A previously derived concept of multiscale modeling of bubble column reactors has been applied to study the behavior of a nonisothermal parallel/consecutive reaction with and without evaporation of one of the reaction products. The concept is based upon the observation that most gas/liquid synthesis reactions are rather slow compared to the rapid local fluctuations of the gas/liquid hydrodynamics but are sufficiently fast to be considerably affected by the medium-and large-scale mixing behavior in industrial scale bubble columns. A simplified one-dimensional steady-state zone model for the bubble column reactor is para meterized in its flow and mixing parameters by the detailed, multidimensional, unsteady-state hydrodynamics and used to calculate the respective mass, energy and bubble size balance equations for the reactor. Local bubble sizes and total mass fluxes between the gas and liquid phase are fed back from the simplified reactor model into the detailed hydrodynamics until convergence between the two models is obtained. The results show that the important interactions between hydrodynamics and mass transfer with reaction can be well represented by the new concept, which makes it an efficient and comparatively simple candidate for the in detail analysis, design and scale-up of bubble column reactors.