singular event considering that the acid, when used, is generally produced in situ via the reaction between formic acid and hydrogen peroxide. This paper is a contribution to fill this gap. A series of batch experiments were carried out to measure the conversion rate in the peroxyformic acid formation reaction in the temperature range 30-60 degrees C. The results from experiments were successfully interpreted through a kinetic mechanism consisting of the reversible formation of the peroxyformic acid and its irreversible decomposition to CO(2) and H(2)O, both catalyzed by hydrogen ions. With the considered kinetic mechanism, a pre-exponential factor of 13065.1 L(6) mol(-2) s(-1) and an activation energy of 43524.2 J mol(-1) were calculated. This last value and enthalpy and entropy of reaction derived from the kinetic data are in quite good accordance with the limited literature data available on this subject

Understanding and modeling of coal pyrolysis assume particular importance, since it is the first step of combustion and gasification processes. The complex reactions occurring during pyrolysis lead to difficulties in the process modeling. The aim of this work is to find a global kinetic model that well represents the pyrolysis of two different coals with opposite rank, a sub-bituminous and an anthracite coal, in order to carry out the kinetic parameters of the process. The Distributed Activation Energy Model (DAEM) was used to fit experimental data obtained with a thermogravimetric analysis. The model assumes that a series of first order parallel reactions occurs sharing the same pre-exponental factor, k(0), and having a continuous distribution of the activation energy. One of the limits of the standard Gaussian DAEM is that with this model is not possible to distinguish the primary from the secondary pyrolysis. A two Gaussians DAEM was developed considering that two classes of reactions take place having the same k(0) and different distribution of activation energy. Since in the model k0 is highly correlated with the mean activation energies, it was fixed at characteristic values taken from literature

Sulfur oxidation appears a very promising route for obtaining ultralow-sulfur fuels requested worldwide by the new regulation mandates. In this work, the oxidizing system constituted by hydrogen peroxide and formic acid was used to study the influence of the solvent on the oxidation rate of sulfur compounds in the organic phase. The experimentation was performed on organic sulfur compounds selected as representative of those contained in crude distillates. The organic solvent seems to play an important role in the reaction kinetics, indicating a strong influence of its aromaticity on the oxidation rate. A different kinetic was found for heterocyclic sulfur compounds such as benzo- and dibenzothiophene when compared with thiols and sulfides, indicating for the last ones a more complex reaction path.

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