In this work an in-house CFD code is used to simulate a single-phase acid-base neutralisation in a tubular reactor. The Reynolds averaged Navier-Stokes (RANS) equations including the k-delta-turbulence model is used to simulate the turbulent flow. Different models are tested to describe the chemical reaction, including the Eddy dissipation concept (EDC) and the presumed probability density function (PDF) models. The EDC-model was developed for gas phase reactions and the objective of this work was to modify the model to make it more suitable for liquid phase reactions. Two different PDF-models are tested, namely the battlement- and the beta-PDF. The simulation results are compared to experimental data and the results has shown that the standard EDC-model is not suitable for liquid phase reactions, a modified version of the model has shown good results. The most promising PDF-model is shown to be the beta-PDF-model.