Hazard Evaluation in the Chemical Process Industries

The safe design and operation of chemical processing equipment requires detailed attention to the hazards inherent in certain chemicals and processes. Chemical plant hazards can occur from many sources. Principal hazards arise from  

Fig ure 12-1. The inoreasing degree of hazard of matter plotted against the inoreasing hazard of a prooess. (Source Shabica [2].) 

Chemical reaction hazards must be considered in assessing whether a process can be operated safely on the manufacturing scale. Furthermore, the effect of scale-up is particularly important. A reaction, which is innocuous on the laboratory or pilot plant scale, can be disastrous in a full-scale manufacturing plant. For example, the heat release from a highly exothermic process, such as the reduction of an aromatic nitro compound, can be easily controlled in laboratory glassware. Flowever, 

Additionally, consequences of possible process maloperations, such as incorrect charging sequence, contamination of reactants, agitation failure and poor temperature control, adding reactants too quickly. 

Chemieal eomponents Proeess temperature Proeess pressure 

Close fitting sleeves through reinforced concrete wall 

The assessment of the hazards of a particular process requires investigating the effects of these parameters through experimental work, interpretating the results in relation to the plant situation, and defining a suitable basis for safe operation. 

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