Pressurized high temperature black liquor gasification might significantly improve the efficiency of the energy and chemical recovery cycle in kraft pulping. The process, which is based on the entrained-flow principle, is under development, and a scale-up from an existing pilot gasifier is planned. We developed a self-consistent computational fluid dynamic (CFD) model, in conjunction with pilot gasifier experiments, as a tool for scale-up. This report compares model predictions against experimental pilot gasifier data. The agreement between model and experiments is encouraging in certain areas, but significant discrepancies resulted for other areas. Model predictions of global performance parameters, such as sulfate reduction efficiency and carbon conversion, are in reasonable agreement with the experiments, but the predicted gas composition differed significantly from results of the experiments. Direct measurements of quantities to validate the current model validation are difficult to obtain because of severe conditions in the gasifier, and many of the model comparisons are based on indirect values. Hence, it is difficult to judge whether the errors come from the experiment or the simulation. Before we can draw a definite conclusion about the model's validity, improved in-situ measurements inside the gasifier are necessary and are currently under development. Successful development of a computational fluid dynamic model will further the development of black liquor gasification, leading to improved efficiency of the energy and chemical recovery cycle in kraft pulping.