Accident factors-the laboratory as a chemical plant

Large-scale feeding and small-scale testing are completely different in terms of risk.

Case 1

A certain R&D team thought that the commercially available peroxybenzoic acid was too expensive to prepare it by itself, and first explored the conditions so that it could scale up production in the future

Figure 25-31 The scene after the strong explosion

Large-scale production of extremely dangerous chemical reagents or chemical raw materials has its own unique production safety facilities and management methods, as well as corresponding precautions, which are difficult to achieve in general chemical laboratories under normal circumstances

Case 2

A research and development team suspected that the commercially available sodium hydrosulfide was of low purity and poor quality, so it carried out large-scale preparation (production) of sodium hydrosulfide in a special gas laboratory;

H ₂ S+NaOH→NaHS+H ₂ O

Because the simple exhaust gas absorption device in the laboratory is only suitable for small-scale reactions, a large amount of hydrogen sulfide exhaust gas leaked due to incomplete absorption, polluting the entire R&D building and causing emergency evacuation of all personnel in the building

Considering the lower boiling point and toxicity of ethylene oxide, and afraid of its volatilization, a researcher first used a dry ice-acetone bath to cool the reaction solution containing the substrate, ethylene oxide and methanol solvent, and then the extremely low temperature The reaction liquid is added to the oxidation flask and then heated

Figure 25-32 Explosion of hydrogenation bottle

Reason analysis: the party’s extremely one-sided thinking → excessive internal cooling and external heating → quenching and heating of the hydrogenation bottle → internal stress change → strength reduction, and the hydrogenation bottle cannot withstand the original prescribed internal pressure and caused an explosion

Related Links: Accident Factors-Poor Management, Failure to Preserve Reagents or Dispose of Waste Reagents