1,721,160 research outputs found
A calorimetric study of the self-polymerization of a commercial monomer: An incident investigation
No full textIn this work the analysis of an incident in transport of dangerous goods is proposed. The objective of this study is to contribute to the determination of the causes that brought about the self-polymerization of commercial divinylbenzene (DVB 63%) contained in an isothermal container, in order to prevent this incident from happening in the future.
Time and conditions during transport/storage of monomers (in particular storage temperature) are very important factors that affect their aptitude of self-polymerization. In particular one hypothesis has been investigated: that the quantity of oxygen in the tanker was insufficient to activate properly the inhibition mechanism. Consequently, the self-polymerization of DVB and the inhibition mechanism of 4-tert-Butylcatechol (TBC) have been studied as a function of temperature and monomer exposure to air with Differential Scanning Calorimetry and Adiabatic Calorimetry techniques
TERAPIA DELLE ALTERAZIONI DELL'EQUILIBRIO ACIDO-BASE E DEL METABOLISMO IDRO-ELETTROLITICO
No full text
Sensitivity analysis for the thermal stability criteria of hydrogen peroxide
Full text linkChemical reactors carrying on exothermic processes may undergo to runaway reactions. To prevent from this hazard, Early Warning Detection Systems (EWDSs) can be used in industry, because they allow the on-line detection at an early stage of the runaway. The stability criterion of Hub and Jones is frequently implemented in EWDSs. Despite its simplicity during the detection step (the criterion is based just on
measurements of the temperatures inside the reactor and jacket), the effectiveness in distinguishing between dangerous and non-dangerous occurrence is strongly affected by the presence of noise in the monitored signals. Furthermore, the numerical methodology for the calculation of the derivative of the measured signals may be of great importance for the definition of alarm conditions. In this paper, the sensitivity analysis of the performances of Hub and Jones criterion with respect to the Savitzky and Golay
smoothing filter degree is discussed. The analysis is applied to experimental data on the decomposition of hydrogen peroxide 35%wt carried out in a Thermal Screening Unit
Screening Analysis for Hazard Assessment of Peroxides Decomposition
No full textIn this study the analysis of different kind of organic peroxides decomposition by screening calorimetry
is proposed. The aim is to analyze the kinetic and thermodynamic of the decomposition reactions and to
evaluate the consequences in particular when the process undergoes to thermal explosion and may be
the cause of incidents. Screening calorimetry data allow us to define the conditions and ranges of
temperature and pressure evolved during the reaction. In the experimental apparatus used (a screening
calorimeter), the experiments have been carried out safely even when there is a rapid and large increase
in temperature and pressure. Scanning and isothermal conditions has been investigated. An Early
Warning Detection System (EWDS) for thermal runaway based on the divergence criterion has also
been applied off-line to the experimental isothermal data, in order to evaluate the sensitivity of the
method applied to both temperature and pressure profiles. The results of the application of the EWDS
have been compared to the ones obtained by Hub and Jones criterion
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