Hydrodynamic modelling of a two-stage biomass gasification reactor

In our study the hydrodynamic behavior of a gasification reactor with two inlets and one outlet was numerically examined by the method of residence time distribution. We developed a Computational Fluid Dynamics (CFD) model of the reactor to solve the momentum and component balance equations of the system. The component balance equation was implemented to support the residence time distribution calculation. The mesh dependency of the CFD solution was checked by error rate and calculation time. In order to characterize the mixing and flow within reactor pulse experiments were performed numerically. A tracer impulse was introduced for 1 s to both inlets at the same time with concentration of 100 mol/m(3) approaching the Dirac delta function and tracer concentration at the outlet boundary of system was recorded. Compartmental modelling has a strong advantage over CFD as it has much smaller computational need. Therefore a compartment model in order to model the hydrodynamic structure of the reactor was also developed and compared to the results obtained by CFD model. (C) 2018 The Authors. Published by Elsevier Ltd on behalf of Energy Institute.