Cyclohexane flammability limits

The transient development of the Cyclohexane vapor cloud at its lower and upper flammable limits (LFL and UFL respectively) over a period of 30 seconds will be shown as a Tecplot movie. The UFL is represented as the paneled interior surface, and that for the LFL, the wire-frame exterior surface in the figures which follow. 

In industry, this reaction is conducted at elevated pressure (10-30 bar) and temperature (80-250 °C). Under such conditions, the content of oxygen must be kept low to avoid the explosive regime. Also, the cyclohexane conversion is kept low (<5%) to avoid the formation of side products. In a microreactor, composition and temperature of the gas phase far above the flammability limit of 4% are possible. A selectivity of 88% was observed. However, it is shown that despite the narrow channels, gas-liquid mass transfer still limits the rate of reaction so that further engineering of a reactor is required that will enable mass transfer free operations and oxygen refilling. 

Phenyllithium can be used as a solution in ethyl ether, but because of its limited stabUity (t 2 = 12 d at 35° C) it is commercially available in solution in mixtures, usuaUy 70 30 wt % cyclohexane ethyl ether (117). In this particular mixture of solvents, a 20 wt % solution, free of chlorobenzene, is stable for at least four months under an inert atmosphere (argon or nitrogen) in sealed containers at room temperature. Phenyllithium is also available in dibutyl ether solution (117). It is classified as a flammable Hquid. 

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