FLUJO PISTON is a dynamic simulator of plug flow reactors which operates as a complement of Microsoft Excel. As a simulation model it is used the strategy of finite segments in series. In the solution of the system generated it was used, the homotopic method in solving systems of nonlinear algebraic equations and the cubic equation of state of Peng-Robinson, PR with mixing rules of van der Waals for the calculations of thermodynamic properties mixtures. Verification of the results obtained using the simulator was compared with data obtained from the commercial simulator HYSYS.