Reactor phase

Having considered reactor temperature and pressure, the reactor phase can now be considered. The reactor phase can be gas, liquid or multiphase. Given a free choice between gas and liquid-phase reactions, operation in the liquid phase is usually preferred. Consider the single reaction system  

Clearly, in the liquid phase much higher concentrations of Cfeed (kmol m-3) can be maintained than in the gas phase. This makes liquid-phase reactions in general more rapid and hence leads to smaller reactor volumes for liquid-phase reactors. 

However, a note of caution should be added. In many multiphase reaction systems, as will be discussed in the next chapter, rates of mass transfer between different phases 

Very often the choice is not available. For example, if reactor temperature is above the critical temperature of the chemical species, then the reactor must be in the gas phase. Even if the temperature can be lowered below critical, an extremely high pressure may be required to operate in the liquid phase. 

The choice of reactor temperature, pressure and hence phase must, in the first instance, take account of the desired equilibrium and selectivity effects. If there is still freedom to choose between gas and liquid phase, operation in the liquid phase is preferred. 

However, a note of caution should be added. In many multiphase reaction systems, rates of mass transfer between different phases can be just as important or more important than reaction kinetics in determining the reactor volume. Mass transfer rates are generally higher in gas-phase than liquid-phase systems. In such situations, it is not so easy to judge whether gas or liquid phase is preferred. 

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When recycling material to the reactor for whatever reason, the pressure drop through the reactor, phase separator (if there is one), and the heat exchangers upstream and downstream of the reactor must be overcome. This means increasing the pressure of any material to be recycled. 

Product (raw materials) Type Reactor phase Catalyst T c(2 P, atm Residence time or space velocity Source and page ... 

Figure 17 Comparison of the iodine numbers and the averaged dp from Lll with indication of the reactor phase (Dankers et al, 2003).

No. Process Name Company or Organization Type of Reactor Phase of R D Process... 

EROS is based on three fundamental concepts reactors, phases, and modes. 

A rule in EROS consists of a global part describing the name, reactors, phases, and kinetics and a reaction part that defines one or more reaction rules. An example of a simple EROS rule for bond formation and cleavage in Tcl looks as follows ... 

Implement second-generation pilot-scale SWPO reactor (Phase II). 

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