Authors:L. Whiting, M. LaBarge, and J. Steinmetzer
One of the critical aspects of an effective reactive chemicals program in the chemical processing industries is the management of our technical and project information. With the continuing evolution of electronic tools for the generation, storage, and retrieval of this technical information, we have new opportunities to improve management of process safety information.
New approaches in the documentation of reactive chemicals information are described. The documentation method is based upon a ‘living' project file organized along process unit operations. The project file captures the project safety information in an ‘information mapped' format. The format provides a simple means to document issue definition, relevant data and information, application of information to resolve the issue, and lines of defense and prevention.
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:K. Yuasa, M. Kumasaki, T. Mizutani, and M. Arai
The thermal behaviors of hazardous gas adsorbents were observed using a C80 calorimeter in order to develop a comprehensive
thermal hazard evaluation procedure for a hazardous gas detoxifying system. Newly modified cells for the C80 were used to
simultaneously monitor the pressure and the heat flow. The cells were also available for adsorbed gas switching. Adsorption/desorption
experiments showed various thermal behaviors of the different gas-adsorbent combinations. The accidental incorporation of
air into the cartridges proved to be a potential risk for heat generation. In addition, two kinds of experimental results
in different states, static pressure and gas-circulation, were compared. As a result, the experimental apparatus used in this
study exhibited the capability of evaluating the thermal hazards under the situation of accidental contamination by either
air or other undesirable gases as well as normal adsorption.
Authors:Shang-Hao Liu, Chun-Ping Lin, and Chi-Min Shu
required data. By TAM III, the obtained thermal runaway data, such as heat flow ( Q ), reaction rate constant ( k iso ), and time to maximum rate ( TMR iso ) can be fully exploited for thermalhazardevaluation and emergency planning, as well as for
Authors:J.-J. Peng, S.-H. Wu, H.-Y. Hou, C.-P. Lin, and C.-M. Shu
Over 90% of the cumene hydroperoxide (CHP) produced in the world is applied in the production of phenol and acetone. The additional
applications were used as a catalyst, a curing agent, and as an initiator for polymerization. Many previous studies from open
literature have verified and employed various aspects of the thermal decomposition and thermokinetics of CHP reactions. An
isothermal microcalorimeter (thermal activity monitor III, TAM III), and a thermal dynamic calorimetry (differential scanning
calorimetry, DSC) were used to resolve the exothermic behaviors, such as exothermic onset temperature (T0), heat power, heat of decomposition (ΔHd), self-heating rate, peak temperature of reaction system, time to maximum rate (TMR), etc. Furthermore, Fourier transform
infrared (FT-IR) spectrometry was used to analyze the CHP products with its derivatives at 150 °C. This study will assess
and validate the thermal hazards of CHP and incompatible reactions of CHP mixed with its derivatives, such as acetonphenone
(AP), and dimethylphenyl carbinol (DMPC), that are essential to process safety design.
The thermal polymerization of inhibited styrene monomer is investigated by Accelerating Rate Calorimetry (ARC). The time-temperature-pressure data generated by this technique are utilized in evaluating the thermal hazards associated with the industrial processing of styrene monomer. Several examples are given on the interpretation and application of ARC data to environments ranging from lab to plant-scale conditions including discussions concerning the similarities and dissimilarities between the ARC and large-scale equipment. The polymerization of styrene monomer is also used to evaluate the performance of the ARC over a broad temperature range, 80–300°C. The data indicate that removal of the radiant heater assembly yields better agreement between the heat of polymerization of styrene as measured by the ARC and corresponding values from the literature. This effect is believed to be observable only under conditions of low reaction rates for long periods of time such as in the case of styrene monomer.
A set of experiments was conducted in an HEL thermal screening unit with synthetic mixtures of raw materials in various proportions
to evaluate the potential thermal hazards at normal and offset process conditions for nitration of symmetrical trichlorobenzene
(TCB). The experiments were carried out in the adiabatic condition. The onset temperatures of the exotherms along with maximum
temperature and pressure rise data for the desired and undesirable reactions were obtained. In the presence of excess nitric
acid and oleum, the reaction shows a severe thermal runaway at the onset temperature of 138C with a rapid rise in temperature
and pressure leading to a potential explosion.
Authors:C. Chang, Y. Chou, J. Tseng, M. Liu, and C. Shu
Many concerns over unsafe or unknown properties of multi-walled carbon nanotubes (MWNTs) have been raised. The thermal characteristics
regarding stability would represent potential hazards during the production or utilization stage and could be determined by
calorimetric tests for various thermokinetic parameters. Differential scanning calorimetry (DSC) was employed to evaluate
the thermokinetic parameters for MWNTs at various compositions.
Thermoanalytical curves showed that the average heat of decomposition (ΔHd) of the MWNTs samples in a manufacturing process was about 31,723 J g−1, by identifying them as an inherently hazardous material. In this study, significant thermal analysis appeared in the presence
of sulfuric acid (H2SO4). From the DSC experiments, the purification process of MWNTs could induce an unexpected reaction in the condition of batch
addition with reactants of H2SO4. The results can be applied for designing emergency relief system and emergency rescue strategies during a perturbed situation