Liquid oxygenation, advantages

In answer to the second part of the question, a power advantage is achieved in exchanging the high pressure liquid oxygen with high pressure cycle nitrogen. This was done in the calculations and is reflected in the numbers presented, (The question obviously arose because of an oversimplified slide of the process flow.) This figure (Fig. 4) has been redrawn for publication here. 

Liquid oxygen conveniently available near the reactor makes it more advantageous to use as an oxidizing agent than air and widens the scope of oxidation under pressure. Spent caustic oxidation units have been set up on the following basis ... 

As we have already mentioned, liquid oxygen is, and probably will remain, the "work horse" of the liquid-propellant oxidizers, A rocket uses about five times as much oxidizer as fuel on a weight basis [6]. Liquid oxygen has a decided advantage in cost since it may be distilled from liquid air and is comparatively cheap. It is also noncorrosive and fairly easy to handle by existing methods. 

These reactions occur with similar rates to those carried out in dipolar aprotic solvents such as DMF or DMSO. An advantage of using the room-temperature ionic liquid for this reaction is that the lower reaction temperatures result in higher selec-tivities for substitution on the oxygen or nitrogen atoms. The by-product (sodium or potassium halide) of the reaction can be extracted with water and the ionic liquid recycled. 

Catalytic oxidation reactions in ionic liquids have been investigated only very recently. This is somewhat surprising in view of the well loiown oxidation stability of ionic liquids, from electrochemical studies [11], and the great commercial importance of oxidation reactions. Moreover, for oxidation reactions with oxygen, the nonvolatile nature of the ionic liquid is of real advantage for the safety of the reaction. While the application of volatile organic solvents may be restricted by the formation of explosive mixtures in the gas phase, this problem does not arise if a nonvolatile ionic liquid is used as the solvent. 

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