4,369 research outputs found
USE OF SCREENING ANALYSIS CALORIMETRY IN THE STUDY OF PEROXIDES DECOMPOSITION.
No full textIn this study the analysis of di-tert-butyl peroxide decomposition in different organic solvents by screening calorimetry is proposed. Organic peroxides are liable to decompose exothermically at normal or high temperatures. The type of solvent changes the effects in the runaway behavior.
Screening calorimetry data allow us to define the conditions and ranges of temperature and pressure involved. In the experimental apparatus used, the experiments are carried out safely even when there is a rapid and large increase in temperature and pressure.
Screening calorimetry represents in this sense a first step in risk analysis studies and also a key in scaling up of processes.
Screening calorimetry data have to be validated by experiments carried out in more complex calorimeters, similar to industrial reactors (adiabatic and reaction calorimeters), but the use of the TSu makes it possible to save time and reduce the number of experiments with laboratory scale calorimeters. In this paper a comparison between screening and adiabatic data for hydrogen peroxide decomposition is shown
Analysis of peroxides decomposition by screening calorimetry
No full textIn this study the analysis of different kind of organic peroxides decomposition by screening calorimetry is proposed. Organic peroxides are liable to decompose exothermically at normal or high temperatures [1,2].
Screening calorimetry data allow us to define conditions and ranges of temperature and pressure evolved; useful results (such as onset temperature, time to maximum rate, maximum pressure, ...) are obtained. The experiments are carried out in safely even when there is rapid and large increases in temperature and pressure.
An Early Warning Detection System (EWDS) based on divergence criterion is also applied to experimental dat
Heritability of some in vivo measurements and conformation scores, and genetic correlations with post mortem data in young Italian Simmental bulls
No full textLa calorimetria di processo: uno strumento per il monitoraggio e controllo di reattori industriali
No full text
Development of a flexible low cost system of lab scale calorimeters
No full textA simple, low cost system of laboratory scale calorimeters is being developed in our laboratory for research, teaching and routine purposes. The system is computer controlled and has been assembled from commercially available components. Its use will be illustrated by a study of the hydrolysis of acetic anhydride
Determination of the heat transfer coefficient in polymerization reactors by temperature oscillation calorimetry
No full textStudio di processi di polimerizzazione in emulsione mediante l'uso di tecniche calorimetriche integrate
No full textApplicazione della Calorimetria a Temperatura Oscillante allo studio di processi di polimerizzazione
No full textTemperature Oscillation Calorimetry (TOC) is a technique for the on line determination
of heat transfer coefficient UA, and is therefore suitable for studying processes where there
is a large increase in the viscosity and a consequent decrease in UA as the reaction
proceeds.
The free radical polymerization of methyl methacrylate in ethyl acetate has been studied
in a stirred, jacketed calorimeter with a volume of two litres. Sinusoidal temperature oscillation
of amplitude 1-2°C and period 5-6 minutes are imposed on the fluid circulating in
the jacket. The heat transfer coefficient is obtained from an analysis of the oscillating
parts of the jacket and reactor temperatures, while the chemical heat flow is obtained from
the non-oscillating parts of these temperatures.
The results obtained show the utility of TOC in studying polymerization processes. A limitation
has been encountered with concentrated solution where both the temperature
oscillation and the value of UA may become irregular. Under these conditions a correlation
between UA and the stirred torque may be used to correct the values of UA
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