In this paper, several small-scale screening test methods were discussed on evaluating the thermal hazard of reactive substances.
Generally the sensitivities of DSC and ARC are not high enough to evaluate the thermal hazards for all reactive substance,
especially, for those of complex reactions containing a phase and/or chemical reaction mechanism change in the lower temperature
range. Using the C80, however, the reaction can easily be detected in the lower temperature range due to its high sensitivity.
Therefore, the C80 gives generally more accurate results than DSC and ARC. Data from C80 and Dewar vessel were compared and
it indicates that the Dewar vessel has also high enough sensitivity to evaluate the thermal hazard and determine the heat
flux in lower temperature range of reactive substances.
Authors:Jo-Ming Tseng, Tung-Feng Hsieh, Yi-Ming Chang, Ya-Chen Yang, Lu-Yen Chen, and Chun-Ping Lin
120–135 °C, for TBHP and TBEC, respectively.
Liquid thermal hazard simulation
We used a 0.5-L Dewarvessel and a 25-kg commercial barrel package, as the reactor sizes to simulate the thermal hazard. The values of
thermal explosion model and the algorithms that were used have been previously described [ 7 , 11 ]. We used a 0.5 L Dewarvessel and a 25 kg commercial package as the reactor sizes to simulate the solid thermal hazard and incompatible reaction. The
Composting technologies rely on standard methods for quality determination. The maturity of a compost is assayed by self-heating experiments in Dewar-vessels. The resulting maximum temperature is classified on a five-level scale. This study demonstrated systematic errors that might occur when assays are performed in Dewars of different size. The vessels were characterized as heat conduction calorimeters and the processes of biochemical decomposition and heat generation and autothermic effects (temperature) were evaluated quantitatively.
Authors:W. Lin, S. Wu, G. Shiu, S. Shieh, and C. Shu
The highly reactive and unstable exothermal features of methyl ethyl ketone peroxide (MEKPO) have led to a large number of
thermal explosions and runaway reaction accidents in the manufacturing process. To evaluate the self-accelerating decomposition
temperature (SADT) of MEKPO in various storage vessels, we used differential scanning calorimetry (DSC) and vent sizing package
2 (VSP2). The thermokinetic parameters were, in turn, used to calculate the SADT from theoretical equations based on the Semenov
This study aimed at the SADT prediction value of various storage vessels in Taiwan compared with the UN 25 kg package and
UN 0.51 L Dewar vessel. An important index, such as SADT, temperature of no return (TNR) and adiabatic time maximum rate (TMRad), was necessary and useful to ensure safe storage or transportation for self-reactive substances in the process industries.
Sulphur factice is produced from a mixture of a vegetable oil and sulphur at temperatures between 130 and 160‡C. The slow exothermal vulcanization results in rubber-like elastomers. We have developed an isothermal calorimeter for measurements both in the liquid and the solid state and simulated the production process at the laboratory scale. The compensating calorimeter consists of a hot plate equipped with thin aluminium rods descending into a Dewar vessel. Besides optimization of the temperature control, remarkable savings of time were achieved by previous elaidinization of the oil using hydrosulphide.