Reactors with two well mixed phases

There are two situations where each phase in a two-phase reactor can be well mixed  

When the phases are a gas and a liquid, separation usually takes place in the reactor, and both process streams leave the reactor through separate ports. The relative volumes of the two phases is determined by the separation rate, caused by the rising velocity of the gas bubbles. The phases may tfien have quite different mean residence times. When there are two liquids, separation usually has to be done outside the reactor, so that the mean residence times of the liquids is the same. 

The calculation of chemical conversions in reactors with two well mixed phases is quite simple, provided the reaction takes place in one phase only. The average reaction rate in the reaction phase can be found as a function of the reactant concentrations. This function may be summarized as in eq. (7.1)  

Note that in this section all symbols with a dash refer to the supply phase the other symbols refer to the reaction phase. The effective rate constant is found 

The total reaction rate is is simply r V, where V is the volume of the reaction phase. The mass balances for the two phases can then be written in the following form (for constant densities of each flow assuming all transferred A is converted) 

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