6.2.1 Liquid Phase

For liquid-phase reactions, the density remains constant and consequently there is no change in either the volume V or the volumetric flow rate υ = υ₀ during the course of the reaction. Therefore concentration is the preferred design variable. The mole balances derived in Chapter 1 (Table S-1) are now applied to each species for the generic reaction

2-1

The mole balances are then coupled to one another using the relative rates of reaction

3-1

to arrive at Table 6-1, which gives the balance equations in terms of concentration for the four types of reactors we have been discussing. We see from Table 6-1 that we have only to specify the parameter values for the system (C_A0, υ₀, etc.) and for the rate law parameters (e.g., k_A, α, β) to solve the coupled ordinary differential equations for either PFR, PBR, or batch reactors, or to solve the coupled algebraic equations for a CSTR.

Table 6-1. Mole Balances For Liquid-Phase Reactions

LIQUIDS