Chemical reactions worst-case scenario

The results within the impact category GWP illustrate the great influence of both, the supply of chemicals (33% batch and 37% Conti wc, resp.) and the energy demand during synthesis (42% batch and 28% Conti wc, resp.) along the whole process chain. The disposal of the chemical refuse as well has a significant impact (23% both, batch and Conti wc). In the case of the worst-case scenario, the influence of the supply of the reaction device amoimts to 10% (assumed hfe time of the micro-structured devices 1 week) decreasing to 3% in Conti Scl (assumed life time of the micro-structured devices 3 month). 

Credible cases are identified when the probability of decomposition is low. Energy calculations of known or proposed chemical reactions and side reactions are carried out to determine a more likely level of energy release than the worst-case scenario. Therefore, it is necessary to define the most energetic reactions. Enthalpies of reaction are calculated, followed by calculations of the adiabatic temperature rise of the system and the corresponding pressure rise. 

Reactive Chemicals Worst Case Scenario - Plausible events within a facility that can result in an uncontrolled chemical reaction that has the potential to cause loss, injury or environmental harm. 

Drugs sometimes have quite complicated chemical structures and are, by definition, biologically active compounds. It should not, therefore, come as a surprise that these reactive molecules undergo chemical reactions that result in their decomposition and deterioration, and that these processes begin as soon as the drug is synthesised or the medicine is formulated. Decomposition reactions of this type lead to, at best, drugs and medicines that are less active than intended (i.e. of low efficacy)-, in the worst-case scenario, decomposition can lead to drugs that are actually toxic to the patient. This is clearly bad news to all except lawyers, so the processes of decomposition and deterioration must be understood in order to minimise the risk to patients. 

At the beginning of the reaction, the curve representing the chemical species mass addition matches well the TOC curve. This indicates that most of the species remaining in the liquid phase are determined and quantified. At reaction times beyond 5 hours the species mass addition (-I-) curve consistently lays below the TOC curve. Greater separation between the two curves can be observed with increasing reaction times. In the worst case scenario, this difference is close to 10% of the initial phenol concentration and can be the result of two contributing factors carbon-containing intermediate species... 

As you might imagine, consideration of the acidic or basic character of the solid adsorbent used for a TLC experiment can be particularly important if the substances to be analyzed contain functional groups that are sensitive to acids or bases. In a worst-case scenario, the adsorbent may function as a catalyst to destroy the functionality by chemical reaction during the course of the analysis this greatly complicates the interpretation of the TLC results. 

Some process operations use operating relief valves as part of their normal operation, often in batch processes. For example, a chemical reaction may generate increasingly high temperatures and pressures. When the internal pressure rises above a certain point, the relief valve opens and the system pressure is reduced. In such situations, the relief valve is not a true safeguard because it is probably not as reliable as a true PSRV and it may not have been designed for the worst case scenario. 

The thermal risk linked to a chemical reaction is the risk of loss of control of the reaction and associated consequences (e.g. triggering a runaway reaction). Therefore, it is necessary to understand how a reaction can switch from its normal course to a runaway condition. In order to make this assessment, the theory of thermal explosion (see Chapter 2) needs to be understood, along with the concepts of risk assessment. This implies that an incident scenario was identified and described, with its triggering conditions and the resulting consequences, in order to assess the severity and probability of occurrence. For thermal risks, the worst case will be to lose the cooling of a reactor or in general to consider that the reaction mass or the substance to be assessed is submitted to adiabatic conditions. Hence, we consider a cooling failure scenario. 

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