Handling of oxygen

It is assumed that oxygen transfer takes place only in the vicinity of the impeller, hence only in the micromixer. A mandate for such a handling of oxygen-uptake kinetics has been presented by Bajpai and Reuss (8) and by Reuss et al. ( ). 

For additional information on the handling of oxygen, refer to the section entitled Oxygen and Oxidizing Gases later in this chapter, and to the monograph on oxygen in Part II. 

In the Talalay process, the froth is produced by chemical rather than mechanical means. Hydrogen peroxide and an enzyme decomposition catalyst are mixed iato the latex and the mixture placed ia the mold. Decomposition of the peroxide by the added enzyme results ia the Hberation of oxygen which causes the latex mix to foam and fill the mold. The foam is then rapidly chilled and CO2 is iatroduced to gel the latex. The gelled foam is then handled ia a manner similar to that used ia the Dunlop process. 

Carbon dioxide systems-Tliis system can be used where there is a handling and storage of gaseous and flammable materials, electrical equipment, and hazardous solids by introducing an inert gas (such as carbon dioxide) into the area in order to reduce the concentration of oxygen to the point where the fire will be extinguished. 

For a catalyst-ignited fire to occur, oxygen must be present exclusion of oxygen permits completely safe handling. Some workers put the catalyst in the reaction vessel and sweep air from the vessel with a gentle flow of nitrogen or carbon dioxide argon is ideal if available, The solvent, which may be cooled to diminish its flammability, is then added. Once all of the catalyst has been wet with solvent, fire will not occur. Air can also be removed from the flask by... 

Liq ozone in concns greater than 30% by wt is extremely unstable, and may expld on contact with even minute traces of organic matter. Not only all precautions for handling liq oxygen, but also extra precautions for a sensitive expl must be observed (Ref 4, p 430)... 

In addition, particularly micro-channel processing is demanded here as the reaction is dangerous owing to the explosive nature of the endoperoxide formed as intermediate. This handling of explosive or toxic compounds for Diels-Alder reactions is also described in [21]. Owing to the use of only small volumes, the hazardous potential can be substantially minimized. This was exemplarily shown for the addition of singlet oxygen. 

So the handling of hydrocarbons presents serious fire hazards. There are many accidents linked to this in the industrial sector. For instance, a serious accident happened when polyethylene was stored. It appeared to be caused by the diffusion of monomer through the mass of polymer, which created an inflammable atmosphere in the storage container. Incorporating a mixture of oxygen and styrene in a reactor cause spontaneous ignition. 

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