Reactive residue curve maps (RRCMs) are useful for the design of reactive distillation columns as a tool to establish feasible zones of reaction separation. However, the calculation of an RRCM usually involves great computational effort due to the nonlinearity of the model equations and its iterative nature for the determination of reactive phase equilibrium. In this study, a simplified method for the generation of RRCMs is presented. This method is based on the application of reaction-invariant composition variables and assumes that the phase equilibrium constants (i.e., the relative volatilities) are independent of the temperature. Specifically, the phase equilibrium constants are calculated using a suitable estimation of the bubble temperature obtained from pure-component boiling temperatures and the, reaction-invariant composition of liquid phase. These assumptions avoid iterative phase equilibrium calculations for obtaining a good approximation of RRCMs. Several reactive systems are used to identify the capabilities and limitations of the proposed method.